Add a shmem memory failure selftest to test the shmem memory failure is correct after modifying shmem return value.
Test that + madvise() call returns 0 at the first time + trigger a SIGBUS when the poisoned shmem page is fault-in again. Signed-off-by: Lisa Wang <[email protected]> --- tools/testing/selftests/mm/Makefile | 3 + tools/testing/selftests/mm/run_vmtests.sh | 1 + .../selftests/mm/shmem_memory_failure_test.c | 98 ++++++++++++++++++++++ 3 files changed, 102 insertions(+) diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 7a5de4e9bf52..ac033851c9eb 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -72,6 +72,7 @@ TEST_GEN_FILES += madv_populate TEST_GEN_FILES += map_fixed_noreplace TEST_GEN_FILES += map_hugetlb TEST_GEN_FILES += map_populate +TEST_GEN_FILES += shmem_memory_failure_test ifneq (,$(filter $(ARCH),arm64 riscv riscv64 x86 x86_64 loongarch32 loongarch64)) TEST_GEN_FILES += memfd_secret endif @@ -259,6 +260,8 @@ $(OUTPUT)/migration: LDLIBS += -lnuma $(OUTPUT)/rmap: LDLIBS += -lnuma +$(OUTPUT)/shmem_memory_failure_test: CFLAGS += -I$(top_srcdir)/tools/include + local_config.mk local_config.h: check_config.sh CC="$(CC)" CFLAGS="$(CFLAGS)" ./check_config.sh diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index afdcfd0d7cef..58fb959a7936 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -402,6 +402,7 @@ CATEGORY="hugetlb" run_test ./hugetlb-soft-offline echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages echo "$enable_soft_offline" > /proc/sys/vm/enable_soft_offline CATEGORY="hugetlb" run_test ./hugetlb-read-hwpoison +CATEGORY="mmap" run_test ./shmem_memory_failure_test fi if [ $VADDR64 -ne 0 ]; then diff --git a/tools/testing/selftests/mm/shmem_memory_failure_test.c b/tools/testing/selftests/mm/shmem_memory_failure_test.c new file mode 100644 index 000000000000..44752024a7fc --- /dev/null +++ b/tools/testing/selftests/mm/shmem_memory_failure_test.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This test makes sure when memory failure happens, shmem can handle + * successfully. + */ +#include <linux/compiler.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <signal.h> +#include <setjmp.h> +#include <errno.h> +#include "kselftest.h" +#include "vm_util.h" + +static sigjmp_buf sigbuf; + +static void signal_handler(int sig, siginfo_t *info, void *ucontext) +{ + siglongjmp(sigbuf, 1); +} + +static void set_signal_handler(int sig, void (*handler)(int, siginfo_t *, void *)) +{ + struct sigaction sa = {}; + + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, NULL) == -1) + ksft_exit_fail_msg("Failed to set SIGBUS handler: %s\n", strerror(errno)); +} + +static unsigned long addr_to_pfn(char *addr) +{ + int pagemap_fd; + unsigned long pfn; + + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("Failed to open /proc/self/pagemap: %s\n", strerror(errno)); + pfn = pagemap_get_pfn(pagemap_fd, addr); + close(pagemap_fd); + + return pfn; +} + +static void test_shmem_memory_failure(size_t total_size, size_t page_size) +{ + unsigned long memory_failure_pfn; + char *memory_failure_mem; + char *memory_failure_addr; + int fd; + + fd = memfd_create("shmem_hwpoison_test", 0); + if (fd < 0) + ksft_exit_skip("memfd_create failed: %s\n", strerror(errno)); + + if (ftruncate(fd, total_size) < 0) + ksft_exit_fail_msg("ftruncate failed: %s\n", strerror(errno)); + + memory_failure_mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (memory_failure_mem == MAP_FAILED) + ksft_exit_fail_msg("mmap failed: %s\n", strerror(errno)); + memory_failure_addr = memory_failure_mem + page_size; + READ_ONCE(memory_failure_addr[0]); + memory_failure_pfn = addr_to_pfn(memory_failure_addr); + + if (madvise(memory_failure_addr, page_size, MADV_HWPOISON) != 0) + ksft_exit_fail_msg("MADV_HWPOISON failed: %s\n", strerror(errno)); + + if (sigsetjmp(sigbuf, 1) == 0) { + READ_ONCE(memory_failure_addr[0]); + ksft_test_result_fail("Read from poisoned page should have triggered SIGBUS\n"); + } else { + ksft_test_result_pass("SIGBUS triggered as expected on poisoned page\n"); + } + + munmap(memory_failure_mem, total_size); + close(fd); + if (unpoison_memory(memory_failure_pfn) < 0) + ksft_exit_fail_msg("unpoison_memory failed: %s\n", strerror(errno)); +} + +int main(int argc, char *argv[]) +{ + const size_t pagesize = getpagesize(); + + ksft_print_header(); + ksft_set_plan(1); + + set_signal_handler(SIGBUS, signal_handler); + test_shmem_memory_failure(pagesize * 4, pagesize); + ksft_finished(); +} -- 2.53.0.959.g497ff81fa9-goog
