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 <sur...@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);
--
2.50.0.727.gbf7dc18ff4-goog
