commit 83ae8287c1c3009459ff29241b647ff61363b22c Author: Noah Goldstein Date: Tue Feb 15 08:18:15 2022 -0600 x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ #29127] Re-cherry-pick commit c627209832 for strcmp-avx2.S change which was omitted in intial cherry pick because at the time this bug was not present on release branch. Fixes BZ #29127. In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would call strcmp-avx2 and wcscmp-avx2 respectively. This would have not checks around vzeroupper and would trigger spurious aborts. This commit fixes that. test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on AVX2 machines with and without RTM. Co-authored-by: H.J. Lu (cherry picked from commit c6272098323153db373f2986c67786ea8c85f1cf) diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S index aa91f6e48a0e1ce5..a9806daadbbfd18b 100644 --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S @@ -345,10 +345,10 @@ L(one_or_less): movq %LOCALE_REG, %rdx # endif jb L(ret_zero) -# ifdef USE_AS_WCSCMP /* 'nbe' covers the case where length is negative (large unsigned). */ - jnbe __wcscmp_avx2 + jnbe OVERFLOW_STRCMP +# ifdef USE_AS_WCSCMP movl (%rdi), %edx xorl %eax, %eax cmpl (%rsi), %edx @@ -357,10 +357,6 @@ L(one_or_less): negl %eax orl $1, %eax # else - /* 'nbe' covers the case where length is negative (large - unsigned). */ - - jnbe __strcmp_avx2 movzbl (%rdi), %eax movzbl (%rsi), %ecx TOLOWER_gpr (%rax, %eax)