The patch titled
Subject: selftests/mm: protection_keys: save/restore nr_hugepages settings
has been added to the -mm mm-nonmm-unstable branch. Its filename is
selftests-mm-protection_keys-save-restore-nr_hugepages-settings.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-protection_keys-save-restore-nr_hugepages-settings.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Subject: selftests/mm: protection_keys: save/restore nr_hugepages settings
Date: Thu, 25 Jan 2024 20:46:07 +0500
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@xxxxxxxxxxxxx
Fixes: 5f23f6d082a9 ("x86/pkeys: Add self-tests")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/protection_keys.c | 34 +++++++++++++++++
1 file changed, 34 insertions(+)
--- a/tools/testing/selftests/mm/protection_keys.c~selftests-mm-protection_keys-save-restore-nr_hugepages-settings
+++ a/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);
_
Patches currently in -mm which might be from usama.anjum@xxxxxxxxxxxxx are
selftests-mm-mremap_test-fix-build-warning.patch
selftests-mm-switch-to-bash-from-sh.patch
selftests-mm-hugetlb_reparenting_test-do-not-unmount.patch
selftests-mm-run_vmtests-remove-sudo-and-conform-to-tap.patch
selftests-mm-save-and-restore-nr_hugepages-value.patch
selftests-mm-protection_keys-save-restore-nr_hugepages-settings.patch
selftests-mm-run_vmtestssh-add-missing-tests.patch
