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Remove __ASSUME_AT_RANDOM.

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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.
This commit is contained in:
Joseph Myers 2014-06-20 20:02:34 +00:00
parent a2a76afe91
commit 4a103975c4
3 changed files with 13 additions and 44 deletions
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6
ChangeLog
View File

@ -1,5 +1,11 @@
2014-06-20 Joseph Myers <joseph@codesourcery.com>
* 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)

48
sysdeps/unix/sysv/linux/dl-osinfo.h
View File

@ -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;
}

3
sysdeps/unix/sysv/linux/kernel-features.h
View File

@ -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