[PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[Hongfu Li]

This series is version 2 of the previous patch [0].  In v2, the changes are
split into two patches for easier review.
[0] https://lore.kernel.org/all/20260518082120.3890552-1-lihongfu@kylinos.cn/

The main changes in this series are to refactor shared tracing and assertion
helpers into a common file, unify both pkey selftests on pkey_assert() and 
per-test tracing for consistent diagnostics, and add missing mmap() return 
checks with MAP_FAILED used throughout for readability and consistency.

Hongfu Li (2):
  selftests/mm: Refactor pkey test helpers and unify assertions
  selftests/mm: add missing mmap() return checks in pkey tests

 tools/testing/selftests/mm/pkey-helpers.h     |  5 +-
 tools/testing/selftests/mm/pkey-powerpc.h     |  2 +-
 .../selftests/mm/pkey_sighandler_tests.c      | 20 ++--
 tools/testing/selftests/mm/pkey_util.c        | 81 +++++++++++++++
 tools/testing/selftests/mm/protection_keys.c  | 98 ++-----------------
 5 files changed, 109 insertions(+), 97 deletions(-)

---
v2:
- Update commit message
- Move shared tracing and assertion helpers to a common file,
  replace assert() with pkey_assert() in sighandler tests
- Drop assert() from main() in protection_keys.c and add a proper error
  message instead.
-- 
2.50.1

[PATCH v2 1/2] selftests/mm: refactor pkey test helpers and unify assertions

[Hongfu Li]

Move shared tracing and assertion helpers to a common file, then
convert the sighandler test to use pkey_assert() for consistent
diagnostic output, and add per-test tracing around test execution.

Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
---
 tools/testing/selftests/mm/pkey-helpers.h     |  5 +-
 .../selftests/mm/pkey_sighandler_tests.c      | 18 ++--
 tools/testing/selftests/mm/pkey_util.c        | 81 ++++++++++++++++++
 tools/testing/selftests/mm/protection_keys.c  | 82 -------------------
 4 files changed, 96 insertions(+), 90 deletions(-)

diff --git a/tools/testing/selftests/mm/pkey-helpers.h b/tools/testing/selftests/mm/pkey-helpers.h
index 7c29f075e40b..de9052386343 100644
--- a/tools/testing/selftests/mm/pkey-helpers.h
+++ b/tools/testing/selftests/mm/pkey-helpers.h
@@ -68,7 +68,10 @@ static inline void sigsafe_printf(const char *format, ...)
 #define dprintf3(args...) dprintf_level(3, args)
 #define dprintf4(args...) dprintf_level(4, args)
 
-extern void abort_hooks(void);
+void cat_into_file(char *str, char *file);
+void tracing_on(void);
+void tracing_off(void);
+void abort_hooks(void);
 #define pkey_assert(condition) do {		\
 	if (!(condition)) {			\
 		dprintf0("assert() at %s::%d test_nr: %d iteration: %d\n", \
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index 302fef54049c..a390d183ebdc 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -19,7 +19,6 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <signal.h>
-#include <assert.h>
 #include <stdlib.h>
 #include <sys/mman.h>
 #include <sys/types.h>
@@ -36,6 +35,10 @@ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 static siginfo_t siginfo = {0};
 
+int iteration_nr = 1;
+int test_nr;
+int dprint_in_signal;
+
 /*
  * We need to use inline assembly instead of glibc's syscall because glibc's
  * syscall will attempt to access the PLT in order to call a library function
@@ -302,7 +305,7 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)
 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
-	assert(stack != MAP_FAILED);
+	pkey_assert(stack != MAP_FAILED);
 
 	/* Allow access to MPK 0 and MPK 1 */
 	pkey_reg = pkey_reg_restrictive_default();
@@ -470,7 +473,7 @@ static void test_pkru_sigreturn(void)
 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
-	assert(stack != MAP_FAILED);
+	pkey_assert(stack != MAP_FAILED);
 
 	/*
 	 * Allow access to MPK 0 and MPK 2. The child thread (to be created
@@ -530,16 +533,17 @@ static void (*pkey_tests[])(void) = {
 
 int main(int argc, char *argv[])
 {
-	int i;
-
 	ksft_print_header();
 	ksft_set_plan(ARRAY_SIZE(pkey_tests));
 
 	if (!is_pkeys_supported())
 		ksft_exit_skip("pkeys not supported\n");
 
-	for (i = 0; i < ARRAY_SIZE(pkey_tests); i++)
-		(*pkey_tests[i])();
+	for (test_nr = 0; test_nr < ARRAY_SIZE(pkey_tests); test_nr++) {
+		tracing_on();
+		(*pkey_tests[test_nr])();
+		tracing_off();
+	}
 
 	ksft_finished();
 	return 0;
diff --git a/tools/testing/selftests/mm/pkey_util.c b/tools/testing/selftests/mm/pkey_util.c
index 255b332f7a08..a080d1dcc82d 100644
--- a/tools/testing/selftests/mm/pkey_util.c
+++ b/tools/testing/selftests/mm/pkey_util.c
@@ -2,9 +2,90 @@
 #define __SANE_USERSPACE_TYPES__
 #include <sys/syscall.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
 
 #include "pkey-helpers.h"
 
+void cat_into_file(char *str, char *file)
+{
+	int fd = open(file, O_RDWR);
+	int ret;
+
+	dprintf2("%s(): writing '%s' to '%s'\n", __func__, str, file);
+	if (fd < 0) {
+		fprintf(stderr, "error opening '%s'\n", str);
+		perror("error: ");
+		exit(__LINE__);
+	}
+
+	ret = write(fd, str, strlen(str));
+	if (ret != strlen(str)) {
+		perror("write to file failed");
+		fprintf(stderr, "filename: '%s' str: '%s'\n", file, str);
+		exit(__LINE__);
+	}
+	close(fd);
+}
+
+#if CONTROL_TRACING > 0
+static int warned_tracing;
+static int tracing_root_ok(void)
+{
+	if (geteuid() != 0) {
+		if (!warned_tracing)
+			fprintf(stderr, "WARNING: not run as root, "
+					"can not do tracing control\n");
+		warned_tracing = 1;
+		return 0;
+	}
+	return 1;
+}
+#endif
+
+void tracing_on(void)
+{
+#if CONTROL_TRACING > 0
+#define TRACEDIR "/sys/kernel/tracing"
+	char pidstr[32];
+
+	if (!tracing_root_ok())
+		return;
+
+	sprintf(pidstr, "%d", getpid());
+	cat_into_file("0", TRACEDIR "/tracing_on");
+	cat_into_file("\n", TRACEDIR "/trace");
+	if (1) {
+		cat_into_file("function_graph", TRACEDIR "/current_tracer");
+		cat_into_file("1", TRACEDIR "/options/funcgraph-proc");
+	} else {
+		cat_into_file("nop", TRACEDIR "/current_tracer");
+	}
+	cat_into_file(pidstr, TRACEDIR "/set_ftrace_pid");
+	cat_into_file("1", TRACEDIR "/tracing_on");
+	dprintf1("enabled tracing\n");
+#endif
+}
+
+void tracing_off(void)
+{
+#if CONTROL_TRACING > 0
+	if (!tracing_root_ok())
+		return;
+	cat_into_file("0", "/sys/kernel/tracing/tracing_on");
+#endif
+}
+
+void abort_hooks(void)
+{
+	fprintf(stderr, "running %s()...\n", __func__);
+	tracing_off();
+#ifdef SLEEP_ON_ABORT
+	sleep(SLEEP_ON_ABORT);
+#endif
+}
+
 int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
 {
 	int ret = syscall(SYS_pkey_alloc, flags, init_val);
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 2085982dba69..3c0cbf8f3eaa 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -61,88 +61,6 @@ noinline int read_ptr(int *ptr)
 	return *ptr;
 }
 
-static void cat_into_file(char *str, char *file)
-{
-	int fd = open(file, O_RDWR);
-	int ret;
-
-	dprintf2("%s(): writing '%s' to '%s'\n", __func__, str, file);
-	/*
-	 * these need to be raw because they are called under
-	 * pkey_assert()
-	 */
-	if (fd < 0) {
-		fprintf(stderr, "error opening '%s'\n", str);
-		perror("error: ");
-		exit(__LINE__);
-	}
-
-	ret = write(fd, str, strlen(str));
-	if (ret != strlen(str)) {
-		perror("write to file failed");
-		fprintf(stderr, "filename: '%s' str: '%s'\n", file, str);
-		exit(__LINE__);
-	}
-	close(fd);
-}
-
-#if CONTROL_TRACING > 0
-static int warned_tracing;
-static int tracing_root_ok(void)
-{
-	if (geteuid() != 0) {
-		if (!warned_tracing)
-			fprintf(stderr, "WARNING: not run as root, "
-					"can not do tracing control\n");
-		warned_tracing = 1;
-		return 0;
-	}
-	return 1;
-}
-#endif
-
-static void tracing_on(void)
-{
-#if CONTROL_TRACING > 0
-#define TRACEDIR "/sys/kernel/tracing"
-	char pidstr[32];
-
-	if (!tracing_root_ok())
-		return;
-
-	sprintf(pidstr, "%d", getpid());
-	cat_into_file("0", TRACEDIR "/tracing_on");
-	cat_into_file("\n", TRACEDIR "/trace");
-	if (1) {
-		cat_into_file("function_graph", TRACEDIR "/current_tracer");
-		cat_into_file("1", TRACEDIR "/options/funcgraph-proc");
-	} else {
-		cat_into_file("nop", TRACEDIR "/current_tracer");
-	}
-	cat_into_file(pidstr, TRACEDIR "/set_ftrace_pid");
-	cat_into_file("1", TRACEDIR "/tracing_on");
-	dprintf1("enabled tracing\n");
-#endif
-}
-
-static void tracing_off(void)
-{
-#if CONTROL_TRACING > 0
-	if (!tracing_root_ok())
-		return;
-	cat_into_file("0", "/sys/kernel/tracing/tracing_on");
-#endif
-}
-
-void abort_hooks(void)
-{
-	fprintf(stderr, "running %s()...\n", __func__);
-	tracing_off();
-#ifdef SLEEP_ON_ABORT
-	sleep(SLEEP_ON_ABORT);
-#endif
-}
-
 /*
  * This attempts to have roughly a page of instructions followed by a few
  * instructions that do a write, and another page of instructions.  That
-- 
2.50.1

[PATCH v2 2/2] selftests/mm: add missing mmap() return checks in pkey tests

[Hongfu Li]

Add missing checks against mmap() return value, replace (void *)-1
with MAP_FAILED for better readability and consistency.

In the unsupported pkeys CPU test path, replace assert() with an
explicit MAP_FAILED check that provides a clearer error message on
failure.

Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
---
 tools/testing/selftests/mm/pkey-powerpc.h        |  2 +-
 .../testing/selftests/mm/pkey_sighandler_tests.c |  2 ++
 tools/testing/selftests/mm/protection_keys.c     | 16 ++++++++++------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/mm/pkey-powerpc.h b/tools/testing/selftests/mm/pkey-powerpc.h
index 17bf2d1b0192..f482b1abcf55 100644
--- a/tools/testing/selftests/mm/pkey-powerpc.h
+++ b/tools/testing/selftests/mm/pkey-powerpc.h
@@ -126,7 +126,7 @@ static inline void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 p
 			size, prot, pkey);
 	pkey_assert(pkey < NR_PKEYS);
 	ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 
 	ret = syscall(__NR_subpage_prot, ptr, size, NULL);
 	if (ret) {
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
index a390d183ebdc..eb7893ac6ebf 100644
--- a/tools/testing/selftests/mm/pkey_sighandler_tests.c
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -320,6 +320,7 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)
 	/* Set up alternate signal stack that will use the default MPK */
 	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	pkey_assert(sigstack.ss_sp != MAP_FAILED);
 	sigstack.ss_flags = 0;
 	sigstack.ss_size = STACK_SIZE;
 
@@ -493,6 +494,7 @@ static void test_pkru_sigreturn(void)
 	/* Set up alternate signal stack that will use the default MPK */
 	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
 			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	pkey_assert(sigstack.ss_sp != MAP_FAILED);
 	sigstack.ss_flags = 0;
 	sigstack.ss_size = STACK_SIZE;
 
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 3c0cbf8f3eaa..ae474e65f3aa 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -585,7 +585,7 @@ static void *malloc_pkey_with_mprotect(long size, int prot, u16 pkey)
 			size, prot, pkey);
 	pkey_assert(pkey < NR_PKEYS);
 	ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
 	pkey_assert(!ret);
 	record_pkey_malloc(ptr, size, prot);
@@ -608,7 +608,7 @@ static void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
 	 */
 	size = ALIGN_UP(size, HPAGE_SIZE * 2);
 	ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	record_pkey_malloc(ptr, size, prot);
 	mprotect_pkey(ptr, size, prot, pkey);
 
@@ -688,7 +688,7 @@ static void *malloc_pkey_hugetlb(long size, int prot, u16 pkey)
 	size = ALIGN_UP(size, HPAGE_SIZE * 2);
 	pkey_assert(pkey < NR_PKEYS);
 	ptr = mmap(NULL, size, PROT_NONE, flags, -1, 0);
-	pkey_assert(ptr != (void *)-1);
+	pkey_assert(ptr != MAP_FAILED);
 	mprotect_pkey(ptr, size, prot, pkey);
 
 	record_pkey_malloc(ptr, size, prot);
@@ -717,7 +717,7 @@ static void *malloc_pkey(long size, int prot, u16 pkey)
 		pkey_assert(malloc_type < nr_malloc_types);
 
 		ret = pkey_malloc[malloc_type](size, prot, pkey);
-		pkey_assert(ret != (void *)-1);
+		pkey_assert(ret != MAP_FAILED);
 
 		malloc_type++;
 		if (malloc_type >= nr_malloc_types)
@@ -1135,6 +1135,7 @@ static void arch_force_pkey_reg_init(void)
 	 * doing the XSAVE size enumeration dance.
 	 */
 	buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+	pkey_assert(buf != MAP_FAILED);
 
 	/* These __builtins require compiling with -mxsave */
 
@@ -1693,7 +1694,10 @@ int main(void)
 		printf("running PKEY tests for unsupported CPU/OS\n");
 
 		ptr  = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-		assert(ptr != (void *)-1);
+		if (ptr == MAP_FAILED) {
+			perror("mmap");
+			return EXIT_FAILURE;
+		}
 		test_mprotect_pkey_on_unsupported_cpu(ptr, 1);
 		exit(0);
 	}
@@ -1706,5 +1710,5 @@ int main(void)
 		run_tests_once();
 
 	printf("done (all tests OK)\n");
-	return 0;
+	return EXIT_SUCCESS;
 }
-- 
2.50.1

Re: [PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[Andrew Morton]

On Mon, 25 May 2026 15:30:24 +0800 Hongfu Li <lihongfu@kylinos.cn> wrote:

> This series is version 2 of the previous patch [0].  In v2, the changes are
> split into two patches for easier review.
> [0] https://lore.kernel.org/all/20260518082120.3890552-1-lihongfu@kylinos.cn/
> 
> The main changes in this series are to refactor shared tracing and assertion
> helpers into a common file, unify both pkey selftests on pkey_assert() and 
> per-test tracing for consistent diagnostics, and add missing mmap() return 
> checks with MAP_FAILED used throughout for readability and consistency.

Thanks.  AI review seems to have found a legitimate problem:
	https://sashiko.dev/#/patchset/20260525073026.27594-1-lihongfu@kylinos.cn

Re: [PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[Hongfu Li]

> > This series is version 2 of the previous patch [0].  In v2, the changes are
> > split into two patches for easier review.
> > [0] https://lore.kernel.org/all/20260518082120.3890552-1-lihongfu@kylinos.cn/
> > 
> > The main changes in this series are to refactor shared tracing and assertion
> > helpers into a common file, unify both pkey selftests on pkey_assert() and 
> > per-test tracing for consistent diagnostics, and add missing mmap() return 
> > checks with MAP_FAILED used throughout for readability and consistency.
> 
> Thanks.  AI review seems to have found a legitimate problem:
> 	https://sashiko.dev/#/patchset/20260525073026.27594-1-lihongfu@kylinos.cn

Thanks. I'll go through the problem reported by the AI review and make
corresponding fixes in v2.

Best regards,
Hongfu

Re: [PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[Lorenzo Stoakes]

On Tue, May 26, 2026 at 03:05:18PM +0800, Hongfu Li wrote:
> > > This series is version 2 of the previous patch [0].  In v2, the changes are
> > > split into two patches for easier review.
> > > [0] https://lore.kernel.org/all/20260518082120.3890552-1-lihongfu@kylinos.cn/
> > >
> > > The main changes in this series are to refactor shared tracing and assertion
> > > helpers into a common file, unify both pkey selftests on pkey_assert() and
> > > per-test tracing for consistent diagnostics, and add missing mmap() return
> > > checks with MAP_FAILED used throughout for readability and consistency.
> >
> > Thanks.  AI review seems to have found a legitimate problem:
> > 	https://sashiko.dev/#/patchset/20260525073026.27594-1-lihongfu@kylinos.cn
>
> Thanks. I'll go through the problem reported by the AI review and make
> corresponding fixes in v2.

You mean v3? :P

>
> Best regards,
> Hongfu
>

Cheers, Lorenzo

Re: [PATCH v2 0/2] selftests/mm: refactor pkey helpers and fix mmap error handling

[Hongfu Li]

> > > > This series is version 2 of the previous patch [0].  In v2, the changes are
> > > > split into two patches for easier review.
> > > > [0] https://lore.kernel.org/all/20260518082120.3890552-1-lihongfu@kylinos.cn/
> > > >
> > > > The main changes in this series are to refactor shared tracing and assertion
> > > > helpers into a common file, unify both pkey selftests on pkey_assert() and
> > > > per-test tracing for consistent diagnostics, and add missing mmap() return
> > > > checks with MAP_FAILED used throughout for readability and consistency.
> > >
> > > Thanks.  AI review seems to have found a legitimate problem:
> > > 	https://sashiko.dev/#/patchset/20260525073026.27594-1-lihongfu@kylinos.cn
> >
> > Thanks. I'll go through the problem reported by the AI review and make
> > corresponding fixes in v2.
> 
> You mean v3? :P

Oh sorry, my mistake. It should be v3, and I've already sent it out.
Here is the link:
https://lore.kernel.org/all/20260527013825.1134225-1-lihongfu@kylinos.cn/

Best regards,
Hongfu