diff options
| -rw-r--r-- | tools/testing/selftests/mm/guard-regions.c | 47 | ||||
| -rw-r--r-- | tools/testing/selftests/mm/vm_util.h | 1 |
2 files changed, 48 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c index ea9b5815e828..280d1831bf73 100644 --- a/tools/testing/selftests/mm/guard-regions.c +++ b/tools/testing/selftests/mm/guard-regions.c @@ -19,6 +19,7 @@ #include <sys/syscall.h> #include <sys/uio.h> #include <unistd.h> +#include "vm_util.h" /* * Ignore the checkpatch warning, as per the C99 standard, section 7.14.1.1: @@ -2032,4 +2033,50 @@ TEST_F(guard_regions, anon_zeropage) ASSERT_EQ(munmap(ptr, 10 * page_size), 0); } +/* + * Assert that /proc/$pid/pagemap correctly identifies guard region ranges. + */ +TEST_F(guard_regions, pagemap) +{ + const unsigned long page_size = self->page_size; + int proc_fd; + char *ptr; + int i; + + proc_fd = open("/proc/self/pagemap", O_RDONLY); + ASSERT_NE(proc_fd, -1); + + ptr = mmap_(self, variant, NULL, 10 * page_size, + PROT_READ | PROT_WRITE, 0, 0); + ASSERT_NE(ptr, MAP_FAILED); + + /* Read from pagemap, and assert no guard regions are detected. */ + for (i = 0; i < 10; i++) { + char *ptr_p = &ptr[i * page_size]; + unsigned long entry = pagemap_get_entry(proc_fd, ptr_p); + unsigned long masked = entry & PM_GUARD_REGION; + + ASSERT_EQ(masked, 0); + } + + /* Install a guard region in every other page. */ + for (i = 0; i < 10; i += 2) { + char *ptr_p = &ptr[i * page_size]; + + ASSERT_EQ(madvise(ptr_p, page_size, MADV_GUARD_INSTALL), 0); + } + + /* Re-read from pagemap, and assert guard regions are detected. */ + for (i = 0; i < 10; i++) { + char *ptr_p = &ptr[i * page_size]; + unsigned long entry = pagemap_get_entry(proc_fd, ptr_p); + unsigned long masked = entry & PM_GUARD_REGION; + + ASSERT_EQ(masked, i % 2 == 0 ? PM_GUARD_REGION : 0); + } + + ASSERT_EQ(close(proc_fd), 0); + ASSERT_EQ(munmap(ptr, 10 * page_size), 0); +} + TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index b60ac68a9dc8..0e629586556b 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -10,6 +10,7 @@ #define PM_SOFT_DIRTY BIT_ULL(55) #define PM_MMAP_EXCLUSIVE BIT_ULL(56) #define PM_UFFD_WP BIT_ULL(57) +#define PM_GUARD_REGION BIT_ULL(58) #define PM_FILE BIT_ULL(61) #define PM_SWAP BIT_ULL(62) #define PM_PRESENT BIT_ULL(63) |