libsandbox: extend symbols format to specify diff syscall name

This enables support for 64-bit time_t syscalls where the glibc symbol
name is not the same as the kernel syscall name.

Closes: https://bugs.gentoo.org/751241
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

5 files changed, 45 insertions, 25 deletions

diff --git a/libsandbox/symbols.h.in b/libsandbox/symbols.h.in
index 40c04e3..ecf141c 100644
--- a/libsandbox/symbols.h.in
+++ b/libsandbox/symbols.h.in
@@ -78,7 +78,7 @@ __utime64
 utimes
 __utimes64
 utimensat
-__utimensat64
+__utimensat64 utimensat_time64
 futimesat
 __futimesat64
 lutimes
diff --git a/libsandbox/trace.c b/libsandbox/trace.c
index ae5f935..b7e65b4 100644
--- a/libsandbox/trace.c
+++ b/libsandbox/trace.c
@@ -305,7 +305,7 @@ static bool trace_check_syscall(const struct syscall_entry *se, void *regs)
 	state.regs = regs;
 	state.nr = nr = se->sys;
 	state.func = name = se->name;
-	if (!SB_NR_IS_DEFINED(nr))      goto done;
+	if (!SB_NR_IS_DEFINED(se->nr))  goto done;
 	else if (nr == SB_NR_MKDIR)     state.pre_check = sb_mkdirat_pre_check;
 	else if (nr == SB_NR_MKDIRAT)   state.pre_check = sb_mkdirat_pre_check;
 	else if (nr == SB_NR_UNLINK)    state.pre_check = sb_unlinkat_pre_check;
@@ -313,8 +313,7 @@ static bool trace_check_syscall(const struct syscall_entry *se, void *regs)
 	else                            state.pre_check = NULL;
 
 	/* Hmm, add these functions to the syscall table and avoid this if() ? */
-	if (!SB_NR_IS_DEFINED(nr))      goto done;
-	else if (nr == SB_NR_CHMOD)     return  trace_check_syscall_C  (&state);
+	     if (nr == SB_NR_CHMOD)     return  trace_check_syscall_C  (&state);
 	else if (nr == SB_NR_CHOWN)     return  trace_check_syscall_C  (&state);
 	else if (nr == SB_NR_CREAT)     return  trace_check_syscall_C  (&state);
 	/* NB: Linux syscall does not have a flags argument. */
@@ -343,7 +342,14 @@ static bool trace_check_syscall(const struct syscall_entry *se, void *regs)
 	else if (nr == SB_NR_UNLINKAT)  return  trace_check_syscall_DCF(&state);
 	else if (nr == SB_NR_UTIME)     return  trace_check_syscall_C  (&state);
 	else if (nr == SB_NR_UTIMES)    return  trace_check_syscall_C  (&state);
-	else if (nr == SB_NR_UTIMENSAT) return _trace_check_syscall_DCF(&state, 1, 4);
+
+	else if (nr == SB_NR_UTIMENSAT) {
+ utimensat:
+		return _trace_check_syscall_DCF(&state, 1, 4);
+	} else if (nr == SB_NR___UTIMENSAT64) {
+		state.nr = SB_NR_UTIMENSAT;
+		goto utimensat;
+	}
 
 	else if (nr == SB_NR_ACCESS) {
 		char *path = do_peekstr(trace_arg(regs, 1));
diff --git a/scripts/gen_symbol_header.awk b/scripts/gen_symbol_header.awk
index 14e0a99..e669c85 100644
--- a/scripts/gen_symbol_header.awk
+++ b/scripts/gen_symbol_header.awk
@@ -3,9 +3,11 @@ BEGIN {
 	COUNT = 0;
 
 	sym_regex = "";
-	while ((getline symbol < SYMBOLS_FILE) > 0) {
-		if (symbol ~ /^ *#/ || symbol ~ /^$/)
+	while ((getline line < SYMBOLS_FILE) > 0) {
+		if (line ~ /^ *#/ || line ~ /^$/)
 			continue;
+		split(line, fields);
+		symbol = fields[1];
 
 		SYMBOLS[++COUNT] = symbol;
 		if (sym_regex)
diff --git a/scripts/gen_symbol_version_map.awk b/scripts/gen_symbol_version_map.awk
index cd0aa84..661cb1d 100644
--- a/scripts/gen_symbol_version_map.awk
+++ b/scripts/gen_symbol_version_map.awk
@@ -1,9 +1,11 @@
 # Read the symbols list and create regexs to use for processing readelf output.
 BEGIN {
 	sym_regex = "";
-	while ((getline symbol < SYMBOLS_FILE) > 0) {
-		if (symbol ~ /^ *#/ || symbol ~ /^$/)
+	while ((getline line < SYMBOLS_FILE) > 0) {
+		if (line ~ /^ *#/ || line ~ /^$/)
 			continue;
+		split(line, fields);
+		symbol = fields[1];
 
 		if (sym_regex)
 			sym_regex = sym_regex "|";
diff --git a/scripts/gen_trace_header.awk b/scripts/gen_trace_header.awk
index e9d84a6..0bb53b1 100644
--- a/scripts/gen_trace_header.awk
+++ b/scripts/gen_trace_header.awk
@@ -1,11 +1,16 @@
 # Read the symbols list and create regexs to use for processing readelf output.
 function read_symbols() {
 	COUNT = 0;
-	while ((getline symbol < SYMBOLS_FILE) > 0) {
-		if (symbol ~ /^ *#/ || symbol ~ /^$/)
+	while ((getline line < SYMBOLS_FILE) > 0) {
+		if (line ~ /^ *#/ || line ~ /^$/)
 			continue;
+		nfields = split(line, fields);
+		symbol = fields[1];
+		syscall = nfields > 1 ? fields[2] : symbol;
 
-		SYMBOLS[++COUNT] = symbol;
+		c = ++COUNT
+		SYMBOLS[c] = symbol;
+		SYSCALLS[c] = syscall;
 	}
 }
 
@@ -13,19 +18,22 @@ BEGIN {
 	read_symbols();
 
 	if (MODE == "gen") {
-		for (x in SYMBOLS) {
-			s = SYMBOLS[x]
-			print "SB_" s " = SYS_" s
+		for (x in SYSCALLS) {
+			print "SB_" SYMBOLS[x] " = SYS_" SYSCALLS[x];
 		}
 		exit(0);
 	}
 }
 
-function out(name, val)
+function out(name, syscall, val)
 {
-	name = toupper(name)
-	print "#define SB_SYS" syscall_prefix "_" name " " val;
-	print "S(" name ")";
+	uname = toupper(name)
+	syscall_define = "SB_SYS" syscall_prefix "_" uname
+	print "#define " syscall_define " " val;
+	if (name == syscall)
+		print "S(" uname ")";
+	else
+		print "{ " syscall_define ", SB_NR_" uname ", \"" uname "\" },";
 }
 
 {
@@ -42,21 +50,23 @@ function out(name, val)
 	# a straight number or an expression (a syscall base)
 	sub(/^[^=]*= /, "");
 
-	for (i = 1; i <= COUNT; ++i)
+	syscall = "<awk_script_error>";
+	for (i = 1; i <= COUNT; ++i) {
 		if (SYMBOLS[i] == name) {
-			SYMBOLS[i] = "";
+			FOUND[i] = 1;
+			syscall = SYSCALLS[i];
 			break;
 		}
+	}
 
-	out(name, $0);
+	out(name, syscall, $0);
 }
 
 END {
 	if (MODE != "gen") {
 		for (x in SYMBOLS) {
-			s = SYMBOLS[x];
-			if (s != "")
-				out(s, "SB_NR_UNDEF");
+			if (!FOUND[x])
+				out(SYMBOLS[x], SYSCALLS[x], "SB_NR_UNDEF");
 		}
 	}
 }