From 812cc95678da2eac1a405996a94ffc8bc239d9b9 Mon Sep 17 00:00:00 2001 From: "Peter S. Mazinger" Date: Sat, 1 Oct 2005 15:48:22 +0000 Subject: Add gcc-4.1 non-TLS __stack_chk_guard support. Run the guard setup only once. --- libc/misc/internals/__uClibc_main.c | 40 +++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 17 deletions(-) (limited to 'libc/misc/internals') diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c index c88649def..b3876ae15 100644 --- a/libc/misc/internals/__uClibc_main.c +++ b/libc/misc/internals/__uClibc_main.c @@ -27,8 +27,12 @@ #include #ifdef __UCLIBC_HAS_SSP__ #include +#include -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__ -- cgit v1.2.3