libsandbox: initial support for tracing of static binaries via ptrace()

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

6 files changed, 95 insertions, 0 deletions

diff --git a/libsandbox/trace/common.c b/libsandbox/trace/common.c
new file mode 100644
index 0000000..20fcb7e
--- /dev/null
+++ b/libsandbox/trace/common.c
@@ -0,0 +1,3 @@
+static int trace_sysnum(void);
+static long trace_raw_ret(void *vregs);
+static unsigned long trace_arg(void *vregs, int num);
diff --git a/libsandbox/trace/linux/arch.c b/libsandbox/trace/linux/arch.c
new file mode 100644
index 0000000..5897b2f
--- /dev/null
+++ b/libsandbox/trace/linux/arch.c
@@ -0,0 +1,17 @@
+#include "common.c"
+
+/* Linux uses ptrace() */
+#if !defined(HAVE_PTRACE) || !defined(HAVE_SYS_PTRACE_H) || !defined(HAVE_SYS_USER_H)
+# define SB_NO_TRACE_ARCH
+#elif defined(__i386__)
+# include "i386.c"
+#elif defined(__x86_64__)
+# include "x86_64.c"
+#else
+# define SB_NO_TRACE_ARCH
+#endif
+
+#ifdef SB_NO_TRACE_ARCH
+# warning "trace: sorry, no support for your architecture"
+# define SB_NO_TRACE
+#endif
diff --git a/libsandbox/trace/linux/common.c b/libsandbox/trace/linux/common.c
new file mode 100644
index 0000000..287af0a
--- /dev/null
+++ b/libsandbox/trace/linux/common.c
@@ -0,0 +1,13 @@
+static long do_peekuser(long offset);
+
+static int trace_errno(long err)
+{
+	return (err < 0 && err > -4096) ? err * -1 : 0;
+}
+
+static long trace_result(void *vregs, int *error)
+{
+	long sr = trace_raw_ret(vregs);
+	*error = trace_errno(sr);
+	return *error ? -1 : sr;
+}
diff --git a/libsandbox/trace/linux/i386.c b/libsandbox/trace/linux/i386.c
new file mode 100644
index 0000000..83cc094
--- /dev/null
+++ b/libsandbox/trace/linux/i386.c
@@ -0,0 +1,24 @@
+static int trace_sysnum(void)
+{
+	return do_peekuser(4 * ORIG_EAX);
+}
+
+static long trace_raw_ret(void *vregs)
+{
+	struct user_regs_struct *regs = vregs;
+	return regs->eax;
+}
+
+static unsigned long trace_arg(void *vregs, int num)
+{
+	struct user_regs_struct *regs = vregs;
+	switch (num) {
+		case 1: return regs->ebx;
+		case 2: return regs->ecx;
+		case 3: return regs->edx;
+		case 4: return regs->esi;
+		case 5: return regs->edi;
+		case 6: return regs->ebp;
+		default: return -1;
+	}
+}
diff --git a/libsandbox/trace/linux/x86_64.c b/libsandbox/trace/linux/x86_64.c
new file mode 100644
index 0000000..1f40036
--- /dev/null
+++ b/libsandbox/trace/linux/x86_64.c
@@ -0,0 +1,24 @@
+static int trace_sysnum(void)
+{
+	return do_peekuser(8 * ORIG_RAX);
+}
+
+static long trace_raw_ret(void *vregs)
+{
+	struct user_regs_struct *regs = vregs;
+	return regs->rax;
+}
+
+static unsigned long trace_arg(void *vregs, int num)
+{
+	struct user_regs_struct *regs = vregs;
+	switch (num) {
+		case 1: return regs->rdi;
+		case 2: return regs->rsi;
+		case 3: return regs->rdx;
+		case 4: return regs->r10;
+		case 5: return regs->r8;
+		case 6: return regs->r9;
+		default: return -1;
+	}
+}
diff --git a/libsandbox/trace/os.c b/libsandbox/trace/os.c
new file mode 100644
index 0000000..945cc61
--- /dev/null
+++ b/libsandbox/trace/os.c
@@ -0,0 +1,14 @@
+#include "common.c"
+
+#undef SB_NO_TRACE
+#if 0
+#elif defined(__linux__)
+# include "linux/arch.c"
+#else
+# define SB_NO_TRACE_OS
+#endif
+
+#ifdef SB_NO_TRACE_OS
+# warning "trace: sorry, no support for your OS"
+# define SB_NO_TRACE
+#endif