Merge tag 'mm-hotfixes-stable-2024-04-26-13-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "11 hotfixes. 8 are cc:stable and the remaining 3 (nice ratio!) address
  post-6.8 issues or aren't considered suitable for backporting.

  All except one of these are for MM. I see no particular theme - it's
  singletons all over"

* tag 'mm-hotfixes-stable-2024-04-26-13-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/hugetlb: fix DEBUG_LOCKS_WARN_ON(1) when dissolve_free_hugetlb_folio()
  selftests: mm: protection_keys: save/restore nr_hugepages value from launch script
  stackdepot: respect __GFP_NOLOCKDEP allocation flag
  hugetlb: check for anon_vma prior to folio allocation
  mm: zswap: fix shrinker NULL crash with cgroup_disable=memory
  mm: turn folio_test_hugetlb into a PageType
  mm: support page_mapcount() on page_has_type() pages
  mm: create FOLIO_FLAG_FALSE and FOLIO_TYPE_OPS macros
  mm/hugetlb: fix missing hugetlb_lock for resv uncharge
  selftests: mm: fix unused and uninitialized variable warning
  selftests/harness: remove use of LINE_MAX

5 files changed, 12 insertions, 43 deletions

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index ba3ddeda24bf..d98702b6955d 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -56,7 +56,6 @@
 #include <asm/types.h>
 #include <ctype.h>
 #include <errno.h>
-#include <limits.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -1159,7 +1158,7 @@ void __run_test(struct __fixture_metadata *f,
 		struct __test_metadata *t)
 {
 	struct __test_xfail *xfail;
-	char test_name[LINE_MAX];
+	char *test_name;
 	const char *diagnostic;
 
 	/* reset test struct */
@@ -1167,8 +1166,12 @@ void __run_test(struct __fixture_metadata *f,
 	t->trigger = 0;
 	memset(t->results->reason, 0, sizeof(t->results->reason));
 
-	snprintf(test_name, sizeof(test_name), "%s%s%s.%s",
-		 f->name, variant->name[0] ? "." : "", variant->name, t->name);
+	if (asprintf(&test_name, "%s%s%s.%s", f->name,
+		variant->name[0] ? "." : "", variant->name, t->name) == -1) {
+		ksft_print_msg("ERROR ALLOCATING MEMORY\n");
+		t->exit_code = KSFT_FAIL;
+		_exit(t->exit_code);
+	}
 
 	ksft_print_msg(" RUN           %s ...\n", test_name);
 
@@ -1206,6 +1209,7 @@ void __run_test(struct __fixture_metadata *f,
 
 	ksft_test_result_code(t->exit_code, test_name,
 			      diagnostic ? "%s" : NULL, diagnostic);
+	free(test_name);
 }
 
 static int test_harness_run(int argc, char **argv)
diff --git a/tools/testing/selftests/mm/mdwe_test.c b/tools/testing/selftests/mm/mdwe_test.c
index 200bedcdc32e..1e01d3ddc11c 100644
--- a/tools/testing/selftests/mm/mdwe_test.c
+++ b/tools/testing/selftests/mm/mdwe_test.c
@@ -7,6 +7,7 @@
 #include <linux/mman.h>
 #include <linux/prctl.h>
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/auxv.h>
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 374a308174d2..48dc151f8fca 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -54,7 +54,6 @@ 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)
 {
@@ -1745,42 +1744,6 @@ void pkey_setup_shadow(void)
 	shadow_pkey_reg = __read_pkey_reg();
 }
 
-pid_t parent_pid;
-
-void restore_settings_atexit(void)
-{
-	if (parent_pid == getpid())
-		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__);
-	}
-
-	parent_pid = getpid();
-	atexit(restore_settings_atexit);
-	close(fd);
-}
-
 int main(void)
 {
 	int nr_iterations = 22;
@@ -1788,7 +1751,6 @@ int main(void)
 
 	srand((unsigned int)time(NULL));
 
-	save_settings();
 	setup_handlers();
 
 	printf("has pkeys: %d\n", pkeys_supported);
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index c2c542fe7b17..4bdb3a0c7a60 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -385,6 +385,7 @@ CATEGORY="ksm_numa" run_test ./ksm_tests -N -m 0
 CATEGORY="ksm" run_test ./ksm_functional_tests
 
 # protection_keys tests
+nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
 if [ -x ./protection_keys_32 ]
 then
 	CATEGORY="pkey" run_test ./protection_keys_32
@@ -394,6 +395,7 @@ if [ -x ./protection_keys_64 ]
 then
 	CATEGORY="pkey" run_test ./protection_keys_64
 fi
+echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages
 
 if [ -x ./soft-dirty ]
 then
diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index 6c988bd2f335..d3c7f5fb3e7b 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -300,7 +300,7 @@ int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, int *fd,
 		char **addr)
 {
 	size_t i;
-	int dummy;
+	int __attribute__((unused)) dummy = 0;
 
 	srand(time(NULL));