diff options
Diffstat (limited to 'tools/testing/selftests/mm/protection_keys.c')
| -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 48dc151f8fca8..f822ae31af22e 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); |