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// SPDX-License-Identifier: GPL-2.0
/*
* Author: SeongJae Park <sj@kernel.org>
*/
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#pragma GCC diagnostic push
#if __GNUC__ >= 11 && __GNUC_MINOR__ >= 1
/* Ignore read(2) overflow and write(2) overread compile warnings */
#pragma GCC diagnostic ignored "-Wstringop-overread"
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#endif
void write_read_with_huge_count(char *file)
{
int filedesc = open(file, O_RDWR);
char buf[25];
int ret;
printf("%s %s\n", __func__, file);
if (filedesc < 0) {
fprintf(stderr, "failed opening %s\n", file);
exit(1);
}
write(filedesc, "", 0xfffffffful);
perror("after write: ");
ret = read(filedesc, buf, 0xfffffffful);
perror("after read: ");
close(filedesc);
}
#pragma GCC diagnostic pop
int main(int argc, char *argv[])
{
if (argc != 2) {
fprintf(stderr, "Usage: %s <file>\n", argv[0]);
exit(1);
}
write_read_with_huge_count(argv[1]);
return 0;
}
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