From 4a103975c4c4929455d60224101013888640cd2f Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 20 Jun 2014 20:02:34 +0000 Subject: Remove __ASSUME_AT_RANDOM. This patch removes __ASSUME_AT_RANDOM now it can be assumed to be true unconditionally. Tested x86_64 that the disassembly of installed shared libraries is unchanged by this patch. * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_AT_RANDOM): Remove macro. * sysdeps/unix/sysv/linux/dl-osinfo.h (_dl_setup_stack_chk_guard) [!__ASSUME_AT_RANDOM]: Remove conditional code. (_dl_setup_pointer_guard) [!__ASSUME_AT_RANDOM]: Likewise. --- ChangeLog | 6 ++++ sysdeps/unix/sysv/linux/dl-osinfo.h | 48 +++++-------------------------- sysdeps/unix/sysv/linux/kernel-features.h | 3 -- 3 files changed, 13 insertions(+), 44 deletions(-) diff --git a/ChangeLog b/ChangeLog index a87a2d0d01..beea12ca42 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2014-06-20 Joseph Myers + * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_AT_RANDOM): + Remove macro. + * sysdeps/unix/sysv/linux/dl-osinfo.h (_dl_setup_stack_chk_guard) + [!__ASSUME_AT_RANDOM]: Remove conditional code. + (_dl_setup_pointer_guard) [!__ASSUME_AT_RANDOM]: Likewise. + * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_ADJ_OFFSET_SS_READ): Remove macro. * sysdeps/unix/sysv/linux/adjtime.c (ADJTIME) diff --git a/sysdeps/unix/sysv/linux/dl-osinfo.h b/sysdeps/unix/sysv/linux/dl-osinfo.h index af1343822f..fd82287f0a 100644 --- a/sysdeps/unix/sysv/linux/dl-osinfo.h +++ b/sysdeps/unix/sysv/linux/dl-osinfo.h @@ -57,39 +57,17 @@ _dl_setup_stack_chk_guard (void *dl_random) unsigned char bytes[sizeof (uintptr_t)]; } ret; -#ifndef __ASSUME_AT_RANDOM - if (__glibc_unlikely (dl_random == NULL)) - { - const size_t filllen = sizeof (ret.bytes) - 1; - ret.num = 0; -# ifdef ENABLE_STACKGUARD_RANDOMIZE - int fd = open_not_cancel_2 ("/dev/urandom", O_RDONLY); - if (fd >= 0) - { - ssize_t reslen = read_not_cancel (fd, ret.bytes + 1, filllen); - close_not_cancel_no_status (fd); - if (reslen == (ssize_t) filllen) - return ret.num; - } -# endif - ret.bytes[filllen] = 255; - ret.bytes[filllen - 1] = '\n'; - } - else -#endif - { - /* We need in the moment only 8 bytes on 32-bit platforms and 16 - bytes on 64-bit platforms. Therefore we can use the data - directly and not use the kernel-provided data to seed a PRNG. */ - memcpy (ret.bytes, dl_random, sizeof (ret)); + /* We need in the moment only 8 bytes on 32-bit platforms and 16 + bytes on 64-bit platforms. Therefore we can use the data + directly and not use the kernel-provided data to seed a PRNG. */ + memcpy (ret.bytes, dl_random, sizeof (ret)); #if BYTE_ORDER == LITTLE_ENDIAN - ret.num &= ~(uintptr_t) 0xff; + ret.num &= ~(uintptr_t) 0xff; #elif BYTE_ORDER == BIG_ENDIAN - ret.num &= ~((uintptr_t) 0xff << (8 * (sizeof (ret) - 1))); + ret.num &= ~((uintptr_t) 0xff << (8 * (sizeof (ret) - 1))); #else # error "BYTE_ORDER unknown" #endif - } return ret.num; } @@ -97,18 +75,6 @@ static inline uintptr_t __attribute__ ((always_inline)) _dl_setup_pointer_guard (void *dl_random, uintptr_t stack_chk_guard) { uintptr_t ret; -#ifndef __ASSUME_AT_RANDOM - if (dl_random == NULL) - { - ret = stack_chk_guard; -# ifndef HP_TIMING_NONAVAIL - hp_timing_t now; - HP_TIMING_NOW (now); - ret ^= now; -# endif - } - else -#endif - memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret)); + memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret)); return ret; } diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index d0673211ad..80655e0162 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -162,9 +162,6 @@ /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29. */ #define __ASSUME_FUTEX_CLOCK_REALTIME 1 -/* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29. */ -#define __ASSUME_AT_RANDOM 1 - /* Support for preadv and pwritev was added in 2.6.30. */ #define __ASSUME_PREADV 1 #define __ASSUME_PWRITEV 1 -- cgit 1.4.1