This patch adds a new kselftest to validate memory failure handling for anonymous pages. The test performs the following operations: 1. Allocates anonymous pages using mmap(). 2. Injects memory failure via madvise syscall. 3. Verifies expected error handling behavior. 4. Unpoison memory.

This test helps ensure that memory failure handling for anonymous pages works correctly, including proper SIGBUS delivery to user processes, page isolation and recovery paths.

Signed-off-by: Miaohe Lin linmiaohe@huawei.com --- MAINTAINERS | 1 + tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/memory-failure.c | 239 ++++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 21 ++ tools/testing/selftests/mm/vm_util.c | 41 ++++ tools/testing/selftests/mm/vm_util.h | 3 + 7 files changed, 307 insertions(+) create mode 100644 tools/testing/selftests/mm/memory-failure.c

diff --git a/MAINTAINERS b/MAINTAINERS index 765ad2daa218..3401b408a07e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11683,6 +11683,7 @@ F: include/linux/memory-failure.h F: include/trace/events/memory-failure.h F: mm/hwpoison-inject.c F: mm/memory-failure.c +F: tools/testing/selftests/mm/memory-failure.c

HYCON HY46XX TOUCHSCREEN SUPPORT M: Giulio Benetti giulio.benetti@benettiengineering.com diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore index c2a8586e51a1..83ad9454dd9d 100644 --- a/tools/testing/selftests/mm/.gitignore +++ b/tools/testing/selftests/mm/.gitignore @@ -12,6 +12,7 @@ map_hugetlb map_populate thuge-gen compaction_test +memory-failure migration mlock2-tests mrelease_test diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index eaf9312097f7..9495f7594e28 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -75,6 +75,7 @@ TEST_GEN_FILES += map_populate ifneq (,$(filter $(ARCH),arm64 riscv riscv64 x86 x86_64)) TEST_GEN_FILES += memfd_secret endif +TEST_GEN_FILES += memory-failure TEST_GEN_FILES += migration TEST_GEN_FILES += mkdirty TEST_GEN_FILES += mlock-random-test diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c new file mode 100644 index 000000000000..37806a58f4b4 --- /dev/null +++ b/tools/testing/selftests/mm/memory-failure.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Memory-failure functional tests. + * + * Author(s): Miaohe Lin linmiaohe@huawei.com + */ + +#include "../kselftest_harness.h" + +#include <sys/mman.h> +#include <linux/mman.h> +#include <linux/string.h> +#include <signal.h> +#include <setjmp.h> +#include <unistd.h> +#include <fcntl.h> + +#include "vm_util.h" + +enum inject_type { + MADV_HARD, + MADV_SOFT, +}; + +enum result_type { + MADV_HARD_ANON, + MADV_SOFT_ANON, +}; + +static jmp_buf signal_jmp_buf; +static siginfo_t siginfo; +const char *pagemap_proc = "/proc/self/pagemap"; +const char *kpageflags_proc = "/proc/kpageflags"; + +FIXTURE(memory_failure) +{ + unsigned long page_size; + unsigned long corrupted_size; + unsigned long pfn; + int pagemap_fd; + int kpageflags_fd; + bool triggered; +}; + +FIXTURE_VARIANT(memory_failure) +{ + enum inject_type type; + int (*inject)(FIXTURE_DATA(memory_failure) * self, void *vaddr); +}; + +static int madv_hard_inject(FIXTURE_DATA(memory_failure) * self, void *vaddr) +{ + return madvise(vaddr, self->page_size, MADV_HWPOISON); +} + +FIXTURE_VARIANT_ADD(memory_failure, madv_hard) +{ + .type = MADV_HARD, + .inject = madv_hard_inject, +}; + +static int madv_soft_inject(FIXTURE_DATA(memory_failure) * self, void *vaddr) +{ + return madvise(vaddr, self->page_size, MADV_SOFT_OFFLINE); +} + +FIXTURE_VARIANT_ADD(memory_failure, madv_soft) +{ + .type = MADV_SOFT, + .inject = madv_soft_inject, +}; + +static void sigbus_action(int signo, siginfo_t *si, void *args) +{ + memcpy(&siginfo, si, sizeof(siginfo_t)); + siglongjmp(signal_jmp_buf, 1); +} + +static int setup_sighandler(void) +{ + struct sigaction sa = { + .sa_sigaction = sigbus_action, + .sa_flags = SA_SIGINFO, + }; + + return sigaction(SIGBUS, &sa, NULL); +} + +FIXTURE_SETUP(memory_failure) +{ + memset(self, 0, sizeof(*self)); + + self->page_size = (unsigned long)sysconf(_SC_PAGESIZE); + + memset(&siginfo, 0, sizeof(siginfo)); + if (setup_sighandler()) + SKIP(return, "setup sighandler failed.\n"); + + self->pagemap_fd = open(pagemap_proc, O_RDONLY); + if (self->pagemap_fd == -1) + SKIP(return, "open %s failed.\n", pagemap_proc); + + self->kpageflags_fd = open(kpageflags_proc, O_RDONLY); + if (self->kpageflags_fd == -1) + SKIP(return, "open %s failed.\n", kpageflags_proc); +} + +static void teardown_sighandler(void) +{ + struct sigaction sa = { + .sa_handler = SIG_DFL, + .sa_flags = SA_SIGINFO, + }; + + sigaction(SIGBUS, &sa, NULL); +} + +FIXTURE_TEARDOWN(memory_failure) +{ + close(self->kpageflags_fd); + close(self->pagemap_fd); + teardown_sighandler(); +} + +static void prepare(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self, + void *vaddr) +{ + self->pfn = pagemap_get_pfn(self->pagemap_fd, vaddr); + ASSERT_NE(self->pfn, -1UL); + + ASSERT_EQ(get_hardware_corrupted_size(&self->corrupted_size), 0); +} + +static bool check_memory(void *vaddr, unsigned long size) +{ + char buf[64]; + + memset(buf, 0xce, sizeof(buf)); + while (size >= sizeof(buf)) { + if (memcmp(vaddr, buf, sizeof(buf))) + return false; + size -= sizeof(buf); + vaddr += sizeof(buf); + } + + return true; +} + +static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self, + void *vaddr, enum result_type type, int setjmp) +{ + unsigned long size; + uint64_t pfn_flags; + + switch (type) { + case MADV_SOFT_ANON: + /* It is not expected to receive a SIGBUS signal. */ + ASSERT_EQ(setjmp, 0); + + /* The page content should remain unchanged. */ + ASSERT_TRUE(check_memory(vaddr, self->page_size)); + + /* The backing pfn of addr should have changed. */ + ASSERT_NE(pagemap_get_pfn(self->pagemap_fd, vaddr), self->pfn); + break; + case MADV_HARD_ANON: + /* The SIGBUS signal should have been received. */ + ASSERT_EQ(setjmp, 1); + + /* Check if siginfo contains correct SIGBUS context. */ + ASSERT_EQ(siginfo.si_signo, SIGBUS); + ASSERT_EQ(siginfo.si_code, BUS_MCEERR_AR); + ASSERT_EQ(1UL << siginfo.si_addr_lsb, self->page_size); + ASSERT_EQ(siginfo.si_addr, vaddr); + + /* XXX Check backing pte is hwpoison entry when supported. */ + ASSERT_TRUE(pagemap_is_swapped(self->pagemap_fd, vaddr)); + break; + default: + SKIP(return, "unexpected inject type %d.\n", type); + } + + /* Check if the value of HardwareCorrupted has increased. */ + ASSERT_EQ(get_hardware_corrupted_size(&size), 0); + ASSERT_EQ(size, self->corrupted_size + self->page_size / 1024); + + /* Check if HWPoison flag is set. */ + ASSERT_EQ(pageflags_get(self->pfn, self->kpageflags_fd, &pfn_flags), 0); + ASSERT_EQ(pfn_flags & KPF_HWPOISON, KPF_HWPOISON); +} + +static void cleanup(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self, + void *vaddr) +{ + unsigned long size; + uint64_t pfn_flags; + + ASSERT_EQ(unpoison_memory(self->pfn), 0); + + /* Check if HWPoison flag is cleared. */ + ASSERT_EQ(pageflags_get(self->pfn, self->kpageflags_fd, &pfn_flags), 0); + ASSERT_NE(pfn_flags & KPF_HWPOISON, KPF_HWPOISON); + + /* Check if the value of HardwareCorrupted has decreased. */ + ASSERT_EQ(get_hardware_corrupted_size(&size), 0); + ASSERT_EQ(size, self->corrupted_size); +} + +TEST_F(memory_failure, anon) +{ + char *addr; + int ret; + + addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (addr == MAP_FAILED) + 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 (!self->triggered) { + self->triggered = true; + ASSERT_EQ(variant->inject(self, addr), 0); + FORCE_READ(*addr); + } + + if (variant->type == MADV_HARD) + check(_metadata, self, addr, MADV_HARD_ANON, ret); + else + check(_metadata, self, addr, MADV_SOFT_ANON, ret); + + cleanup(_metadata, self, addr); + + ASSERT_EQ(munmap(addr, self->page_size), 0); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 2dadbfc6e535..043ac00a98b8 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -87,6 +87,8 @@ separated by spaces: test VMA merge cases behave as expected - rmap test rmap behaves as expected +- memory-failure + test memory-failure behaves as expected

example: ./run_vmtests.sh -t "hmm mmap ksm" EOF @@ -535,6 +537,25 @@ CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned

CATEGORY="rmap" run_test ./rmap

+# Try to load hwpoison_inject if not present. +HWPOISON_DIR=/sys/kernel/debug/hwpoison/ +if [ ! -d "$HWPOISON_DIR" ]; then + if ! modprobe -q -R hwpoison_inject; then + echo "Module hwpoison_inject not found, skipping..." + else + modprobe hwpoison_inject > /dev/null 2>&1 + LOADED_MOD=1 + fi +fi + +if [ -d "$HWPOISON_DIR" ]; then + CATEGORY="memory-failure" run_test ./memory-failure +fi + +if [ -n "${LOADED_MOD}" ]; then + modprobe -r hwpoison_inject > /dev/null 2>&1 +fi + if [ "${HAVE_HUGEPAGES}" = 1 ]; then echo "$orig_nr_hugepgs" > /proc/sys/vm/nr_hugepages fi diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index d954bf91afd5..a6d4ff7dfdc0 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -723,3 +723,44 @@ int ksm_stop(void) close(ksm_fd); return ret == 1 ? 0 : -errno; } + +int get_hardware_corrupted_size(unsigned long *val) +{ + unsigned long size; + char *line = NULL; + size_t linelen = 0; + FILE *f = fopen("/proc/meminfo", "r"); + int ret = -1; + + if (!f) + return ret; + + while (getline(&line, &linelen, f) > 0) { + if (sscanf(line, "HardwareCorrupted: %12lu kB", &size) == 1) { + *val = size; + ret = 0; + break; + } + } + + free(line); + fclose(f); + return ret; +} + +int unpoison_memory(unsigned long pfn) +{ + int unpoison_fd, len; + char buf[32]; + ssize_t ret; + + unpoison_fd = open("/sys/kernel/debug/hwpoison/unpoison-pfn", O_WRONLY); + if (unpoison_fd < 0) + return -errno; + + len = sprintf(buf, "0x%lx\n", pfn); + ret = write(unpoison_fd, buf, len); + close(unpoison_fd); + + return ret > 0 ? 0 : -errno; +} diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 6ad32b1830f1..b0c4ea994082 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -20,6 +20,7 @@

#define KPF_COMPOUND_HEAD BIT_ULL(15) #define KPF_COMPOUND_TAIL BIT_ULL(16) +#define KPF_HWPOISON BIT_ULL(19) #define KPF_THP BIT_ULL(22) /* * Ignore the checkpatch warning, we must read from x but don't want to do @@ -147,6 +148,8 @@ long ksm_get_full_scans(void); int ksm_use_zero_pages(void); int ksm_start(void); int ksm_stop(void); +int get_hardware_corrupted_size(unsigned long *val); +int unpoison_memory(unsigned long pfn);

/* * On ppc64 this will only work with radix 2M hugepage size

This patch adds a new testcase to validate memory failure handling for dirty pagecache. This performs similar operations as clean pagecaches except fsync() is not used to keep pages dirty.

This test helps ensure that memory failure handling for dirty pagecache works correctly, including proper SIGBUS delivery, page isolation, and recovery paths.

Signed-off-by: Miaohe Lin linmiaohe@huawei.com --- tools/testing/selftests/mm/memory-failure.c | 58 +++++++++++++++++++-- 1 file changed, 54 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c index 41bc669cef60..275ab1c6de0c 100644 --- a/tools/testing/selftests/mm/memory-failure.c +++ b/tools/testing/selftests/mm/memory-failure.c @@ -26,8 +26,10 @@ enum inject_type { enum result_type { MADV_HARD_ANON, MADV_HARD_CLEAN_PAGECACHE, + MADV_HARD_DIRTY_PAGECACHE, MADV_SOFT_ANON, MADV_SOFT_CLEAN_PAGECACHE, + MADV_SOFT_DIRTY_PAGECACHE, };

static jmp_buf signal_jmp_buf; @@ -159,6 +161,7 @@ static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure case MADV_SOFT_ANON: 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);

@@ -169,6 +172,7 @@ static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure ASSERT_NE(pagemap_get_pfn(self->pagemap_fd, vaddr), self->pfn); break; case MADV_HARD_ANON: + case MADV_HARD_DIRTY_PAGECACHE: /* The SIGBUS signal should have been received. */ ASSERT_EQ(setjmp, 1);

@@ -241,18 +245,27 @@ TEST_F(memory_failure, anon) ASSERT_EQ(munmap(addr, self->page_size), 0); }

+static int prepare_file(const char *fname, unsigned long size) +{ + int fd; + + fd = open(fname, O_RDWR | O_CREAT, 0664); + if (fd >= 0) { + unlink(fname); + ftruncate(fd, size); + } + return fd; +} + TEST_F(memory_failure, clean_pagecache) { - const char *fname = "./clean-page-cache-test-file"; int fd; char *addr; int ret;

- fd = open(fname, O_RDWR | O_CREAT, 0664); + fd = prepare_file("./clean-page-cache-test-file", self->page_size); if (fd < 0) SKIP(return, "failed to open test file.\n"); - unlink(fname); - ftruncate(fd, self->page_size);

addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); @@ -282,4 +295,41 @@ TEST_F(memory_failure, clean_pagecache) ASSERT_EQ(close(fd), 0); }

+TEST_F(memory_failure, dirty_pagecache) +{ + int fd; + char *addr; + int ret; + + fd = prepare_file("./dirty-page-cache-test-file", self->page_size); + if (fd < 0) + SKIP(return, "failed to open test file.\n"); + + addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) + 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 (!self->triggered) { + self->triggered = true; + ASSERT_EQ(variant->inject(self, addr), 0); + FORCE_READ(*addr); + } + + if (variant->type == MADV_HARD) + check(_metadata, self, addr, MADV_HARD_DIRTY_PAGECACHE, ret); + else + check(_metadata, self, addr, MADV_SOFT_DIRTY_PAGECACHE, ret); + + cleanup(_metadata, self, addr); + + ASSERT_EQ(munmap(addr, self->page_size), 0); + + ASSERT_EQ(close(fd), 0); +} + TEST_HARNESS_MAIN