Extend /proc/pid/maps tearing test 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 | 62 +++++++++++++++++++ 1 file changed, 62 insertions(+)
diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c index 764821ffd63d..6acdafdac9db 100644 --- a/tools/testing/selftests/proc/proc-maps-race.c +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -30,6 +30,8 @@ #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> @@ -239,6 +241,21 @@ static void capture_mod_pattern(int maps_fd, assert(strcmp(restored_first_line->text, first_line->text) == 0); }
+static void 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; + assert(!ioctl(maps_fd, PROCMAP_QUERY, &q)); + *vma_start = q.vma_start; + *vma_end = q.vma_end; +} + static inline void split_vma(const struct vma_modifier_info *mod_info) { assert(mmap(mod_info->addr, page_size, mod_info->prot | PROT_EXEC, @@ -299,6 +316,8 @@ static void test_maps_tearing_from_split(int maps_fd, do { bool last_line_changed; bool first_line_changed; + unsigned long vma_start; + unsigned long vma_end;
read_boundary_lines(maps_fd, page1, page2, &new_last_line, &new_first_line);
@@ -329,6 +348,19 @@ static void test_maps_tearing_from_split(int maps_fd, first_line_changed = strcmp(new_first_line.text, first_line->text) != 0; assert(last_line_changed == first_line_changed);
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + query_addr_at(maps_fd, mod_info->addr + 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((vma_start == last_line->start_addr && + vma_end == 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); } while (end_ts.tv_sec - start_ts.tv_sec < test_duration_sec);
@@ -390,6 +422,9 @@ static void test_maps_tearing_from_resize(int maps_fd,
clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); do { + unsigned long vma_start; + unsigned long vma_end; + read_boundary_lines(maps_fd, page1, page2, &new_last_line, &new_first_line);
/* Check if we read vmas after shrinking it */ @@ -409,6 +444,17 @@ static void test_maps_tearing_from_resize(int maps_fd, assert(!strcmp(new_last_line.text, restored_last_line.text) && !strcmp(new_first_line.text, restored_first_line.text)); } + + /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + query_addr_at(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(vma_start == last_line->start_addr && + (vma_end - vma_start == page_size * 3 || + vma_end - vma_start == page_size)); + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); } while (end_ts.tv_sec - start_ts.tv_sec < test_duration_sec);
@@ -479,6 +525,9 @@ static void test_maps_tearing_from_remap(int maps_fd,
clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); do { + unsigned long vma_start; + unsigned long vma_end; + read_boundary_lines(maps_fd, page1, page2, &new_last_line, &new_first_line);
/* Check if we read vmas after remapping it */ @@ -498,6 +547,19 @@ static void test_maps_tearing_from_remap(int maps_fd, assert(!strcmp(new_last_line.text, restored_last_line.text) && !strcmp(new_first_line.text, restored_first_line.text)); } + + /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + query_addr_at(maps_fd, mod_info->addr + 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((vma_start == last_line->start_addr && + vma_end - vma_start == page_size * 3) || + (vma_start == last_line->start_addr + page_size && + vma_end - vma_start == page_size)); + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); } while (end_ts.tv_sec - start_ts.tv_sec < test_duration_sec);