diff options
| -rw-r--r-- | string/test-strncmp.c | 23 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcmp-avx2.S | 1 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcmp-evex.S | 1 |
3 files changed, 25 insertions, 0 deletions
diff --git a/string/test-strncmp.c b/string/test-strncmp.c index 831cb77..df7cea4 100644 --- a/string/test-strncmp.c +++ b/string/test-strncmp.c @@ -424,6 +424,28 @@ check3 (void) } static void +check4 (void) +{ + /* To trigger bug 28895; We need 1) both s1 and s2 to be within 32 bytes of + the end of the page. 2) For there to be no mismatch/null byte before the + first page cross. 3) For length (`n`) to be large enough for one string to + cross the page. And 4) for there to be either mismatch/null bytes before + the start of the strings. */ + + size_t size = 10; + size_t addr_mask = (getpagesize () - 1) ^ (sizeof (CHAR) - 1); + CHAR *s1 = (CHAR *)(buf1 + (addr_mask & 0xffa)); + CHAR *s2 = (CHAR *)(buf2 + (addr_mask & 0xfed)); + int exp_result; + + STRCPY (s1, L ("tst-tlsmod%")); + STRCPY (s2, L ("tst-tls-manydynamic73mod")); + exp_result = SIMPLE_STRNCMP (s1, s2, size); + FOR_EACH_IMPL (impl, 0) + check_result (impl, s1, s2, size, exp_result); +} + +static void check_overflow (void) { size_t i, j, of_mask, of_idx; @@ -546,6 +568,7 @@ test_main (void) check1 (); check2 (); check3 (); + check4 (); printf ("%23s", ""); FOR_EACH_IMPL (impl, 0) diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S index 99e5349..07a5a2c 100644 --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S @@ -661,6 +661,7 @@ L(ret8): # ifdef USE_AS_STRNCMP .p2align 4,, 10 L(return_page_cross_end_check): + andl %r10d, %ecx tzcntl %ecx, %ecx leal -VEC_SIZE(%rax, %rcx), %ecx cmpl %ecx, %edx diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S index 6f42e31..56d8c11 100644 --- a/sysdeps/x86_64/multiarch/strcmp-evex.S +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S @@ -689,6 +689,7 @@ L(ret8): # ifdef USE_AS_STRNCMP .p2align 4,, 10 L(return_page_cross_end_check): + andl %r10d, %ecx tzcntl %ecx, %ecx leal -VEC_SIZE(%rax, %rcx, SIZE_OF_CHAR), %ecx # ifdef USE_AS_WCSCMP |