Linux patch 5.17.125.17-16

Signed-off-by: Mike Pagano <mpagano@gentoo.org>

2 files changed, 4654 insertions, 0 deletions

diff --git a/0000_README b/0000_README
index 8aed7c53..ecb45bb4 100644
--- a/0000_README
+++ b/0000_README
@@ -87,6 +87,10 @@ Patch:  1010_linux-5.17.11.patch
 From:   http://www.kernel.org
 Desc:   Linux 5.17.11
 
+Patch:  1011_linux-5.17.12.patch
+From:   http://www.kernel.org
+Desc:   Linux 5.17.12
+
 Patch:  1500_XATTR_USER_PREFIX.patch
 From:   https://bugs.gentoo.org/show_bug.cgi?id=470644
 Desc:   Support for namespace user.pax.* on tmpfs.
diff --git a/1011_linux-5.17.12.patch b/1011_linux-5.17.12.patch
new file mode 100644
index 00000000..185a60e2
--- /dev/null
+++ b/1011_linux-5.17.12.patch
@@ -0,0 +1,4650 @@
+diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
+index 59f881f367793..ad67b848d04ee 100644
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -4355,6 +4355,12 @@
+ 			fully seed the kernel's CRNG. Default is controlled
+ 			by CONFIG_RANDOM_TRUST_CPU.
+ 
++	random.trust_bootloader={on,off}
++			[KNL] Enable or disable trusting the use of a
++			seed passed by the bootloader (if available) to
++			fully seed the kernel's CRNG. Default is controlled
++			by CONFIG_RANDOM_TRUST_BOOTLOADER.
++
+ 	randomize_kstack_offset=
+ 			[KNL] Enable or disable kernel stack offset
+ 			randomization, which provides roughly 5 bits of
+diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
+index 0f86e9f931293..264735c5d0bda 100644
+--- a/Documentation/admin-guide/sysctl/kernel.rst
++++ b/Documentation/admin-guide/sysctl/kernel.rst
+@@ -1025,28 +1025,22 @@ This is a directory, with the following entries:
+ * ``boot_id``: a UUID generated the first time this is retrieved, and
+   unvarying after that;
+ 
++* ``uuid``: a UUID generated every time this is retrieved (this can
++  thus be used to generate UUIDs at will);
++
+ * ``entropy_avail``: the pool's entropy count, in bits;
+ 
+ * ``poolsize``: the entropy pool size, in bits;
+ 
+ * ``urandom_min_reseed_secs``: obsolete (used to determine the minimum
+-  number of seconds between urandom pool reseeding).
+-
+-* ``uuid``: a UUID generated every time this is retrieved (this can
+-  thus be used to generate UUIDs at will);
++  number of seconds between urandom pool reseeding). This file is
++  writable for compatibility purposes, but writing to it has no effect
++  on any RNG behavior;
+ 
+ * ``write_wakeup_threshold``: when the entropy count drops below this
+   (as a number of bits), processes waiting to write to ``/dev/random``
+-  are woken up.
+-
+-If ``drivers/char/random.c`` is built with ``ADD_INTERRUPT_BENCH``
+-defined, these additional entries are present:
+-
+-* ``add_interrupt_avg_cycles``: the average number of cycles between
+-  interrupts used to feed the pool;
+-
+-* ``add_interrupt_avg_deviation``: the standard deviation seen on the
+-  number of cycles between interrupts used to feed the pool.
++  are woken up. This file is writable for compatibility purposes, but
++  writing to it has no effect on any RNG behavior.
+ 
+ 
+ randomize_va_space
+diff --git a/Makefile b/Makefile
+index b821f270a4ca6..25c44dda0ef37 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1,7 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0
+ VERSION = 5
+ PATCHLEVEL = 17
+-SUBLEVEL = 11
++SUBLEVEL = 12
+ EXTRAVERSION =
+ NAME = Superb Owl
+ 
+diff --git a/arch/alpha/include/asm/timex.h b/arch/alpha/include/asm/timex.h
+index b565cc6f408e9..f89798da8a147 100644
+--- a/arch/alpha/include/asm/timex.h
++++ b/arch/alpha/include/asm/timex.h
+@@ -28,5 +28,6 @@ static inline cycles_t get_cycles (void)
+ 	__asm__ __volatile__ ("rpcc %0" : "=r"(ret));
+ 	return ret;
+ }
++#define get_cycles get_cycles
+ 
+ #endif
+diff --git a/arch/arm/include/asm/timex.h b/arch/arm/include/asm/timex.h
+index 7c3b3671d6c25..6d1337c169cd3 100644
+--- a/arch/arm/include/asm/timex.h
++++ b/arch/arm/include/asm/timex.h
+@@ -11,5 +11,6 @@
+ 
+ typedef unsigned long cycles_t;
+ #define get_cycles()	({ cycles_t c; read_current_timer(&c) ? 0 : c; })
++#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
+ 
+ #endif
+diff --git a/arch/ia64/include/asm/timex.h b/arch/ia64/include/asm/timex.h
+index 869a3ac6bf23a..7ccc077a60bed 100644
+--- a/arch/ia64/include/asm/timex.h
++++ b/arch/ia64/include/asm/timex.h
+@@ -39,6 +39,7 @@ get_cycles (void)
+ 	ret = ia64_getreg(_IA64_REG_AR_ITC);
+ 	return ret;
+ }
++#define get_cycles get_cycles
+ 
+ extern void ia64_cpu_local_tick (void);
+ extern unsigned long long ia64_native_sched_clock (void);
+diff --git a/arch/m68k/include/asm/timex.h b/arch/m68k/include/asm/timex.h
+index 6a21d93582805..f4a7a340f4cae 100644
+--- a/arch/m68k/include/asm/timex.h
++++ b/arch/m68k/include/asm/timex.h
+@@ -35,7 +35,7 @@ static inline unsigned long random_get_entropy(void)
+ {
+ 	if (mach_random_get_entropy)
+ 		return mach_random_get_entropy();
+-	return 0;
++	return random_get_entropy_fallback();
+ }
+ #define random_get_entropy	random_get_entropy
+ 
+diff --git a/arch/mips/include/asm/timex.h b/arch/mips/include/asm/timex.h
+index 8026baf46e729..2e107886f97ac 100644
+--- a/arch/mips/include/asm/timex.h
++++ b/arch/mips/include/asm/timex.h
+@@ -76,25 +76,24 @@ static inline cycles_t get_cycles(void)
+ 	else
+ 		return 0;	/* no usable counter */
+ }
++#define get_cycles get_cycles
+ 
+ /*
+  * Like get_cycles - but where c0_count is not available we desperately
+  * use c0_random in an attempt to get at least a little bit of entropy.
+- *
+- * R6000 and R6000A neither have a count register nor a random register.
+- * That leaves no entropy source in the CPU itself.
+  */
+ static inline unsigned long random_get_entropy(void)
+ {
+-	unsigned int prid = read_c0_prid();
+-	unsigned int imp = prid & PRID_IMP_MASK;
++	unsigned int c0_random;
+ 
+-	if (can_use_mips_counter(prid))
++	if (can_use_mips_counter(read_c0_prid()))
+ 		return read_c0_count();
+-	else if (likely(imp != PRID_IMP_R6000 && imp != PRID_IMP_R6000A))
+-		return read_c0_random();
++
++	if (cpu_has_3kex)
++		c0_random = (read_c0_random() >> 8) & 0x3f;
+ 	else
+-		return 0;	/* no usable register */
++		c0_random = read_c0_random() & 0x3f;
++	return (random_get_entropy_fallback() << 6) | (0x3f - c0_random);
+ }
+ #define random_get_entropy random_get_entropy
+ 
+diff --git a/arch/nios2/include/asm/timex.h b/arch/nios2/include/asm/timex.h
+index a769f871b28d9..40a1adc9bd03e 100644
+--- a/arch/nios2/include/asm/timex.h
++++ b/arch/nios2/include/asm/timex.h
+@@ -8,5 +8,8 @@
+ typedef unsigned long cycles_t;
+ 
+ extern cycles_t get_cycles(void);
++#define get_cycles get_cycles
++
++#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
+ 
+ #endif
+diff --git a/arch/parisc/include/asm/timex.h b/arch/parisc/include/asm/timex.h
+index 06b510f8172e3..b4622cb06a75e 100644
+--- a/arch/parisc/include/asm/timex.h
++++ b/arch/parisc/include/asm/timex.h
+@@ -13,9 +13,10 @@
+ 
+ typedef unsigned long cycles_t;
+ 
+-static inline cycles_t get_cycles (void)
++static inline cycles_t get_cycles(void)
+ {
+ 	return mfctl(16);
+ }
++#define get_cycles get_cycles
+ 
+ #endif
+diff --git a/arch/powerpc/include/asm/timex.h b/arch/powerpc/include/asm/timex.h
+index fa2e76e4093a3..14b4489de52c5 100644
+--- a/arch/powerpc/include/asm/timex.h
++++ b/arch/powerpc/include/asm/timex.h
+@@ -19,6 +19,7 @@ static inline cycles_t get_cycles(void)
+ {
+ 	return mftb();
+ }
++#define get_cycles get_cycles
+ 
+ #endif	/* __KERNEL__ */
+ #endif	/* _ASM_POWERPC_TIMEX_H */
+diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
+index 507cae273bc62..d6a7428f6248d 100644
+--- a/arch/riscv/include/asm/timex.h
++++ b/arch/riscv/include/asm/timex.h
+@@ -41,7 +41,7 @@ static inline u32 get_cycles_hi(void)
+ static inline unsigned long random_get_entropy(void)
+ {
+ 	if (unlikely(clint_time_val == NULL))
+-		return 0;
++		return random_get_entropy_fallback();
+ 	return get_cycles();
+ }
+ #define random_get_entropy()	random_get_entropy()
+diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h
+index 50d9b04ecbd14..bc50ee0e91ff1 100644
+--- a/arch/s390/include/asm/timex.h
++++ b/arch/s390/include/asm/timex.h
+@@ -201,6 +201,7 @@ static inline cycles_t get_cycles(void)
+ {
+ 	return (cycles_t) get_tod_clock() >> 2;
+ }
++#define get_cycles get_cycles
+ 
+ int get_phys_clock(unsigned long *clock);
+ void init_cpu_timer(void);
+diff --git a/arch/sparc/include/asm/timex_32.h b/arch/sparc/include/asm/timex_32.h
+index 542915b462097..f86326a6f89e0 100644
+--- a/arch/sparc/include/asm/timex_32.h
++++ b/arch/sparc/include/asm/timex_32.h
+@@ -9,8 +9,6 @@
+ 
+ #define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
+ 
+-/* XXX Maybe do something better at some point... -DaveM */
+-typedef unsigned long cycles_t;
+-#define get_cycles()	(0)
++#include <asm-generic/timex.h>
+ 
+ #endif
+diff --git a/arch/um/include/asm/timex.h b/arch/um/include/asm/timex.h
+index e392a9a5bc9bd..9f27176adb26d 100644
+--- a/arch/um/include/asm/timex.h
++++ b/arch/um/include/asm/timex.h
+@@ -2,13 +2,8 @@
+ #ifndef __UM_TIMEX_H
+ #define __UM_TIMEX_H
+ 
+-typedef unsigned long cycles_t;
+-
+-static inline cycles_t get_cycles (void)
+-{
+-	return 0;
+-}
+-
+ #define CLOCK_TICK_RATE (HZ)
+ 
++#include <asm-generic/timex.h>
++
+ #endif
+diff --git a/arch/x86/include/asm/timex.h b/arch/x86/include/asm/timex.h
+index a4a8b1b16c0c1..956e4145311b1 100644
+--- a/arch/x86/include/asm/timex.h
++++ b/arch/x86/include/asm/timex.h
+@@ -5,6 +5,15 @@
+ #include <asm/processor.h>
+ #include <asm/tsc.h>
+ 
++static inline unsigned long random_get_entropy(void)
++{
++	if (!IS_ENABLED(CONFIG_X86_TSC) &&
++	    !cpu_feature_enabled(X86_FEATURE_TSC))
++		return random_get_entropy_fallback();
++	return rdtsc();
++}
++#define random_get_entropy random_get_entropy
++
+ /* Assume we use the PIT time source for the clock tick */
+ #define CLOCK_TICK_RATE		PIT_TICK_RATE
+ 
+diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
+index 01a300a9700b9..fbdc3d9514943 100644
+--- a/arch/x86/include/asm/tsc.h
++++ b/arch/x86/include/asm/tsc.h
+@@ -20,13 +20,12 @@ extern void disable_TSC(void);
+ 
+ static inline cycles_t get_cycles(void)
+ {
+-#ifndef CONFIG_X86_TSC
+-	if (!boot_cpu_has(X86_FEATURE_TSC))
++	if (!IS_ENABLED(CONFIG_X86_TSC) &&
++	    !cpu_feature_enabled(X86_FEATURE_TSC))
+ 		return 0;
+-#endif
+-
+ 	return rdtsc();
+ }
++#define get_cycles get_cycles
+ 
+ extern struct system_counterval_t convert_art_to_tsc(u64 art);
+ extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
+diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
+index 32333dfc85b6a..495329ae6b1b2 100644
+--- a/arch/x86/kvm/mmu/mmu.c
++++ b/arch/x86/kvm/mmu/mmu.c
+@@ -5416,14 +5416,16 @@ void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid)
+ 	uint i;
+ 
+ 	if (pcid == kvm_get_active_pcid(vcpu)) {
+-		mmu->invlpg(vcpu, gva, mmu->root_hpa);
++		if (mmu->invlpg)
++			mmu->invlpg(vcpu, gva, mmu->root_hpa);
+ 		tlb_flush = true;
+ 	}
+ 
+ 	for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) {
+ 		if (VALID_PAGE(mmu->prev_roots[i].hpa) &&
+ 		    pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) {
+-			mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa);
++			if (mmu->invlpg)
++				mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa);
+ 			tlb_flush = true;
+ 		}
+ 	}
+diff --git a/arch/xtensa/include/asm/timex.h b/arch/xtensa/include/asm/timex.h
+index 233ec75e60c69..3f2462f2d0270 100644
+--- a/arch/xtensa/include/asm/timex.h
++++ b/arch/xtensa/include/asm/timex.h
+@@ -29,10 +29,6 @@
+ 
+ extern unsigned long ccount_freq;
+ 
+-typedef unsigned long long cycles_t;
+-
+-#define get_cycles()	(0)
+-
+ void local_timer_setup(unsigned cpu);
+ 
+ /*
+@@ -59,4 +55,6 @@ static inline void set_linux_timer (unsigned long ccompare)
+ 	xtensa_set_sr(ccompare, SREG_CCOMPARE + LINUX_TIMER);
+ }
+ 
++#include <asm-generic/timex.h>
++
+ #endif	/* _XTENSA_TIMEX_H */
+diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
+index a4b638bea6f16..cc2fe0618178e 100644
+--- a/drivers/acpi/sysfs.c
++++ b/drivers/acpi/sysfs.c
+@@ -415,19 +415,30 @@ static ssize_t acpi_data_show(struct file *filp, struct kobject *kobj,
+ 			      loff_t offset, size_t count)
+ {
+ 	struct acpi_data_attr *data_attr;
+-	void *base;
+-	ssize_t rc;
++	void __iomem *base;
++	ssize_t size;
+ 
+ 	data_attr = container_of(bin_attr, struct acpi_data_attr, attr);
++	size = data_attr->attr.size;
++
++	if (offset < 0)
++		return -EINVAL;
++
++	if (offset >= size)
++		return 0;
+ 
+-	base = acpi_os_map_memory(data_attr->addr, data_attr->attr.size);
++	if (count > size - offset)
++		count = size - offset;
++
++	base = acpi_os_map_iomem(data_attr->addr, size);
+ 	if (!base)
+ 		return -ENOMEM;
+-	rc = memory_read_from_buffer(buf, count, &offset, base,
+-				     data_attr->attr.size);
+-	acpi_os_unmap_memory(base, data_attr->attr.size);
+ 
+-	return rc;
++	memcpy_fromio(buf, base + offset, count);
++
++	acpi_os_unmap_iomem(base, size);
++
++	return count;
+ }
+ 
+ static int acpi_bert_data_init(void *th, struct acpi_data_attr *data_attr)
+diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
+index 740811893c570..55f48375e3fe5 100644
+--- a/drivers/char/Kconfig
++++ b/drivers/char/Kconfig
+@@ -449,6 +449,7 @@ config RANDOM_TRUST_BOOTLOADER
+ 	device randomness. Say Y here to assume the entropy provided by the
+ 	booloader is trustworthy so it will be added to the kernel's entropy
+ 	pool. Otherwise, say N here so it will be regarded as device input that
+-	only mixes the entropy pool.
++	only mixes the entropy pool. This can also be configured at boot with
++	"random.trust_bootloader=on/off".
+ 
+ endmenu
+diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
+index a3db27916256d..cfb085de876b7 100644
+--- a/drivers/char/hw_random/core.c
++++ b/drivers/char/hw_random/core.c
+@@ -15,6 +15,7 @@
+ #include <linux/err.h>
+ #include <linux/fs.h>
+ #include <linux/hw_random.h>
++#include <linux/random.h>
+ #include <linux/kernel.h>
+ #include <linux/kthread.h>
+ #include <linux/sched/signal.h>
+diff --git a/drivers/char/random.c b/drivers/char/random.c
+index 3404a91edf292..92428bfdc1431 100644
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -1,320 +1,26 @@
++// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+ /*
+- * random.c -- A strong random number generator
+- *
+  * Copyright (C) 2017-2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+- *
+  * Copyright Matt Mackall <mpm@selenic.com>, 2003, 2004, 2005
+- *
+- * Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999.  All
+- * rights reserved.
+- *
+- * Redistribution and use in source and binary forms, with or without
+- * modification, are permitted provided that the following conditions
+- * are met:
+- * 1. Redistributions of source code must retain the above copyright
+- *    notice, and the entire permission notice in its entirety,
+- *    including the disclaimer of warranties.
+- * 2. Redistributions in binary form must reproduce the above copyright
+- *    notice, this list of conditions and the following disclaimer in the
+- *    documentation and/or other materials provided with the distribution.
+- * 3. The name of the author may not be used to endorse or promote
+- *    products derived from this software without specific prior
+- *    written permission.
+- *
+- * ALTERNATIVELY, this product may be distributed under the terms of
+- * the GNU General Public License, in which case the provisions of the GPL are
+- * required INSTEAD OF the above restrictions.  (This clause is
+- * necessary due to a potential bad interaction between the GPL and
+- * the restrictions contained in a BSD-style copyright.)
+- *
+- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
+- * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
+- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+- * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+- * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
+- * DAMAGE.
+- */
+-
+-/*
+- * (now, with legal B.S. out of the way.....)
+- *
+- * This routine gathers environmental noise from device drivers, etc.,
+- * and returns good random numbers, suitable for cryptographic use.
+- * Besides the obvious cryptographic uses, these numbers are also good
+- * for seeding TCP sequence numbers, and other places where it is
+- * desirable to have numbers which are not only random, but hard to
+- * predict by an attacker.
+- *
+- * Theory of operation
+- * ===================
+- *
+- * Computers are very predictable devices.  Hence it is extremely hard
+- * to produce truly random numbers on a computer --- as opposed to
+- * pseudo-random numbers, which can easily generated by using a
+- * algorithm.  Unfortunately, it is very easy for attackers to guess
+- * the sequence of pseudo-random number generators, and for some
+- * applications this is not acceptable.  So instead, we must try to
+- * gather "environmental noise" from the computer's environment, which
+- * must be hard for outside attackers to observe, and use that to
+- * generate random numbers.  In a Unix environment, this is best done
+- * from inside the kernel.
+- *
+- * Sources of randomness from the environment include inter-keyboard
+- * timings, inter-interrupt timings from some interrupts, and other
+- * events which are both (a) non-deterministic and (b) hard for an
+- * outside observer to measure.  Randomness from these sources are
+- * added to an "entropy pool", which is mixed using a CRC-like function.
+- * This is not cryptographically strong, but it is adequate assuming
+- * the randomness is not chosen maliciously, and it is fast enough that
+- * the overhead of doing it on every interrupt is very reasonable.
+- * As random bytes are mixed into the entropy pool, the routines keep
+- * an *estimate* of how many bits of randomness have been stored into
+- * the random number generator's internal state.
+- *
+- * When random bytes are desired, they are obtained by taking the BLAKE2s
+- * hash of the contents of the "entropy pool".  The BLAKE2s hash avoids
+- * exposing the internal state of the entropy pool.  It is believed to
+- * be computationally infeasible to derive any useful information
+- * about the input of BLAKE2s from its output.  Even if it is possible to
+- * analyze BLAKE2s in some clever way, as long as the amount of data
+- * returned from the generator is less than the inherent entropy in
+- * the pool, the output data is totally unpredictable.  For this
+- * reason, the routine decreases its internal estimate of how many
+- * bits of "true randomness" are contained in the entropy pool as it
+- * outputs random numbers.
+- *
+- * If this estimate goes to zero, the routine can still generate
+- * random numbers; however, an attacker may (at least in theory) be
+- * able to infer the future output of the generator from prior
+- * outputs.  This requires successful cryptanalysis of BLAKE2s, which is
+- * not believed to be feasible, but there is a remote possibility.
+- * Nonetheless, these numbers should be useful for the vast majority
+- * of purposes.
+- *
+- * Exported interfaces ---- output
+- * ===============================
+- *
+- * There are four exported interfaces; two for use within the kernel,
+- * and two for use from userspace.
+- *
+- * Exported interfaces ---- userspace output
+- * -----------------------------------------
+- *
+- * The userspace interfaces are two character devices /dev/random and
+- * /dev/urandom.  /dev/random is suitable for use when very high
+- * quality randomness is desired (for example, for key generation or
+- * one-time pads), as it will only return a maximum of the number of
+- * bits of randomness (as estimated by the random number generator)
+- * contained in the entropy pool.
+- *
+- * The /dev/urandom device does not have this limit, and will return
+- * as many bytes as are requested.  As more and more random bytes are
+- * requested without giving time for the entropy pool to recharge,
+- * this will result in random numbers that are merely cryptographically
+- * strong.  For many applications, however, this is acceptable.
+- *
+- * Exported interfaces ---- kernel output
+- * --------------------------------------
+- *
+- * The primary kernel interface is
+- *
+- *	void get_random_bytes(void *buf, int nbytes);
+- *
+- * This interface will return the requested number of random bytes,
+- * and place it in the requested buffer.  This is equivalent to a
+- * read from /dev/urandom.
+- *
+- * For less critical applications, there are the functions:
+- *
+- *	u32 get_random_u32()
+- *	u64 get_random_u64()
+- *	unsigned int get_random_int()
+- *	unsigned long get_random_long()
+- *
+- * These are produced by a cryptographic RNG seeded from get_random_bytes,
+- * and so do not deplete the entropy pool as much.  These are recommended
+- * for most in-kernel operations *if the result is going to be stored in
+- * the kernel*.
+- *
+- * Specifically, the get_random_int() family do not attempt to do
+- * "anti-backtracking".  If you capture the state of the kernel (e.g.
+- * by snapshotting the VM), you can figure out previous get_random_int()
+- * return values.  But if the value is stored in the kernel anyway,
+- * this is not a problem.
+- *
+- * It *is* safe to expose get_random_int() output to attackers (e.g. as
+- * network cookies); given outputs 1..n, it's not feasible to predict
+- * outputs 0 or n+1.  The only concern is an attacker who breaks into
+- * the kernel later; the get_random_int() engine is not reseeded as
+- * often as the get_random_bytes() one.
+- *
+- * get_random_bytes() is needed for keys that need to stay secret after
+- * they are erased from the kernel.  For example, any key that will
+- * be wrapped and stored encrypted.  And session encryption keys: we'd
+- * like to know that after the session is closed and the keys erased,
+- * the plaintext is unrecoverable to someone who recorded the ciphertext.
+- *
+- * But for network ports/cookies, stack canaries, PRNG seeds, address
+- * space layout randomization, session *authentication* keys, or other
+- * applications where the sensitive data is stored in the kernel in
+- * plaintext for as long as it's sensitive, the get_random_int() family
+- * is just fine.
+- *
+- * Consider ASLR.  We want to keep the address space secret from an
+- * outside attacker while the process is running, but once the address
+- * space is torn down, it's of no use to an attacker any more.  And it's
+- * stored in kernel data structures as long as it's alive, so worrying
+- * about an attacker's ability to extrapolate it from the get_random_int()
+- * CRNG is silly.
+- *
+- * Even some cryptographic keys are safe to generate with get_random_int().
+- * In particular, keys for SipHash are generally fine.  Here, knowledge
+- * of the key authorizes you to do something to a kernel object (inject
+- * packets to a network connection, or flood a hash table), and the
+- * key is stored with the object being protected.  Once it goes away,
+- * we no longer care if anyone knows the key.
+- *
+- * prandom_u32()
+- * -------------
+- *
+- * For even weaker applications, see the pseudorandom generator
+- * prandom_u32(), prandom_max(), and prandom_bytes().  If the random
+- * numbers aren't security-critical at all, these are *far* cheaper.
+- * Useful for self-tests, random error simulation, randomized backoffs,
+- * and any other application where you trust that nobody is trying to
+- * maliciously mess with you by guessing the "random" numbers.
+- *
+- * Exported interfaces ---- input
+- * ==============================
+- *
+- * The current exported interfaces for gathering environmental noise
+- * from the devices are:
+- *
+- *	void add_device_randomness(const void *buf, unsigned int size);
+- *	void add_input_randomness(unsigned int type, unsigned int code,
+- *                                unsigned int value);
+- *	void add_interrupt_randomness(int irq);
+- *	void add_disk_randomness(struct gendisk *disk);
+- *	void add_hwgenerator_randomness(const char *buffer, size_t count,
+- *					size_t entropy);
+- *	void add_bootloader_randomness(const void *buf, unsigned int size);
+- *
+- * add_device_randomness() is for adding data to the random pool that
+- * is likely to differ between two devices (or possibly even per boot).
+- * This would be things like MAC addresses or serial numbers, or the
+- * read-out of the RTC. This does *not* add any actual entropy to the
+- * pool, but it initializes the pool to different values for devices
+- * that might otherwise be identical and have very little entropy
+- * available to them (particularly common in the embedded world).
+- *
+- * add_input_randomness() uses the input layer interrupt timing, as well as
+- * the event type information from the hardware.
+- *
+- * add_interrupt_randomness() uses the interrupt timing as random
+- * inputs to the entropy pool. Using the cycle counters and the irq source
+- * as inputs, it feeds the randomness roughly once a second.
+- *
+- * add_disk_randomness() uses what amounts to the seek time of block
+- * layer request events, on a per-disk_devt basis, as input to the
+- * entropy pool. Note that high-speed solid state drives with very low
+- * seek times do not make for good sources of entropy, as their seek
+- * times are usually fairly consistent.
+- *
+- * All of these routines try to estimate how many bits of randomness a
+- * particular randomness source.  They do this by keeping track of the
+- * first and second order deltas of the event timings.
+- *
+- * add_hwgenerator_randomness() is for true hardware RNGs, and will credit
+- * entropy as specified by the caller. If the entropy pool is full it will
+- * block until more entropy is needed.
+- *
+- * add_bootloader_randomness() is the same as add_hwgenerator_randomness() or
+- * add_device_randomness(), depending on whether or not the configuration
+- * option CONFIG_RANDOM_TRUST_BOOTLOADER is set.
+- *
+- * Ensuring unpredictability at system startup
+- * ============================================
+- *
+- * When any operating system starts up, it will go through a sequence
+- * of actions that are fairly predictable by an adversary, especially
+- * if the start-up does not involve interaction with a human operator.
+- * This reduces the actual number of bits of unpredictability in the
+- * entropy pool below the value in entropy_count.  In order to
+- * counteract this effect, it helps to carry information in the
+- * entropy pool across shut-downs and start-ups.  To do this, put the
+- * following lines an appropriate script which is run during the boot
+- * sequence:
+- *
+- *	echo "Initializing random number generator..."
+- *	random_seed=/var/run/random-seed
+- *	# Carry a random seed from start-up to start-up
+- *	# Load and then save the whole entropy pool
+- *	if [ -f $random_seed ]; then
+- *		cat $random_seed >/dev/urandom
+- *	else
+- *		touch $random_seed
+- *	fi
+- *	chmod 600 $random_seed
+- *	dd if=/dev/urandom of=$random_seed count=1 bs=512
+- *
+- * and the following lines in an appropriate script which is run as
+- * the system is shutdown:
+- *
+- *	# Carry a random seed from shut-down to start-up
+- *	# Save the whole entropy pool
+- *	echo "Saving random seed..."
+- *	random_seed=/var/run/random-seed
+- *	touch $random_seed
+- *	chmod 600 $random_seed
+- *	dd if=/dev/urandom of=$random_seed count=1 bs=512
+- *
+- * For example, on most modern systems using the System V init
+- * scripts, such code fragments would be found in
+- * /etc/rc.d/init.d/random.  On older Linux systems, the correct script
+- * location might be in /etc/rcb.d/rc.local or /etc/rc.d/rc.0.
+- *
+- * Effectively, these commands cause the contents of the entropy pool
+- * to be saved at shut-down time and reloaded into the entropy pool at
+- * start-up.  (The 'dd' in the addition to the bootup script is to
+- * make sure that /etc/random-seed is different for every start-up,
+- * even if the system crashes without executing rc.0.)  Even with
+- * complete knowledge of the start-up activities, predicting the state
+- * of the entropy pool requires knowledge of the previous history of
+- * the system.
+- *
+- * Configuring the /dev/random driver under Linux
+- * ==============================================
+- *
+- * The /dev/random driver under Linux uses minor numbers 8 and 9 of
+- * the /dev/mem major number (#1).  So if your system does not have
+- * /dev/random and /dev/urandom created already, they can be created
+- * by using the commands:
+- *
+- *	mknod /dev/random c 1 8
+- *	mknod /dev/urandom c 1 9
+- *
+- * Acknowledgements:
+- * =================
+- *
+- * Ideas for constructing this random number generator were derived
+- * from Pretty Good Privacy's random number generator, and from private
+- * discussions with Phil Karn.  Colin Plumb provided a faster random
+- * number generator, which speed up the mixing function of the entropy
+- * pool, taken from PGPfone.  Dale Worley has also contributed many
+- * useful ideas and suggestions to improve this driver.
+- *
+- * Any flaws in the design are solely my responsibility, and should
+- * not be attributed to the Phil, Colin, or any of authors of PGP.
+- *
+- * Further background information on this topic may be obtained from
+- * RFC 1750, "Randomness Recommendations for Security", by Donald
+- * Eastlake, Steve Crocker, and Jeff Schiller.
++ * Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999. All rights reserved.
++ *
++ * This driver produces cryptographically secure pseudorandom data. It is divided
++ * into roughly six sections, each with a section header:
++ *
++ *   - Initialization and readiness waiting.
++ *   - Fast key erasure RNG, the "crng".
++ *   - Entropy accumulation and extraction routines.
++ *   - Entropy collection routines.
++ *   - Userspace reader/writer interfaces.
++ *   - Sysctl interface.
++ *
++ * The high level overview is that there is one input pool, into which
++ * various pieces of data are hashed. Prior to initialization, some of that
++ * data is then "credited" as having a certain number of bits of entropy.
++ * When enough bits of entropy are available, the hash is finalized and
++ * handed as a key to a stream cipher that expands it indefinitely for
++ * various consumers. This key is periodically refreshed as the various
++ * entropy collectors, described below, add data to the input pool.
+  */
+ 
+ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+@@ -344,1371 +50,1080 @@
+ #include <linux/syscalls.h>
+ #include <linux/completion.h>
+ #include <linux/uuid.h>
++#include <linux/uaccess.h>
++#include <linux/siphash.h>
++#include <linux/uio.h>
+ #include <crypto/chacha.h>
+ #include <crypto/blake2s.h>
+-
+ #include <asm/processor.h>
+-#include <linux/uaccess.h>
+ #include <asm/irq.h>
+ #include <asm/irq_regs.h>
+ #include <asm/io.h>
+ 
+-#define CREATE_TRACE_POINTS
+-#include <trace/events/random.h>
+-
+-/* #define ADD_INTERRUPT_BENCH */
+-
+-/*
+- * If the entropy count falls under this number of bits, then we
+- * should wake up processes which are selecting or polling on write
+- * access to /dev/random.
+- */
+-static int random_write_wakeup_bits = 28 * (1 << 5);
+-
+-/*
+- * Originally, we used a primitive polynomial of degree .poolwords
+- * over GF(2).  The taps for various sizes are defined below.  They
+- * were chosen to be evenly spaced except for the last tap, which is 1
+- * to get the twisting happening as fast as possible.
+- *
+- * For the purposes of better mixing, we use the CRC-32 polynomial as
+- * well to make a (modified) twisted Generalized Feedback Shift
+- * Register.  (See M. Matsumoto & Y. Kurita, 1992.  Twisted GFSR
+- * generators.  ACM Transactions on Modeling and Computer Simulation
+- * 2(3):179-194.  Also see M. Matsumoto & Y. Kurita, 1994.  Twisted
+- * GFSR generators II.  ACM Transactions on Modeling and Computer
+- * Simulation 4:254-266)
++/*********************************************************************
+  *
+- * Thanks to Colin Plumb for suggesting this.
++ * Initialization and readiness waiting.
+  *
+- * The mixing operation is much less sensitive than the output hash,
+- * where we use BLAKE2s.  All that we want of mixing operation is that
+- * it be a good non-cryptographic hash; i.e. it not produce collisions
+- * when fed "random" data of the sort we expect to see.  As long as
+- * the pool state differs for different inputs, we have preserved the
+- * input entropy and done a good job.  The fact that an intelligent
+- * attacker can construct inputs that will produce controlled
+- * alterations to the pool's state is not important because we don't
+- * consider such inputs to contribute any randomness.  The only
+- * property we need with respect to them is that the attacker can't
+- * increase his/her knowledge of the pool's state.  Since all
+- * additions are reversible (knowing the final state and the input,
+- * you can reconstruct the initial state), if an attacker has any
+- * uncertainty about the initial state, he/she can only shuffle that
+- * uncertainty about, but never cause any collisions (which would
+- * decrease the uncertainty).
++ * Much of the RNG infrastructure is devoted to various dependencies
++ * being able to wait until the RNG has collected enough entropy and
++ * is ready for safe consumption.
+  *
+- * Our mixing functions were analyzed by Lacharme, Roeck, Strubel, and
+- * Videau in their paper, "The Linux Pseudorandom Number Generator
+- * Revisited" (see: http://eprint.iacr.org/2012/251.pdf).  In their
+- * paper, they point out that we are not using a true Twisted GFSR,
+- * since Matsumoto & Kurita used a trinomial feedback polynomial (that
+- * is, with only three taps, instead of the six that we are using).
+- * As a result, the resulting polynomial is neither primitive nor
+- * irreducible, and hence does not have a maximal period over
+- * GF(2**32).  They suggest a slight change to the generator
+- * polynomial which improves the resulting TGFSR polynomial to be
+- * irreducible, which we have made here.
+- */
+-enum poolinfo {
+-	POOL_WORDS = 128,
+-	POOL_WORDMASK = POOL_WORDS - 1,
+-	POOL_BYTES = POOL_WORDS * sizeof(u32),
+-	POOL_BITS = POOL_BYTES * 8,
+-	POOL_BITSHIFT = ilog2(POOL_BITS),
+-
+-	/* To allow fractional bits to be tracked, the entropy_count field is
+-	 * denominated in units of 1/8th bits. */
+-	POOL_ENTROPY_SHIFT = 3,
+-#define POOL_ENTROPY_BITS() (input_pool.entropy_count >> POOL_ENTROPY_SHIFT)
+-	POOL_FRACBITS = POOL_BITS << POOL_ENTROPY_SHIFT,
+-
+-	/* x^128 + x^104 + x^76 + x^51 +x^25 + x + 1 */
+-	POOL_TAP1 = 104,
+-	POOL_TAP2 = 76,
+-	POOL_TAP3 = 51,
+-	POOL_TAP4 = 25,
+-	POOL_TAP5 = 1,
+-
+-	EXTRACT_SIZE = BLAKE2S_HASH_SIZE / 2
+-};
++ *********************************************************************/
+ 
+ /*
+- * Static global variables
++ * crng_init is protected by base_crng->lock, and only increases
++ * its value (from empty->early->ready).
+  */
+-static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
++static enum {
++	CRNG_EMPTY = 0, /* Little to no entropy collected */
++	CRNG_EARLY = 1, /* At least POOL_EARLY_BITS collected */
++	CRNG_READY = 2  /* Fully initialized with POOL_READY_BITS collected */
++} crng_init __read_mostly = CRNG_EMPTY;
++static DEFINE_STATIC_KEY_FALSE(crng_is_ready);
++#define crng_ready() (static_branch_likely(&crng_is_ready) || crng_init >= CRNG_READY)
++/* Various types of waiters for crng_init->CRNG_READY transition. */
++static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
+ static struct fasync_struct *fasync;
++static DEFINE_SPINLOCK(random_ready_chain_lock);
++static RAW_NOTIFIER_HEAD(random_ready_chain);
+ 
+-static DEFINE_SPINLOCK(random_ready_list_lock);
+-static LIST_HEAD(random_ready_list);
+-
+-struct crng_state {
+-	u32 state[16];
+-	unsigned long init_time;
+-	spinlock_t lock;
+-};
+-
+-static struct crng_state primary_crng = {
+-	.lock = __SPIN_LOCK_UNLOCKED(primary_crng.lock),
+-	.state[0] = CHACHA_CONSTANT_EXPA,
+-	.state[1] = CHACHA_CONSTANT_ND_3,
+-	.state[2] = CHACHA_CONSTANT_2_BY,
+-	.state[3] = CHACHA_CONSTANT_TE_K,
+-};
+-
+-/*
+- * crng_init =  0 --> Uninitialized
+- *		1 --> Initialized
+- *		2 --> Initialized from input_pool
+- *
+- * crng_init is protected by primary_crng->lock, and only increases
+- * its value (from 0->1->2).
+- */
+-static int crng_init = 0;
+-static bool crng_need_final_init = false;
+-#define crng_ready() (likely(crng_init > 1))
+-static int crng_init_cnt = 0;
+-static unsigned long crng_global_init_time = 0;
+-#define CRNG_INIT_CNT_THRESH (2 * CHACHA_KEY_SIZE)
+-static void _extract_crng(struct crng_state *crng, u8 out[CHACHA_BLOCK_SIZE]);
+-static void _crng_backtrack_protect(struct crng_state *crng,
+-				    u8 tmp[CHACHA_BLOCK_SIZE], int used);
+-static void process_random_ready_list(void);
+-static void _get_random_bytes(void *buf, int nbytes);
+-
+-static struct ratelimit_state unseeded_warning =
+-	RATELIMIT_STATE_INIT("warn_unseeded_randomness", HZ, 3);
++/* Control how we warn userspace. */
+ static struct ratelimit_state urandom_warning =
+ 	RATELIMIT_STATE_INIT("warn_urandom_randomness", HZ, 3);
+-
+-static int ratelimit_disable __read_mostly;
+-
++static int ratelimit_disable __read_mostly =
++	IS_ENABLED(CONFIG_WARN_ALL_UNSEEDED_RANDOM);
+ module_param_named(ratelimit_disable, ratelimit_disable, int, 0644);
+ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression");
+ 
+-/**********************************************************************
+- *
+- * OS independent entropy store.   Here are the functions which handle
+- * storing entropy in an entropy pool.
+- *
+- **********************************************************************/
+-
+-static u32 input_pool_data[POOL_WORDS] __latent_entropy;
+-
+-static struct {
+-	spinlock_t lock;
+-	u16 add_ptr;
+-	u16 input_rotate;
+-	int entropy_count;
+-} input_pool = {
+-	.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),
+-};
+-
+-static ssize_t extract_entropy(void *buf, size_t nbytes, int min);
+-static ssize_t _extract_entropy(void *buf, size_t nbytes);
+-
+-static void crng_reseed(struct crng_state *crng, bool use_input_pool);
+-
+-static const u32 twist_table[8] = {
+-	0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
+-	0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
+-
+ /*
+- * This function adds bytes into the entropy "pool".  It does not
+- * update the entropy estimate.  The caller should call
+- * credit_entropy_bits if this is appropriate.
++ * Returns whether or not the input pool has been seeded and thus guaranteed
++ * to supply cryptographically secure random numbers. This applies to: the
++ * /dev/urandom device, the get_random_bytes function, and the get_random_{u32,
++ * ,u64,int,long} family of functions.
+  *
+- * The pool is stirred with a primitive polynomial of the appropriate
+- * degree, and then twisted.  We twist by three bits at a time because
+- * it's cheap to do so and helps slightly in the expected case where
+- * the entropy is concentrated in the low-order bits.
++ * Returns: true if the input pool has been seeded.
++ *          false if the input pool has not been seeded.
+  */
+-static void _mix_pool_bytes(const void *in, int nbytes)
+-{
+-	unsigned long i;
+-	int input_rotate;
+-	const u8 *bytes = in;
+-	u32 w;
+-
+-	input_rotate = input_pool.input_rotate;
+-	i = input_pool.add_ptr;
+-
+-	/* mix one byte at a time to simplify size handling and churn faster */
+-	while (nbytes--) {
+-		w = rol32(*bytes++, input_rotate);
+-		i = (i - 1) & POOL_WORDMASK;
+-
+-		/* XOR in the various taps */
+-		w ^= input_pool_data[i];
+-		w ^= input_pool_data[(i + POOL_TAP1) & POOL_WORDMASK];
+-		w ^= input_pool_data[(i + POOL_TAP2) & POOL_WORDMASK];
+-		w ^= input_pool_data[(i + POOL_TAP3) & POOL_WORDMASK];
+-		w ^= input_pool_data[(i + POOL_TAP4) & POOL_WORDMASK];
+-		w ^= input_pool_data[(i + POOL_TAP5) & POOL_WORDMASK];
+-
+-		/* Mix the result back in with a twist */
+-		input_pool_data[i] = (w >> 3) ^ twist_table[w & 7];
+-
+-		/*
+-		 * Normally, we add 7 bits of rotation to the pool.
+-		 * At the beginning of the pool, add an extra 7 bits
+-		 * rotation, so that successive passes spread the
+-		 * input bits across the pool evenly.
+-		 */
+-		input_rotate = (input_rotate + (i ? 7 : 14)) & 31;
+-	}
+-
+-	input_pool.input_rotate = input_rotate;
+-	input_pool.add_ptr = i;
+-}
+-
+-static void __mix_pool_bytes(const void *in, int nbytes)
++bool rng_is_initialized(void)
+ {
+-	trace_mix_pool_bytes_nolock(nbytes, _RET_IP_);
+-	_mix_pool_bytes(in, nbytes);
++	return crng_ready();
+ }
++EXPORT_SYMBOL(rng_is_initialized);
+ 
+-static void mix_pool_bytes(const void *in, int nbytes)
++static void __cold crng_set_ready(struct work_struct *work)
+ {
+-	unsigned long flags;
+-
+-	trace_mix_pool_bytes(nbytes, _RET_IP_);
+-	spin_lock_irqsave(&input_pool.lock, flags);
+-	_mix_pool_bytes(in, nbytes);
+-	spin_unlock_irqrestore(&input_pool.lock, flags);
++	static_branch_enable(&crng_is_ready);
+ }
+ 
+-struct fast_pool {
+-	u32 pool[4];
+-	unsigned long last;
+-	u16 reg_idx;
+-	u8 count;
+-};
++/* Used by wait_for_random_bytes(), and considered an entropy collector, below. */
++static void try_to_generate_entropy(void);
+ 
+ /*
+- * This is a fast mixing routine used by the interrupt randomness
+- * collector.  It's hardcoded for an 128 bit pool and assumes that any
+- * locks that might be needed are taken by the caller.
++ * Wait for the input pool to be seeded and thus guaranteed to supply
++ * cryptographically secure random numbers. This applies to: the /dev/urandom
++ * device, the get_random_bytes function, and the get_random_{u32,u64,int,long}
++ * family of functions. Using any of these functions without first calling
++ * this function forfeits the guarantee of security.
++ *
++ * Returns: 0 if the input pool has been seeded.
++ *          -ERESTARTSYS if the function was interrupted by a signal.
+  */
+-static void fast_mix(struct fast_pool *f)
++int wait_for_random_bytes(void)
+ {
+-	u32 a = f->pool[0],	b = f->pool[1];
+-	u32 c = f->pool[2],	d = f->pool[3];
+-
+-	a += b;			c += d;
+-	b = rol32(b, 6);	d = rol32(d, 27);
+-	d ^= a;			b ^= c;
+-
+-	a += b;			c += d;
+-	b = rol32(b, 16);	d = rol32(d, 14);
+-	d ^= a;			b ^= c;
+-
+-	a += b;			c += d;
+-	b = rol32(b, 6);	d = rol32(d, 27);
+-	d ^= a;			b ^= c;
+-
+-	a += b;			c += d;
+-	b = rol32(b, 16);	d = rol32(d, 14);
+-	d ^= a;			b ^= c;
++	while (!crng_ready()) {
++		int ret;
+ 
+-	f->pool[0] = a;  f->pool[1] = b;
+-	f->pool[2] = c;  f->pool[3] = d;
+-	f->count++;
++		try_to_generate_entropy();
++		ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ);
++		if (ret)
++			return ret > 0 ? 0 : ret;
++	}
++	return 0;
+ }
++EXPORT_SYMBOL(wait_for_random_bytes);
+ 
+-static void process_random_ready_list(void)
++/*
++ * Add a callback function that will be invoked when the input
++ * pool is initialised.
++ *
++ * returns: 0 if callback is successfully added
++ *	    -EALREADY if pool is already initialised (callback not called)
++ */
++int __cold register_random_ready_notifier(struct notifier_block *nb)
+ {
+ 	unsigned long flags;
+-	struct random_ready_callback *rdy, *tmp;
++	int ret = -EALREADY;
+ 
+-	spin_lock_irqsave(&random_ready_list_lock, flags);
+-	list_for_each_entry_safe(rdy, tmp, &random_ready_list, list) {
+-		struct module *owner = rdy->owner;
++	if (crng_ready())
++		return ret;
+ 
+-		list_del_init(&rdy->list);
+-		rdy->func(rdy);
+-		module_put(owner);
+-	}
+-	spin_unlock_irqrestore(&random_ready_list_lock, flags);
++	spin_lock_irqsave(&random_ready_chain_lock, flags);
++	if (!crng_ready())
++		ret = raw_notifier_chain_register(&random_ready_chain, nb);
++	spin_unlock_irqrestore(&random_ready_chain_lock, flags);
++	return ret;
+ }
+ 
+ /*
+- * Credit (or debit) the entropy store with n bits of entropy.
+- * Use credit_entropy_bits_safe() if the value comes from userspace
+- * or otherwise should be checked for extreme values.
++ * Delete a previously registered readiness callback function.
+  */
+-static void credit_entropy_bits(int nbits)
++int __cold unregister_random_ready_notifier(struct notifier_block *nb)
+ {
+-	int entropy_count, entropy_bits, orig;
+-	int nfrac = nbits << POOL_ENTROPY_SHIFT;
+-
+-	/* Ensure that the multiplication can avoid being 64 bits wide. */
+-	BUILD_BUG_ON(2 * (POOL_ENTROPY_SHIFT + POOL_BITSHIFT) > 31);
+-
+-	if (!nbits)
+-		return;
+-
+-retry:
+-	entropy_count = orig = READ_ONCE(input_pool.entropy_count);
+-	if (nfrac < 0) {
+-		/* Debit */
+-		entropy_count += nfrac;
+-	} else {
+-		/*
+-		 * Credit: we have to account for the possibility of
+-		 * overwriting already present entropy.	 Even in the
+-		 * ideal case of pure Shannon entropy, new contributions
+-		 * approach the full value asymptotically:
+-		 *
+-		 * entropy <- entropy + (pool_size - entropy) *
+-		 *	(1 - exp(-add_entropy/pool_size))
+-		 *
+-		 * For add_entropy <= pool_size/2 then
+-		 * (1 - exp(-add_entropy/pool_size)) >=
+-		 *    (add_entropy/pool_size)*0.7869...
+-		 * so we can approximate the exponential with
+-		 * 3/4*add_entropy/pool_size and still be on the
+-		 * safe side by adding at most pool_size/2 at a time.
+-		 *
+-		 * The use of pool_size-2 in the while statement is to
+-		 * prevent rounding artifacts from making the loop
+-		 * arbitrarily long; this limits the loop to log2(pool_size)*2
+-		 * turns no matter how large nbits is.
+-		 */
+-		int pnfrac = nfrac;
+-		const int s = POOL_BITSHIFT + POOL_ENTROPY_SHIFT + 2;
+-		/* The +2 corresponds to the /4 in the denominator */
+-
+-		do {
+-			unsigned int anfrac = min(pnfrac, POOL_FRACBITS / 2);
+-			unsigned int add =
+-				((POOL_FRACBITS - entropy_count) * anfrac * 3) >> s;
+-
+-			entropy_count += add;
+-			pnfrac -= anfrac;
+-		} while (unlikely(entropy_count < POOL_FRACBITS - 2 && pnfrac));
+-	}
+-
+-	if (WARN_ON(entropy_count < 0)) {
+-		pr_warn("negative entropy/overflow: count %d\n", entropy_count);
+-		entropy_count = 0;
+-	} else if (entropy_count > POOL_FRACBITS)
+-		entropy_count = POOL_FRACBITS;
+-	if (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig)
+-		goto retry;
+-
+-	trace_credit_entropy_bits(nbits, entropy_count >> POOL_ENTROPY_SHIFT, _RET_IP_);
++	unsigned long flags;
++	int ret;
+ 
+-	entropy_bits = entropy_count >> POOL_ENTROPY_SHIFT;
+-	if (crng_init < 2 && entropy_bits >= 128)
+-		crng_reseed(&primary_crng, true);
++	spin_lock_irqsave(&random_ready_chain_lock, flags);
++	ret = raw_notifier_chain_unregister(&random_ready_chain, nb);
++	spin_unlock_irqrestore(&random_ready_chain_lock, flags);
++	return ret;
+ }
+ 
+-static int credit_entropy_bits_safe(int nbits)
++static void __cold process_random_ready_list(void)
+ {
+-	if (nbits < 0)
+-		return -EINVAL;
+-
+-	/* Cap the value to avoid overflows */
+-	nbits = min(nbits, POOL_BITS);
++	unsigned long flags;
+ 
+-	credit_entropy_bits(nbits);
+-	return 0;
++	spin_lock_irqsave(&random_ready_chain_lock, flags);
++	raw_notifier_call_chain(&random_ready_chain, 0, NULL);
++	spin_unlock_irqrestore(&random_ready_chain_lock, flags);
+ }
+ 
++#define warn_unseeded_randomness() \
++	if (IS_ENABLED(CONFIG_WARN_ALL_UNSEEDED_RANDOM) && !crng_ready()) \
++		printk_deferred(KERN_NOTICE "random: %s called from %pS with crng_init=%d\n", \
++				__func__, (void *)_RET_IP_, crng_init)
++
++
+ /*********************************************************************
+  *
+- * CRNG using CHACHA20
++ * Fast key erasure RNG, the "crng".
++ *
++ * These functions expand entropy from the entropy extractor into
++ * long streams for external consumption using the "fast key erasure"
++ * RNG described at <https://blog.cr.yp.to/20170723-random.html>.
++ *
++ * There are a few exported interfaces for use by other drivers:
++ *
++ *	void get_random_bytes(void *buf, size_t len)
++ *	u32 get_random_u32()
++ *	u64 get_random_u64()
++ *	unsigned int get_random_int()
++ *	unsigned long get_random_long()
++ *
++ * These interfaces will return the requested number of random bytes
++ * into the given buffer or as a return value. This is equivalent to
++ * a read from /dev/urandom. The u32, u64, int, and long family of
++ * functions may be higher performance for one-off random integers,
++ * because they do a bit of buffering and do not invoke reseeding
++ * until the buffer is emptied.
+  *
+  *********************************************************************/
+ 
+-#define CRNG_RESEED_INTERVAL (300 * HZ)
++enum {
++	CRNG_RESEED_START_INTERVAL = HZ,
++	CRNG_RESEED_INTERVAL = 60 * HZ
++};
+ 
+-static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
++static struct {
++	u8 key[CHACHA_KEY_SIZE] __aligned(__alignof__(long));
++	unsigned long birth;
++	unsigned long generation;
++	spinlock_t lock;
++} base_crng = {
++	.lock = __SPIN_LOCK_UNLOCKED(base_crng.lock)
++};
+ 
+-/*
+- * Hack to deal with crazy userspace progams when they are all trying
+- * to access /dev/urandom in parallel.  The programs are almost
+- * certainly doing something terribly wrong, but we'll work around
+- * their brain damage.
+- */
+-static struct crng_state **crng_node_pool __read_mostly;
++struct crng {
++	u8 key[CHACHA_KEY_SIZE];
++	unsigned long generation;
++	local_lock_t lock;
++};
+ 
+-static void invalidate_batched_entropy(void);
+-static void numa_crng_init(void);
++static DEFINE_PER_CPU(struct crng, crngs) = {
++	.generation = ULONG_MAX,
++	.lock = INIT_LOCAL_LOCK(crngs.lock),
++};
+ 
+-static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
+-static int __init parse_trust_cpu(char *arg)
+-{
+-	return kstrtobool(arg, &trust_cpu);
+-}
+-early_param("random.trust_cpu", parse_trust_cpu);
++/* Used by crng_reseed() and crng_make_state() to extract a new seed from the input pool. */
++static void extract_entropy(void *buf, size_t len);
+ 
+-static bool crng_init_try_arch(struct crng_state *crng)
++/* This extracts a new crng key from the input pool. */
++static void crng_reseed(void)
+ {
+-	int i;
+-	bool arch_init = true;
+-	unsigned long rv;
+-
+-	for (i = 4; i < 16; i++) {
+-		if (!arch_get_random_seed_long(&rv) &&
+-		    !arch_get_random_long(&rv)) {
+-			rv = random_get_entropy();
+-			arch_init = false;
+-		}
+-		crng->state[i] ^= rv;
+-	}
++	unsigned long flags;
++	unsigned long next_gen;
++	u8 key[CHACHA_KEY_SIZE];
+ 
+-	return arch_init;
++	extract_entropy(key, sizeof(key));
++
++	/*
++	 * We copy the new key into the base_crng, overwriting the old one,
++	 * and update the generation counter. We avoid hitting ULONG_MAX,
++	 * because the per-cpu crngs are initialized to ULONG_MAX, so this
++	 * forces new CPUs that come online to always initialize.
++	 */
++	spin_lock_irqsave(&base_crng.lock, flags);
++	memcpy(base_crng.key, key, sizeof(base_crng.key));
++	next_gen = base_crng.generation + 1;
++	if (next_gen == ULONG_MAX)
++		++next_gen;
++	WRITE_ONCE(base_crng.generation, next_gen);
++	WRITE_ONCE(base_crng.birth, jiffies);
++	if (!static_branch_likely(&crng_is_ready))
++		crng_init = CRNG_READY;
++	spin_unlock_irqrestore(&base_crng.lock, flags);
++	memzero_explicit(key, sizeof(key));
+ }
+ 
+-static bool __init crng_init_try_arch_early(void)
++/*
++ * This generates a ChaCha block using the provided key, and then
++ * immediately overwites that key with half the block. It returns
++ * the resultant ChaCha state to the user, along with the second
++ * half of the block containing 32 bytes of random data that may
++ * be used; random_data_len may not be greater than 32.
++ *
++ * The returned ChaCha state contains within it a copy of the old
++ * key value, at index 4, so the state should always be zeroed out
++ * immediately after using in order to maintain forward secrecy.
++ * If the state cannot be erased in a timely manner, then it is
++ * safer to set the random_data parameter to &chacha_state[4] so
++ * that this function overwrites it before returning.
++ */
++static void crng_fast_key_erasure(u8 key[CHACHA_KEY_SIZE],
++				  u32 chacha_state[CHACHA_STATE_WORDS],
++				  u8 *random_data, size_t random_data_len)
+ {
+-	int i;
+-	bool arch_init = true;
+-	unsigned long rv;
+-
+-	for (i = 4; i < 16; i++) {
+-		if (!arch_get_random_seed_long_early(&rv) &&
+-		    !arch_get_random_long_early(&rv)) {
+-			rv = random_get_entropy();
+-			arch_init = false;
+-		}
+-		primary_crng.state[i] ^= rv;
+-	}
++	u8 first_block[CHACHA_BLOCK_SIZE];
+ 
+-	return arch_init;
+-}
++	BUG_ON(random_data_len > 32);
+ 
+-static void crng_initialize_secondary(struct crng_state *crng)
+-{
+-	chacha_init_consts(crng->state);
+-	_get_random_bytes(&crng->state[4], sizeof(u32) * 12);
+-	crng_init_try_arch(crng);
+-	crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
++	chacha_init_consts(chacha_state);
++	memcpy(&chacha_state[4], key, CHACHA_KEY_SIZE);
++	memset(&chacha_state[12], 0, sizeof(u32) * 4);
++	chacha20_block(chacha_state, first_block);
++
++	memcpy(key, first_block, CHACHA_KEY_SIZE);
++	memcpy(random_data, first_block + CHACHA_KEY_SIZE, random_data_len);
++	memzero_explicit(first_block, sizeof(first_block));
+ }
+ 
+-static void __init crng_initialize_primary(void)
+-{
+-	_extract_entropy(&primary_crng.state[4], sizeof(u32) * 12);
+-	if (crng_init_try_arch_early() && trust_cpu && crng_init < 2) {
+-		invalidate_batched_entropy();
+-		numa_crng_init();
+-		crng_init = 2;
+-		pr_notice("crng init done (trusting CPU's manufacturer)\n");
++/*
++ * Return whether the crng seed is considered to be sufficiently old
++ * that a reseeding is needed. This happens if the last reseeding
++ * was CRNG_RESEED_INTERVAL ago, or during early boot, at an interval
++ * proportional to the uptime.
++ */
++static bool crng_has_old_seed(void)
++{
++	static bool early_boot = true;
++	unsigned long interval = CRNG_RESEED_INTERVAL;
++
++	if (unlikely(READ_ONCE(early_boot))) {
++		time64_t uptime = ktime_get_seconds();
++		if (uptime >= CRNG_RESEED_INTERVAL / HZ * 2)
++			WRITE_ONCE(early_boot, false);
++		else
++			interval = max_t(unsigned int, CRNG_RESEED_START_INTERVAL,
++					 (unsigned int)uptime / 2 * HZ);
+ 	}
+-	primary_crng.init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
++	return time_is_before_jiffies(READ_ONCE(base_crng.birth) + interval);
+ }
+ 
+-static void crng_finalize_init(void)
++/*
++ * This function returns a ChaCha state that you may use for generating
++ * random data. It also returns up to 32 bytes on its own of random data
++ * that may be used; random_data_len may not be greater than 32.
++ */
++static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS],
++			    u8 *random_data, size_t random_data_len)
+ {
+-	if (!system_wq) {
+-		/* We can't call numa_crng_init until we have workqueues,
+-		 * so mark this for processing later. */
+-		crng_need_final_init = true;
+-		return;
+-	}
++	unsigned long flags;
++	struct crng *crng;
+ 
+-	invalidate_batched_entropy();
+-	numa_crng_init();
+-	crng_init = 2;
+-	crng_need_final_init = false;
+-	process_random_ready_list();
+-	wake_up_interruptible(&crng_init_wait);
+-	kill_fasync(&fasync, SIGIO, POLL_IN);
+-	pr_notice("crng init done\n");
+-	if (unseeded_warning.missed) {
+-		pr_notice("%d get_random_xx warning(s) missed due to ratelimiting\n",
+-			  unseeded_warning.missed);
+-		unseeded_warning.missed = 0;
++	BUG_ON(random_data_len > 32);
++
++	/*
++	 * For the fast path, we check whether we're ready, unlocked first, and
++	 * then re-check once locked later. In the case where we're really not
++	 * ready, we do fast key erasure with the base_crng directly, extracting
++	 * when crng_init is CRNG_EMPTY.
++	 */
++	if (!crng_ready()) {
++		bool ready;
++
++		spin_lock_irqsave(&base_crng.lock, flags);
++		ready = crng_ready();
++		if (!ready) {
++			if (crng_init == CRNG_EMPTY)
++				extract_entropy(base_crng.key, sizeof(base_crng.key));
++			crng_fast_key_erasure(base_crng.key, chacha_state,
++					      random_data, random_data_len);
++		}
++		spin_unlock_irqrestore(&base_crng.lock, flags);
++		if (!ready)
++			return;
+ 	}
+-	if (urandom_warning.missed) {
+-		pr_notice("%d urandom warning(s) missed due to ratelimiting\n",
+-			  urandom_warning.missed);
+-		urandom_warning.missed = 0;
++
++	/*
++	 * If the base_crng is old enough, we reseed, which in turn bumps the
++	 * generation counter that we check below.
++	 */
++	if (unlikely(crng_has_old_seed()))
++		crng_reseed();
++
++	local_lock_irqsave(&crngs.lock, flags);
++	crng = raw_cpu_ptr(&crngs);
++
++	/*
++	 * If our per-cpu crng is older than the base_crng, then it means
++	 * somebody reseeded the base_crng. In that case, we do fast key
++	 * erasure on the base_crng, and use its output as the new key
++	 * for our per-cpu crng. This brings us up to date with base_crng.
++	 */
++	if (unlikely(crng->generation != READ_ONCE(base_crng.generation))) {
++		spin_lock(&base_crng.lock);
++		crng_fast_key_erasure(base_crng.key, chacha_state,
++				      crng->key, sizeof(crng->key));
++		crng->generation = base_crng.generation;
++		spin_unlock(&base_crng.lock);
+ 	}
++
++	/*
++	 * Finally, when we've made it this far, our per-cpu crng has an up
++	 * to date key, and we can do fast key erasure with it to produce
++	 * some random data and a ChaCha state for the caller. All other
++	 * branches of this function are "unlikely", so most of the time we
++	 * should wind up here immediately.
++	 */
++	crng_fast_key_erasure(crng->key, chacha_state, random_data, random_data_len);
++	local_unlock_irqrestore(&crngs.lock, flags);
+ }
+ 
+-static void do_numa_crng_init(struct work_struct *work)
++static void _get_random_bytes(void *buf, size_t len)
+ {
+-	int i;
+-	struct crng_state *crng;
+-	struct crng_state **pool;
+-
+-	pool = kcalloc(nr_node_ids, sizeof(*pool), GFP_KERNEL | __GFP_NOFAIL);
+-	for_each_online_node(i) {
+-		crng = kmalloc_node(sizeof(struct crng_state),
+-				    GFP_KERNEL | __GFP_NOFAIL, i);
+-		spin_lock_init(&crng->lock);
+-		crng_initialize_secondary(crng);
+-		pool[i] = crng;
+-	}
+-	/* pairs with READ_ONCE() in select_crng() */
+-	if (cmpxchg_release(&crng_node_pool, NULL, pool) != NULL) {
+-		for_each_node(i)
+-			kfree(pool[i]);
+-		kfree(pool);
+-	}
+-}
++	u32 chacha_state[CHACHA_STATE_WORDS];
++	u8 tmp[CHACHA_BLOCK_SIZE];
++	size_t first_block_len;
+ 
+-static DECLARE_WORK(numa_crng_init_work, do_numa_crng_init);
++	if (!len)
++		return;
+ 
+-static void numa_crng_init(void)
+-{
+-	if (IS_ENABLED(CONFIG_NUMA))
+-		schedule_work(&numa_crng_init_work);
+-}
++	first_block_len = min_t(size_t, 32, len);
++	crng_make_state(chacha_state, buf, first_block_len);
++	len -= first_block_len;
++	buf += first_block_len;
+ 
+-static struct crng_state *select_crng(void)
+-{
+-	if (IS_ENABLED(CONFIG_NUMA)) {
+-		struct crng_state **pool;
+-		int nid = numa_node_id();
+-
+-		/* pairs with cmpxchg_release() in do_numa_crng_init() */
+-		pool = READ_ONCE(crng_node_pool);
+-		if (pool && pool[nid])
+-			return pool[nid];
++	while (len) {
++		if (len < CHACHA_BLOCK_SIZE) {
++			chacha20_block(chacha_state, tmp);
++			memcpy(buf, tmp, len);
++			memzero_explicit(tmp, sizeof(tmp));
++			break;
++		}
++
++		chacha20_block(chacha_state, buf);
++		if (unlikely(chacha_state[12] == 0))
++			++chacha_state[13];
++		len -= CHACHA_BLOCK_SIZE;
++		buf += CHACHA_BLOCK_SIZE;
+ 	}
+ 
+-	return &primary_crng;
++	memzero_explicit(chacha_state, sizeof(chacha_state));
+ }
+ 
+ /*
+- * crng_fast_load() can be called by code in the interrupt service
+- * path.  So we can't afford to dilly-dally. Returns the number of
+- * bytes processed from cp.
++ * This function is the exported kernel interface.  It returns some
++ * number of good random numbers, suitable for key generation, seeding
++ * TCP sequence numbers, etc.  It does not rely on the hardware random
++ * number generator.  For random bytes direct from the hardware RNG
++ * (when available), use get_random_bytes_arch(). In order to ensure
++ * that the randomness provided by this function is okay, the function
++ * wait_for_random_bytes() should be called and return 0 at least once
++ * at any point prior.
+  */
+-static size_t crng_fast_load(const u8 *cp, size_t len)
++void get_random_bytes(void *buf, size_t len)
+ {
+-	unsigned long flags;
+-	u8 *p;
+-	size_t ret = 0;
+-
+-	if (!spin_trylock_irqsave(&primary_crng.lock, flags))
+-		return 0;
+-	if (crng_init != 0) {
+-		spin_unlock_irqrestore(&primary_crng.lock, flags);
+-		return 0;
+-	}
+-	p = (u8 *)&primary_crng.state[4];
+-	while (len > 0 && crng_init_cnt < CRNG_INIT_CNT_THRESH) {
+-		p[crng_init_cnt % CHACHA_KEY_SIZE] ^= *cp;
+-		cp++; crng_init_cnt++; len--; ret++;
+-	}
+-	spin_unlock_irqrestore(&primary_crng.lock, flags);
+-	if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) {
+-		invalidate_batched_entropy();
+-		crng_init = 1;
+-		pr_notice("fast init done\n");
+-	}
+-	return ret;
++	warn_unseeded_randomness();
++	_get_random_bytes(buf, len);
+ }
++EXPORT_SYMBOL(get_random_bytes);
+ 
+-/*
+- * crng_slow_load() is called by add_device_randomness, which has two
+- * attributes.  (1) We can't trust the buffer passed to it is
+- * guaranteed to be unpredictable (so it might not have any entropy at
+- * all), and (2) it doesn't have the performance constraints of
+- * crng_fast_load().
+- *
+- * So we do something more comprehensive which is guaranteed to touch
+- * all of the primary_crng's state, and which uses a LFSR with a
+- * period of 255 as part of the mixing algorithm.  Finally, we do
+- * *not* advance crng_init_cnt since buffer we may get may be something
+- * like a fixed DMI table (for example), which might very well be
+- * unique to the machine, but is otherwise unvarying.
+- */
+-static int crng_slow_load(const u8 *cp, size_t len)
++static ssize_t get_random_bytes_user(struct iov_iter *iter)
+ {
+-	unsigned long flags;
+-	static u8 lfsr = 1;
+-	u8 tmp;
+-	unsigned int i, max = CHACHA_KEY_SIZE;
+-	const u8 *src_buf = cp;
+-	u8 *dest_buf = (u8 *)&primary_crng.state[4];
++	u32 chacha_state[CHACHA_STATE_WORDS];
++	u8 block[CHACHA_BLOCK_SIZE];
++	size_t ret = 0, copied;
+ 
+-	if (!spin_trylock_irqsave(&primary_crng.lock, flags))
+-		return 0;
+-	if (crng_init != 0) {
+-		spin_unlock_irqrestore(&primary_crng.lock, flags);
++	if (unlikely(!iov_iter_count(iter)))
+ 		return 0;
+-	}
+-	if (len > max)
+-		max = len;
+-
+-	for (i = 0; i < max; i++) {
+-		tmp = lfsr;
+-		lfsr >>= 1;
+-		if (tmp & 1)
+-			lfsr ^= 0xE1;
+-		tmp = dest_buf[i % CHACHA_KEY_SIZE];
+-		dest_buf[i % CHACHA_KEY_SIZE] ^= src_buf[i % len] ^ lfsr;
+-		lfsr += (tmp << 3) | (tmp >> 5);
+-	}
+-	spin_unlock_irqrestore(&primary_crng.lock, flags);
+-	return 1;
+-}
+ 
+-static void crng_reseed(struct crng_state *crng, bool use_input_pool)
+-{
+-	unsigned long flags;
+-	int i, num;
+-	union {
+-		u8 block[CHACHA_BLOCK_SIZE];
+-		u32 key[8];
+-	} buf;
+-
+-	if (use_input_pool) {
+-		num = extract_entropy(&buf, 32, 16);
+-		if (num == 0)
+-			return;
+-	} else {
+-		_extract_crng(&primary_crng, buf.block);
+-		_crng_backtrack_protect(&primary_crng, buf.block,
+-					CHACHA_KEY_SIZE);
+-	}
+-	spin_lock_irqsave(&crng->lock, flags);
+-	for (i = 0; i < 8; i++) {
+-		unsigned long rv;
+-		if (!arch_get_random_seed_long(&rv) &&
+-		    !arch_get_random_long(&rv))
+-			rv = random_get_entropy();
+-		crng->state[i + 4] ^= buf.key[i] ^ rv;
++	/*
++	 * Immediately overwrite the ChaCha key at index 4 with random
++	 * bytes, in case userspace causes copy_to_user() below to sleep
++	 * forever, so that we still retain forward secrecy in that case.
++	 */
++	crng_make_state(chacha_state, (u8 *)&chacha_state[4], CHACHA_KEY_SIZE);
++	/*
++	 * However, if we're doing a read of len <= 32, we don't need to
++	 * use chacha_state after, so we can simply return those bytes to
++	 * the user directly.
++	 */
++	if (iov_iter_count(iter) <= CHACHA_KEY_SIZE) {
++		ret = copy_to_iter(&chacha_state[4], CHACHA_KEY_SIZE, iter);
++		goto out_zero_chacha;
+ 	}
+-	memzero_explicit(&buf, sizeof(buf));
+-	WRITE_ONCE(crng->init_time, jiffies);
+-	spin_unlock_irqrestore(&crng->lock, flags);
+-	if (crng == &primary_crng && crng_init < 2)
+-		crng_finalize_init();
+-}
+ 
+-static void _extract_crng(struct crng_state *crng, u8 out[CHACHA_BLOCK_SIZE])
+-{
+-	unsigned long flags, init_time;
++	for (;;) {
++		chacha20_block(chacha_state, block);
++		if (unlikely(chacha_state[12] == 0))
++			++chacha_state[13];
++
++		copied = copy_to_iter(block, sizeof(block), iter);
++		ret += copied;
++		if (!iov_iter_count(iter) || copied != sizeof(block))
++			break;
+ 
+-	if (crng_ready()) {
+-		init_time = READ_ONCE(crng->init_time);
+-		if (time_after(READ_ONCE(crng_global_init_time), init_time) ||
+-		    time_after(jiffies, init_time + CRNG_RESEED_INTERVAL))
+-			crng_reseed(crng, crng == &primary_crng);
++		BUILD_BUG_ON(PAGE_SIZE % sizeof(block) != 0);
++		if (ret % PAGE_SIZE == 0) {
++			if (signal_pending(current))
++				break;
++			cond_resched();
++		}
+ 	}
+-	spin_lock_irqsave(&crng->lock, flags);
+-	chacha20_block(&crng->state[0], out);
+-	if (crng->state[12] == 0)
+-		crng->state[13]++;
+-	spin_unlock_irqrestore(&crng->lock, flags);
+-}
+ 
+-static void extract_crng(u8 out[CHACHA_BLOCK_SIZE])
+-{
+-	_extract_crng(select_crng(), out);
++	memzero_explicit(block, sizeof(block));
++out_zero_chacha:
++	memzero_explicit(chacha_state, sizeof(chacha_state));
++	return ret ? ret : -EFAULT;
+ }
+ 
+ /*
+- * Use the leftover bytes from the CRNG block output (if there is
+- * enough) to mutate the CRNG key to provide backtracking protection.
++ * Batched entropy returns random integers. The quality of the random
++ * number is good as /dev/urandom. In order to ensure that the randomness
++ * provided by this function is okay, the function wait_for_random_bytes()
++ * should be called and return 0 at least once at any point prior.
+  */
+-static void _crng_backtrack_protect(struct crng_state *crng,
+-				    u8 tmp[CHACHA_BLOCK_SIZE], int used)
+-{
+-	unsigned long flags;
+-	u32 *s, *d;
+-	int i;
+ 
+-	used = round_up(used, sizeof(u32));
+-	if (used + CHACHA_KEY_SIZE > CHACHA_BLOCK_SIZE) {
+-		extract_crng(tmp);
+-		used = 0;
+-	}
+-	spin_lock_irqsave(&crng->lock, flags);
+-	s = (u32 *)&tmp[used];
+-	d = &crng->state[4];
+-	for (i = 0; i < 8; i++)
+-		*d++ ^= *s++;
+-	spin_unlock_irqrestore(&crng->lock, flags);
+-}
+-
+-static void crng_backtrack_protect(u8 tmp[CHACHA_BLOCK_SIZE], int used)
++#define DEFINE_BATCHED_ENTROPY(type)						\
++struct batch_ ##type {								\
++	/*									\
++	 * We make this 1.5x a ChaCha block, so that we get the			\
++	 * remaining 32 bytes from fast key erasure, plus one full		\
++	 * block from the detached ChaCha state. We can increase		\
++	 * the size of this later if needed so long as we keep the		\
++	 * formula of (integer_blocks + 0.5) * CHACHA_BLOCK_SIZE.		\
++	 */									\
++	type entropy[CHACHA_BLOCK_SIZE * 3 / (2 * sizeof(type))];		\
++	local_lock_t lock;							\
++	unsigned long generation;						\
++	unsigned int position;							\
++};										\
++										\
++static DEFINE_PER_CPU(struct batch_ ##type, batched_entropy_ ##type) = {	\
++	.lock = INIT_LOCAL_LOCK(batched_entropy_ ##type.lock),			\
++	.position = UINT_MAX							\
++};										\
++										\
++type get_random_ ##type(void)							\
++{										\
++	type ret;								\
++	unsigned long flags;							\
++	struct batch_ ##type *batch;						\
++	unsigned long next_gen;							\
++										\
++	warn_unseeded_randomness();						\
++										\
++	if  (!crng_ready()) {							\
++		_get_random_bytes(&ret, sizeof(ret));				\
++		return ret;							\
++	}									\
++										\
++	local_lock_irqsave(&batched_entropy_ ##type.lock, flags);		\
++	batch = raw_cpu_ptr(&batched_entropy_##type);				\
++										\
++	next_gen = READ_ONCE(base_crng.generation);				\
++	if (batch->position >= ARRAY_SIZE(batch->entropy) ||			\
++	    next_gen != batch->generation) {					\
++		_get_random_bytes(batch->entropy, sizeof(batch->entropy));	\
++		batch->position = 0;						\
++		batch->generation = next_gen;					\
++	}									\
++										\
++	ret = batch->entropy[batch->position];					\
++	batch->entropy[batch->position] = 0;					\
++	++batch->position;							\
++	local_unlock_irqrestore(&batched_entropy_ ##type.lock, flags);		\
++	return ret;								\
++}										\
++EXPORT_SYMBOL(get_random_ ##type);
++
++DEFINE_BATCHED_ENTROPY(u64)
++DEFINE_BATCHED_ENTROPY(u32)
++
++#ifdef CONFIG_SMP
++/*
++ * This function is called when the CPU is coming up, with entry
++ * CPUHP_RANDOM_PREPARE, which comes before CPUHP_WORKQUEUE_PREP.
++ */
++int __cold random_prepare_cpu(unsigned int cpu)
+ {
+-	_crng_backtrack_protect(select_crng(), tmp, used);
++	/*
++	 * When the cpu comes back online, immediately invalidate both
++	 * the per-cpu crng and all batches, so that we serve fresh
++	 * randomness.
++	 */
++	per_cpu_ptr(&crngs, cpu)->generation = ULONG_MAX;
++	per_cpu_ptr(&batched_entropy_u32, cpu)->position = UINT_MAX;
++	per_cpu_ptr(&batched_entropy_u64, cpu)->position = UINT_MAX;
++	return 0;
+ }
++#endif
+ 
+-static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
++/*
++ * This function will use the architecture-specific hardware random
++ * number generator if it is available. It is not recommended for
++ * use. Use get_random_bytes() instead. It returns the number of
++ * bytes filled in.
++ */
++size_t __must_check get_random_bytes_arch(void *buf, size_t len)
+ {
+-	ssize_t ret = 0, i = CHACHA_BLOCK_SIZE;
+-	u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4);
+-	int large_request = (nbytes > 256);
+-
+-	while (nbytes) {
+-		if (large_request && need_resched()) {
+-			if (signal_pending(current)) {
+-				if (ret == 0)
+-					ret = -ERESTARTSYS;
+-				break;
+-			}
+-			schedule();
+-		}
++	size_t left = len;
++	u8 *p = buf;
++
++	while (left) {
++		unsigned long v;
++		size_t block_len = min_t(size_t, left, sizeof(unsigned long));
+ 
+-		extract_crng(tmp);
+-		i = min_t(int, nbytes, CHACHA_BLOCK_SIZE);
+-		if (copy_to_user(buf, tmp, i)) {
+-			ret = -EFAULT;
++		if (!arch_get_random_long(&v))
+ 			break;
+-		}
+ 
+-		nbytes -= i;
+-		buf += i;
+-		ret += i;
++		memcpy(p, &v, block_len);
++		p += block_len;
++		left -= block_len;
+ 	}
+-	crng_backtrack_protect(tmp, i);
+-
+-	/* Wipe data just written to memory */
+-	memzero_explicit(tmp, sizeof(tmp));
+ 
+-	return ret;
++	return len - left;
+ }
++EXPORT_SYMBOL(get_random_bytes_arch);
+ 
+-/*********************************************************************
++
++/**********************************************************************
+  *
+- * Entropy input management
++ * Entropy accumulation and extraction routines.
+  *
+- *********************************************************************/
++ * Callers may add entropy via:
++ *
++ *     static void mix_pool_bytes(const void *buf, size_t len)
++ *
++ * After which, if added entropy should be credited:
++ *
++ *     static void credit_init_bits(size_t bits)
++ *
++ * Finally, extract entropy via:
++ *
++ *     static void extract_entropy(void *buf, size_t len)
++ *
++ **********************************************************************/
+ 
+-/* There is one of these per entropy source */
+-struct timer_rand_state {
+-	cycles_t last_time;
+-	long last_delta, last_delta2;
++enum {
++	POOL_BITS = BLAKE2S_HASH_SIZE * 8,
++	POOL_READY_BITS = POOL_BITS, /* When crng_init->CRNG_READY */
++	POOL_EARLY_BITS = POOL_READY_BITS / 2 /* When crng_init->CRNG_EARLY */
+ };
+ 
+-#define INIT_TIMER_RAND_STATE { INITIAL_JIFFIES, };
++static struct {
++	struct blake2s_state hash;
++	spinlock_t lock;
++	unsigned int init_bits;
++} input_pool = {
++	.hash.h = { BLAKE2S_IV0 ^ (0x01010000 | BLAKE2S_HASH_SIZE),
++		    BLAKE2S_IV1, BLAKE2S_IV2, BLAKE2S_IV3, BLAKE2S_IV4,
++		    BLAKE2S_IV5, BLAKE2S_IV6, BLAKE2S_IV7 },
++	.hash.outlen = BLAKE2S_HASH_SIZE,
++	.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),
++};
++
++static void _mix_pool_bytes(const void *buf, size_t len)
++{
++	blake2s_update(&input_pool.hash, buf, len);
++}
+ 
+ /*
+- * Add device- or boot-specific data to the input pool to help
+- * initialize it.
+- *
+- * None of this adds any entropy; it is meant to avoid the problem of
+- * the entropy pool having similar initial state across largely
+- * identical devices.
++ * This function adds bytes into the input pool. It does not
++ * update the initialization bit counter; the caller should call
++ * credit_init_bits if this is appropriate.
+  */
+-void add_device_randomness(const void *buf, unsigned int size)
++static void mix_pool_bytes(const void *buf, size_t len)
+ {
+-	unsigned long time = random_get_entropy() ^ jiffies;
+ 	unsigned long flags;
+ 
+-	if (!crng_ready() && size)
+-		crng_slow_load(buf, size);
+-
+-	trace_add_device_randomness(size, _RET_IP_);
+ 	spin_lock_irqsave(&input_pool.lock, flags);
+-	_mix_pool_bytes(buf, size);
+-	_mix_pool_bytes(&time, sizeof(time));
++	_mix_pool_bytes(buf, len);
+ 	spin_unlock_irqrestore(&input_pool.lock, flags);
+ }
+-EXPORT_SYMBOL(add_device_randomness);
+-
+-static struct timer_rand_state input_timer_state = INIT_TIMER_RAND_STATE;
+ 
+ /*
+- * This function adds entropy to the entropy "pool" by using timing
+- * delays.  It uses the timer_rand_state structure to make an estimate
+- * of how many bits of entropy this call has added to the pool.
+- *
+- * The number "num" is also added to the pool - it should somehow describe
+- * the type of event which just happened.  This is currently 0-255 for
+- * keyboard scan codes, and 256 upwards for interrupts.
+- *
++ * This is an HKDF-like construction for using the hashed collected entropy
++ * as a PRF key, that's then expanded block-by-block.
+  */
+-static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
++static void extract_entropy(void *buf, size_t len)
+ {
++	unsigned long flags;
++	u8 seed[BLAKE2S_HASH_SIZE], next_key[BLAKE2S_HASH_SIZE];
+ 	struct {
+-		long jiffies;
+-		unsigned int cycles;
+-		unsigned int num;
+-	} sample;
+-	long delta, delta2, delta3;
+-
+-	sample.jiffies = jiffies;
+-	sample.cycles = random_get_entropy();
+-	sample.num = num;
+-	mix_pool_bytes(&sample, sizeof(sample));
+-
+-	/*
+-	 * Calculate number of bits of randomness we probably added.
+-	 * We take into account the first, second and third-order deltas
+-	 * in order to make our estimate.
+-	 */
+-	delta = sample.jiffies - READ_ONCE(state->last_time);
+-	WRITE_ONCE(state->last_time, sample.jiffies);
+-
+-	delta2 = delta - READ_ONCE(state->last_delta);
+-	WRITE_ONCE(state->last_delta, delta);
+-
+-	delta3 = delta2 - READ_ONCE(state->last_delta2);
+-	WRITE_ONCE(state->last_delta2, delta2);
++		unsigned long rdseed[32 / sizeof(long)];
++		size_t counter;
++	} block;
++	size_t i;
++
++	for (i = 0; i < ARRAY_SIZE(block.rdseed); ++i) {
++		if (!arch_get_random_seed_long(&block.rdseed[i]) &&
++		    !arch_get_random_long(&block.rdseed[i]))
++			block.rdseed[i] = random_get_entropy();
++	}
+ 
+-	if (delta < 0)
+-		delta = -delta;
+-	if (delta2 < 0)
+-		delta2 = -delta2;
+-	if (delta3 < 0)
+-		delta3 = -delta3;
+-	if (delta > delta2)
+-		delta = delta2;
+-	if (delta > delta3)
+-		delta = delta3;
++	spin_lock_irqsave(&input_pool.lock, flags);
+ 
+-	/*
+-	 * delta is now minimum absolute delta.
+-	 * Round down by 1 bit on general principles,
+-	 * and limit entropy estimate to 12 bits.
+-	 */
+-	credit_entropy_bits(min_t(int, fls(delta >> 1), 11));
+-}
++	/* seed = HASHPRF(last_key, entropy_input) */
++	blake2s_final(&input_pool.hash, seed);
+ 
+-void add_input_randomness(unsigned int type, unsigned int code,
+-			  unsigned int value)
+-{
+-	static unsigned char last_value;
++	/* next_key = HASHPRF(seed, RDSEED || 0) */
++	block.counter = 0;
++	blake2s(next_key, (u8 *)&block, seed, sizeof(next_key), sizeof(block), sizeof(seed));
++	blake2s_init_key(&input_pool.hash, BLAKE2S_HASH_SIZE, next_key, sizeof(next_key));
+ 
+-	/* ignore autorepeat and the like */
+-	if (value == last_value)
+-		return;
++	spin_unlock_irqrestore(&input_pool.lock, flags);
++	memzero_explicit(next_key, sizeof(next_key));
++
++	while (len) {
++		i = min_t(size_t, len, BLAKE2S_HASH_SIZE);
++		/* output = HASHPRF(seed, RDSEED || ++counter) */
++		++block.counter;
++		blake2s(buf, (u8 *)&block, seed, i, sizeof(block), sizeof(seed));
++		len -= i;
++		buf += i;
++	}
+ 
+-	last_value = value;
+-	add_timer_randomness(&input_timer_state,
+-			     (type << 4) ^ code ^ (code >> 4) ^ value);
+-	trace_add_input_randomness(POOL_ENTROPY_BITS());
++	memzero_explicit(seed, sizeof(seed));
++	memzero_explicit(&block, sizeof(block));
+ }
+-EXPORT_SYMBOL_GPL(add_input_randomness);
+-
+-static DEFINE_PER_CPU(struct fast_pool, irq_randomness);
+ 
+-#ifdef ADD_INTERRUPT_BENCH
+-static unsigned long avg_cycles, avg_deviation;
++#define credit_init_bits(bits) if (!crng_ready()) _credit_init_bits(bits)
+ 
+-#define AVG_SHIFT 8 /* Exponential average factor k=1/256 */
+-#define FIXED_1_2 (1 << (AVG_SHIFT - 1))
+-
+-static void add_interrupt_bench(cycles_t start)
++static void __cold _credit_init_bits(size_t bits)
+ {
+-	long delta = random_get_entropy() - start;
+-
+-	/* Use a weighted moving average */
+-	delta = delta - ((avg_cycles + FIXED_1_2) >> AVG_SHIFT);
+-	avg_cycles += delta;
+-	/* And average deviation */
+-	delta = abs(delta) - ((avg_deviation + FIXED_1_2) >> AVG_SHIFT);
+-	avg_deviation += delta;
+-}
+-#else
+-#define add_interrupt_bench(x)
+-#endif
++	static struct execute_work set_ready;
++	unsigned int new, orig, add;
++	unsigned long flags;
+ 
+-static u32 get_reg(struct fast_pool *f, struct pt_regs *regs)
+-{
+-	u32 *ptr = (u32 *)regs;
+-	unsigned int idx;
++	if (!bits)
++		return;
+ 
+-	if (regs == NULL)
+-		return 0;
+-	idx = READ_ONCE(f->reg_idx);
+-	if (idx >= sizeof(struct pt_regs) / sizeof(u32))
+-		idx = 0;
+-	ptr += idx++;
+-	WRITE_ONCE(f->reg_idx, idx);
+-	return *ptr;
+-}
++	add = min_t(size_t, bits, POOL_BITS);
+ 
+-void add_interrupt_randomness(int irq)
+-{
+-	struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness);
+-	struct pt_regs *regs = get_irq_regs();
+-	unsigned long now = jiffies;
+-	cycles_t cycles = random_get_entropy();
+-	u32 c_high, j_high;
+-	u64 ip;
+-
+-	if (cycles == 0)
+-		cycles = get_reg(fast_pool, regs);
+-	c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
+-	j_high = (sizeof(now) > 4) ? now >> 32 : 0;
+-	fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
+-	fast_pool->pool[1] ^= now ^ c_high;
+-	ip = regs ? instruction_pointer(regs) : _RET_IP_;
+-	fast_pool->pool[2] ^= ip;
+-	fast_pool->pool[3] ^=
+-		(sizeof(ip) > 4) ? ip >> 32 : get_reg(fast_pool, regs);
+-
+-	fast_mix(fast_pool);
+-	add_interrupt_bench(cycles);
+-
+-	if (unlikely(crng_init == 0)) {
+-		if ((fast_pool->count >= 64) &&
+-		    crng_fast_load((u8 *)fast_pool->pool, sizeof(fast_pool->pool)) > 0) {
+-			fast_pool->count = 0;
+-			fast_pool->last = now;
++	do {
++		orig = READ_ONCE(input_pool.init_bits);
++		new = min_t(unsigned int, POOL_BITS, orig + add);
++	} while (cmpxchg(&input_pool.init_bits, orig, new) != orig);
++
++	if (orig < POOL_READY_BITS && new >= POOL_READY_BITS) {
++		crng_reseed(); /* Sets crng_init to CRNG_READY under base_crng.lock. */
++		execute_in_process_context(crng_set_ready, &set_ready);
++		process_random_ready_list();
++		wake_up_interruptible(&crng_init_wait);
++		kill_fasync(&fasync, SIGIO, POLL_IN);
++		pr_notice("crng init done\n");
++		if (urandom_warning.missed)
++			pr_notice("%d urandom warning(s) missed due to ratelimiting\n",
++				  urandom_warning.missed);
++	} else if (orig < POOL_EARLY_BITS && new >= POOL_EARLY_BITS) {
++		spin_lock_irqsave(&base_crng.lock, flags);
++		/* Check if crng_init is CRNG_EMPTY, to avoid race with crng_reseed(). */
++		if (crng_init == CRNG_EMPTY) {
++			extract_entropy(base_crng.key, sizeof(base_crng.key));
++			crng_init = CRNG_EARLY;
+ 		}
+-		return;
++		spin_unlock_irqrestore(&base_crng.lock, flags);
+ 	}
++}
+ 
+-	if ((fast_pool->count < 64) && !time_after(now, fast_pool->last + HZ))
+-		return;
+-
+-	if (!spin_trylock(&input_pool.lock))
+-		return;
+-
+-	fast_pool->last = now;
+-	__mix_pool_bytes(&fast_pool->pool, sizeof(fast_pool->pool));
+-	spin_unlock(&input_pool.lock);
+ 
+-	fast_pool->count = 0;
++/**********************************************************************
++ *
++ * Entropy collection routines.
++ *
++ * The following exported functions are used for pushing entropy into
++ * the above entropy accumulation routines:
++ *
++ *	void add_device_randomness(const void *buf, size_t len);
++ *	void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy);
++ *	void add_bootloader_randomness(const void *buf, size_t len);
++ *	void add_interrupt_randomness(int irq);
++ *	void add_input_randomness(unsigned int type, unsigned int code, unsigned int value);
++ *	void add_disk_randomness(struct gendisk *disk);
++ *
++ * add_device_randomness() adds data to the input pool that
++ * is likely to differ between two devices (or possibly even per boot).
++ * This would be things like MAC addresses or serial numbers, or the
++ * read-out of the RTC. This does *not* credit any actual entropy to
++ * the pool, but it initializes the pool to different values for devices
++ * that might otherwise be identical and have very little entropy
++ * available to them (particularly common in the embedded world).
++ *
++ * add_hwgenerator_randomness() is for true hardware RNGs, and will credit
++ * entropy as specified by the caller. If the entropy pool is full it will
++ * block until more entropy is needed.
++ *
++ * add_bootloader_randomness() is called by bootloader drivers, such as EFI
++ * and device tree, and credits its input depending on whether or not the
++ * configuration option CONFIG_RANDOM_TRUST_BOOTLOADER is set.
++ *
++ * add_interrupt_randomness() uses the interrupt timing as random
++ * inputs to the entropy pool. Using the cycle counters and the irq source
++ * as inputs, it feeds the input pool roughly once a second or after 64
++ * interrupts, crediting 1 bit of entropy for whichever comes first.
++ *
++ * add_input_randomness() uses the input layer interrupt timing, as well
++ * as the event type information from the hardware.
++ *
++ * add_disk_randomness() uses what amounts to the seek time of block
++ * layer request events, on a per-disk_devt basis, as input to the
++ * entropy pool. Note that high-speed solid state drives with very low
++ * seek times do not make for good sources of entropy, as their seek
++ * times are usually fairly consistent.
++ *
++ * The last two routines try to estimate how many bits of entropy
++ * to credit. They do this by keeping track of the first and second
++ * order deltas of the event timings.
++ *
++ **********************************************************************/
+ 
+-	/* award one bit for the contents of the fast pool */
+-	credit_entropy_bits(1);
++static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
++static bool trust_bootloader __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER);
++static int __init parse_trust_cpu(char *arg)
++{
++	return kstrtobool(arg, &trust_cpu);
+ }
+-EXPORT_SYMBOL_GPL(add_interrupt_randomness);
+-
+-#ifdef CONFIG_BLOCK
+-void add_disk_randomness(struct gendisk *disk)
++static int __init parse_trust_bootloader(char *arg)
+ {
+-	if (!disk || !disk->random)
+-		return;
+-	/* first major is 1, so we get >= 0x200 here */
+-	add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
+-	trace_add_disk_randomness(disk_devt(disk), POOL_ENTROPY_BITS());
++	return kstrtobool(arg, &trust_bootloader);
+ }
+-EXPORT_SYMBOL_GPL(add_disk_randomness);
+-#endif
+-
+-/*********************************************************************
+- *
+- * Entropy extraction routines
+- *
+- *********************************************************************/
++early_param("random.trust_cpu", parse_trust_cpu);
++early_param("random.trust_bootloader", parse_trust_bootloader);
+ 
+ /*
+- * This function decides how many bytes to actually take from the
+- * given pool, and also debits the entropy count accordingly.
++ * The first collection of entropy occurs at system boot while interrupts
++ * are still turned off. Here we push in latent entropy, RDSEED, a timestamp,
++ * utsname(), and the command line. Depending on the above configuration knob,
++ * RDSEED may be considered sufficient for initialization. Note that much
++ * earlier setup may already have pushed entropy into the input pool by the
++ * time we get here.
+  */
+-static size_t account(size_t nbytes, int min)
++int __init random_init(const char *command_line)
+ {
+-	int entropy_count, orig;
+-	size_t ibytes, nfrac;
++	ktime_t now = ktime_get_real();
++	unsigned int i, arch_bytes;
++	unsigned long entropy;
+ 
+-	BUG_ON(input_pool.entropy_count > POOL_FRACBITS);
++#if defined(LATENT_ENTROPY_PLUGIN)
++	static const u8 compiletime_seed[BLAKE2S_BLOCK_SIZE] __initconst __latent_entropy;
++	_mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed));
++#endif
+ 
+-	/* Can we pull enough? */
+-retry:
+-	entropy_count = orig = READ_ONCE(input_pool.entropy_count);
+-	if (WARN_ON(entropy_count < 0)) {
+-		pr_warn("negative entropy count: count %d\n", entropy_count);
+-		entropy_count = 0;
++	for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE;
++	     i < BLAKE2S_BLOCK_SIZE; i += sizeof(entropy)) {
++		if (!arch_get_random_seed_long_early(&entropy) &&
++		    !arch_get_random_long_early(&entropy)) {
++			entropy = random_get_entropy();
++			arch_bytes -= sizeof(entropy);
++		}
++		_mix_pool_bytes(&entropy, sizeof(entropy));
+ 	}
++	_mix_pool_bytes(&now, sizeof(now));
++	_mix_pool_bytes(utsname(), sizeof(*(utsname())));
++	_mix_pool_bytes(command_line, strlen(command_line));
++	add_latent_entropy();
+ 
+-	/* never pull more than available */
+-	ibytes = min_t(size_t, nbytes, entropy_count >> (POOL_ENTROPY_SHIFT + 3));
+-	if (ibytes < min)
+-		ibytes = 0;
+-	nfrac = ibytes << (POOL_ENTROPY_SHIFT + 3);
+-	if ((size_t)entropy_count > nfrac)
+-		entropy_count -= nfrac;
+-	else
+-		entropy_count = 0;
+-
+-	if (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig)
+-		goto retry;
+-
+-	trace_debit_entropy(8 * ibytes);
+-	if (ibytes && POOL_ENTROPY_BITS() < random_write_wakeup_bits) {
+-		wake_up_interruptible(&random_write_wait);
+-		kill_fasync(&fasync, SIGIO, POLL_OUT);
+-	}
++	if (crng_ready())
++		crng_reseed();
++	else if (trust_cpu)
++		credit_init_bits(arch_bytes * 8);
+ 
+-	return ibytes;
++	return 0;
+ }
+ 
+ /*
+- * This function does the actual extraction for extract_entropy.
++ * Add device- or boot-specific data to the input pool to help
++ * initialize it.
+  *
+- * Note: we assume that .poolwords is a multiple of 16 words.
++ * None of this adds any entropy; it is meant to avoid the problem of
++ * the entropy pool having similar initial state across largely
++ * identical devices.
+  */
+-static void extract_buf(u8 *out)
++void add_device_randomness(const void *buf, size_t len)
+ {
+-	struct blake2s_state state __aligned(__alignof__(unsigned long));
+-	u8 hash[BLAKE2S_HASH_SIZE];
+-	unsigned long *salt;
++	unsigned long entropy = random_get_entropy();
+ 	unsigned long flags;
+ 
+-	blake2s_init(&state, sizeof(hash));
+-
+-	/*
+-	 * If we have an architectural hardware random number
+-	 * generator, use it for BLAKE2's salt & personal fields.
+-	 */
+-	for (salt = (unsigned long *)&state.h[4];
+-	     salt < (unsigned long *)&state.h[8]; ++salt) {
+-		unsigned long v;
+-		if (!arch_get_random_long(&v))
+-			break;
+-		*salt ^= v;
+-	}
+-
+-	/* Generate a hash across the pool */
+ 	spin_lock_irqsave(&input_pool.lock, flags);
+-	blake2s_update(&state, (const u8 *)input_pool_data, POOL_BYTES);
+-	blake2s_final(&state, hash); /* final zeros out state */
+-
+-	/*
+-	 * We mix the hash back into the pool to prevent backtracking
+-	 * attacks (where the attacker knows the state of the pool
+-	 * plus the current outputs, and attempts to find previous
+-	 * outputs), unless the hash function can be inverted. By
+-	 * mixing at least a hash worth of hash data back, we make
+-	 * brute-forcing the feedback as hard as brute-forcing the
+-	 * hash.
+-	 */
+-	__mix_pool_bytes(hash, sizeof(hash));
++	_mix_pool_bytes(&entropy, sizeof(entropy));
++	_mix_pool_bytes(buf, len);
+ 	spin_unlock_irqrestore(&input_pool.lock, flags);
+-
+-	/* Note that EXTRACT_SIZE is half of hash size here, because above
+-	 * we've dumped the full length back into mixer. By reducing the
+-	 * amount that we emit, we retain a level of forward secrecy.
+-	 */
+-	memcpy(out, hash, EXTRACT_SIZE);
+-	memzero_explicit(hash, sizeof(hash));
+ }
++EXPORT_SYMBOL(add_device_randomness);
+ 
+-static ssize_t _extract_entropy(void *buf, size_t nbytes)
++/*
++ * Interface for in-kernel drivers of true hardware RNGs.
++ * Those devices may produce endless random bits and will be throttled
++ * when our pool is full.
++ */
++void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy)
+ {
+-	ssize_t ret = 0, i;
+-	u8 tmp[EXTRACT_SIZE];
+-
+-	while (nbytes) {
+-		extract_buf(tmp);
+-		i = min_t(int, nbytes, EXTRACT_SIZE);
+-		memcpy(buf, tmp, i);
+-		nbytes -= i;
+-		buf += i;
+-		ret += i;
+-	}
++	mix_pool_bytes(buf, len);
++	credit_init_bits(entropy);
+ 
+-	/* Wipe data just returned from memory */
+-	memzero_explicit(tmp, sizeof(tmp));
+-
+-	return ret;
++	/*
++	 * Throttle writing to once every CRNG_RESEED_INTERVAL, unless
++	 * we're not yet initialized.
++	 */
++	if (!kthread_should_stop() && crng_ready())
++		schedule_timeout_interruptible(CRNG_RESEED_INTERVAL);
+ }
++EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
+ 
+ /*
+- * This function extracts randomness from the "entropy pool", and
+- * returns it in a buffer.
+- *
+- * The min parameter specifies the minimum amount we can pull before
+- * failing to avoid races that defeat catastrophic reseeding.
++ * Handle random seed passed by bootloader, and credit it if
++ * CONFIG_RANDOM_TRUST_BOOTLOADER is set.
+  */
+-static ssize_t extract_entropy(void *buf, size_t nbytes, int min)
++void __cold add_bootloader_randomness(const void *buf, size_t len)
+ {
+-	trace_extract_entropy(nbytes, POOL_ENTROPY_BITS(), _RET_IP_);
+-	nbytes = account(nbytes, min);
+-	return _extract_entropy(buf, nbytes);
++	mix_pool_bytes(buf, len);
++	if (trust_bootloader)
++		credit_init_bits(len * 8);
+ }
++EXPORT_SYMBOL_GPL(add_bootloader_randomness);
+ 
+-#define warn_unseeded_randomness(previous) \
+-	_warn_unseeded_randomness(__func__, (void *)_RET_IP_, (previous))
++struct fast_pool {
++	struct work_struct mix;
++	unsigned long pool[4];
++	unsigned long last;
++	unsigned int count;
++};
+ 
+-static void _warn_unseeded_randomness(const char *func_name, void *caller, void **previous)
+-{
+-#ifdef CONFIG_WARN_ALL_UNSEEDED_RANDOM
+-	const bool print_once = false;
++static DEFINE_PER_CPU(struct fast_pool, irq_randomness) = {
++#ifdef CONFIG_64BIT
++#define FASTMIX_PERM SIPHASH_PERMUTATION
++	.pool = { SIPHASH_CONST_0, SIPHASH_CONST_1, SIPHASH_CONST_2, SIPHASH_CONST_3 }
+ #else
+-	static bool print_once __read_mostly;
+-#endif
+-
+-	if (print_once || crng_ready() ||
+-	    (previous && (caller == READ_ONCE(*previous))))
+-		return;
+-	WRITE_ONCE(*previous, caller);
+-#ifndef CONFIG_WARN_ALL_UNSEEDED_RANDOM
+-	print_once = true;
++#define FASTMIX_PERM HSIPHASH_PERMUTATION
++	.pool = { HSIPHASH_CONST_0, HSIPHASH_CONST_1, HSIPHASH_CONST_2, HSIPHASH_CONST_3 }
+ #endif
+-	if (__ratelimit(&unseeded_warning))
+-		printk_deferred(KERN_NOTICE "random: %s called from %pS with crng_init=%d\n",
+-				func_name, caller, crng_init);
+-}
++};
+ 
+ /*
+- * This function is the exported kernel interface.  It returns some
+- * number of good random numbers, suitable for key generation, seeding
+- * TCP sequence numbers, etc.  It does not rely on the hardware random
+- * number generator.  For random bytes direct from the hardware RNG
+- * (when available), use get_random_bytes_arch(). In order to ensure
+- * that the randomness provided by this function is okay, the function
+- * wait_for_random_bytes() should be called and return 0 at least once
+- * at any point prior.
++ * This is [Half]SipHash-1-x, starting from an empty key. Because
++ * the key is fixed, it assumes that its inputs are non-malicious,
++ * and therefore this has no security on its own. s represents the
++ * four-word SipHash state, while v represents a two-word input.
+  */
+-static void _get_random_bytes(void *buf, int nbytes)
+-{
+-	u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4);
+-
+-	trace_get_random_bytes(nbytes, _RET_IP_);
+-
+-	while (nbytes >= CHACHA_BLOCK_SIZE) {
+-		extract_crng(buf);
+-		buf += CHACHA_BLOCK_SIZE;
+-		nbytes -= CHACHA_BLOCK_SIZE;
+-	}
+-
+-	if (nbytes > 0) {
+-		extract_crng(tmp);
+-		memcpy(buf, tmp, nbytes);
+-		crng_backtrack_protect(tmp, nbytes);
+-	} else
+-		crng_backtrack_protect(tmp, CHACHA_BLOCK_SIZE);
+-	memzero_explicit(tmp, sizeof(tmp));
+-}
+-
+-void get_random_bytes(void *buf, int nbytes)
++static void fast_mix(unsigned long s[4], unsigned long v1, unsigned long v2)
+ {
+-	static void *previous;
+-
+-	warn_unseeded_randomness(&previous);
+-	_get_random_bytes(buf, nbytes);
++	s[3] ^= v1;
++	FASTMIX_PERM(s[0], s[1], s[2], s[3]);
++	s[0] ^= v1;
++	s[3] ^= v2;
++	FASTMIX_PERM(s[0], s[1], s[2], s[3]);
++	s[0] ^= v2;
+ }
+-EXPORT_SYMBOL(get_random_bytes);
+ 
++#ifdef CONFIG_SMP
+ /*
+- * Each time the timer fires, we expect that we got an unpredictable
+- * jump in the cycle counter. Even if the timer is running on another
+- * CPU, the timer activity will be touching the stack of the CPU that is
+- * generating entropy..
+- *
+- * Note that we don't re-arm the timer in the timer itself - we are
+- * happy to be scheduled away, since that just makes the load more
+- * complex, but we do not want the timer to keep ticking unless the
+- * entropy loop is running.
+- *
+- * So the re-arming always happens in the entropy loop itself.
++ * This function is called when the CPU has just come online, with
++ * entry CPUHP_AP_RANDOM_ONLINE, just after CPUHP_AP_WORKQUEUE_ONLINE.
+  */
+-static void entropy_timer(struct timer_list *t)
++int __cold random_online_cpu(unsigned int cpu)
+ {
+-	credit_entropy_bits(1);
++	/*
++	 * During CPU shutdown and before CPU onlining, add_interrupt_
++	 * randomness() may schedule mix_interrupt_randomness(), and
++	 * set the MIX_INFLIGHT flag. However, because the worker can
++	 * be scheduled on a different CPU during this period, that
++	 * flag will never be cleared. For that reason, we zero out
++	 * the flag here, which runs just after workqueues are onlined
++	 * for the CPU again. This also has the effect of setting the
++	 * irq randomness count to zero so that new accumulated irqs
++	 * are fresh.
++	 */
++	per_cpu_ptr(&irq_randomness, cpu)->count = 0;
++	return 0;
+ }
++#endif
+ 
+-/*
+- * If we have an actual cycle counter, see if we can
+- * generate enough entropy with timing noise
+- */
+-static void try_to_generate_entropy(void)
++static void mix_interrupt_randomness(struct work_struct *work)
+ {
+-	struct {
+-		unsigned long now;
+-		struct timer_list timer;
+-	} stack;
+-
+-	stack.now = random_get_entropy();
++	struct fast_pool *fast_pool = container_of(work, struct fast_pool, mix);
++	/*
++	 * The size of the copied stack pool is explicitly 2 longs so that we
++	 * only ever ingest half of the siphash output each time, retaining
++	 * the other half as the next "key" that carries over. The entropy is
++	 * supposed to be sufficiently dispersed between bits so on average
++	 * we don't wind up "losing" some.
++	 */
++	unsigned long pool[2];
++	unsigned int count;
+ 
+-	/* Slow counter - or none. Don't even bother */
+-	if (stack.now == random_get_entropy())
++	/* Check to see if we're running on the wrong CPU due to hotplug. */
++	local_irq_disable();
++	if (fast_pool != this_cpu_ptr(&irq_randomness)) {
++		local_irq_enable();
+ 		return;
+-
+-	timer_setup_on_stack(&stack.timer, entropy_timer, 0);
+-	while (!crng_ready()) {
+-		if (!timer_pending(&stack.timer))
+-			mod_timer(&stack.timer, jiffies + 1);
+-		mix_pool_bytes(&stack.now, sizeof(stack.now));
+-		schedule();
+-		stack.now = random_get_entropy();
+ 	}
+ 
+-	del_timer_sync(&stack.timer);
+-	destroy_timer_on_stack(&stack.timer);
+-	mix_pool_bytes(&stack.now, sizeof(stack.now));
+-}
+-
+-/*
+- * Wait for the urandom pool to be seeded and thus guaranteed to supply
+- * cryptographically secure random numbers. This applies to: the /dev/urandom
+- * device, the get_random_bytes function, and the get_random_{u32,u64,int,long}
+- * family of functions. Using any of these functions without first calling
+- * this function forfeits the guarantee of security.
+- *
+- * Returns: 0 if the urandom pool has been seeded.
+- *          -ERESTARTSYS if the function was interrupted by a signal.
+- */
+-int wait_for_random_bytes(void)
+-{
+-	if (likely(crng_ready()))
+-		return 0;
+-
+-	do {
+-		int ret;
+-		ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ);
+-		if (ret)
+-			return ret > 0 ? 0 : ret;
++	/*
++	 * Copy the pool to the stack so that the mixer always has a
++	 * consistent view, before we reenable irqs again.
++	 */
++	memcpy(pool, fast_pool->pool, sizeof(pool));
++	count = fast_pool->count;
++	fast_pool->count = 0;
++	fast_pool->last = jiffies;
++	local_irq_enable();
+ 
+-		try_to_generate_entropy();
+-	} while (!crng_ready());
++	mix_pool_bytes(pool, sizeof(pool));
++	credit_init_bits(max(1u, (count & U16_MAX) / 64));
+ 
+-	return 0;
++	memzero_explicit(pool, sizeof(pool));
+ }
+-EXPORT_SYMBOL(wait_for_random_bytes);
+ 
+-/*
+- * Returns whether or not the urandom pool has been seeded and thus guaranteed
+- * to supply cryptographically secure random numbers. This applies to: the
+- * /dev/urandom device, the get_random_bytes function, and the get_random_{u32,
+- * ,u64,int,long} family of functions.
+- *
+- * Returns: true if the urandom pool has been seeded.
+- *          false if the urandom pool has not been seeded.
+- */
+-bool rng_is_initialized(void)
+-{
+-	return crng_ready();
+-}
+-EXPORT_SYMBOL(rng_is_initialized);
+-
+-/*
+- * Add a callback function that will be invoked when the nonblocking
+- * pool is initialised.
+- *
+- * returns: 0 if callback is successfully added
+- *	    -EALREADY if pool is already initialised (callback not called)
+- *	    -ENOENT if module for callback is not alive
+- */
+-int add_random_ready_callback(struct random_ready_callback *rdy)
++void add_interrupt_randomness(int irq)
+ {
+-	struct module *owner;
+-	unsigned long flags;
+-	int err = -EALREADY;
+-
+-	if (crng_ready())
+-		return err;
+-
+-	owner = rdy->owner;
+-	if (!try_module_get(owner))
+-		return -ENOENT;
+-
+-	spin_lock_irqsave(&random_ready_list_lock, flags);
+-	if (crng_ready())
+-		goto out;
+-
+-	owner = NULL;
++	enum { MIX_INFLIGHT = 1U << 31 };
++	unsigned long entropy = random_get_entropy();
++	struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness);
++	struct pt_regs *regs = get_irq_regs();
++	unsigned int new_count;
+ 
+-	list_add(&rdy->list, &random_ready_list);
+-	err = 0;
++	fast_mix(fast_pool->pool, entropy,
++		 (regs ? instruction_pointer(regs) : _RET_IP_) ^ swab(irq));
++	new_count = ++fast_pool->count;
+ 
+-out:
+-	spin_unlock_irqrestore(&random_ready_list_lock, flags);
++	if (new_count & MIX_INFLIGHT)
++		return;
+ 
+-	module_put(owner);
++	if (new_count < 64 && !time_is_before_jiffies(fast_pool->last + HZ))
++		return;
+ 
+-	return err;
++	if (unlikely(!fast_pool->mix.func))
++		INIT_WORK(&fast_pool->mix, mix_interrupt_randomness);
++	fast_pool->count |= MIX_INFLIGHT;
++	queue_work_on(raw_smp_processor_id(), system_highpri_wq, &fast_pool->mix);
+ }
+-EXPORT_SYMBOL(add_random_ready_callback);
++EXPORT_SYMBOL_GPL(add_interrupt_randomness);
++
++/* There is one of these per entropy source */
++struct timer_rand_state {
++	unsigned long last_time;
++	long last_delta, last_delta2;
++};
+ 
+ /*
+- * Delete a previously registered readiness callback function.
++ * This function adds entropy to the entropy "pool" by using timing
++ * delays. It uses the timer_rand_state structure to make an estimate
++ * of how many bits of entropy this call has added to the pool. The
++ * value "num" is also added to the pool; it should somehow describe
++ * the type of event that just happened.
+  */
+-void del_random_ready_callback(struct random_ready_callback *rdy)
++static void add_timer_randomness(struct timer_rand_state *state, unsigned int num)
+ {
+-	unsigned long flags;
+-	struct module *owner = NULL;
++	unsigned long entropy = random_get_entropy(), now = jiffies, flags;
++	long delta, delta2, delta3;
++	unsigned int bits;
+ 
+-	spin_lock_irqsave(&random_ready_list_lock, flags);
+-	if (!list_empty(&rdy->list)) {
+-		list_del_init(&rdy->list);
+-		owner = rdy->owner;
++	/*
++	 * If we're in a hard IRQ, add_interrupt_randomness() will be called
++	 * sometime after, so mix into the fast pool.
++	 */
++	if (in_hardirq()) {
++		fast_mix(this_cpu_ptr(&irq_randomness)->pool, entropy, num);
++	} else {
++		spin_lock_irqsave(&input_pool.lock, flags);
++		_mix_pool_bytes(&entropy, sizeof(entropy));
++		_mix_pool_bytes(&num, sizeof(num));
++		spin_unlock_irqrestore(&input_pool.lock, flags);
+ 	}
+-	spin_unlock_irqrestore(&random_ready_list_lock, flags);
+ 
+-	module_put(owner);
+-}
+-EXPORT_SYMBOL(del_random_ready_callback);
++	if (crng_ready())
++		return;
+ 
+-/*
+- * This function will use the architecture-specific hardware random
+- * number generator if it is available.  The arch-specific hw RNG will
+- * almost certainly be faster than what we can do in software, but it
+- * is impossible to verify that it is implemented securely (as
+- * opposed, to, say, the AES encryption of a sequence number using a
+- * key known by the NSA).  So it's useful if we need the speed, but
+- * only if we're willing to trust the hardware manufacturer not to
+- * have put in a back door.
+- *
+- * Return number of bytes filled in.
+- */
+-int __must_check get_random_bytes_arch(void *buf, int nbytes)
+-{
+-	int left = nbytes;
+-	u8 *p = buf;
++	/*
++	 * Calculate number of bits of randomness we probably added.
++	 * We take into account the first, second and third-order deltas
++	 * in order to make our estimate.
++	 */
++	delta = now - READ_ONCE(state->last_time);
++	WRITE_ONCE(state->last_time, now);
++
++	delta2 = delta - READ_ONCE(state->last_delta);
++	WRITE_ONCE(state->last_delta, delta);
+ 
+-	trace_get_random_bytes_arch(left, _RET_IP_);
+-	while (left) {
+-		unsigned long v;
+-		int chunk = min_t(int, left, sizeof(unsigned long));
++	delta3 = delta2 - READ_ONCE(state->last_delta2);
++	WRITE_ONCE(state->last_delta2, delta2);
+ 
+-		if (!arch_get_random_long(&v))
+-			break;
++	if (delta < 0)
++		delta = -delta;
++	if (delta2 < 0)
++		delta2 = -delta2;
++	if (delta3 < 0)
++		delta3 = -delta3;
++	if (delta > delta2)
++		delta = delta2;
++	if (delta > delta3)
++		delta = delta3;
+ 
+-		memcpy(p, &v, chunk);
+-		p += chunk;
+-		left -= chunk;
+-	}
++	/*
++	 * delta is now minimum absolute delta. Round down by 1 bit
++	 * on general principles, and limit entropy estimate to 11 bits.
++	 */
++	bits = min(fls(delta >> 1), 11);
+ 
+-	return nbytes - left;
++	/*
++	 * As mentioned above, if we're in a hard IRQ, add_interrupt_randomness()
++	 * will run after this, which uses a different crediting scheme of 1 bit
++	 * per every 64 interrupts. In order to let that function do accounting
++	 * close to the one in this function, we credit a full 64/64 bit per bit,
++	 * and then subtract one to account for the extra one added.
++	 */
++	if (in_hardirq())
++		this_cpu_ptr(&irq_randomness)->count += max(1u, bits * 64) - 1;
++	else
++		_credit_init_bits(bits);
+ }
+-EXPORT_SYMBOL(get_random_bytes_arch);
+ 
+-/*
+- * init_std_data - initialize pool with system data
+- *
+- * This function clears the pool's entropy count and mixes some system
+- * data into the pool to prepare it for use. The pool is not cleared
+- * as that can only decrease the entropy in the pool.
+- */
+-static void __init init_std_data(void)
++void add_input_randomness(unsigned int type, unsigned int code, unsigned int value)
+ {
+-	int i;
+-	ktime_t now = ktime_get_real();
+-	unsigned long rv;
+-
+-	mix_pool_bytes(&now, sizeof(now));
+-	for (i = POOL_BYTES; i > 0; i -= sizeof(rv)) {
+-		if (!arch_get_random_seed_long(&rv) &&
+-		    !arch_get_random_long(&rv))
+-			rv = random_get_entropy();
+-		mix_pool_bytes(&rv, sizeof(rv));
+-	}
+-	mix_pool_bytes(utsname(), sizeof(*(utsname())));
++	static unsigned char last_value;
++	static struct timer_rand_state input_timer_state = { INITIAL_JIFFIES };
++
++	/* Ignore autorepeat and the like. */
++	if (value == last_value)
++		return;
++
++	last_value = value;
++	add_timer_randomness(&input_timer_state,
++			     (type << 4) ^ code ^ (code >> 4) ^ value);
+ }
++EXPORT_SYMBOL_GPL(add_input_randomness);
+ 
+-/*
+- * Note that setup_arch() may call add_device_randomness()
+- * long before we get here. This allows seeding of the pools
+- * with some platform dependent data very early in the boot
+- * process. But it limits our options here. We must use
+- * statically allocated structures that already have all
+- * initializations complete at compile time. We should also
+- * take care not to overwrite the precious per platform data
+- * we were given.
+- */
+-int __init rand_initialize(void)
++#ifdef CONFIG_BLOCK
++void add_disk_randomness(struct gendisk *disk)
+ {
+-	init_std_data();
+-	if (crng_need_final_init)
+-		crng_finalize_init();
+-	crng_initialize_primary();
+-	crng_global_init_time = jiffies;
+-	if (ratelimit_disable) {
+-		urandom_warning.interval = 0;
+-		unseeded_warning.interval = 0;
+-	}
+-	return 0;
++	if (!disk || !disk->random)
++		return;
++	/* First major is 1, so we get >= 0x200 here. */
++	add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
+ }
++EXPORT_SYMBOL_GPL(add_disk_randomness);
+ 
+-#ifdef CONFIG_BLOCK
+-void rand_initialize_disk(struct gendisk *disk)
++void __cold rand_initialize_disk(struct gendisk *disk)
+ {
+ 	struct timer_rand_state *state;
+ 
+@@ -1724,109 +1139,189 @@ void rand_initialize_disk(struct gendisk *disk)
+ }
+ #endif
+ 
+-static ssize_t urandom_read_nowarn(struct file *file, char __user *buf,
+-				   size_t nbytes, loff_t *ppos)
++/*
++ * Each time the timer fires, we expect that we got an unpredictable
++ * jump in the cycle counter. Even if the timer is running on another
++ * CPU, the timer activity will be touching the stack of the CPU that is
++ * generating entropy..
++ *
++ * Note that we don't re-arm the timer in the timer itself - we are
++ * happy to be scheduled away, since that just makes the load more
++ * complex, but we do not want the timer to keep ticking unless the
++ * entropy loop is running.
++ *
++ * So the re-arming always happens in the entropy loop itself.
++ */
++static void __cold entropy_timer(struct timer_list *t)
+ {
+-	int ret;
+-
+-	nbytes = min_t(size_t, nbytes, INT_MAX >> (POOL_ENTROPY_SHIFT + 3));
+-	ret = extract_crng_user(buf, nbytes);
+-	trace_urandom_read(8 * nbytes, 0, POOL_ENTROPY_BITS());
+-	return ret;
++	credit_init_bits(1);
+ }
+ 
+-static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes,
+-			    loff_t *ppos)
++/*
++ * If we have an actual cycle counter, see if we can
++ * generate enough entropy with timing noise
++ */
++static void __cold try_to_generate_entropy(void)
+ {
+-	static int maxwarn = 10;
++	struct {
++		unsigned long entropy;
++		struct timer_list timer;
++	} stack;
++
++	stack.entropy = random_get_entropy();
++
++	/* Slow counter - or none. Don't even bother */
++	if (stack.entropy == random_get_entropy())
++		return;
+ 
+-	if (!crng_ready() && maxwarn > 0) {
+-		maxwarn--;
+-		if (__ratelimit(&urandom_warning))
+-			pr_notice("%s: uninitialized urandom read (%zd bytes read)\n",
+-				  current->comm, nbytes);
++	timer_setup_on_stack(&stack.timer, entropy_timer, 0);
++	while (!crng_ready() && !signal_pending(current)) {
++		if (!timer_pending(&stack.timer))
++			mod_timer(&stack.timer, jiffies + 1);
++		mix_pool_bytes(&stack.entropy, sizeof(stack.entropy));
++		schedule();
++		stack.entropy = random_get_entropy();
+ 	}
+ 
+-	return urandom_read_nowarn(file, buf, nbytes, ppos);
++	del_timer_sync(&stack.timer);
++	destroy_timer_on_stack(&stack.timer);
++	mix_pool_bytes(&stack.entropy, sizeof(stack.entropy));
+ }
+ 
+-static ssize_t random_read(struct file *file, char __user *buf, size_t nbytes,
+-			   loff_t *ppos)
++
++/**********************************************************************
++ *
++ * Userspace reader/writer interfaces.
++ *
++ * getrandom(2) is the primary modern interface into the RNG and should
++ * be used in preference to anything else.
++ *
++ * Reading from /dev/random has the same functionality as calling
++ * getrandom(2) with flags=0. In earlier versions, however, it had
++ * vastly different semantics and should therefore be avoided, to
++ * prevent backwards compatibility issues.
++ *
++ * Reading from /dev/urandom has the same functionality as calling
++ * getrandom(2) with flags=GRND_INSECURE. Because it does not block
++ * waiting for the RNG to be ready, it should not be used.
++ *
++ * Writing to either /dev/random or /dev/urandom adds entropy to
++ * the input pool but does not credit it.
++ *
++ * Polling on /dev/random indicates when the RNG is initialized, on
++ * the read side, and when it wants new entropy, on the write side.
++ *
++ * Both /dev/random and /dev/urandom have the same set of ioctls for
++ * adding entropy, getting the entropy count, zeroing the count, and
++ * reseeding the crng.
++ *
++ **********************************************************************/
++
++SYSCALL_DEFINE3(getrandom, char __user *, ubuf, size_t, len, unsigned int, flags)
+ {
++	struct iov_iter iter;
++	struct iovec iov;
+ 	int ret;
+ 
+-	ret = wait_for_random_bytes();
+-	if (ret != 0)
++	if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
++		return -EINVAL;
++
++	/*
++	 * Requesting insecure and blocking randomness at the same time makes
++	 * no sense.
++	 */
++	if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
++		return -EINVAL;
++
++	if (!crng_ready() && !(flags & GRND_INSECURE)) {
++		if (flags & GRND_NONBLOCK)
++			return -EAGAIN;
++		ret = wait_for_random_bytes();
++		if (unlikely(ret))
++			return ret;
++	}
++
++	ret = import_single_range(READ, ubuf, len, &iov, &iter);
++	if (unlikely(ret))
+ 		return ret;
+-	return urandom_read_nowarn(file, buf, nbytes, ppos);
++	return get_random_bytes_user(&iter);
+ }
+ 
+ static __poll_t random_poll(struct file *file, poll_table *wait)
+ {
+-	__poll_t mask;
+-
+ 	poll_wait(file, &crng_init_wait, wait);
+-	poll_wait(file, &random_write_wait, wait);
+-	mask = 0;
+-	if (crng_ready())
+-		mask |= EPOLLIN | EPOLLRDNORM;
+-	if (POOL_ENTROPY_BITS() < random_write_wakeup_bits)
+-		mask |= EPOLLOUT | EPOLLWRNORM;
+-	return mask;
++	return crng_ready() ? EPOLLIN | EPOLLRDNORM : EPOLLOUT | EPOLLWRNORM;
+ }
+ 
+-static int write_pool(const char __user *buffer, size_t count)
++static ssize_t write_pool_user(struct iov_iter *iter)
+ {
+-	size_t bytes;
+-	u32 t, buf[16];
+-	const char __user *p = buffer;
++	u8 block[BLAKE2S_BLOCK_SIZE];
++	ssize_t ret = 0;
++	size_t copied;
+ 
+-	while (count > 0) {
+-		int b, i = 0;
++	if (unlikely(!iov_iter_count(iter)))
++		return 0;
+ 
+-		bytes = min(count, sizeof(buf));
+-		if (copy_from_user(&buf, p, bytes))
+-			return -EFAULT;
++	for (;;) {
++		copied = copy_from_iter(block, sizeof(block), iter);
++		ret += copied;
++		mix_pool_bytes(block, copied);
++		if (!iov_iter_count(iter) || copied != sizeof(block))
++			break;
+ 
+-		for (b = bytes; b > 0; b -= sizeof(u32), i++) {
+-			if (!arch_get_random_int(&t))
++		BUILD_BUG_ON(PAGE_SIZE % sizeof(block) != 0);
++		if (ret % PAGE_SIZE == 0) {
++			if (signal_pending(current))
+ 				break;
+-			buf[i] ^= t;
++			cond_resched();
+ 		}
++	}
+ 
+-		count -= bytes;
+-		p += bytes;
++	memzero_explicit(block, sizeof(block));
++	return ret ? ret : -EFAULT;
++}
++
++static ssize_t random_write_iter(struct kiocb *kiocb, struct iov_iter *iter)
++{
++	return write_pool_user(iter);
++}
+ 
+-		mix_pool_bytes(buf, bytes);
+-		cond_resched();
++static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
++{
++	static int maxwarn = 10;
++
++	if (!crng_ready()) {
++		if (!ratelimit_disable && maxwarn <= 0)
++			++urandom_warning.missed;
++		else if (ratelimit_disable || __ratelimit(&urandom_warning)) {
++			--maxwarn;
++			pr_notice("%s: uninitialized urandom read (%zu bytes read)\n",
++				  current->comm, iov_iter_count(iter));
++		}
+ 	}
+ 
+-	return 0;
++	return get_random_bytes_user(iter);
+ }
+ 
+-static ssize_t random_write(struct file *file, const char __user *buffer,
+-			    size_t count, loff_t *ppos)
++static ssize_t random_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
+ {
+-	size_t ret;
++	int ret;
+ 
+-	ret = write_pool(buffer, count);
+-	if (ret)
++	ret = wait_for_random_bytes();
++	if (ret != 0)
+ 		return ret;
+-
+-	return (ssize_t)count;
++	return get_random_bytes_user(iter);
+ }
+ 
+ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+ {
+-	int size, ent_count;
+ 	int __user *p = (int __user *)arg;
+-	int retval;
++	int ent_count;
+ 
+ 	switch (cmd) {
+ 	case RNDGETENTCNT:
+-		/* inherently racy, no point locking */
+-		ent_count = POOL_ENTROPY_BITS();
+-		if (put_user(ent_count, p))
++		/* Inherently racy, no point locking. */
++		if (put_user(input_pool.init_bits, p))
+ 			return -EFAULT;
+ 		return 0;
+ 	case RNDADDTOENTCNT:
+@@ -1834,40 +1329,48 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+ 			return -EPERM;
+ 		if (get_user(ent_count, p))
+ 			return -EFAULT;
+-		return credit_entropy_bits_safe(ent_count);
+-	case RNDADDENTROPY:
++		if (ent_count < 0)
++			return -EINVAL;
++		credit_init_bits(ent_count);
++		return 0;
++	case RNDADDENTROPY: {
++		struct iov_iter iter;
++		struct iovec iov;
++		ssize_t ret;
++		int len;
++
+ 		if (!capable(CAP_SYS_ADMIN))
+ 			return -EPERM;
+ 		if (get_user(ent_count, p++))
+ 			return -EFAULT;
+ 		if (ent_count < 0)
+ 			return -EINVAL;
+-		if (get_user(size, p++))
++		if (get_user(len, p++))
++			return -EFAULT;
++		ret = import_single_range(WRITE, p, len, &iov, &iter);
++		if (unlikely(ret))
++			return ret;
++		ret = write_pool_user(&iter);
++		if (unlikely(ret < 0))
++			return ret;
++		/* Since we're crediting, enforce that it was all written into the pool. */
++		if (unlikely(ret != len))
+ 			return -EFAULT;
+-		retval = write_pool((const char __user *)p, size);
+-		if (retval < 0)
+-			return retval;
+-		return credit_entropy_bits_safe(ent_count);
++		credit_init_bits(ent_count);
++		return 0;
++	}
+ 	case RNDZAPENTCNT:
+ 	case RNDCLEARPOOL:
+-		/*
+-		 * Clear the entropy pool counters. We no longer clear
+-		 * the entropy pool, as that's silly.
+-		 */
++		/* No longer has any effect. */
+ 		if (!capable(CAP_SYS_ADMIN))
+ 			return -EPERM;
+-		if (xchg(&input_pool.entropy_count, 0) && random_write_wakeup_bits) {
+-			wake_up_interruptible(&random_write_wait);
+-			kill_fasync(&fasync, SIGIO, POLL_OUT);
+-		}
+ 		return 0;
+ 	case RNDRESEEDCRNG:
+ 		if (!capable(CAP_SYS_ADMIN))
+ 			return -EPERM;
+-		if (crng_init < 2)
++		if (!crng_ready())
+ 			return -ENODATA;
+-		crng_reseed(&primary_crng, true);
+-		WRITE_ONCE(crng_global_init_time, jiffies - 1);
++		crng_reseed();
+ 		return 0;
+ 	default:
+ 		return -EINVAL;
+@@ -1880,55 +1383,56 @@ static int random_fasync(int fd, struct file *filp, int on)
+ }
+ 
+ const struct file_operations random_fops = {
+-	.read = random_read,
+-	.write = random_write,
++	.read_iter = random_read_iter,
++	.write_iter = random_write_iter,
+ 	.poll = random_poll,
+ 	.unlocked_ioctl = random_ioctl,
+ 	.compat_ioctl = compat_ptr_ioctl,
+ 	.fasync = random_fasync,
+ 	.llseek = noop_llseek,
++	.splice_read = generic_file_splice_read,
++	.splice_write = iter_file_splice_write,
+ };
+ 
+ const struct file_operations urandom_fops = {
+-	.read = urandom_read,
+-	.write = random_write,
++	.read_iter = urandom_read_iter,
++	.write_iter = random_write_iter,
+ 	.unlocked_ioctl = random_ioctl,
+ 	.compat_ioctl = compat_ptr_ioctl,
+ 	.fasync = random_fasync,
+ 	.llseek = noop_llseek,
++	.splice_read = generic_file_splice_read,
++	.splice_write = iter_file_splice_write,
+ };
+ 
+-SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
+-		flags)
+-{
+-	int ret;
+-
+-	if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
+-		return -EINVAL;
+-
+-	/*
+-	 * Requesting insecure and blocking randomness at the same time makes
+-	 * no sense.
+-	 */
+-	if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
+-		return -EINVAL;
+-
+-	if (count > INT_MAX)
+-		count = INT_MAX;
+-
+-	if (!(flags & GRND_INSECURE) && !crng_ready()) {
+-		if (flags & GRND_NONBLOCK)
+-			return -EAGAIN;
+-		ret = wait_for_random_bytes();
+-		if (unlikely(ret))
+-			return ret;
+-	}
+-	return urandom_read_nowarn(NULL, buf, count, NULL);
+-}
+ 
+ /********************************************************************
+  *
+- * Sysctl interface
++ * Sysctl interface.
++ *
++ * These are partly unused legacy knobs with dummy values to not break
++ * userspace and partly still useful things. They are usually accessible
++ * in /proc/sys/kernel/random/ and are as follows:
++ *
++ * - boot_id - a UUID representing the current boot.
++ *
++ * - uuid - a random UUID, different each time the file is read.
++ *
++ * - poolsize - the number of bits of entropy that the input pool can
++ *   hold, tied to the POOL_BITS constant.
++ *
++ * - entropy_avail - the number of bits of entropy currently in the
++ *   input pool. Always <= poolsize.
++ *
++ * - write_wakeup_threshold - the amount of entropy in the input pool
++ *   below which write polls to /dev/random will unblock, requesting
++ *   more entropy, tied to the POOL_READY_BITS constant. It is writable
++ *   to avoid breaking old userspaces, but writing to it does not
++ *   change any behavior of the RNG.
++ *
++ * - urandom_min_reseed_secs - fixed to the value CRNG_RESEED_INTERVAL.
++ *   It is writable to avoid breaking old userspaces, but writing
++ *   to it does not change any behavior of the RNG.
+  *
+  ********************************************************************/
+ 
+@@ -1936,25 +1440,28 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
+ 
+ #include <linux/sysctl.h>
+ 
+-static int min_write_thresh;
+-static int max_write_thresh = POOL_BITS;
+-static int random_min_urandom_seed = 60;
+-static char sysctl_bootid[16];
++static int sysctl_random_min_urandom_seed = CRNG_RESEED_INTERVAL / HZ;
++static int sysctl_random_write_wakeup_bits = POOL_READY_BITS;
++static int sysctl_poolsize = POOL_BITS;
++static u8 sysctl_bootid[UUID_SIZE];
+ 
+ /*
+  * This function is used to return both the bootid UUID, and random
+- * UUID.  The difference is in whether table->data is NULL; if it is,
++ * UUID. The difference is in whether table->data is NULL; if it is,
+  * then a new UUID is generated and returned to the user.
+- *
+- * If the user accesses this via the proc interface, the UUID will be
+- * returned as an ASCII string in the standard UUID format; if via the
+- * sysctl system call, as 16 bytes of binary data.
+  */
+-static int proc_do_uuid(struct ctl_table *table, int write, void *buffer,
++static int proc_do_uuid(struct ctl_table *table, int write, void *buf,
+ 			size_t *lenp, loff_t *ppos)
+ {
+-	struct ctl_table fake_table;
+-	unsigned char buf[64], tmp_uuid[16], *uuid;
++	u8 tmp_uuid[UUID_SIZE], *uuid;
++	char uuid_string[UUID_STRING_LEN + 1];
++	struct ctl_table fake_table = {
++		.data = uuid_string,
++		.maxlen = UUID_STRING_LEN
++	};
++
++	if (write)
++		return -EPERM;
+ 
+ 	uuid = table->data;
+ 	if (!uuid) {
+@@ -1969,32 +1476,17 @@ static int proc_do_uuid(struct ctl_table *table, int write, void *buffer,
+ 		spin_unlock(&bootid_spinlock);
+ 	}
+ 
+-	sprintf(buf, "%pU", uuid);
+-
+-	fake_table.data = buf;
+-	fake_table.maxlen = sizeof(buf);
+-
+-	return proc_dostring(&fake_table, write, buffer, lenp, ppos);
++	snprintf(uuid_string, sizeof(uuid_string), "%pU", uuid);
++	return proc_dostring(&fake_table, 0, buf, lenp, ppos);
+ }
+ 
+-/*
+- * Return entropy available scaled to integral bits
+- */
+-static int proc_do_entropy(struct ctl_table *table, int write, void *buffer,
+-			   size_t *lenp, loff_t *ppos)
++/* The same as proc_dointvec, but writes don't change anything. */
++static int proc_do_rointvec(struct ctl_table *table, int write, void *buf,
++			    size_t *lenp, loff_t *ppos)
+ {
+-	struct ctl_table fake_table;
+-	int entropy_count;
+-
+-	entropy_count = *(int *)table->data >> POOL_ENTROPY_SHIFT;
+-
+-	fake_table.data = &entropy_count;
+-	fake_table.maxlen = sizeof(entropy_count);
+-
+-	return proc_dointvec(&fake_table, write, buffer, lenp, ppos);
++	return write ? 0 : proc_dointvec(table, 0, buf, lenp, ppos);
+ }
+ 
+-static int sysctl_poolsize = POOL_BITS;
+ static struct ctl_table random_table[] = {
+ 	{
+ 		.procname	= "poolsize",
+@@ -2005,62 +1497,42 @@ static struct ctl_table random_table[] = {
+ 	},
+ 	{
+ 		.procname	= "entropy_avail",
++		.data		= &input_pool.init_bits,
+ 		.maxlen		= sizeof(int),
+ 		.mode		= 0444,
+-		.proc_handler	= proc_do_entropy,
+-		.data		= &input_pool.entropy_count,
++		.proc_handler	= proc_dointvec,
+ 	},
+ 	{
+ 		.procname	= "write_wakeup_threshold",
+-		.data		= &random_write_wakeup_bits,
++		.data		= &sysctl_random_write_wakeup_bits,
+ 		.maxlen		= sizeof(int),
+ 		.mode		= 0644,
+-		.proc_handler	= proc_dointvec_minmax,
+-		.extra1		= &min_write_thresh,
+-		.extra2		= &max_write_thresh,
++		.proc_handler	= proc_do_rointvec,
+ 	},
+ 	{
+ 		.procname	= "urandom_min_reseed_secs",
+-		.data		= &random_min_urandom_seed,
++		.data		= &sysctl_random_min_urandom_seed,
+ 		.maxlen		= sizeof(int),
+ 		.mode		= 0644,
+-		.proc_handler	= proc_dointvec,
++		.proc_handler	= proc_do_rointvec,
+ 	},
+ 	{
+ 		.procname	= "boot_id",
+ 		.data		= &sysctl_bootid,
+-		.maxlen		= 16,
+ 		.mode		= 0444,
+ 		.proc_handler	= proc_do_uuid,
+ 	},
+ 	{
+ 		.procname	= "uuid",
+-		.maxlen		= 16,
+ 		.mode		= 0444,
+ 		.proc_handler	= proc_do_uuid,
+ 	},
+-#ifdef ADD_INTERRUPT_BENCH
+-	{
+-		.procname	= "add_interrupt_avg_cycles",
+-		.data		= &avg_cycles,
+-		.maxlen		= sizeof(avg_cycles),
+-		.mode		= 0444,
+-		.proc_handler	= proc_doulongvec_minmax,
+-	},
+-	{
+-		.procname	= "add_interrupt_avg_deviation",
+-		.data		= &avg_deviation,
+-		.maxlen		= sizeof(avg_deviation),
+-		.mode		= 0444,
+-		.proc_handler	= proc_doulongvec_minmax,
+-	},
+-#endif
+ 	{ }
+ };
+ 
+ /*
+- * rand_initialize() is called before sysctl_init(),
+- * so we cannot call register_sysctl_init() in rand_initialize()
++ * random_init() is called before sysctl_init(),
++ * so we cannot call register_sysctl_init() in random_init()
+  */
+ static int __init random_sysctls_init(void)
+ {
+@@ -2068,170 +1540,4 @@ static int __init random_sysctls_init(void)
+ 	return 0;
+ }
+ device_initcall(random_sysctls_init);
+-#endif	/* CONFIG_SYSCTL */
+-
+-struct batched_entropy {
+-	union {
+-		u64 entropy_u64[CHACHA_BLOCK_SIZE / sizeof(u64)];
+-		u32 entropy_u32[CHACHA_BLOCK_SIZE / sizeof(u32)];
+-	};
+-	unsigned int position;
+-	spinlock_t batch_lock;
+-};
+-
+-/*
+- * Get a random word for internal kernel use only. The quality of the random
+- * number is good as /dev/urandom, but there is no backtrack protection, with
+- * the goal of being quite fast and not depleting entropy. In order to ensure
+- * that the randomness provided by this function is okay, the function
+- * wait_for_random_bytes() should be called and return 0 at least once at any
+- * point prior.
+- */
+-static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64) = {
+-	.batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u64.lock),
+-};
+-
+-u64 get_random_u64(void)
+-{
+-	u64 ret;
+-	unsigned long flags;
+-	struct batched_entropy *batch;
+-	static void *previous;
+-
+-	warn_unseeded_randomness(&previous);
+-
+-	batch = raw_cpu_ptr(&batched_entropy_u64);
+-	spin_lock_irqsave(&batch->batch_lock, flags);
+-	if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
+-		extract_crng((u8 *)batch->entropy_u64);
+-		batch->position = 0;
+-	}
+-	ret = batch->entropy_u64[batch->position++];
+-	spin_unlock_irqrestore(&batch->batch_lock, flags);
+-	return ret;
+-}
+-EXPORT_SYMBOL(get_random_u64);
+-
+-static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32) = {
+-	.batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u32.lock),
+-};
+-u32 get_random_u32(void)
+-{
+-	u32 ret;
+-	unsigned long flags;
+-	struct batched_entropy *batch;
+-	static void *previous;
+-
+-	warn_unseeded_randomness(&previous);
+-
+-	batch = raw_cpu_ptr(&batched_entropy_u32);
+-	spin_lock_irqsave(&batch->batch_lock, flags);
+-	if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) {
+-		extract_crng((u8 *)batch->entropy_u32);
+-		batch->position = 0;
+-	}
+-	ret = batch->entropy_u32[batch->position++];
+-	spin_unlock_irqrestore(&batch->batch_lock, flags);
+-	return ret;
+-}
+-EXPORT_SYMBOL(get_random_u32);
+-
+-/* It's important to invalidate all potential batched entropy that might
+- * be stored before the crng is initialized, which we can do lazily by
+- * simply resetting the counter to zero so that it's re-extracted on the
+- * next usage. */
+-static void invalidate_batched_entropy(void)
+-{
+-	int cpu;
+-	unsigned long flags;
+-
+-	for_each_possible_cpu(cpu) {
+-		struct batched_entropy *batched_entropy;
+-
+-		batched_entropy = per_cpu_ptr(&batched_entropy_u32, cpu);
+-		spin_lock_irqsave(&batched_entropy->batch_lock, flags);
+-		batched_entropy->position = 0;
+-		spin_unlock(&batched_entropy->batch_lock);
+-
+-		batched_entropy = per_cpu_ptr(&batched_entropy_u64, cpu);
+-		spin_lock(&batched_entropy->batch_lock);
+-		batched_entropy->position = 0;
+-		spin_unlock_irqrestore(&batched_entropy->batch_lock, flags);
+-	}
+-}
+-
+-/**
+- * randomize_page - Generate a random, page aligned address
+- * @start:	The smallest acceptable address the caller will take.
+- * @range:	The size of the area, starting at @start, within which the
+- *		random address must fall.
+- *
+- * If @start + @range would overflow, @range is capped.
+- *
+- * NOTE: Historical use of randomize_range, which this replaces, presumed that
+- * @start was already page aligned.  We now align it regardless.
+- *
+- * Return: A page aligned address within [start, start + range).  On error,
+- * @start is returned.
+- */
+-unsigned long randomize_page(unsigned long start, unsigned long range)
+-{
+-	if (!PAGE_ALIGNED(start)) {
+-		range -= PAGE_ALIGN(start) - start;
+-		start = PAGE_ALIGN(start);
+-	}
+-
+-	if (start > ULONG_MAX - range)
+-		range = ULONG_MAX - start;
+-
+-	range >>= PAGE_SHIFT;
+-
+-	if (range == 0)
+-		return start;
+-
+-	return start + (get_random_long() % range << PAGE_SHIFT);
+-}
+-
+-/* Interface for in-kernel drivers of true hardware RNGs.
+- * Those devices may produce endless random bits and will be throttled
+- * when our pool is full.
+- */
+-void add_hwgenerator_randomness(const char *buffer, size_t count,
+-				size_t entropy)
+-{
+-	if (unlikely(crng_init == 0)) {
+-		size_t ret = crng_fast_load(buffer, count);
+-		mix_pool_bytes(buffer, ret);
+-		count -= ret;
+-		buffer += ret;
+-		if (!count || crng_init == 0)
+-			return;
+-	}
+-
+-	/* Throttle writing if we're above the trickle threshold.
+-	 * We'll be woken up again once below random_write_wakeup_thresh,
+-	 * when the calling thread is about to terminate, or once
+-	 * CRNG_RESEED_INTERVAL has lapsed.
+-	 */
+-	wait_event_interruptible_timeout(random_write_wait,
+-			!system_wq || kthread_should_stop() ||
+-			POOL_ENTROPY_BITS() <= random_write_wakeup_bits,
+-			CRNG_RESEED_INTERVAL);
+-	mix_pool_bytes(buffer, count);
+-	credit_entropy_bits(entropy);
+-}
+-EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
+-
+-/* Handle random seed passed by bootloader.
+- * If the seed is trustworthy, it would be regarded as hardware RNGs. Otherwise
+- * it would be regarded as device data.
+- * The decision is controlled by CONFIG_RANDOM_TRUST_BOOTLOADER.
+- */
+-void add_bootloader_randomness(const void *buf, unsigned int size)
+-{
+-	if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER))
+-		add_hwgenerator_randomness(buf, size, size * 8);
+-	else
+-		add_device_randomness(buf, size);
+-}
+-EXPORT_SYMBOL_GPL(add_bootloader_randomness);
++#endif
+diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_client.c b/drivers/hid/amd-sfh-hid/amd_sfh_client.c
+index c5de0ec4f9d03..444acd9e2cd6a 100644
+--- a/drivers/hid/amd-sfh-hid/amd_sfh_client.c
++++ b/drivers/hid/amd-sfh-hid/amd_sfh_client.c
+@@ -227,6 +227,17 @@ int amd_sfh_hid_client_init(struct amd_mp2_dev *privdata)
+ 		dev_dbg(dev, "sid 0x%x status 0x%x\n",
+ 			cl_data->sensor_idx[i], cl_data->sensor_sts[i]);
+ 	}
++	if (privdata->mp2_ops->discovery_status &&
++	    privdata->mp2_ops->discovery_status(privdata) == 0) {
++		amd_sfh_hid_client_deinit(privdata);
++		for (i = 0; i < cl_data->num_hid_devices; i++) {
++			devm_kfree(dev, cl_data->feature_report[i]);
++			devm_kfree(dev, in_data->input_report[i]);
++			devm_kfree(dev, cl_data->report_descr[i]);
++		}
++		dev_warn(dev, "Failed to discover, sensors not enabled\n");
++		return -EOPNOTSUPP;
++	}
+ 	schedule_delayed_work(&cl_data->work_buffer, msecs_to_jiffies(AMD_SFH_IDLE_LOOP));
+ 	return 0;
+ 
+diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+index 19fa734a9a793..abd7f65860958 100644
+--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
++++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+@@ -130,6 +130,12 @@ static int amd_sfh_irq_init_v2(struct amd_mp2_dev *privdata)
+ 	return 0;
+ }
+ 
++static int amd_sfh_dis_sts_v2(struct amd_mp2_dev *privdata)
++{
++	return (readl(privdata->mmio + AMD_P2C_MSG(1)) &
++		      SENSOR_DISCOVERY_STATUS_MASK) >> SENSOR_DISCOVERY_STATUS_SHIFT;
++}
++
+ void amd_start_sensor(struct amd_mp2_dev *privdata, struct amd_mp2_sensor_info info)
+ {
+ 	union sfh_cmd_param cmd_param;
+@@ -245,6 +251,7 @@ static const struct amd_mp2_ops amd_sfh_ops_v2 = {
+ 	.response = amd_sfh_wait_response_v2,
+ 	.clear_intr = amd_sfh_clear_intr_v2,
+ 	.init_intr = amd_sfh_irq_init_v2,
++	.discovery_status = amd_sfh_dis_sts_v2,
+ };
+ 
+ static const struct amd_mp2_ops amd_sfh_ops = {
+diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.h b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.h
+index 97b99861fae25..9aa88a91ac8d1 100644
+--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.h
++++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.h
+@@ -39,6 +39,9 @@
+ 
+ #define AMD_SFH_IDLE_LOOP	200
+ 
++#define SENSOR_DISCOVERY_STATUS_MASK		GENMASK(5, 3)
++#define SENSOR_DISCOVERY_STATUS_SHIFT		3
++
+ /* SFH Command register */
+ union sfh_cmd_base {
+ 	u32 ul;
+@@ -143,5 +146,6 @@ struct amd_mp2_ops {
+ 	 int (*response)(struct amd_mp2_dev *mp2, u8 sid, u32 sensor_sts);
+ 	 void (*clear_intr)(struct amd_mp2_dev *privdata);
+ 	 int (*init_intr)(struct amd_mp2_dev *privdata);
++	 int (*discovery_status)(struct amd_mp2_dev *privdata);
+ };
+ #endif
+diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
+index 411a428ace4d4..481e565cc5c42 100644
+--- a/include/linux/cpuhotplug.h
++++ b/include/linux/cpuhotplug.h
+@@ -100,6 +100,7 @@ enum cpuhp_state {
+ 	CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
+ 	CPUHP_PADATA_DEAD,
+ 	CPUHP_AP_DTPM_CPU_DEAD,
++	CPUHP_RANDOM_PREPARE,
+ 	CPUHP_WORKQUEUE_PREP,
+ 	CPUHP_POWER_NUMA_PREPARE,
+ 	CPUHP_HRTIMERS_PREPARE,
+@@ -240,6 +241,7 @@ enum cpuhp_state {
+ 	CPUHP_AP_PERF_CSKY_ONLINE,
+ 	CPUHP_AP_WATCHDOG_ONLINE,
+ 	CPUHP_AP_WORKQUEUE_ONLINE,
++	CPUHP_AP_RANDOM_ONLINE,
+ 	CPUHP_AP_RCUTREE_ONLINE,
+ 	CPUHP_AP_BASE_CACHEINFO_ONLINE,
+ 	CPUHP_AP_ONLINE_DYN,
+diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h
+index 8e6dd908da216..aa1d4da03538b 100644
+--- a/include/linux/hw_random.h
++++ b/include/linux/hw_random.h
+@@ -60,7 +60,5 @@ extern int devm_hwrng_register(struct device *dev, struct hwrng *rng);
+ /** Unregister a Hardware Random Number Generator driver. */
+ extern void hwrng_unregister(struct hwrng *rng);
+ extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng);
+-/** Feed random bits into the pool. */
+-extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);
+ 
+ #endif /* LINUX_HWRANDOM_H_ */
+diff --git a/include/linux/mm.h b/include/linux/mm.h
+index 5744a3fc47169..9cb0ff065e8b1 100644
+--- a/include/linux/mm.h
++++ b/include/linux/mm.h
+@@ -2678,6 +2678,7 @@ extern int install_special_mapping(struct mm_struct *mm,
+ 				   unsigned long flags, struct page **pages);
+ 
+ unsigned long randomize_stack_top(unsigned long stack_top);
++unsigned long randomize_page(unsigned long start, unsigned long range);
+ 
+ extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
+ 
+diff --git a/include/linux/prandom.h b/include/linux/prandom.h
+index 056d31317e499..a4aadd2dc153e 100644
+--- a/include/linux/prandom.h
++++ b/include/linux/prandom.h
+@@ -10,6 +10,7 @@
+ 
+ #include <linux/types.h>
+ #include <linux/percpu.h>
++#include <linux/siphash.h>
+ 
+ u32 prandom_u32(void);
+ void prandom_bytes(void *buf, size_t nbytes);
+@@ -27,15 +28,10 @@ DECLARE_PER_CPU(unsigned long, net_rand_noise);
+  * The core SipHash round function.  Each line can be executed in
+  * parallel given enough CPU resources.
+  */
+-#define PRND_SIPROUND(v0, v1, v2, v3) ( \
+-	v0 += v1, v1 = rol64(v1, 13),  v2 += v3, v3 = rol64(v3, 16), \
+-	v1 ^= v0, v0 = rol64(v0, 32),  v3 ^= v2,                     \
+-	v0 += v3, v3 = rol64(v3, 21),  v2 += v1, v1 = rol64(v1, 17), \
+-	v3 ^= v0,                      v1 ^= v2, v2 = rol64(v2, 32)  \
+-)
++#define PRND_SIPROUND(v0, v1, v2, v3) SIPHASH_PERMUTATION(v0, v1, v2, v3)
+ 
+-#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261)
+-#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573)
++#define PRND_K0 (SIPHASH_CONST_0 ^ SIPHASH_CONST_2)
++#define PRND_K1 (SIPHASH_CONST_1 ^ SIPHASH_CONST_3)
+ 
+ #elif BITS_PER_LONG == 32
+ /*
+@@ -43,14 +39,9 @@ DECLARE_PER_CPU(unsigned long, net_rand_noise);
+  * This is weaker, but 32-bit machines are not used for high-traffic
+  * applications, so there is less output for an attacker to analyze.
+  */
+-#define PRND_SIPROUND(v0, v1, v2, v3) ( \
+-	v0 += v1, v1 = rol32(v1,  5),  v2 += v3, v3 = rol32(v3,  8), \
+-	v1 ^= v0, v0 = rol32(v0, 16),  v3 ^= v2,                     \
+-	v0 += v3, v3 = rol32(v3,  7),  v2 += v1, v1 = rol32(v1, 13), \
+-	v3 ^= v0,                      v1 ^= v2, v2 = rol32(v2, 16)  \
+-)
+-#define PRND_K0 0x6c796765
+-#define PRND_K1 0x74656462
++#define PRND_SIPROUND(v0, v1, v2, v3) HSIPHASH_PERMUTATION(v0, v1, v2, v3)
++#define PRND_K0 (HSIPHASH_CONST_0 ^ HSIPHASH_CONST_2)
++#define PRND_K1 (HSIPHASH_CONST_1 ^ HSIPHASH_CONST_3)
+ 
+ #else
+ #error Unsupported BITS_PER_LONG
+diff --git a/include/linux/random.h b/include/linux/random.h
+index c45b2693e51fb..917470c4490ac 100644
+--- a/include/linux/random.h
++++ b/include/linux/random.h
+@@ -1,9 +1,5 @@
+ /* SPDX-License-Identifier: GPL-2.0 */
+-/*
+- * include/linux/random.h
+- *
+- * Include file for the random number generator.
+- */
++
+ #ifndef _LINUX_RANDOM_H
+ #define _LINUX_RANDOM_H
+ 
+@@ -14,41 +10,26 @@
+ 
+ #include <uapi/linux/random.h>
+ 
+-struct random_ready_callback {
+-	struct list_head list;
+-	void (*func)(struct random_ready_callback *rdy);
+-	struct module *owner;
+-};
++struct notifier_block;
+ 
+-extern void add_device_randomness(const void *, unsigned int);
+-extern void add_bootloader_randomness(const void *, unsigned int);
++void add_device_randomness(const void *buf, size_t len);
++void add_bootloader_randomness(const void *buf, size_t len);
++void add_input_randomness(unsigned int type, unsigned int code,
++			  unsigned int value) __latent_entropy;
++void add_interrupt_randomness(int irq) __latent_entropy;
++void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy);
+ 
+ #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
+ static inline void add_latent_entropy(void)
+ {
+-	add_device_randomness((const void *)&latent_entropy,
+-			      sizeof(latent_entropy));
++	add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
+ }
+ #else
+-static inline void add_latent_entropy(void) {}
+-#endif
+-
+-extern void add_input_randomness(unsigned int type, unsigned int code,
+-				 unsigned int value) __latent_entropy;
+-extern void add_interrupt_randomness(int irq) __latent_entropy;
+-
+-extern void get_random_bytes(void *buf, int nbytes);
+-extern int wait_for_random_bytes(void);
+-extern int __init rand_initialize(void);
+-extern bool rng_is_initialized(void);
+-extern int add_random_ready_callback(struct random_ready_callback *rdy);
+-extern void del_random_ready_callback(struct random_ready_callback *rdy);
+-extern int __must_check get_random_bytes_arch(void *buf, int nbytes);
+-
+-#ifndef MODULE
+-extern const struct file_operations random_fops, urandom_fops;
++static inline void add_latent_entropy(void) { }
+ #endif
+ 
++void get_random_bytes(void *buf, size_t len);
++size_t __must_check get_random_bytes_arch(void *buf, size_t len);
+ u32 get_random_u32(void);
+ u64 get_random_u64(void);
+ static inline unsigned int get_random_int(void)
+@@ -80,36 +61,38 @@ static inline unsigned long get_random_long(void)
+ 
+ static inline unsigned long get_random_canary(void)
+ {
+-	unsigned long val = get_random_long();
+-
+-	return val & CANARY_MASK;
++	return get_random_long() & CANARY_MASK;
+ }
+ 
++int __init random_init(const char *command_line);
++bool rng_is_initialized(void);
++int wait_for_random_bytes(void);
++int register_random_ready_notifier(struct notifier_block *nb);
++int unregister_random_ready_notifier(struct notifier_block *nb);
++
+ /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes).
+  * Returns the result of the call to wait_for_random_bytes. */
+-static inline int get_random_bytes_wait(void *buf, int nbytes)
++static inline int get_random_bytes_wait(void *buf, size_t nbytes)
+ {
+ 	int ret = wait_for_random_bytes();
+ 	get_random_bytes(buf, nbytes);
+ 	return ret;
+ }
+ 
+-#define declare_get_random_var_wait(var) \
+-	static inline int get_random_ ## var ## _wait(var *out) { \
++#define declare_get_random_var_wait(name, ret_type) \
++	static inline int get_random_ ## name ## _wait(ret_type *out) { \
+ 		int ret = wait_for_random_bytes(); \
+ 		if (unlikely(ret)) \
+ 			return ret; \
+-		*out = get_random_ ## var(); \
++		*out = get_random_ ## name(); \
+ 		return 0; \
+ 	}
+-declare_get_random_var_wait(u32)
+-declare_get_random_var_wait(u64)
+-declare_get_random_var_wait(int)
+-declare_get_random_var_wait(long)
++declare_get_random_var_wait(u32, u32)
++declare_get_random_var_wait(u64, u32)
++declare_get_random_var_wait(int, unsigned int)
++declare_get_random_var_wait(long, unsigned long)
+ #undef declare_get_random_var
+ 
+-unsigned long randomize_page(unsigned long start, unsigned long range);
+-
+ /*
+  * This is designed to be standalone for just prandom
+  * users, but for now we include it from <linux/random.h>
+@@ -120,22 +103,10 @@ unsigned long randomize_page(unsigned long start, unsigned long range);
+ #ifdef CONFIG_ARCH_RANDOM
+ # include <asm/archrandom.h>
+ #else
+-static inline bool __must_check arch_get_random_long(unsigned long *v)
+-{
+-	return false;
+-}
+-static inline bool __must_check arch_get_random_int(unsigned int *v)
+-{
+-	return false;
+-}
+-static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
+-{
+-	return false;
+-}
+-static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
+-{
+-	return false;
+-}
++static inline bool __must_check arch_get_random_long(unsigned long *v) { return false; }
++static inline bool __must_check arch_get_random_int(unsigned int *v) { return false; }
++static inline bool __must_check arch_get_random_seed_long(unsigned long *v) { return false; }
++static inline bool __must_check arch_get_random_seed_int(unsigned int *v) { return false; }
+ #endif
+ 
+ /*
+@@ -158,4 +129,13 @@ static inline bool __init arch_get_random_long_early(unsigned long *v)
+ }
+ #endif
+ 
++#ifdef CONFIG_SMP
++int random_prepare_cpu(unsigned int cpu);
++int random_online_cpu(unsigned int cpu);
++#endif
++
++#ifndef MODULE
++extern const struct file_operations random_fops, urandom_fops;
++#endif
++
+ #endif /* _LINUX_RANDOM_H */
+diff --git a/include/linux/siphash.h b/include/linux/siphash.h
+index cce8a9acc76cb..3af1428da5597 100644
+--- a/include/linux/siphash.h
++++ b/include/linux/siphash.h
+@@ -138,4 +138,32 @@ static inline u32 hsiphash(const void *data, size_t len,
+ 	return ___hsiphash_aligned(data, len, key);
+ }
+ 
++/*
++ * These macros expose the raw SipHash and HalfSipHash permutations.
++ * Do not use them directly! If you think you have a use for them,
++ * be sure to CC the maintainer of this file explaining why.
++ */
++
++#define SIPHASH_PERMUTATION(a, b, c, d) ( \
++	(a) += (b), (b) = rol64((b), 13), (b) ^= (a), (a) = rol64((a), 32), \
++	(c) += (d), (d) = rol64((d), 16), (d) ^= (c), \
++	(a) += (d), (d) = rol64((d), 21), (d) ^= (a), \
++	(c) += (b), (b) = rol64((b), 17), (b) ^= (c), (c) = rol64((c), 32))
++
++#define SIPHASH_CONST_0 0x736f6d6570736575ULL
++#define SIPHASH_CONST_1 0x646f72616e646f6dULL
++#define SIPHASH_CONST_2 0x6c7967656e657261ULL
++#define SIPHASH_CONST_3 0x7465646279746573ULL
++
++#define HSIPHASH_PERMUTATION(a, b, c, d) ( \
++	(a) += (b), (b) = rol32((b), 5), (b) ^= (a), (a) = rol32((a), 16), \
++	(c) += (d), (d) = rol32((d), 8), (d) ^= (c), \
++	(a) += (d), (d) = rol32((d), 7), (d) ^= (a), \
++	(c) += (b), (b) = rol32((b), 13), (b) ^= (c), (c) = rol32((c), 16))
++
++#define HSIPHASH_CONST_0 0U
++#define HSIPHASH_CONST_1 0U
++#define HSIPHASH_CONST_2 0x6c796765U
++#define HSIPHASH_CONST_3 0x74656462U
++
+ #endif /* _LINUX_SIPHASH_H */
+diff --git a/include/linux/timex.h b/include/linux/timex.h
+index 059b18eb1f1fa..3871b06bd302c 100644
+--- a/include/linux/timex.h
++++ b/include/linux/timex.h
+@@ -62,6 +62,8 @@
+ #include <linux/types.h>
+ #include <linux/param.h>
+ 
++unsigned long random_get_entropy_fallback(void);
++
+ #include <asm/timex.h>
+ 
+ #ifndef random_get_entropy
+@@ -74,8 +76,14 @@
+  *
+  * By default we use get_cycles() for this purpose, but individual
+  * architectures may override this in their asm/timex.h header file.
++ * If a given arch does not have get_cycles(), then we fallback to
++ * using random_get_entropy_fallback().
+  */
+-#define random_get_entropy()	get_cycles()
++#ifdef get_cycles
++#define random_get_entropy()	((unsigned long)get_cycles())
++#else
++#define random_get_entropy()	random_get_entropy_fallback()
++#endif
+ #endif
+ 
+ /*
+diff --git a/include/trace/events/random.h b/include/trace/events/random.h
+deleted file mode 100644
+index a2d9aa16a5d7a..0000000000000
+--- a/include/trace/events/random.h
++++ /dev/null
+@@ -1,233 +0,0 @@
+-/* SPDX-License-Identifier: GPL-2.0 */
+-#undef TRACE_SYSTEM
+-#define TRACE_SYSTEM random
+-
+-#if !defined(_TRACE_RANDOM_H) || defined(TRACE_HEADER_MULTI_READ)
+-#define _TRACE_RANDOM_H
+-
+-#include <linux/writeback.h>
+-#include <linux/tracepoint.h>
+-
+-TRACE_EVENT(add_device_randomness,
+-	TP_PROTO(int bytes, unsigned long IP),
+-
+-	TP_ARGS(bytes, IP),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	bytes			)
+-		__field(unsigned long,	IP			)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->bytes		= bytes;
+-		__entry->IP		= IP;
+-	),
+-
+-	TP_printk("bytes %d caller %pS",
+-		__entry->bytes, (void *)__entry->IP)
+-);
+-
+-DECLARE_EVENT_CLASS(random__mix_pool_bytes,
+-	TP_PROTO(int bytes, unsigned long IP),
+-
+-	TP_ARGS(bytes, IP),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	bytes			)
+-		__field(unsigned long,	IP			)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->bytes		= bytes;
+-		__entry->IP		= IP;
+-	),
+-
+-	TP_printk("input pool: bytes %d caller %pS",
+-		  __entry->bytes, (void *)__entry->IP)
+-);
+-
+-DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes,
+-	TP_PROTO(int bytes, unsigned long IP),
+-
+-	TP_ARGS(bytes, IP)
+-);
+-
+-DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes_nolock,
+-	TP_PROTO(int bytes, unsigned long IP),
+-
+-	TP_ARGS(bytes, IP)
+-);
+-
+-TRACE_EVENT(credit_entropy_bits,
+-	TP_PROTO(int bits, int entropy_count, unsigned long IP),
+-
+-	TP_ARGS(bits, entropy_count, IP),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	bits			)
+-		__field(	  int,	entropy_count		)
+-		__field(unsigned long,	IP			)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->bits		= bits;
+-		__entry->entropy_count	= entropy_count;
+-		__entry->IP		= IP;
+-	),
+-
+-	TP_printk("input pool: bits %d entropy_count %d caller %pS",
+-		  __entry->bits, __entry->entropy_count, (void *)__entry->IP)
+-);
+-
+-TRACE_EVENT(debit_entropy,
+-	TP_PROTO(int debit_bits),
+-
+-	TP_ARGS( debit_bits),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	debit_bits		)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->debit_bits	= debit_bits;
+-	),
+-
+-	TP_printk("input pool: debit_bits %d", __entry->debit_bits)
+-);
+-
+-TRACE_EVENT(add_input_randomness,
+-	TP_PROTO(int input_bits),
+-
+-	TP_ARGS(input_bits),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	input_bits		)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->input_bits	= input_bits;
+-	),
+-
+-	TP_printk("input_pool_bits %d", __entry->input_bits)
+-);
+-
+-TRACE_EVENT(add_disk_randomness,
+-	TP_PROTO(dev_t dev, int input_bits),
+-
+-	TP_ARGS(dev, input_bits),
+-
+-	TP_STRUCT__entry(
+-		__field(	dev_t,	dev			)
+-		__field(	  int,	input_bits		)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->dev		= dev;
+-		__entry->input_bits	= input_bits;
+-	),
+-
+-	TP_printk("dev %d,%d input_pool_bits %d", MAJOR(__entry->dev),
+-		  MINOR(__entry->dev), __entry->input_bits)
+-);
+-
+-DECLARE_EVENT_CLASS(random__get_random_bytes,
+-	TP_PROTO(int nbytes, unsigned long IP),
+-
+-	TP_ARGS(nbytes, IP),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	nbytes			)
+-		__field(unsigned long,	IP			)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->nbytes		= nbytes;
+-		__entry->IP		= IP;
+-	),
+-
+-	TP_printk("nbytes %d caller %pS", __entry->nbytes, (void *)__entry->IP)
+-);
+-
+-DEFINE_EVENT(random__get_random_bytes, get_random_bytes,
+-	TP_PROTO(int nbytes, unsigned long IP),
+-
+-	TP_ARGS(nbytes, IP)
+-);
+-
+-DEFINE_EVENT(random__get_random_bytes, get_random_bytes_arch,
+-	TP_PROTO(int nbytes, unsigned long IP),
+-
+-	TP_ARGS(nbytes, IP)
+-);
+-
+-DECLARE_EVENT_CLASS(random__extract_entropy,
+-	TP_PROTO(int nbytes, int entropy_count, unsigned long IP),
+-
+-	TP_ARGS(nbytes, entropy_count, IP),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	nbytes			)
+-		__field(	  int,	entropy_count		)
+-		__field(unsigned long,	IP			)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->nbytes		= nbytes;
+-		__entry->entropy_count	= entropy_count;
+-		__entry->IP		= IP;
+-	),
+-
+-	TP_printk("input pool: nbytes %d entropy_count %d caller %pS",
+-		  __entry->nbytes, __entry->entropy_count, (void *)__entry->IP)
+-);
+-
+-
+-DEFINE_EVENT(random__extract_entropy, extract_entropy,
+-	TP_PROTO(int nbytes, int entropy_count, unsigned long IP),
+-
+-	TP_ARGS(nbytes, entropy_count, IP)
+-);
+-
+-TRACE_EVENT(urandom_read,
+-	TP_PROTO(int got_bits, int pool_left, int input_left),
+-
+-	TP_ARGS(got_bits, pool_left, input_left),
+-
+-	TP_STRUCT__entry(
+-		__field(	  int,	got_bits		)
+-		__field(	  int,	pool_left		)
+-		__field(	  int,	input_left		)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->got_bits	= got_bits;
+-		__entry->pool_left	= pool_left;
+-		__entry->input_left	= input_left;
+-	),
+-
+-	TP_printk("got_bits %d nonblocking_pool_entropy_left %d "
+-		  "input_entropy_left %d", __entry->got_bits,
+-		  __entry->pool_left, __entry->input_left)
+-);
+-
+-TRACE_EVENT(prandom_u32,
+-
+-	TP_PROTO(unsigned int ret),
+-
+-	TP_ARGS(ret),
+-
+-	TP_STRUCT__entry(
+-		__field(   unsigned int, ret)
+-	),
+-
+-	TP_fast_assign(
+-		__entry->ret = ret;
+-	),
+-
+-	TP_printk("ret=%u" , __entry->ret)
+-);
+-
+-#endif /* _TRACE_RANDOM_H */
+-
+-/* This part must be outside protection */
+-#include <trace/define_trace.h>
+diff --git a/init/main.c b/init/main.c
+index 9a5097b2251a5..0aa2e1c17b1c3 100644
+--- a/init/main.c
++++ b/init/main.c
+@@ -1035,21 +1035,18 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
+ 	softirq_init();
+ 	timekeeping_init();
+ 	kfence_init();
++	time_init();
+ 
+ 	/*
+ 	 * For best initial stack canary entropy, prepare it after:
+ 	 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
+-	 * - timekeeping_init() for ktime entropy used in rand_initialize()
+-	 * - rand_initialize() to get any arch-specific entropy like RDRAND
+-	 * - add_latent_entropy() to get any latent entropy
+-	 * - adding command line entropy
++	 * - timekeeping_init() for ktime entropy used in random_init()
++	 * - time_init() for making random_get_entropy() work on some platforms
++	 * - random_init() to initialize the RNG from from early entropy sources
+ 	 */
+-	rand_initialize();
+-	add_latent_entropy();
+-	add_device_randomness(command_line, strlen(command_line));
++	random_init(command_line);
+ 	boot_init_stack_canary();
+ 
+-	time_init();
+ 	perf_event_init();
+ 	profile_init();
+ 	call_function_init();
+diff --git a/kernel/cpu.c b/kernel/cpu.c
+index 5601216eb51bd..da871eb075662 100644
+--- a/kernel/cpu.c
++++ b/kernel/cpu.c
+@@ -34,6 +34,7 @@
+ #include <linux/scs.h>
+ #include <linux/percpu-rwsem.h>
+ #include <linux/cpuset.h>
++#include <linux/random.h>
+ 
+ #include <trace/events/power.h>
+ #define CREATE_TRACE_POINTS
+@@ -1659,6 +1660,11 @@ static struct cpuhp_step cpuhp_hp_states[] = {
+ 		.startup.single		= perf_event_init_cpu,
+ 		.teardown.single	= perf_event_exit_cpu,
+ 	},
++	[CPUHP_RANDOM_PREPARE] = {
++		.name			= "random:prepare",
++		.startup.single		= random_prepare_cpu,
++		.teardown.single	= NULL,
++	},
+ 	[CPUHP_WORKQUEUE_PREP] = {
+ 		.name			= "workqueue:prepare",
+ 		.startup.single		= workqueue_prepare_cpu,
+@@ -1782,6 +1788,11 @@ static struct cpuhp_step cpuhp_hp_states[] = {
+ 		.startup.single		= workqueue_online_cpu,
+ 		.teardown.single	= workqueue_offline_cpu,
+ 	},
++	[CPUHP_AP_RANDOM_ONLINE] = {
++		.name			= "random:online",
++		.startup.single		= random_online_cpu,
++		.teardown.single	= NULL,
++	},
+ 	[CPUHP_AP_RCUTREE_ONLINE] = {
+ 		.name			= "RCU/tree:online",
+ 		.startup.single		= rcutree_online_cpu,
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 3b1398fbddaf8..871c912860ed5 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -17,6 +17,7 @@
+ #include <linux/clocksource.h>
+ #include <linux/jiffies.h>
+ #include <linux/time.h>
++#include <linux/timex.h>
+ #include <linux/tick.h>
+ #include <linux/stop_machine.h>
+ #include <linux/pvclock_gtod.h>
+@@ -2380,6 +2381,20 @@ static int timekeeping_validate_timex(const struct __kernel_timex *txc)
+ 	return 0;
+ }
+ 
++/**
++ * random_get_entropy_fallback - Returns the raw clock source value,
++ * used by random.c for platforms with no valid random_get_entropy().
++ */
++unsigned long random_get_entropy_fallback(void)
++{
++	struct tk_read_base *tkr = &tk_core.timekeeper.tkr_mono;
++	struct clocksource *clock = READ_ONCE(tkr->clock);
++
++	if (unlikely(timekeeping_suspended || !clock))
++		return 0;
++	return clock->read(clock);
++}
++EXPORT_SYMBOL_GPL(random_get_entropy_fallback);
+ 
+ /**
+  * do_adjtimex() - Accessor function to NTP __do_adjtimex function
+diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
+index 440fd666c16d1..c7dfe1000111d 100644
+--- a/lib/Kconfig.debug
++++ b/lib/Kconfig.debug
+@@ -1566,8 +1566,7 @@ config WARN_ALL_UNSEEDED_RANDOM
+ 	  so architecture maintainers really need to do what they can
+ 	  to get the CRNG seeded sooner after the system is booted.
+ 	  However, since users cannot do anything actionable to
+-	  address this, by default the kernel will issue only a single
+-	  warning for the first use of unseeded randomness.
++	  address this, by default this option is disabled.
+ 
+ 	  Say Y here if you want to receive warnings for all uses of
+ 	  unseeded randomness.  This will be of use primarily for
+diff --git a/lib/random32.c b/lib/random32.c
+index a57a0e18819d0..976632003ec65 100644
+--- a/lib/random32.c
++++ b/lib/random32.c
+@@ -41,7 +41,6 @@
+ #include <linux/bitops.h>
+ #include <linux/slab.h>
+ #include <asm/unaligned.h>
+-#include <trace/events/random.h>
+ 
+ /**
+  *	prandom_u32_state - seeded pseudo-random number generator.
+@@ -387,7 +386,6 @@ u32 prandom_u32(void)
+ 	struct siprand_state *state = get_cpu_ptr(&net_rand_state);
+ 	u32 res = siprand_u32(state);
+ 
+-	trace_prandom_u32(res);
+ 	put_cpu_ptr(&net_rand_state);
+ 	return res;
+ }
+@@ -553,9 +551,11 @@ static void prandom_reseed(struct timer_list *unused)
+  * To avoid worrying about whether it's safe to delay that interrupt
+  * long enough to seed all CPUs, just schedule an immediate timer event.
+  */
+-static void prandom_timer_start(struct random_ready_callback *unused)
++static int prandom_timer_start(struct notifier_block *nb,
++			       unsigned long action, void *data)
+ {
+ 	mod_timer(&seed_timer, jiffies);
++	return 0;
+ }
+ 
+ #ifdef CONFIG_RANDOM32_SELFTEST
+@@ -619,13 +619,13 @@ core_initcall(prandom32_state_selftest);
+  */
+ static int __init prandom_init_late(void)
+ {
+-	static struct random_ready_callback random_ready = {
+-		.func = prandom_timer_start
++	static struct notifier_block random_ready = {
++		.notifier_call = prandom_timer_start
+ 	};
+-	int ret = add_random_ready_callback(&random_ready);
++	int ret = register_random_ready_notifier(&random_ready);
+ 
+ 	if (ret == -EALREADY) {
+-		prandom_timer_start(&random_ready);
++		prandom_timer_start(&random_ready, 0, NULL);
+ 		ret = 0;
+ 	}
+ 	return ret;
+diff --git a/lib/siphash.c b/lib/siphash.c
+index 72b9068ab57bf..71d315a6ad623 100644
+--- a/lib/siphash.c
++++ b/lib/siphash.c
+@@ -18,19 +18,13 @@
+ #include <asm/word-at-a-time.h>
+ #endif
+ 
+-#define SIPROUND \
+-	do { \
+-	v0 += v1; v1 = rol64(v1, 13); v1 ^= v0; v0 = rol64(v0, 32); \
+-	v2 += v3; v3 = rol64(v3, 16); v3 ^= v2; \
+-	v0 += v3; v3 = rol64(v3, 21); v3 ^= v0; \
+-	v2 += v1; v1 = rol64(v1, 17); v1 ^= v2; v2 = rol64(v2, 32); \
+-	} while (0)
++#define SIPROUND SIPHASH_PERMUTATION(v0, v1, v2, v3)
+ 
+ #define PREAMBLE(len) \
+-	u64 v0 = 0x736f6d6570736575ULL; \
+-	u64 v1 = 0x646f72616e646f6dULL; \
+-	u64 v2 = 0x6c7967656e657261ULL; \
+-	u64 v3 = 0x7465646279746573ULL; \
++	u64 v0 = SIPHASH_CONST_0; \
++	u64 v1 = SIPHASH_CONST_1; \
++	u64 v2 = SIPHASH_CONST_2; \
++	u64 v3 = SIPHASH_CONST_3; \
+ 	u64 b = ((u64)(len)) << 56; \
+ 	v3 ^= key->key[1]; \
+ 	v2 ^= key->key[0]; \
+@@ -389,19 +383,13 @@ u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third,
+ }
+ EXPORT_SYMBOL(hsiphash_4u32);
+ #else
+-#define HSIPROUND \
+-	do { \
+-	v0 += v1; v1 = rol32(v1, 5); v1 ^= v0; v0 = rol32(v0, 16); \
+-	v2 += v3; v3 = rol32(v3, 8); v3 ^= v2; \
+-	v0 += v3; v3 = rol32(v3, 7); v3 ^= v0; \
+-	v2 += v1; v1 = rol32(v1, 13); v1 ^= v2; v2 = rol32(v2, 16); \
+-	} while (0)
++#define HSIPROUND HSIPHASH_PERMUTATION(v0, v1, v2, v3)
+ 
+ #define HPREAMBLE(len) \
+-	u32 v0 = 0; \
+-	u32 v1 = 0; \
+-	u32 v2 = 0x6c796765U; \
+-	u32 v3 = 0x74656462U; \
++	u32 v0 = HSIPHASH_CONST_0; \
++	u32 v1 = HSIPHASH_CONST_1; \
++	u32 v2 = HSIPHASH_CONST_2; \
++	u32 v3 = HSIPHASH_CONST_3; \
+ 	u32 b = ((u32)(len)) << 24; \
+ 	v3 ^= key->key[1]; \
+ 	v2 ^= key->key[0]; \
+diff --git a/lib/vsprintf.c b/lib/vsprintf.c
+index fbf261bbea950..35cc358f8daee 100644
+--- a/lib/vsprintf.c
++++ b/lib/vsprintf.c
+@@ -762,14 +762,16 @@ static void enable_ptr_key_workfn(struct work_struct *work)
+ 
+ static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
+ 
+-static void fill_random_ptr_key(struct random_ready_callback *unused)
++static int fill_random_ptr_key(struct notifier_block *nb,
++			       unsigned long action, void *data)
+ {
+ 	/* This may be in an interrupt handler. */
+ 	queue_work(system_unbound_wq, &enable_ptr_key_work);
++	return 0;
+ }
+ 
+-static struct random_ready_callback random_ready = {
+-	.func = fill_random_ptr_key
++static struct notifier_block random_ready = {
++	.notifier_call = fill_random_ptr_key
+ };
+ 
+ static int __init initialize_ptr_random(void)
+@@ -783,7 +785,7 @@ static int __init initialize_ptr_random(void)
+ 		return 0;
+ 	}
+ 
+-	ret = add_random_ready_callback(&random_ready);
++	ret = register_random_ready_notifier(&random_ready);
+ 	if (!ret) {
+ 		return 0;
+ 	} else if (ret == -EALREADY) {
+diff --git a/mm/util.c b/mm/util.c
+index d3102081add00..5223d7e2f65ec 100644
+--- a/mm/util.c
++++ b/mm/util.c
+@@ -343,6 +343,38 @@ unsigned long randomize_stack_top(unsigned long stack_top)
+ #endif
+ }
+ 
++/**
++ * randomize_page - Generate a random, page aligned address
++ * @start:	The smallest acceptable address the caller will take.
++ * @range:	The size of the area, starting at @start, within which the
++ *		random address must fall.
++ *
++ * If @start + @range would overflow, @range is capped.
++ *
++ * NOTE: Historical use of randomize_range, which this replaces, presumed that
++ * @start was already page aligned.  We now align it regardless.
++ *
++ * Return: A page aligned address within [start, start + range).  On error,
++ * @start is returned.
++ */
++unsigned long randomize_page(unsigned long start, unsigned long range)
++{
++	if (!PAGE_ALIGNED(start)) {
++		range -= PAGE_ALIGN(start) - start;
++		start = PAGE_ALIGN(start);
++	}
++
++	if (start > ULONG_MAX - range)
++		range = ULONG_MAX - start;
++
++	range >>= PAGE_SHIFT;
++
++	if (range == 0)
++		return start;
++
++	return start + (get_random_long() % range << PAGE_SHIFT);
++}
++
+ #ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
+ unsigned long arch_randomize_brk(struct mm_struct *mm)
+ {
+diff --git a/sound/pci/ctxfi/ctatc.c b/sound/pci/ctxfi/ctatc.c
+index 78f35e88aed6b..fbdb8a3d5b8e5 100644
+--- a/sound/pci/ctxfi/ctatc.c
++++ b/sound/pci/ctxfi/ctatc.c
+@@ -36,6 +36,7 @@
+ 			    | ((IEC958_AES3_CON_FS_48000) << 24))
+ 
+ static const struct snd_pci_quirk subsys_20k1_list[] = {
++	SND_PCI_QUIRK(PCI_VENDOR_ID_CREATIVE, 0x0021, "SB046x", CTSB046X),
+ 	SND_PCI_QUIRK(PCI_VENDOR_ID_CREATIVE, 0x0022, "SB055x", CTSB055X),
+ 	SND_PCI_QUIRK(PCI_VENDOR_ID_CREATIVE, 0x002f, "SB055x", CTSB055X),
+ 	SND_PCI_QUIRK(PCI_VENDOR_ID_CREATIVE, 0x0029, "SB073x", CTSB073X),
+@@ -64,6 +65,7 @@ static const struct snd_pci_quirk subsys_20k2_list[] = {
+ 
+ static const char *ct_subsys_name[NUM_CTCARDS] = {
+ 	/* 20k1 models */
++	[CTSB046X]	= "SB046x",
+ 	[CTSB055X]	= "SB055x",
+ 	[CTSB073X]	= "SB073x",
+ 	[CTUAA]		= "UAA",
+diff --git a/sound/pci/ctxfi/cthardware.h b/sound/pci/ctxfi/cthardware.h
+index f406b626a28c4..2875cec83b8f2 100644
+--- a/sound/pci/ctxfi/cthardware.h
++++ b/sound/pci/ctxfi/cthardware.h
+@@ -26,8 +26,9 @@ enum CHIPTYP {
+ 
+ enum CTCARDS {
+ 	/* 20k1 models */
++	CTSB046X,
++	CT20K1_MODEL_FIRST = CTSB046X,
+ 	CTSB055X,
+-	CT20K1_MODEL_FIRST = CTSB055X,
+ 	CTSB073X,
+ 	CTUAA,
+ 	CT20K1_UNKNOWN,