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| author | Noah Goldstein <goldstein.w.n@gmail.com> | 2021-12-03 15:29:25 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2021-12-03 21:14:11 -0800 |
| commit | 4df1fa6ddc8925a75f3da644d5da3bb16eb33f02 (patch) | |
| tree | d21bb734dffee2cff4502c8d9383f31f8960d58e | |
| parent | 23c77f60181eb549f11ec2f913b4270af29eee38 (diff) | |
| download | glibc-4df1fa6ddc8925a75f3da644d5da3bb16eb33f02.tar.gz glibc-4df1fa6ddc8925a75f3da644d5da3bb16eb33f02.tar.xz glibc-4df1fa6ddc8925a75f3da644d5da3bb16eb33f02.zip | |
x86-64: Use notl in EVEX strcmp [BZ #28646]
Must use notl %edi here as lower bits are for CHAR comparisons potentially out of range thus can be 0 without indicating mismatch. This fixes BZ #28646. Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
| -rw-r--r-- | string/test-strcmp.c | 28 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcmp-evex.S | 14 |
2 files changed, 36 insertions, 6 deletions
diff --git a/string/test-strcmp.c b/string/test-strcmp.c index 77ae73110f..42178a260b 100644 --- a/string/test-strcmp.c +++ b/string/test-strcmp.c @@ -23,6 +23,7 @@ # define TEST_NAME "strcmp" #endif #include "test-string.h" +#include <support/test-driver.h> #ifdef WIDE # include <wchar.h> @@ -390,6 +391,32 @@ check2 (void) } } +static void +check3 (void) +{ + size_t size = 0xd000 + 0x4000; + CHAR *s1, *s2; + CHAR *buffer1 = mmap (NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, -1, 0); + CHAR *buffer2 = mmap (NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, -1, 0); + if (buffer1 == MAP_FAILED || buffer1 == MAP_FAILED) + error (EXIT_UNSUPPORTED, errno, "mmap failed"); + + s1 = (CHAR *) (buffer1 + 0x8f8 / sizeof (CHAR)); + s2 = (CHAR *) (buffer2 + 0xcff3 / sizeof (CHAR)); + + STRCPY(s1, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/util/PathDocFileFactory.java")); + STRCPY(s2, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/taglets/ThrowsTaglet.java")); + + int exp_result = SIMPLE_STRCMP (s1, s2); + FOR_EACH_IMPL (impl, 0) + check_result (impl, s1, s2, exp_result); + + munmap ((void *) buffer1, size); + munmap ((void *) buffer2, size); +} + int test_main (void) { @@ -398,6 +425,7 @@ test_main (void) test_init (); check(); check2 (); + check3 (); printf ("%23s", ""); FOR_EACH_IMPL (impl, 0) diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S index 0bea318abd..b68e1f7a1e 100644 --- a/sysdeps/x86_64/multiarch/strcmp-evex.S +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S @@ -646,12 +646,13 @@ L(loop_cross_page): in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */ VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4} kmovd %k3, %edi + /* Must use notl %edi here as lower bits are for CHAR + comparisons potentially out of range thus can be 0 without + indicating mismatch. */ + notl %edi # ifdef USE_AS_WCSCMP /* Don't use subl since it is the upper 8 bits of EDI below. */ - notl %edi andl $0xff, %edi -# else - incl %edi # endif # ifdef USE_AS_WCSCMP @@ -733,12 +734,13 @@ L(loop_cross_page_2_vec): in YMM1 and 32 bytes at (VEC_SIZE * 3)(%rdx, %r10). */ VPCMP $0, (VEC_SIZE * 3)(%rdx, %r10), %YMM1, %k3{%k4} kmovd %k3, %edi + /* Must use notl %edi here as lower bits are for CHAR + comparisons potentially out of range thus can be 0 without + indicating mismatch. */ + notl %edi # ifdef USE_AS_WCSCMP /* Don't use subl since it is the upper 8 bits of EDI below. */ - notl %edi andl $0xff, %edi -# else - incl %edi # endif # ifdef USE_AS_WCSCMP |