Add a shmem memory failure selftest to test the shmem memory failure is correct after modifying shmem return value.
Specifically, test the expected behavior under various scenarios combining page dirtiness (dirty vs clean) and failure types (hard vs soft): + Dirty + Hard: Trigger a SIGBUS on injection, and trigger another SIGBUS when reading the page again. + Dirty + Soft: No SIGBUS is triggered, and the original value can be read successfully. + Clean + Hard: No SIGBUS is triggered on injection, but trigger a SIGBUS when trying to read the page again. + Clean + Soft: No SIGBUS is triggered, and the page can be read successfully. Signed-off-by: Lisa Wang <[email protected]> --- tools/testing/selftests/mm/memory-failure.c | 111 +++++++++++++++++++++++++++- 1 file changed, 108 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c index 3d9e0b9ffb41..43949b3b3565 100644 --- a/tools/testing/selftests/mm/memory-failure.c +++ b/tools/testing/selftests/mm/memory-failure.c @@ -30,9 +30,14 @@ enum result_type { MADV_HARD_ANON, MADV_HARD_CLEAN_PAGECACHE, MADV_HARD_DIRTY_PAGECACHE, + MADV_HARD_CLEAN_SHMEM, + MADV_HARD_DIRTY_SHMEM, MADV_SOFT_ANON, MADV_SOFT_CLEAN_PAGECACHE, MADV_SOFT_DIRTY_PAGECACHE, + MADV_SOFT_CLEAN_SHMEM, + MADV_SOFT_DIRTY_SHMEM, + READ_ERROR, }; static jmp_buf signal_jmp_buf; @@ -165,17 +170,21 @@ static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure case MADV_HARD_CLEAN_PAGECACHE: case MADV_SOFT_CLEAN_PAGECACHE: case MADV_SOFT_DIRTY_PAGECACHE: - /* It is not expected to receive a SIGBUS signal. */ - ASSERT_EQ(setjmp, 0); - + case MADV_SOFT_DIRTY_SHMEM: /* The page content should remain unchanged. */ ASSERT_TRUE(check_memory(vaddr, self->page_size)); + case MADV_HARD_CLEAN_SHMEM: + case MADV_SOFT_CLEAN_SHMEM: + /* It is not expected to receive a SIGBUS signal. */ + ASSERT_EQ(setjmp, 0); /* The backing pfn of addr should have changed. */ ASSERT_NE(pagemap_get_pfn(self->pagemap_fd, vaddr), self->pfn); break; case MADV_HARD_ANON: case MADV_HARD_DIRTY_PAGECACHE: + case MADV_HARD_DIRTY_SHMEM: + case READ_ERROR: /* The SIGBUS signal should have been received. */ ASSERT_EQ(setjmp, 1); @@ -260,6 +269,20 @@ static int prepare_file(const char *fname, unsigned long size) return fd; } +static int prepare_shmem(const char *fname, unsigned long size) +{ + int fd; + + fd = memfd_create(fname, 0); + if (fd < 0) + return -1; + if (ftruncate(fd, size) < 0) { + close(fd); + return -1; + } + return fd; +} + /* Borrowed from mm/gup_longterm.c. */ static int get_fs_type(int fd) { @@ -356,4 +379,86 @@ TEST_F(memory_failure, dirty_pagecache) ASSERT_EQ(close(fd), 0); } +TEST_F(memory_failure, dirty_shmem) +{ + int fd; + char *addr; + int ret; + + fd = prepare_shmem("shmem-file", self->page_size); + if (fd < 0) + SKIP(return, "failed to open test shmem-file.\n"); + + addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) { + close(fd); + SKIP(return, "mmap failed, not enough memory.\n"); + } + memset(addr, 0xce, self->page_size); + + prepare(_metadata, self, addr); + + ret = sigsetjmp(signal_jmp_buf, 1); + if (ret == 0) + ASSERT_EQ(variant->inject(self, addr), 0); + + if (variant->type == MADV_HARD) { + check(_metadata, self, addr, MADV_HARD_DIRTY_SHMEM, ret); + ret = sigsetjmp(signal_jmp_buf, 1); + if (ret == 0) + FORCE_READ(*addr); + check(_metadata, self, addr, READ_ERROR, ret); + } else { + check(_metadata, self, addr, MADV_SOFT_DIRTY_SHMEM, ret); + } + + ASSERT_EQ(munmap(addr, self->page_size), 0); + + ASSERT_EQ(close(fd), 0); + cleanup(_metadata, self, addr); +} + +TEST_F(memory_failure, clean_shmem) +{ + int fd; + char *addr; + int ret; + + fd = prepare_shmem("shmem-file", self->page_size); + if (fd < 0) + SKIP(return, "failed to open test shmem-file.\n"); + + addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) { + close(fd); + SKIP(return, "mmap failed, not enough memory.\n"); + } + FORCE_READ(*addr); + + prepare(_metadata, self, addr); + + ret = sigsetjmp(signal_jmp_buf, 1); + if (ret == 0) + ASSERT_EQ(variant->inject(self, addr), 0); + + if (variant->type == MADV_HARD) { + check(_metadata, self, addr, MADV_HARD_CLEAN_SHMEM, ret); + ret = sigsetjmp(signal_jmp_buf, 1); + if (ret == 0) + FORCE_READ(*addr); + check(_metadata, self, addr, READ_ERROR, ret); + } else { + /* Test the address accessability without check_memory(). */ + FORCE_READ(*addr); + check(_metadata, self, addr, MADV_SOFT_CLEAN_SHMEM, ret); + } + + ASSERT_EQ(munmap(addr, self->page_size), 0); + + ASSERT_EQ(close(fd), 0); + cleanup(_metadata, self, addr); +} + TEST_HARNESS_MAIN -- 2.54.0.1013.g208068f2d8-goog
