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author | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2024-02-15 07:40:56 -0500 |
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committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2024-02-28 08:35:10 -0500 |
commit | bf9688e623262c5fa9f91e4de0e84db45025076f (patch) | |
tree | a606a0976a7980421055f08ec3b6ad7c67eda1aa /io | |
parent | b53e73ea809adac9be6b7808299f6741ea798e50 (diff) | |
download | glibc-bf9688e623262c5fa9f91e4de0e84db45025076f.tar.gz glibc-bf9688e623262c5fa9f91e4de0e84db45025076f.tar.xz glibc-bf9688e623262c5fa9f91e4de0e84db45025076f.zip |
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>
Diffstat (limited to 'io')
-rw-r--r-- | io/Makefile | 2 | ||||
-rw-r--r-- | io/tst-read-zero.c | 39 |
2 files changed, 41 insertions, 0 deletions
diff --git a/io/Makefile b/io/Makefile index 54d950d51f..19932d50f7 100644 --- a/io/Makefile +++ b/io/Makefile @@ -215,6 +215,7 @@ tests := \ tst-openat \ tst-posix_fallocate \ tst-posix_fallocate64 \ + tst-read-zero \ tst-readlinkat \ tst-renameat \ tst-stat \ @@ -290,6 +291,7 @@ CFLAGS-read.c += -fexceptions -fasynchronous-unwind-tables $(config-cflags-wno-i CFLAGS-write.c += -fexceptions -fasynchronous-unwind-tables $(config-cflags-wno-ignored-attributes) CFLAGS-close.c += -fexceptions -fasynchronous-unwind-tables CFLAGS-lseek64.c += $(config-cflags-wno-ignored-attributes) +CFLAGS-tst-read-zero.c += $(no-fortify-source),-D_FORTIFY_SOURCE=$(supported-fortify) CFLAGS-test-stat.c += -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE CFLAGS-test-lfs.c += -D_LARGEFILE64_SOURCE diff --git a/io/tst-read-zero.c b/io/tst-read-zero.c new file mode 100644 index 0000000000..8d1d30a543 --- /dev/null +++ b/io/tst-read-zero.c @@ -0,0 +1,39 @@ +/* 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> |