Current optimized memchr for x86_64 does for input arguments pointers
module 64 in range of [49,63] if there is no searchr char in the rest
of 64-byte block a pointer addition which might overflow:
* sysdeps/x86_64/memchr.S
77 .p2align 4
78 L(unaligned_no_match):
79 add %rcx, %rdx
Add (uintptr_t)s % 16 to n in %rdx.
80 sub $16, %rdx
81 jbe L(return_null)
This patch fixes by adding a saturated math that sets a maximum pointer
value if it overflows (UINTPTR_MAX).
Checked on x86_64-linux-gnu and powerpc64-linux-gnu.
[BZ# 19387]
* sysdeps/x86_64/memchr.S (memchr): Avoid overflow in pointer
addition.
* string/test-memchr.c (do_test): Remove alignment limitation.
(test_main): Add test that trigger BZ# 19387.
Current optimized powercp64/power7 memchr uses a strategy to check for
p versus align(p+n) (where 'p' is the input char pointer and n the
maximum size to check for the byte) without taking care for possible
overflow on the pointer addition in case of large 'n'.
It was triggered by 3038145ca2 where default rawmemchr (used to
created ppc64 rawmemchr in ifunc selection) now uses memchr (p, c, (size_t)-1)
on its implementation.
This patch fixes it by implement a satured addition where overflows
sets the maximum pointer size to UINTPTR_MAX.
Checked on powerpc64le-linux-gnu.
[BZ# 20971]
* sysdeps/powerpc/powerpc64/power7/memchr.S (__memchr): Avoid
overflow in pointer addition.
* string/test-memchr.c (do_test): Add an argument to pass as
the size on memchr.
(test_main): Add check for SIZE_MAX.
* string/test-strlen.c: New file.
* string/test-string.h: New file.
* string/test-strcmp.c: New file.
* string/test-strchr.c: New file.
* string/test-strrchr.c: New file.
* string/test-strcpy.c: New file.
* string/test-stpcpy.c: New file.
* string/test-strncpy.c: New file.
* string/test-stpncpy.c: New file.
* string/test-strpbrk.c: New file.
* string/test-strcspn.c: New file.
* string/test-strspn.c: New file.
* string/test-strcat.c: New file.
* string/test-strncmp.c: New file.
* string/test-memchr.c: New file.
* string/test-memcmp.c: New file.
* string/test-memset.c: New file.
* string/test-memcpy.c: New file.
* string/test-mempcpy.c: New file.
* string/test-memmove.c: New file.
* string/Makefile (strop-tests): New variable.
(tests): Add strop-tests.
(distribute): Add test-string.h.
Joseph Myers
Adhemerval Zanella
Stefan Liebler
Allan McRae
Siddhesh Poyarekar
H.J. Lu
Paul Eggert
Jakub Jelinek
Roland McGrath
Ulrich Drepper