Add gcc-4.1 non-TLS __stack_chk_guard support. Run the guard setup only once.

libc/misc/internals/__uClibc_main.c

@@ -27,8 +27,12 @@
 #include <sys/sysmacros.h>
 #ifdef __UCLIBC_HAS_SSP__
 #include <ssp-internal.h>
+#include <stdint.h>
 
-unsigned long __guard = 0UL;
+/* for gcc-3.x + Etoh ssp */
+uintptr_t __guard /* segfaults with attribute_relro */;
+/* for gcc-4.1 non-TLS */
+uintptr_t __stack_chk_guard /* attribute_relro */;
 #endif
 
 /*
@@ -107,11 +111,9 @@ static int __check_suid(void)
 }
 
 #ifdef __UCLIBC_HAS_SSP__
-static __always_inline void __guard_setup(void)
+static __always_inline uintptr_t _dl_guard_setup(void)
 {
-	if (__guard != 0UL)
-		return;
-
+	uintptr_t ret;
 #ifndef __SSP_QUICK_CANARY__
 
 	size_t size;
@@ -124,10 +126,9 @@ static __always_inline void __guard_setup(void)
 		mib[1] = KERN_RANDOM;
 		mib[2] = RANDOM_ERANDOM;
 
-		size = sizeof(unsigned long);
-		if (SYSCTL(mib, 3, &__guard, &size, NULL, 0) != (-1))
-			if (__guard != 0UL)
-				return;
+		if (SYSCTL(mib, 3, &ret, &size, NULL, 0) != (-1))
+			if (size == (size_t) sizeof(ret))
+				return ret;
 	}
 # endif /* ifdef __SSP_USE_ERANDOM__ */
 	{
@@ -141,25 +142,26 @@ static __always_inline void __guard_setup(void)
 		if ((fd = OPEN("/dev/erandom", O_RDONLY)) == (-1))
 # endif
 			fd = OPEN("/dev/urandom", O_RDONLY);
-		if (fd != (-1)) {
-			size = READ(fd, (char *) &__guard, sizeof(__guard));
+		if (fd >= 0) {
+			size = READ(fd, &ret, sizeof(ret));
 			CLOSE(fd);
-			if (size == sizeof(__guard))
-				return;
+			if (size == (size_t) sizeof(ret))
+				return ret;
 		}
 	}
 #endif /* ifndef __SSP_QUICK_CANARY__ */
 
 	/* Start with the "terminator canary". */
-	__guard = 0xFF0A0D00UL;
+	ret = 0xFF0A0D00UL;
 
 	/* Everything failed? Or we are using a weakened model of the 
 	 * terminator canary */
 	{
 		struct timeval tv;
-		GETTIMEOFDAY(&tv, NULL);
-		__guard ^= tv.tv_usec ^ tv.tv_sec;
+		if (GETTIMEOFDAY(&tv, NULL) != (-1))
+			ret ^= tv.tv_usec ^ tv.tv_sec;
 	}
+	return ret;
 }
 #endif /* __UCLIBC_HAS_SSP__ */
 
@@ -198,7 +200,11 @@ void __uClibc_init(void)
 #endif
 
 #ifdef __UCLIBC_HAS_SSP__
-    __guard_setup ();
+    uintptr_t stack_chk_guard = _dl_guard_setup();
+    /* for gcc-3.x + Etoh ssp */
+    __guard = stack_chk_guard;
+    /* for gcc-4.1 non-TLS */
+    __stack_chk_guard = stack_chk_guard;
 #endif
 
 #ifdef __UCLIBC_HAS_LOCALE__

libc/sysdeps/linux/common/Makefile

@@ -25,21 +25,31 @@ ifeq ($(strip $(EXCLUDE_BRK)),y)
 SRCS := $(filter-out sbrk.c,$(SRCS))
 endif
 
+SRCS := $(filter-out ssp-local.c,$(SRCS))
 ifneq ($(strip $(UCLIBC_HAS_SSP)),y)
 SRCS := $(filter-out ssp.c,$(SRCS))
+NONSHARED_OBJ_LIST=
+else
+NONSHARED_OBJ_LIST=../../../nonshared_obj.sysdeps.common
 endif
 ssp.o: CFLAGS += $(SSP_DISABLE_FLAGS)
+ssp-local.o: CFLAGS += $(SSP_DISABLE_FLAGS)
 
 OBJS  = $(patsubst %.c,%.o, $(SRCS))
 
+NONSHARED_OBJS = ssp-local.o
+
 OBJ_LIST=../../../obj.sysdeps.common
 
-all: $(OBJ_LIST)
+all: $(OBJ_LIST) $(NONSHARED_OBJ_LIST)
 
 $(OBJ_LIST): $(OBJS)
 	echo $(patsubst %, sysdeps/linux/common/%, $(OBJS)) > $(OBJ_LIST)
 
-$(OBJS): %.o : %.c
+$(NONSHARED_OBJ_LIST): $(NONSHARED_OBJS)
+	echo $(patsubst %, sysdeps/linux/common/%, $(NONSHARED_OBJS)) > $(NONSHARED_OBJ_LIST)
+
+$(OBJS) $(NONSHARED_OBJS): %.o : %.c
 	$(CC) $(CFLAGS) -c $< -o $@
 	$(STRIPTOOL) -x -R .note -R .comment $*.o
 
@@ -47,4 +57,4 @@ headers:
 	$(LN) -fs ../libc/sysdeps/linux/common/fpu_control.h $(TOPDIR)/include/
 
 clean:
-	$(RM) *.[oa] *~ core
+	$(RM) *.o *~ core

libc/sysdeps/linux/common/ssp-local.c

@@ -0,0 +1,35 @@
+/* Copyright (C) 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/*
+ * Peter S. Mazinger ps.m[@]gmx.net
+ * copied stack_chk_fail_local.c from glibc and adapted for uClibc
+ */
+
+#include <features.h>
+
+extern void __stack_chk_fail (void) __attribute__ ((noreturn));
+
+/* On some architectures, this helps needless PIC pointer setup
+   that would be needed just for the __stack_chk_fail call.  */
+
+void __attribute__ ((noreturn)) attribute_hidden
+__stack_chk_fail_local (void)
+{
+  __stack_chk_fail ();
+}

libc/sysdeps/linux/common/ssp.c

@@ -61,12 +61,43 @@ void __attribute__ ((noreturn)) __stack_smash_handler(char func[], int damaged _
 void __attribute__ ((noreturn)) __stack_smash_handler(char func[], int damaged)
 {
 	extern char *__progname;
-	const char message[] = ": stack smashing attack in function ";
+	static const char message[] = ": stack smashing attack in function ";
 
 	block_signals();
 
 	ssp_write(STDERR_FILENO, __progname, message, func);
 
+	/* The loop is added only to keep gcc happy. */
+	while(1)
+		terminate();
+}
+
+void __attribute__ ((noreturn)) __stack_chk_fail(void)
+{
+	extern char *__progname;
+	static const char msg1[] = "stack smashing detected: ";
+	static const char msg3[] = " terminated";
+
+	block_signals();
+
+	ssp_write(STDERR_FILENO, msg1, __progname, msg3);
+
+	/* The loop is added only to keep gcc happy. */
+	while(1)
+		terminate();
+}
+
+void __attribute__ ((noreturn)) __chk_fail(void)
+{
+	extern char *__progname;
+	static const char msg1[] = "buffer overflow detected: ";
+	static const char msg3[] = " terminated";
+
+	block_signals();
+
+	ssp_write(STDERR_FILENO, msg1, __progname, msg3);
+
+	/* The loop is added only to keep gcc happy. */
 	while(1)
 		terminate();
 }