glibc/io/tst-read-zero.c
Siddhesh Poyarekar bf9688e623 cdefs: Drop access attribute for _FORTIFY_SOURCE=3 (BZ #31383)
When passed a pointer to a zero-sized struct, the access attribute
without the third argument misleads -Wstringop-overflow diagnostics to
think that a function is writing 1 byte into the zero-sized structs.
The attribute doesn't add that much value in this context, so drop it
completely for _FORTIFY_SOURCE=3.

Resolves: BZ #31383
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-02-28 08:35:10 -05:00

40 lines
1.3 KiB
C

/* read smoke test for 0-sized structures.
Copyright The GNU Toolchain Authors.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Zero-sized structures should not result in any overflow warnings or
errors when fortification is enabled. */
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <support/check.h>
int
do_test (void)
{
struct test_st {} test_info[16];
int fd = open ("/dev/zero", O_RDONLY, 0);
if (fd == -1)
FAIL_UNSUPPORTED ("Unable to open /dev/zero: %m");
TEST_VERIFY_EXIT (read (fd, test_info, sizeof(test_info)) == 0);
return 0;
}
#include <support/test-driver.c>