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Fix size parameter comparisions.

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[BZ #13592]
There are several signed compares of the size argument, whereas
it really is unsigned.  Depending on situations e.g. a "memset(ptr, 0,
-1)" segfault (but for the wrong reasons, because jumping into nirvana)
or succeeds even.

In normal use this is harmless, as a size with signbit set indicates
more than half the address space which on x86_64 is impossible to
allocate, but as the size is used to index some jump tables this
potentially could have other unwanted side effects.
This commit is contained in:
Michael Matz 2012-04-05 10:48:14 +02:00 committed by Andreas Jaeger
parent 349fa79f55
commit e80d6f94e1
3 changed files with 16 additions and 11 deletions
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5
ChangeLog
View File

@ -1,3 +1,8 @@
2012-04-05 Michael Matz <matz@suse.de>
[BZ #13592]
* sysdeps/x86_64/memset.S: Fix size paramater comparisions.
2012-04-05 Andreas Jaeger <aj@suse.de>
[BZ #13908]

10
NEWS
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@ -15,11 +15,11 @@ Version 2.16
10110, 10135, 10140, 10210, 10346, 10545, 10716, 11174, 11322, 11365,
11451, 11494, 12047, 12340, 13058, 13525, 13526, 13527, 13528, 13529,
13530, 13531, 13532, 13533, 13547, 13551, 13552, 13553, 13555, 13559,
13566, 13583, 13618, 13637, 13656, 13658, 13673, 13691, 13695, 13704,
13706, 13726, 13738, 13760, 13761, 13786, 13792, 13806, 13824, 13840,
13841, 13844, 13846, 13851, 13852, 13854, 13871, 13879, 13883, 13892,
13908, 13910, 13911, 13912, 13913, 13915, 13916, 13917, 13918, 13919,
13920, 13921, 13926, 13928, 13938
13566, 13583, 13592, 13618, 13637, 13656, 13658, 13673, 13691, 13695,
13704, 13706, 13726, 13738, 13760, 13761, 13786, 13792, 13806, 13824,
13840, 13841, 13844, 13846, 13851, 13852, 13854, 13871, 13879, 13883,
13892, 13908, 13910, 13911, 13912, 13913, 13915, 13916, 13917, 13918,
13919, 13920, 13921, 13926, 13928, 13938
* ISO C11 support:

12
sysdeps/x86_64/memset.S
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@ -1,6 +1,6 @@
/* memset/bzero -- set memory area to CH/0
Optimized version for x86-64.
Copyright (C) 2002-2005, 2007, 2008, 2011 Free Software Foundation, Inc.
Copyright (C) 2002-2012 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
@ -52,7 +52,7 @@ L(ck2):
imul %r9,%rdx
L(now_dw_aligned):
cmp $0x90,%r8
jg L(ck_mem_ops_method)
ja L(ck_mem_ops_method)
L(now_dw_aligned_small):
add %r8,%rdi
#ifndef PIC
@ -604,7 +604,7 @@ L(aligned_now):
punpcklqdq %xmm0,%xmm0
cmp $0xb0,%r8 # 176
jge L(byte32sse2_pre)
jae L(byte32sse2_pre)
add %r8,%rdi
# ifndef PIC
@ -864,7 +864,7 @@ L(byte32sse2_pre):
mov __x86_64_shared_cache_size(%rip),%r9d # The largest cache size
cmp %r9,%r8
jg L(sse2_nt_move_pre)
ja L(sse2_nt_move_pre)
#jmp L(byte32sse2)
.balign 16
L(byte32sse2):
@ -880,7 +880,7 @@ L(byte32sse2):
movdqa %xmm0,0x70(%rdi)
lea 0x80(%rdi),%rdi
jge L(byte32sse2)
jae L(byte32sse2)
add %r8,%rdi
# ifndef PIC
lea L(SSExDx)(%rip),%r11
@ -914,7 +914,7 @@ L(sse2_nt_move):
movntdq %xmm0,0x70(%rdi)
lea 0x80(%rdi),%rdi
jge L(sse2_nt_move)
jae L(sse2_nt_move)
sfence
add %r8,%rdi
# ifndef PIC