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authorKyle Evans <kevans@FreeBSD.org>2019-11-25 03:49:38 +0000
committerKyle Evans <kevans@FreeBSD.org>2019-11-25 03:49:38 +0000
commitbf6ee21ac9b83c8e679c549932d0065739cbc17c (patch)
tree322419ec27ac9f90339eb4b81fbed2cde16f3214
parent62b436d466744fb6a09330878e077b614df67270 (diff)
Notes
-rw-r--r--lib/libc/secure/stack_protector.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/lib/libc/secure/stack_protector.c b/lib/libc/secure/stack_protector.c
index 34bb7d0332a3b..63c02cd960338 100644
--- a/lib/libc/secure/stack_protector.c
+++ b/lib/libc/secure/stack_protector.c
@@ -40,11 +40,29 @@ __FBSDID("$FreeBSD$");
#include <unistd.h>
#include "libc_private.h"
+/*
+ * We give __guard_setup a defined priority early on so that statically linked
+ * applications have a defined priority at which __stack_chk_guard will be
+ * getting initialized. This will not matter to most applications, because
+ * they're either not usually statically linked or they simply don't do things
+ * in constructors that would be adversely affected by their positioning with
+ * respect to this initialization.
+ *
+ * This conditional should be removed when GCC 4.2 is removed.
+ */
+#if __has_attribute(__constructor__) || __GNUC_PREREQ__(4, 3)
+#define _GUARD_SETUP_CTOR_ATTR \
+ __attribute__((__constructor__ (200), __used__));
+#else
+#define _GUARD_SETUP_CTOR_ATTR \
+ __attribute__((__constructor__, __used__));
+#endif
+
extern int __sysctl(const int *name, u_int namelen, void *oldp,
size_t *oldlenp, void *newp, size_t newlen);
long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
-static void __guard_setup(void) __attribute__((__constructor__, __used__));
+static void __guard_setup(void) _GUARD_SETUP_CTOR_ATTR;
static void __fail(const char *);
void __stack_chk_fail(void);
void __chk_fail(void);