Commit 0210c43e authored by Peter Xu's avatar Peter Xu Committed by Andrew Morton
Browse files

selftests/mm: let uffd_handle_page_fault() take wp parameter 

Make the handler optionally apply WP bit when resolving page faults for
either missing or minor page faults.  This moves towards removing global
test_uffdio_wp outside of the common code.

Link: https://lkml.kernel.org/r/20230412164341.328618-1-peterx@redhat.com


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 50834084

tools/testing/selftests/mm/uffd-common.c

+9 −8
Original line number Diff line number Diff line
@@ -353,7 +353,7 @@ void wp_range(int ufd, __u64 start, __u64 len, bool wp) 
		err("clear WP failed: address=0x%"PRIx64, (uint64_t)start);

}



static void continue_range(int ufd, __u64 start, __u64 len)

static void continue_range(int ufd, __u64 start, __u64 len, bool wp)

{

	struct uffdio_continue req;

	int ret;
@@ -361,7 +361,7 @@ static void continue_range(int ufd, __u64 start, __u64 len) 
	req.range.start = start;

	req.range.len = len;

	req.mode = 0;

	if (test_uffdio_wp)

	if (wp)

		req.mode |= UFFDIO_CONTINUE_MODE_WP;



	if (ioctl(ufd, UFFDIO_CONTINUE, &req))
@@ -429,7 +429,8 @@ void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args) 
				    area_dst_alias));

		for (b = 0; b < page_size; ++b)

			area[b] = ~area[b];

		continue_range(uffd, msg->arg.pagefault.address, page_size);

		continue_range(uffd, msg->arg.pagefault.address, page_size,

			       args->apply_wp);

		args->minor_faults++;

	} else {

		/*
@@ -459,7 +460,7 @@ void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args) 
		offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;

		offset &= ~(page_size-1);



		if (copy_page(uffd, offset))

		if (copy_page(uffd, offset, args->apply_wp))

			args->missing_faults++;

	}

}
@@ -555,7 +556,7 @@ static void wake_range(int ufd, unsigned long addr, unsigned long len) 
			addr), exit(1);

}



int __copy_page(int ufd, unsigned long offset, bool retry)

int __copy_page(int ufd, unsigned long offset, bool retry, bool wp)

{

	struct uffdio_copy uffdio_copy;
@@ -564,7 +565,7 @@ int __copy_page(int ufd, unsigned long offset, bool retry) 
	uffdio_copy.dst = (unsigned long) area_dst + offset;

	uffdio_copy.src = (unsigned long) area_src + offset;

	uffdio_copy.len = page_size;

	if (test_uffdio_wp)

	if (wp)

		uffdio_copy.mode = UFFDIO_COPY_MODE_WP;

	else

		uffdio_copy.mode = 0;
@@ -587,7 +588,7 @@ int __copy_page(int ufd, unsigned long offset, bool retry) 
	return 0;

}



int copy_page(int ufd, unsigned long offset)

int copy_page(int ufd, unsigned long offset, bool wp)

{

	return __copy_page(ufd, offset, false);

	return __copy_page(ufd, offset, false, wp);

}

tools/testing/selftests/mm/uffd-common.h

+4 −2
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ 
/* Userfaultfd test statistics */

struct uffd_args {

	int cpu;

	/* Whether apply wr-protects when installing pages */

	bool apply_wp;

	unsigned long missing_faults;

	unsigned long wp_faults;

	unsigned long minor_faults;
@@ -104,8 +106,8 @@ void userfaultfd_open(uint64_t *features); 
int uffd_read_msg(int ufd, struct uffd_msg *msg);

void wp_range(int ufd, __u64 start, __u64 len, bool wp);

void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args);

int __copy_page(int ufd, unsigned long offset, bool retry);

int copy_page(int ufd, unsigned long offset);

int __copy_page(int ufd, unsigned long offset, bool retry, bool wp);

int copy_page(int ufd, unsigned long offset, bool wp);

void *uffd_poll_thread(void *arg);



#define TEST_ANON	1

tools/testing/selftests/mm/uffd-stress.c

+10 −6
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ static void uffd_stats_reset(struct uffd_args *args, unsigned long n_cpus) 


	for (i = 0; i < n_cpus; i++) {

		args[i].cpu = i;

		args[i].apply_wp = test_uffdio_wp;

		args[i].missing_faults = 0;

		args[i].wp_faults = 0;

		args[i].minor_faults = 0;
@@ -155,7 +156,7 @@ static void *locking_thread(void *arg) 


static int copy_page_retry(int ufd, unsigned long offset)

{

	return __copy_page(ufd, offset, true);

	return __copy_page(ufd, offset, true, test_uffdio_wp);

}



pthread_mutex_t uffd_read_mutex = PTHREAD_MUTEX_INITIALIZER;
@@ -308,7 +309,7 @@ static void sighndl(int sig, siginfo_t *siginfo, void *ptr) 
 * This also tests UFFD_FEATURE_EVENT_FORK event along with the signal

 * feature. Using monitor thread, verify no userfault events are generated.

 */

static int faulting_process(int signal_test)

static int faulting_process(int signal_test, bool wp)

{

	unsigned long nr;

	unsigned long long count;
@@ -343,7 +344,7 @@ static int faulting_process(int signal_test) 
					if (steps == 1) {

						/* This is a MISSING request */

						steps++;

						if (copy_page(uffd, offset))

						if (copy_page(uffd, offset, wp))

							signalled++;

					} else {

						/* This is a WP request */
@@ -507,6 +508,7 @@ static int userfaultfd_events_test(void) 
			  true, test_uffdio_wp, false))

		err("register failure");



	args.apply_wp = test_uffdio_wp;

	if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &args))

		err("uffd_poll_thread create");
@@ -515,7 +517,7 @@ static int userfaultfd_events_test(void) 
		err("fork");



	if (!pid)

		exit(faulting_process(0));

		exit(faulting_process(0, test_uffdio_wp));



	waitpid(pid, &err, 0);

	if (err)
@@ -551,11 +553,12 @@ static int userfaultfd_sig_test(void) 
			  true, test_uffdio_wp, false))

		err("register failure");



	if (faulting_process(1))

	if (faulting_process(1, test_uffdio_wp))

		err("faulting process failed");



	uffd_test_ops->release_pages(area_dst);



	args.apply_wp = test_uffdio_wp;

	if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &args))

		err("uffd_poll_thread create");
@@ -564,7 +567,7 @@ static int userfaultfd_sig_test(void) 
		err("fork");



	if (!pid)

		exit(faulting_process(2));

		exit(faulting_process(2, test_uffdio_wp));



	waitpid(pid, &err, 0);

	if (err)
@@ -628,6 +631,7 @@ static int userfaultfd_minor_test(void) 
		       page_size);

	}



	args.apply_wp = test_uffdio_wp;

	if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &args))

		err("uffd_poll_thread create");