56 lines
1.6 KiB
Diff
56 lines
1.6 KiB
Diff
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From c6272098323153db373f2986c67786ea8c85f1cf Mon Sep 17 00:00:00 2001
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From: Noah Goldstein <goldstein.w.n@gmail.com>
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Date: Tue, 15 Feb 2022 08:18:15 -0600
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Subject: [PATCH] x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ
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#28896]
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Content-type: text/plain; charset=UTF-8
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In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would
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call strcmp-avx2 and wcscmp-avx2 respectively. This would have
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not checks around vzeroupper and would trigger spurious
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aborts. This commit fixes that.
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test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on
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AVX2 machines with and without RTM.
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Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
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---
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sysdeps/x86_64/multiarch/strcmp-avx2.S | 8 ++------
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1 file changed, 2 insertions(+), 6 deletions(-)
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Conflicts:
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sysdeps/x86_64/multiarch/strcmp-avx2.S
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(split into two patches due to upstream bug differences)
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diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
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index 28cc98b6..e267c6cb 100644
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--- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
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+++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
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@@ -345,10 +345,10 @@ L(one_or_less):
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movq %LOCALE_REG, %rdx
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# endif
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jb L(ret_zero)
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-# ifdef USE_AS_WCSCMP
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/* 'nbe' covers the case where length is negative (large
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unsigned). */
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- jnbe __wcscmp_avx2
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+ jnbe OVERFLOW_STRCMP
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+# ifdef USE_AS_WCSCMP
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movl (%rdi), %edx
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xorl %eax, %eax
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cmpl (%rsi), %edx
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@@ -357,10 +357,6 @@ L(one_or_less):
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negl %eax
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orl $1, %eax
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# else
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- /* 'nbe' covers the case where length is negative (large
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- unsigned). */
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-
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- jnbe __strcmp_avx2
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movzbl (%rdi), %eax
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movzbl (%rsi), %ecx
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TOLOWER_gpr (%rax, %eax)
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--
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GitLab
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