eff6aa17aa
When testing overflow and overread, there is no need to keep unnecessary
compilation warnings, we should simply ignore them.
The motivation for this patch is to eliminate the compilation warning,
maybe one day we will compile the kernel with "-Werror -Wall", at which
point this compilation warning will turn into a compilation error, we
should fix this error in advance.
How to reproduce the problem (with gcc-11.3.1):
$ make -C tools/testing/selftests/
...
warning: `write' reading 4294967295 bytes from a region of size 1
[-Wstringop-overread]
warning: `read' writing 4294967295 bytes into a region of size 25
overflows the destination [-Wstringop-overflow=]
"-Wno-stringop-overread" is supported at least in gcc-11.1.0.
Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d14c547abd484d3540b692bb8048c4a6efe92c8b
Link: https://lkml.kernel.org/r/tencent_51C4ACA8CB3895C2D7F35178440283602107@qq.com
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
49 lines
992 B
C
49 lines
992 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Author: SeongJae Park <sj@kernel.org>
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*/
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#include <fcntl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stdio.h>
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#pragma GCC diagnostic push
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#if __GNUC__ >= 11 && __GNUC_MINOR__ >= 1
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/* Ignore read(2) overflow and write(2) overread compile warnings */
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#pragma GCC diagnostic ignored "-Wstringop-overread"
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#pragma GCC diagnostic ignored "-Wstringop-overflow"
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#endif
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void write_read_with_huge_count(char *file)
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{
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int filedesc = open(file, O_RDWR);
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char buf[25];
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int ret;
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printf("%s %s\n", __func__, file);
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if (filedesc < 0) {
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fprintf(stderr, "failed opening %s\n", file);
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exit(1);
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}
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write(filedesc, "", 0xfffffffful);
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perror("after write: ");
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ret = read(filedesc, buf, 0xfffffffful);
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perror("after read: ");
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close(filedesc);
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}
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#pragma GCC diagnostic pop
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int main(int argc, char *argv[])
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{
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if (argc != 2) {
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fprintf(stderr, "Usage: %s <file>\n", argv[0]);
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exit(1);
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}
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write_read_with_huge_count(argv[1]);
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return 0;
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}
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