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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-01-03 12:19:12 -0200 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-01-03 14:24:53 -0200 |
| commit | 8dad72997af2be0dc72a4bc7dbe82d85c90334fc (patch) | |
| tree | dc5d83dfccb1e2fba0354ecc9f13a538d47fbb42 /sysdeps | |
| parent | d4d629e6187e33050902824a94498b6096eacac9 (diff) | |
| download | glibc-8dad72997af2be0dc72a4bc7dbe82d85c90334fc.zip glibc-8dad72997af2be0dc72a4bc7dbe82d85c90334fc.tar.gz glibc-8dad72997af2be0dc72a4bc7dbe82d85c90334fc.tar.bz2 | |
Fix x86 strncat optimized implementation for large sizes
Similar to BZ#19387, BZ#21014, and BZ#20971, both x86 sse2 strncat
optimized assembly implementations do not handle the size overflow
correctly.
The x86_64 one is in fact an issue with strcpy-sse2-unaligned, but
that is triggered also with strncat optimized implementation.
This patch uses a similar strategy used on 3daef2c8ee4df2, where
saturared math is used for overflow case.
Checked on x86_64-linux-gnu and i686-linux-gnu. It fixes BZ #19390.
[BZ #19390]
* string/test-strncat.c (test_main): Add tests with SIZE_MAX as
maximum string size.
* sysdeps/i386/i686/multiarch/strcat-sse2.S (STRCAT): Avoid overflow
in pointer addition.
* sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S (STRCPY):
Likewise.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/i386/i686/multiarch/strcat-sse2.S | 2 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/sysdeps/i386/i686/multiarch/strcat-sse2.S b/sysdeps/i386/i686/multiarch/strcat-sse2.S index 145ae66..6359c73 100644 --- a/sysdeps/i386/i686/multiarch/strcat-sse2.S +++ b/sysdeps/i386/i686/multiarch/strcat-sse2.S @@ -227,6 +227,8 @@ L(StartStrcpyPart): pxor %xmm0, %xmm0 # ifdef USE_AS_STRNCAT add %ecx, %ebx + sbb %edx, %edx + or %edx, %ebx # endif sub %ecx, %eax jmp L(Unalign16Both) diff --git a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S index c038043..6a5ab7a 100644 --- a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S +++ b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S @@ -99,6 +99,8 @@ L(Unalign16Both): sub %rcx, %rdi # ifdef USE_AS_STRNCPY add %rcx, %r8 + sbb %rcx, %rcx + or %rcx, %r8 # endif mov $16, %rcx movdqa (%rsi, %rcx), %xmm1 |