Commit aadc099c authored by Suren Baghdasaryan's avatar Suren Baghdasaryan Committed by Andrew Morton
Browse files

selftests/proc: add verbose mode for /proc/pid/maps tearing tests 

Add verbose mode to the /proc/pid/maps tearing tests to print debugging
information.  VERBOSE environment variable is used to enable it.

Usage example: VERBOSE=1 ./proc-maps-race

Link: https://lkml.kernel.org/r/20250719182854.3166724-5-surenb@google.com


Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeongjun Park <aha310510@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: T.J. Mercier <tjmercier@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Ye Bin <yebin10@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6a45336b

tools/testing/selftests/proc/proc-maps-race.c

+141 −12
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ FIXTURE(proc_maps_race) 
	int shared_mem_size;

	int page_size;

	int vma_count;

	bool verbose;

	int maps_fd;

	pid_t pid;

};
@@ -188,12 +189,104 @@ static void stop_vma_modifier(struct vma_modifier_info *mod_info) 
	signal_state(mod_info, SETUP_MODIFY_MAPS);

}



static void print_first_lines(char *text, int nr)

{

	const char *end = text;



	while (nr && (end = strchr(end, '\n')) != NULL) {

		nr--;

		end++;

	}



	if (end) {

		int offs = end - text;



		text[offs] = '\0';

		printf(text);

		text[offs] = '\n';

		printf("\n");

	} else {

		printf(text);

	}

}



static void print_last_lines(char *text, int nr)

{

	const char *start = text + strlen(text);



	nr++; /* to ignore the last newline */

	while (nr) {

		while (start > text && *start != '\n')

			start--;

		nr--;

		start--;

	}

	printf(start);

}



static void print_boundaries(const char *title, FIXTURE_DATA(proc_maps_race) *self)

{

	if (!self->verbose)

		return;



	printf("%s", title);

	/* Print 3 boundary lines from each page */

	print_last_lines(self->page1.data, 3);

	printf("-----------------page boundary-----------------\n");

	print_first_lines(self->page2.data, 3);

}



static bool print_boundaries_on(bool condition, const char *title,

				FIXTURE_DATA(proc_maps_race) *self)

{

	if (self->verbose && condition)

		print_boundaries(title, self);



	return condition;

}



static void report_test_start(const char *name, bool verbose)

{

	if (verbose)

		printf("==== %s ====\n", name);

}



static struct timespec print_ts;



static void start_test_loop(struct timespec *ts, bool verbose)

{

	if (verbose)

		print_ts.tv_sec = ts->tv_sec;

}



static void end_test_iteration(struct timespec *ts, bool verbose)

{

	if (!verbose)

		return;



	/* Update every second */

	if (print_ts.tv_sec == ts->tv_sec)

		return;



	printf(".");

	fflush(stdout);

	print_ts.tv_sec = ts->tv_sec;

}



static void end_test_loop(bool verbose)

{

	if (verbose)

		printf("\n");

}



static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self,

				struct line_content *mod_last_line,

				struct line_content *mod_first_line,

				struct line_content *restored_last_line,

				struct line_content *restored_first_line)

{

	print_boundaries("Before modification", self);



	signal_state(self->mod_info, SETUP_MODIFY_MAPS);

	wait_for_state(self->mod_info, SETUP_MAPS_MODIFIED);
@@ -201,6 +294,8 @@ static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self, 
	if (!read_boundary_lines(self, mod_last_line, mod_first_line))

		return false;



	print_boundaries("After modification", self);



	signal_state(self->mod_info, SETUP_RESTORE_MAPS);

	wait_for_state(self->mod_info, SETUP_MAPS_RESTORED);
@@ -208,6 +303,8 @@ static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self, 
	if (!read_boundary_lines(self, restored_last_line, restored_first_line))

		return false;



	print_boundaries("After restore", self);



	if (!self->mod_info->vma_mod_check(mod_last_line, mod_first_line,

					   restored_last_line, restored_first_line))

		return false;
@@ -295,6 +392,7 @@ static inline bool check_remap_result(struct line_content *mod_last_line, 


FIXTURE_SETUP(proc_maps_race)

{

	const char *verbose = getenv("VERBOSE");

	const char *duration = getenv("DURATION");

	struct vma_modifier_info *mod_info;

	pthread_mutexattr_t mutex_attr;
@@ -303,6 +401,7 @@ FIXTURE_SETUP(proc_maps_race) 
	char fname[32];



	self->page_size = (unsigned long)sysconf(_SC_PAGESIZE);

	self->verbose = verbose && !strncmp(verbose, "1", 1);

	duration_sec = duration ? atol(duration) : 0;

	self->duration_sec = duration_sec ? duration_sec : 5UL;
@@ -444,6 +543,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) 
	mod_info->vma_restore = merge_vma;

	mod_info->vma_mod_check = check_split_result;



	report_test_start("Tearing from split", self->verbose);

	ASSERT_TRUE(capture_mod_pattern(self, &split_last_line, &split_first_line,

					&restored_last_line, &restored_first_line));
@@ -455,6 +555,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) 
	struct timespec start_ts, end_ts;



	clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);

	start_test_loop(&start_ts, self->verbose);

	do {

		bool last_line_changed;

		bool first_line_changed;
@@ -472,12 +573,18 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) 
			 * In that case new first line will be the same as the

			 * last restored line.

			 */

			ASSERT_FALSE(strcmp(new_first_line.text, split_first_line.text) &&

				     strcmp(new_first_line.text, restored_last_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, split_first_line.text) &&

					strcmp(new_first_line.text, restored_last_line.text),

					"Split result invalid", self));

		} else {

			/* The vmas should be consistent with merge results */

			ASSERT_FALSE(strcmp(new_last_line.text, restored_last_line.text));

			ASSERT_FALSE(strcmp(new_first_line.text, restored_first_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_last_line.text, restored_last_line.text),

					"Merge result invalid", self));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, restored_first_line.text),

					"Merge result invalid", self));

		}

		/*

		 * First and last lines should change in unison. If the last
@@ -489,7 +596,9 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) 
		ASSERT_EQ(last_line_changed, first_line_changed);



		clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);

		end_test_iteration(&end_ts, self->verbose);

	} while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);

	end_test_loop(self->verbose);



	/* Signal the modifyer thread to stop and wait until it exits */

	signal_state(mod_info, TEST_DONE);
@@ -513,6 +622,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_resize) 
	mod_info->vma_restore = expand_vma;

	mod_info->vma_mod_check = check_shrink_result;



	report_test_start("Tearing from resize", self->verbose);

	ASSERT_TRUE(capture_mod_pattern(self, &shrunk_last_line, &shrunk_first_line,

					&restored_last_line, &restored_first_line));
@@ -524,6 +634,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_resize) 
	struct timespec start_ts, end_ts;



	clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);

	start_test_loop(&start_ts, self->verbose);

	do {

		ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
@@ -537,16 +648,24 @@ TEST_F(proc_maps_race, test_maps_tearing_from_resize) 
			 * again. In that case new first line will be the same

			 * as the last restored line.

			 */

			ASSERT_FALSE(strcmp(new_first_line.text, shrunk_first_line.text) &&

				     strcmp(new_first_line.text, restored_last_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, shrunk_first_line.text) &&

					strcmp(new_first_line.text, restored_last_line.text),

					"Shrink result invalid", self));

		} else {

			/* The vmas should be consistent with the original/resored state */

			ASSERT_FALSE(strcmp(new_last_line.text, restored_last_line.text));

			ASSERT_FALSE(strcmp(new_first_line.text, restored_first_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_last_line.text, restored_last_line.text),

					"Expand result invalid", self));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, restored_first_line.text),

					"Expand result invalid", self));

		}



		clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);

		end_test_iteration(&end_ts, self->verbose);

	} while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);

	end_test_loop(self->verbose);



	/* Signal the modifyer thread to stop and wait until it exits */

	signal_state(mod_info, TEST_DONE);
@@ -570,6 +689,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_remap) 
	mod_info->vma_restore = patch_vma;

	mod_info->vma_mod_check = check_remap_result;



	report_test_start("Tearing from remap", self->verbose);

	ASSERT_TRUE(capture_mod_pattern(self, &remapped_last_line, &remapped_first_line,

					&restored_last_line, &restored_first_line));
@@ -581,6 +701,7 @@ TEST_F(proc_maps_race, test_maps_tearing_from_remap) 
	struct timespec start_ts, end_ts;



	clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);

	start_test_loop(&start_ts, self->verbose);

	do {

		ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
@@ -594,16 +715,24 @@ TEST_F(proc_maps_race, test_maps_tearing_from_remap) 
			 * again. In that case new first line will be the same

			 * as the last restored line.

			 */

			ASSERT_FALSE(strcmp(new_first_line.text, remapped_first_line.text) &&

				     strcmp(new_first_line.text, restored_last_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, remapped_first_line.text) &&

					strcmp(new_first_line.text, restored_last_line.text),

					"Remap result invalid", self));

		} else {

			/* The vmas should be consistent with the original/resored state */

			ASSERT_FALSE(strcmp(new_last_line.text, restored_last_line.text));

			ASSERT_FALSE(strcmp(new_first_line.text, restored_first_line.text));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_last_line.text, restored_last_line.text),

					"Remap restore result invalid", self));

			ASSERT_FALSE(print_boundaries_on(

					strcmp(new_first_line.text, restored_first_line.text),

					"Remap restore result invalid", self));

		}



		clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);

		end_test_iteration(&end_ts, self->verbose);

	} while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);

	end_test_loop(self->verbose);



	/* Signal the modifyer thread to stop and wait until it exits */

	signal_state(mod_info, TEST_DONE);