diff options
Diffstat (limited to 'x86-Fix-__wcsncmp_avx2-in-strcmp-avx2.S-BZ-28755.patch')
| -rw-r--r-- | x86-Fix-__wcsncmp_avx2-in-strcmp-avx2.S-BZ-28755.patch | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/x86-Fix-__wcsncmp_avx2-in-strcmp-avx2.S-BZ-28755.patch b/x86-Fix-__wcsncmp_avx2-in-strcmp-avx2.S-BZ-28755.patch new file mode 100644 index 0000000..7b8597b --- /dev/null +++ b/x86-Fix-__wcsncmp_avx2-in-strcmp-avx2.S-BZ-28755.patch @@ -0,0 +1,40 @@ +From ddf0992cf57a93200e0c782e2a94d0733a5a0b87 Mon Sep 17 00:00:00 2001 +From: Noah Goldstein <goldstein.w.n@gmail.com> +Date: Sun, 9 Jan 2022 16:02:21 -0600 +Subject: [PATCH] x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755] + +Fixes [BZ# 28755] for wcsncmp by redirecting length >= 2^56 to +__wcscmp_avx2. For x86_64 this covers the entire address range so any +length larger could not possibly be used to bound `s1` or `s2`. + +test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass. + +Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> +--- + sysdeps/x86_64/multiarch/strcmp-avx2.S | 10 ++++++++++ + 1 file changed, 10 insertions(+) + +diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S +index a45f9d2..9c73b58 100644 +--- a/sysdeps/x86_64/multiarch/strcmp-avx2.S ++++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S +@@ -87,6 +87,16 @@ ENTRY (STRCMP) + je L(char0) + jb L(zero) + # ifdef USE_AS_WCSCMP ++# ifndef __ILP32__ ++ movq %rdx, %rcx ++ /* Check if length could overflow when multiplied by ++ sizeof(wchar_t). Checking top 8 bits will cover all potential ++ overflow cases as well as redirect cases where its impossible to ++ length to bound a valid memory region. In these cases just use ++ 'wcscmp'. */ ++ shrq $56, %rcx ++ jnz __wcscmp_avx2 ++# endif + /* Convert units: from wide to byte char. */ + shl $2, %RDX_LP + # endif +-- +1.8.3.1 + |