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-rw-r--r--tools/testing/selftests/vm/userfaultfd.c157
1 files changed, 133 insertions, 24 deletions
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 3911a9ccb0bb..61e5cfeb1350 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -54,6 +54,7 @@
#include <linux/userfaultfd.h>
#include <setjmp.h>
#include <stdbool.h>
+#include <assert.h>
#include "../kselftest.h"
@@ -76,6 +77,8 @@ static int test_type;
#define ALARM_INTERVAL_SECS 10
static volatile bool test_uffdio_copy_eexist = true;
static volatile bool test_uffdio_zeropage_eexist = true;
+/* Whether to test uffd write-protection */
+static bool test_uffdio_wp = false;
static bool map_shared;
static int huge_fd;
@@ -90,6 +93,7 @@ pthread_attr_t attr;
struct uffd_stats {
int cpu;
unsigned long missing_faults;
+ unsigned long wp_faults;
};
/* pthread_mutex_t starts at page offset 0 */
@@ -139,9 +143,29 @@ static void uffd_stats_reset(struct uffd_stats *uffd_stats,
for (i = 0; i < n_cpus; i++) {
uffd_stats[i].cpu = i;
uffd_stats[i].missing_faults = 0;
+ uffd_stats[i].wp_faults = 0;
}
}
+static void uffd_stats_report(struct uffd_stats *stats, int n_cpus)
+{
+ int i;
+ unsigned long long miss_total = 0, wp_total = 0;
+
+ for (i = 0; i < n_cpus; i++) {
+ miss_total += stats[i].missing_faults;
+ wp_total += stats[i].wp_faults;
+ }
+
+ printf("userfaults: %llu missing (", miss_total);
+ for (i = 0; i < n_cpus; i++)
+ printf("%lu+", stats[i].missing_faults);
+ printf("\b), %llu wp (", wp_total);
+ for (i = 0; i < n_cpus; i++)
+ printf("%lu+", stats[i].wp_faults);
+ printf("\b)\n");
+}
+
static int anon_release_pages(char *rel_area)
{
int ret = 0;
@@ -262,10 +286,15 @@ struct uffd_test_ops {
void (*alias_mapping)(__u64 *start, size_t len, unsigned long offset);
};
-#define ANON_EXPECTED_IOCTLS ((1 << _UFFDIO_WAKE) | \
+#define SHMEM_EXPECTED_IOCTLS ((1 << _UFFDIO_WAKE) | \
(1 << _UFFDIO_COPY) | \
(1 << _UFFDIO_ZEROPAGE))
+#define ANON_EXPECTED_IOCTLS ((1 << _UFFDIO_WAKE) | \
+ (1 << _UFFDIO_COPY) | \
+ (1 << _UFFDIO_ZEROPAGE) | \
+ (1 << _UFFDIO_WRITEPROTECT))
+
static struct uffd_test_ops anon_uffd_test_ops = {
.expected_ioctls = ANON_EXPECTED_IOCTLS,
.allocate_area = anon_allocate_area,
@@ -274,7 +303,7 @@ static struct uffd_test_ops anon_uffd_test_ops = {
};
static struct uffd_test_ops shmem_uffd_test_ops = {
- .expected_ioctls = ANON_EXPECTED_IOCTLS,
+ .expected_ioctls = SHMEM_EXPECTED_IOCTLS,
.allocate_area = shmem_allocate_area,
.release_pages = shmem_release_pages,
.alias_mapping = noop_alias_mapping,
@@ -298,6 +327,21 @@ static int my_bcmp(char *str1, char *str2, size_t n)
return 0;
}
+static void wp_range(int ufd, __u64 start, __u64 len, bool wp)
+{
+ struct uffdio_writeprotect prms = { 0 };
+
+ /* Write protection page faults */
+ prms.range.start = start;
+ prms.range.len = len;
+ /* Undo write-protect, do wakeup after that */
+ prms.mode = wp ? UFFDIO_WRITEPROTECT_MODE_WP : 0;
+
+ if (ioctl(ufd, UFFDIO_WRITEPROTECT, &prms))
+ fprintf(stderr, "clear WP failed for address 0x%Lx\n",
+ start), exit(1);
+}
+
static void *locking_thread(void *arg)
{
unsigned long cpu = (unsigned long) arg;
@@ -436,7 +480,10 @@ static 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;
- uffdio_copy.mode = 0;
+ if (test_uffdio_wp)
+ uffdio_copy.mode = UFFDIO_COPY_MODE_WP;
+ else
+ uffdio_copy.mode = 0;
uffdio_copy.copy = 0;
if (ioctl(ufd, UFFDIO_COPY, &uffdio_copy)) {
/* real retval in ufdio_copy.copy */
@@ -493,15 +540,21 @@ static void uffd_handle_page_fault(struct uffd_msg *msg,
fprintf(stderr, "unexpected msg event %u\n",
msg->event), exit(1);
- if (bounces & BOUNCE_VERIFY &&
- msg->arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WRITE)
- fprintf(stderr, "unexpected write fault\n"), exit(1);
+ if (msg->arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WP) {
+ wp_range(uffd, msg->arg.pagefault.address, page_size, false);
+ stats->wp_faults++;
+ } else {
+ /* Missing page faults */
+ if (bounces & BOUNCE_VERIFY &&
+ msg->arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WRITE)
+ fprintf(stderr, "unexpected write fault\n"), exit(1);
- offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;
- offset &= ~(page_size-1);
+ offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;
+ offset &= ~(page_size-1);
- if (copy_page(uffd, offset))
- stats->missing_faults++;
+ if (copy_page(uffd, offset))
+ stats->missing_faults++;
+ }
}
static void *uffd_poll_thread(void *arg)
@@ -587,11 +640,30 @@ static void *uffd_read_thread(void *arg)
static void *background_thread(void *arg)
{
unsigned long cpu = (unsigned long) arg;
- unsigned long page_nr;
+ unsigned long page_nr, start_nr, mid_nr, end_nr;
+
+ start_nr = cpu * nr_pages_per_cpu;
+ end_nr = (cpu+1) * nr_pages_per_cpu;
+ mid_nr = (start_nr + end_nr) / 2;
+
+ /* Copy the first half of the pages */
+ for (page_nr = start_nr; page_nr < mid_nr; page_nr++)
+ copy_page_retry(uffd, page_nr * page_size);
- for (page_nr = cpu * nr_pages_per_cpu;
- page_nr < (cpu+1) * nr_pages_per_cpu;
- page_nr++)
+ /*
+ * If we need to test uffd-wp, set it up now. Then we'll have
+ * at least the first half of the pages mapped already which
+ * can be write-protected for testing
+ */
+ if (test_uffdio_wp)
+ wp_range(uffd, (unsigned long)area_dst + start_nr * page_size,
+ nr_pages_per_cpu * page_size, true);
+
+ /*
+ * Continue the 2nd half of the page copying, handling write
+ * protection faults if any
+ */
+ for (page_nr = mid_nr; page_nr < end_nr; page_nr++)
copy_page_retry(uffd, page_nr * page_size);
return NULL;
@@ -753,17 +825,31 @@ static int faulting_process(int signal_test)
}
for (nr = 0; nr < split_nr_pages; nr++) {
+ int steps = 1;
+ unsigned long offset = nr * page_size;
+
if (signal_test) {
if (sigsetjmp(*sigbuf, 1) != 0) {
- if (nr == lastnr) {
+ if (steps == 1 && nr == lastnr) {
fprintf(stderr, "Signal repeated\n");
return 1;
}
lastnr = nr;
if (signal_test == 1) {
- if (copy_page(uffd, nr * page_size))
- signalled++;
+ if (steps == 1) {
+ /* This is a MISSING request */
+ steps++;
+ if (copy_page(uffd, offset))
+ signalled++;
+ } else {
+ /* This is a WP request */
+ assert(steps == 2);
+ wp_range(uffd,
+ (__u64)area_dst +
+ offset,
+ page_size, false);
+ }
} else {
signalled++;
continue;
@@ -776,8 +862,13 @@ static int faulting_process(int signal_test)
fprintf(stderr,
"nr %lu memory corruption %Lu %Lu\n",
nr, count,
- count_verify[nr]), exit(1);
- }
+ count_verify[nr]);
+ }
+ /*
+ * Trigger write protection if there is by writting
+ * the same value back.
+ */
+ *area_count(area_dst, nr) = count;
}
if (signal_test)
@@ -799,6 +890,11 @@ static int faulting_process(int signal_test)
nr, count,
count_verify[nr]), exit(1);
}
+ /*
+ * Trigger write protection if there is by writting
+ * the same value back.
+ */
+ *area_count(area_dst, nr) = count;
}
if (uffd_test_ops->release_pages(area_dst))
@@ -902,6 +998,8 @@ static int userfaultfd_zeropage_test(void)
uffdio_register.range.start = (unsigned long) area_dst;
uffdio_register.range.len = nr_pages * page_size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ if (test_uffdio_wp)
+ uffdio_register.mode |= UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
fprintf(stderr, "register failure\n"), exit(1);
@@ -947,6 +1045,8 @@ static int userfaultfd_events_test(void)
uffdio_register.range.start = (unsigned long) area_dst;
uffdio_register.range.len = nr_pages * page_size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ if (test_uffdio_wp)
+ uffdio_register.mode |= UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
fprintf(stderr, "register failure\n"), exit(1);
@@ -977,7 +1077,8 @@ static int userfaultfd_events_test(void)
return 1;
close(uffd);
- printf("userfaults: %ld\n", stats.missing_faults);
+
+ uffd_stats_report(&stats, 1);
return stats.missing_faults != nr_pages;
}
@@ -1007,6 +1108,8 @@ static int userfaultfd_sig_test(void)
uffdio_register.range.start = (unsigned long) area_dst;
uffdio_register.range.len = nr_pages * page_size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ if (test_uffdio_wp)
+ uffdio_register.mode |= UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
fprintf(stderr, "register failure\n"), exit(1);
@@ -1139,6 +1242,8 @@ static int userfaultfd_stress(void)
uffdio_register.range.start = (unsigned long) area_dst;
uffdio_register.range.len = nr_pages * page_size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ if (test_uffdio_wp)
+ uffdio_register.mode |= UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register)) {
fprintf(stderr, "register failure\n");
return 1;
@@ -1193,6 +1298,11 @@ static int userfaultfd_stress(void)
if (stress(uffd_stats))
return 1;
+ /* Clear all the write protections if there is any */
+ if (test_uffdio_wp)
+ wp_range(uffd, (unsigned long)area_dst,
+ nr_pages * page_size, false);
+
/* unregister */
if (ioctl(uffd, UFFDIO_UNREGISTER, &uffdio_register.range)) {
fprintf(stderr, "unregister failure\n");
@@ -1231,10 +1341,7 @@ static int userfaultfd_stress(void)
area_src_alias = area_dst_alias;
area_dst_alias = tmp_area;
- printf("userfaults:");
- for (cpu = 0; cpu < nr_cpus; cpu++)
- printf(" %lu", uffd_stats[cpu].missing_faults);
- printf("\n");
+ uffd_stats_report(uffd_stats, nr_cpus);
}
if (err)
@@ -1274,6 +1381,8 @@ static void set_test_type(const char *type)
if (!strcmp(type, "anon")) {
test_type = TEST_ANON;
uffd_test_ops = &anon_uffd_test_ops;
+ /* Only enable write-protect test for anonymous test */
+ test_uffdio_wp = true;
} else if (!strcmp(type, "hugetlb")) {
test_type = TEST_HUGETLB;
uffd_test_ops = &hugetlb_uffd_test_ops;
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-05 19:50:08 +0000