@@ -5,6 +5,7 @@ hugepage-mremap
hugepage-shm
hugepage-vmemmap
hugetlb-madvise
+hugetlb-read-hwpoison
khugepaged
map_hugetlb
map_populate
@@ -38,6 +38,7 @@ TEST_GEN_PROGS += gup_longterm
TEST_GEN_PROGS += gup_test
TEST_GEN_PROGS += hmm-tests
TEST_GEN_PROGS += hugetlb-madvise
+TEST_GEN_PROGS += hugetlb-read-hwpoison
TEST_GEN_PROGS += hugepage-mmap
TEST_GEN_PROGS += hugepage-mremap
TEST_GEN_PROGS += hugepage-shm
new file mode 100644
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <linux/magic.h>
+#include <sys/mman.h>
+#include <sys/statfs.h>
+#include <errno.h>
+#include <stdbool.h>
+
+#include "../kselftest.h"
+
+#define PREFIX " ... "
+#define ERROR_PREFIX " !!! "
+
+#define MAX_WRITE_READ_CHUNK_SIZE (getpagesize() * 16)
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+enum test_status {
+ TEST_PASSED = 0,
+ TEST_FAILED = 1,
+ TEST_SKIPPED = 2,
+};
+
+static char *status_to_str(enum test_status status)
+{
+ switch (status) {
+ case TEST_PASSED:
+ return "TEST_PASSED";
+ case TEST_FAILED:
+ return "TEST_FAILED";
+ case TEST_SKIPPED:
+ return "TEST_SKIPPED";
+ default:
+ return "TEST_???";
+ }
+}
+
+static int setup_filemap(char *filemap, size_t len, size_t wr_chunk_size)
+{
+ char iter = 0;
+
+ for (size_t offset = 0; offset < len;
+ offset += wr_chunk_size) {
+ iter++;
+ memset(filemap + offset, iter, wr_chunk_size);
+ }
+
+ return 0;
+}
+
+static bool verify_chunk(char *buf, size_t len, char val)
+{
+ size_t i;
+
+ for (i = 0; i < len; ++i) {
+ if (buf[i] != val) {
+ printf(PREFIX ERROR_PREFIX "check fail: buf[%lu] = %u != %u\n",
+ i, buf[i], val);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool seek_read_hugepage_filemap(int fd, size_t len, size_t wr_chunk_size,
+ off_t offset, size_t expected)
+{
+ char buf[MAX_WRITE_READ_CHUNK_SIZE];
+ ssize_t ret_count = 0;
+ ssize_t total_ret_count = 0;
+ char val = offset / wr_chunk_size + offset % wr_chunk_size;
+
+ printf(PREFIX PREFIX "init val=%u with offset=0x%lx\n", val, offset);
+ printf(PREFIX PREFIX "expect to read 0x%lx bytes of data in total\n",
+ expected);
+ if (lseek(fd, offset, SEEK_SET) < 0) {
+ perror(PREFIX ERROR_PREFIX "seek failed");
+ return false;
+ }
+
+ while (offset + total_ret_count < len) {
+ ret_count = read(fd, buf, wr_chunk_size);
+ if (ret_count == 0) {
+ printf(PREFIX PREFIX "read reach end of the file\n");
+ break;
+ } else if (ret_count < 0) {
+ perror(PREFIX ERROR_PREFIX "read failed");
+ break;
+ }
+ ++val;
+ if (!verify_chunk(buf, ret_count, val))
+ return false;
+
+ total_ret_count += ret_count;
+ }
+ printf(PREFIX PREFIX "actually read 0x%lx bytes of data in total\n",
+ total_ret_count);
+
+ return total_ret_count == expected;
+}
+
+static bool read_hugepage_filemap(int fd, size_t len,
+ size_t wr_chunk_size, size_t expected)
+{
+ char buf[MAX_WRITE_READ_CHUNK_SIZE];
+ ssize_t ret_count = 0;
+ ssize_t total_ret_count = 0;
+ char val = 0;
+
+ printf(PREFIX PREFIX "expect to read 0x%lx bytes of data in total\n",
+ expected);
+ while (total_ret_count < len) {
+ ret_count = read(fd, buf, wr_chunk_size);
+ if (ret_count == 0) {
+ printf(PREFIX PREFIX "read reach end of the file\n");
+ break;
+ } else if (ret_count < 0) {
+ perror(PREFIX ERROR_PREFIX "read failed");
+ break;
+ }
+ ++val;
+ if (!verify_chunk(buf, ret_count, val))
+ return false;
+
+ total_ret_count += ret_count;
+ }
+ printf(PREFIX PREFIX "actually read 0x%lx bytes of data in total\n",
+ total_ret_count);
+
+ return total_ret_count == expected;
+}
+
+static enum test_status
+test_hugetlb_read(int fd, size_t len, size_t wr_chunk_size)
+{
+ enum test_status status = TEST_SKIPPED;
+ char *filemap = NULL;
+
+ if (ftruncate(fd, len) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate failed");
+ return status;
+ }
+
+ filemap = mmap(NULL, len, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE, fd, 0);
+ if (filemap == MAP_FAILED) {
+ perror(PREFIX ERROR_PREFIX "mmap for primary mapping failed");
+ goto done;
+ }
+
+ setup_filemap(filemap, len, wr_chunk_size);
+ status = TEST_FAILED;
+
+ if (read_hugepage_filemap(fd, len, wr_chunk_size, len))
+ status = TEST_PASSED;
+
+ munmap(filemap, len);
+done:
+ if (ftruncate(fd, 0) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate back to 0 failed");
+ status = TEST_FAILED;
+ }
+
+ return status;
+}
+
+static enum test_status
+test_hugetlb_read_hwpoison(int fd, size_t len, size_t wr_chunk_size,
+ bool skip_hwpoison_page)
+{
+ enum test_status status = TEST_SKIPPED;
+ char *filemap = NULL;
+ char *hwp_addr = NULL;
+ const unsigned long pagesize = getpagesize();
+
+ if (ftruncate(fd, len) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate failed");
+ return status;
+ }
+
+ filemap = mmap(NULL, len, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE, fd, 0);
+ if (filemap == MAP_FAILED) {
+ perror(PREFIX ERROR_PREFIX "mmap for primary mapping failed");
+ goto done;
+ }
+
+ setup_filemap(filemap, len, wr_chunk_size);
+ status = TEST_FAILED;
+
+ /*
+ * Poisoned hugetlb page layout (assume hugepagesize=2MB):
+ * |<---------------------- 1MB ---------------------->|
+ * |<---- healthy page ---->|<---- HWPOISON page ----->|
+ * |<------------------- (1MB - 8KB) ----------------->|
+ */
+ hwp_addr = filemap + len / 2 + pagesize;
+ if (madvise(hwp_addr, pagesize, MADV_HWPOISON) < 0) {
+ perror(PREFIX ERROR_PREFIX "MADV_HWPOISON failed");
+ goto unmap;
+ }
+
+ if (!skip_hwpoison_page) {
+ /*
+ * Userspace should be able to read (1MB + 1 page) from
+ * the beginning of the HWPOISONed hugepage.
+ */
+ if (read_hugepage_filemap(fd, len, wr_chunk_size,
+ len / 2 + pagesize))
+ status = TEST_PASSED;
+ } else {
+ /*
+ * Userspace should be able to read (1MB - 2 pages) from
+ * HWPOISONed hugepage.
+ */
+ if (seek_read_hugepage_filemap(fd, len, wr_chunk_size,
+ len / 2 + MAX(2 * pagesize, wr_chunk_size),
+ len / 2 - MAX(2 * pagesize, wr_chunk_size)))
+ status = TEST_PASSED;
+ }
+
+unmap:
+ munmap(filemap, len);
+done:
+ if (ftruncate(fd, 0) < 0) {
+ perror(PREFIX ERROR_PREFIX "ftruncate back to 0 failed");
+ status = TEST_FAILED;
+ }
+
+ return status;
+}
+
+static int create_hugetlbfs_file(struct statfs *file_stat)
+{
+ int fd;
+
+ fd = memfd_create("hugetlb_tmp", MFD_HUGETLB);
+ if (fd < 0) {
+ perror(PREFIX ERROR_PREFIX "could not open hugetlbfs file");
+ return -1;
+ }
+
+ memset(file_stat, 0, sizeof(*file_stat));
+ if (fstatfs(fd, file_stat)) {
+ perror(PREFIX ERROR_PREFIX "fstatfs failed");
+ goto close;
+ }
+ if (file_stat->f_type != HUGETLBFS_MAGIC) {
+ printf(PREFIX ERROR_PREFIX "not hugetlbfs file\n");
+ goto close;
+ }
+
+ return fd;
+close:
+ close(fd);
+ return -1;
+}
+
+int main(void)
+{
+ int fd;
+ struct statfs file_stat;
+ enum test_status status;
+ /* Test read() in different granularity. */
+ size_t wr_chunk_sizes[] = {
+ getpagesize() / 2, getpagesize(),
+ getpagesize() * 2, getpagesize() * 4
+ };
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(wr_chunk_sizes); ++i) {
+ printf("Write/read chunk size=0x%lx\n",
+ wr_chunk_sizes[i]);
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB read regression test...\n");
+ status = test_hugetlb_read(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i]);
+ printf(PREFIX "HugeTLB read regression test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB read HWPOISON test...\n");
+ status = test_hugetlb_read_hwpoison(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i], false);
+ printf(PREFIX "HugeTLB read HWPOISON test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+
+ fd = create_hugetlbfs_file(&file_stat);
+ if (fd < 0)
+ goto create_failure;
+ printf(PREFIX "HugeTLB seek then read HWPOISON test...\n");
+ status = test_hugetlb_read_hwpoison(fd, file_stat.f_bsize,
+ wr_chunk_sizes[i], true);
+ printf(PREFIX "HugeTLB seek then read HWPOISON test...%s\n",
+ status_to_str(status));
+ close(fd);
+ if (status == TEST_FAILED)
+ return -1;
+ }
+
+ return 0;
+
+create_failure:
+ printf(ERROR_PREFIX "Abort test: failed to create hugetlbfs file\n");
+ return -1;
+}
Add tests for the improvement made to read operation on HWPOISON hugetlb page with different read granularities. For each chunk size, three read scenarios are tested: 1. Simple regression test on read without HWPOISON. 2. Sequential read page by page should succeed until encounters the 1st raw HWPOISON subpage. 3. After skip raw HWPOISON subpage by lseek, read()s always succeed. Signed-off-by: Jiaqi Yan <jiaqiyan@google.com> --- tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + .../selftests/mm/hugetlb-read-hwpoison.c | 322 ++++++++++++++++++ 3 files changed, 324 insertions(+) create mode 100644 tools/testing/selftests/mm/hugetlb-read-hwpoison.c