b4a002889d
DAMON debugfs interface users were able to trigger warning by writing
some files with arbitrarily large 'count' parameter. The issue is fixed
with commit db7a347b26fe ("mm/damon/dbgfs: use '__GFP_NOWARN' for
user-specified size buffer allocation"). This commit adds a test case
for the issue in DAMON selftests to avoid future regressions.
Link: https://lkml.kernel.org/r/20211201150440.1088-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
40 lines
711 B
C
40 lines
711 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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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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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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