Extend /proc/pid/maps tearing tests to verify PROCMAP_QUERY ioctl operation correctness while the vma is being concurrently modified.
Signed-off-by: Suren Baghdasaryan surenb@google.com --- tools/testing/selftests/proc/proc-maps-race.c | 65 +++++++++++++++++++ 1 file changed, 65 insertions(+)
diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c index 66773685a047..d40854a07ec1 100644 --- a/tools/testing/selftests/proc/proc-maps-race.c +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -32,6 +32,8 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> +#include <linux/fs.h> +#include <sys/ioctl.h> #include <sys/mman.h> #include <sys/stat.h> #include <sys/types.h> @@ -317,6 +319,25 @@ static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self, strcmp(restored_first_line->text, self->first_line.text) == 0; }
+static bool query_addr_at(int maps_fd, void *addr, + unsigned long *vma_start, unsigned long *vma_end) +{ + struct procmap_query q; + + memset(&q, 0, sizeof(q)); + q.size = sizeof(q); + /* Find the VMA at the split address */ + q.query_addr = (unsigned long long)addr; + q.query_flags = 0; + if (ioctl(maps_fd, PROCMAP_QUERY, &q)) + return false; + + *vma_start = q.vma_start; + *vma_end = q.vma_end; + + return true; +} + static inline bool split_vma(FIXTURE_DATA(proc_maps_race) *self) { return mmap(self->mod_info->addr, self->page_size, self->mod_info->prot | PROT_EXEC, @@ -559,6 +580,8 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) do { bool last_line_changed; bool first_line_changed; + unsigned long vma_start; + unsigned long vma_end;
ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
@@ -595,6 +618,19 @@ TEST_F(proc_maps_race, test_maps_tearing_from_split) first_line_changed = strcmp(new_first_line.text, self->first_line.text) != 0; ASSERT_EQ(last_line_changed, first_line_changed);
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size, + &vma_start, &vma_end)); + /* + * The vma at the split address can be either the same as + * original one (if read before the split) or the same as the + * first line in the second page (if read after the split). + */ + ASSERT_TRUE((vma_start == self->last_line.start_addr && + vma_end == self->last_line.end_addr) || + (vma_start == split_first_line.start_addr && + vma_end == split_first_line.end_addr)); + 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); @@ -636,6 +672,9 @@ TEST_F(proc_maps_race, test_maps_tearing_from_resize) clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); start_test_loop(&start_ts, self->verbose); do { + unsigned long vma_start; + unsigned long vma_end; + ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
/* Check if we read vmas after shrinking it */ @@ -662,6 +701,16 @@ TEST_F(proc_maps_race, test_maps_tearing_from_resize) "Expand result invalid", self)); }
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr, &vma_start, &vma_end)); + /* + * The vma should stay at the same address and have either the + * original size of 3 pages or 1 page if read after shrinking. + */ + ASSERT_TRUE(vma_start == self->last_line.start_addr && + (vma_end - vma_start == self->page_size * 3 || + vma_end - vma_start == self->page_size)); + 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); @@ -703,6 +752,9 @@ TEST_F(proc_maps_race, test_maps_tearing_from_remap) clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); start_test_loop(&start_ts, self->verbose); do { + unsigned long vma_start; + unsigned long vma_end; + ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
/* Check if we read vmas after remapping it */ @@ -729,6 +781,19 @@ TEST_F(proc_maps_race, test_maps_tearing_from_remap) "Remap restore result invalid", self)); }
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size, + &vma_start, &vma_end)); + /* + * The vma should either stay at the same address and have the + * original size of 3 pages or we should find the remapped vma + * at the remap destination address with size of 1 page. + */ + ASSERT_TRUE((vma_start == self->last_line.start_addr && + vma_end - vma_start == self->page_size * 3) || + (vma_start == self->last_line.start_addr + self->page_size && + vma_end - vma_start == self->page_size)); + 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);