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author | Muhammad Usama Anjum <usama.anjum@collabora.com> | 2024-01-25 18:46:07 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-23 02:38:55 +0300 |
commit | c23ea61726d57d11d5c16a0b7943da85b7bd9f3f (patch) | |
tree | 0e6f6c99b4a0810a107f51abdf6c56636de000c6 /tools/testing/selftests/mm | |
parent | 7d695b1c3695b4d0417674f15e2ccde12a272e16 (diff) | |
download | linux-c23ea61726d57d11d5c16a0b7943da85b7bd9f3f.tar.xz |
selftests/mm: protection_keys: save/restore nr_hugepages settings
Save and restore nr_hugepages before changing it during the test. A test
should not change system wide settings.
Link: https://lkml.kernel.org/r/20240125154608.720072-5-usama.anjum@collabora.com
Fixes: 5f23f6d082a9 ("x86/pkeys: Add self-tests")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools/testing/selftests/mm')
-rw-r--r-- | tools/testing/selftests/mm/protection_keys.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c index 48dc151f8fca..f822ae31af22 100644 --- a/tools/testing/selftests/mm/protection_keys.c +++ b/tools/testing/selftests/mm/protection_keys.c @@ -54,6 +54,7 @@ int test_nr; u64 shadow_pkey_reg; int dprint_in_signal; char dprint_in_signal_buffer[DPRINT_IN_SIGNAL_BUF_SIZE]; +char buf[256]; void cat_into_file(char *str, char *file) { @@ -1744,6 +1745,38 @@ void pkey_setup_shadow(void) shadow_pkey_reg = __read_pkey_reg(); } +void restore_settings_atexit(void) +{ + cat_into_file(buf, "/proc/sys/vm/nr_hugepages"); +} + +void save_settings(void) +{ + int fd; + int err; + + if (geteuid()) + return; + + fd = open("/proc/sys/vm/nr_hugepages", O_RDONLY); + if (fd < 0) { + fprintf(stderr, "error opening\n"); + perror("error: "); + exit(__LINE__); + } + + /* -1 to guarantee leaving the trailing \0 */ + err = read(fd, buf, sizeof(buf)-1); + if (err < 0) { + fprintf(stderr, "error reading\n"); + perror("error: "); + exit(__LINE__); + } + + atexit(restore_settings_atexit); + close(fd); +} + int main(void) { int nr_iterations = 22; @@ -1751,6 +1784,7 @@ int main(void) srand((unsigned int)time(NULL)); + save_settings(); setup_handlers(); printf("has pkeys: %d\n", pkeys_supported); |