From 9fef7039a7d04947bc89296ee0d187bc8d89b772 Mon Sep 17 00:00:00 2001 From: Noah Goldstein Date: Thu, 24 Mar 2022 15:50:33 -0500 Subject: [PATCH] x86: Fix fallback for wcsncmp_avx2 in strcmp-avx2.S [BZ #28896] Content-type: text/plain; charset=UTF-8 Overflow case for __wcsncmp_avx2_rtm should be __wcscmp_avx2_rtm not __wcscmp_avx2. commit ddf0992cf57a93200e0c782e2a94d0733a5a0b87 Author: Noah Goldstein Date: Sun Jan 9 16:02:21 2022 -0600 x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755] Set the wrong fallback function for `__wcsncmp_avx2_rtm`. It was set to fallback on to `__wcscmp_avx2` instead of `__wcscmp_avx2_rtm` which can cause spurious aborts. This change will need to be backported. All string/memory tests pass. Reviewed-by: H.J. Lu --- sysdeps/x86/tst-strncmp-rtm.c | 15 +++++++++++++++ sysdeps/x86_64/multiarch/strcmp-avx2.S | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c index aef9866c..ba6543be 100644 --- a/sysdeps/x86/tst-strncmp-rtm.c +++ b/sysdeps/x86/tst-strncmp-rtm.c @@ -70,6 +70,16 @@ function_overflow (void) return 1; } +__attribute__ ((noinline, noclone)) +static int +function_overflow2 (void) +{ + if (STRNCMP (string1, string2, SIZE_MAX >> 4) == 0) + return 0; + else + return 1; +} + static int do_test (void) { @@ -77,5 +87,10 @@ do_test (void) if (status != EXIT_SUCCESS) return status; status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow); + if (status != EXIT_SUCCESS) + return status; + status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow2); + if (status != EXIT_SUCCESS) + return status; return status; } diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S index 179cc0e3..782f9472 100644 --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S @@ -122,7 +122,7 @@ ENTRY(STRCMP) are cases where length is large enough that it can never be a bound on valid memory so just use wcscmp. */ shrq $56, %rcx - jnz __wcscmp_avx2 + jnz OVERFLOW_STRCMP leaq (, %rdx, 4), %rdx # endif -- GitLab