stdlib: Remove attr_write from mbstows if dst is NULL [BZ: 29265]

mbstows is defined if dst is NULL and is defined to special cased if
dst is NULL so the fortify objsize check if incorrect in that case.

Tested on x86-64 linux.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This commit is contained in:
Noah Goldstein 2022-06-22 08:24:21 -07:00
parent dd06af4f81
commit 464d189b96
3 changed files with 21 additions and 5 deletions

View File

@ -373,6 +373,9 @@ CFLAGS-tst-qsort.c += $(stack-align-test-flags)
CFLAGS-tst-makecontext.c += -funwind-tables
CFLAGS-tst-makecontext2.c += $(stack-align-test-flags)
CFLAGS-testmb.c += -D_FORTIFY_SOURCE=2 -Wall -Werror
# Run a test on the header files we use.
tests-special += $(objpfx)isomac.out

View File

@ -96,6 +96,11 @@ extern size_t __mbstowcs_chk (wchar_t *__restrict __dst,
const char *__restrict __src,
size_t __len, size_t __dstlen) __THROW
__attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
extern size_t __REDIRECT_NTH (__mbstowcs_chk_nulldst,
(wchar_t *__restrict __dst,
const char *__restrict __src,
size_t __len), mbstowcs_chk)
__attr_access ((__read_only__, 2));
extern size_t __REDIRECT_NTH (__mbstowcs_alias,
(wchar_t *__restrict __dst,
const char *__restrict __src,
@ -108,16 +113,17 @@ extern size_t __REDIRECT_NTH (__mbstowcs_chk_warn,
__warnattr ("mbstowcs called with dst buffer smaller than len "
"* sizeof (wchar_t)");
__fortify_function size_t
__always_inline __fortify_function size_t
__NTH (mbstowcs (wchar_t *__restrict __dst, const char *__restrict __src,
size_t __len))
{
return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t),
__glibc_objsize (__dst),
__dst, __src, __len);
if (__builtin_constant_p (__dst == NULL) && __dst == NULL)
return __mbstowcs_chk_nulldst (__dst, __src, __len);
else
return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t),
__glibc_objsize (__dst), __dst, __src, __len);
}
extern size_t __wcstombs_chk (char *__restrict __dst,
const wchar_t *__restrict __src,
size_t __len, size_t __dstlen) __THROW

View File

@ -16,6 +16,13 @@ main (int argc, char *argv[])
lose = 1;
}
i = mbstowcs (NULL, "bar", 4);
if (!(i == 3 && w[1] == 'a'))
{
puts ("mbstowcs FAILED2!");
lose = 1;
}
mbstowcs (w, "blah", 5);
i = wcstombs (c, w, 10);
if (i != 4)