| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20230428004139.2899856-7-jiaqiyan@google.com>
Date: Fri, 28 Apr 2023 00:41:38 +0000
From: Jiaqi Yan <jiaqiyan@...gle.com>
To: mike.kravetz@...cle.com, peterx@...hat.com, naoya.horiguchi@....com
Cc: songmuchun@...edance.com, duenwen@...gle.com,
axelrasmussen@...gle.com, jthoughton@...gle.com,
rientjes@...gle.com, linmiaohe@...wei.com, shy828301@...il.com,
baolin.wang@...ux.alibaba.com, wangkefeng.wang@...wei.com,
akpm@...ux-foundation.org, linux-mm@...ck.org,
linux-kernel@...r.kernel.org, Jiaqi Yan <jiaqiyan@...gle.com>
Subject: [RFC PATCH v1 6/7] selftest/mm: test PAGESIZE unmapping HWPOISON pages
After injecting memory errors to byte addresses inside HugeTLB page,
the updated test checks
1. only a raw page is unmapped, and userspace gets correct SIGBUS
from kernel.
2. other subpages in the same hugepage are still mapped and data not
corrupted.
Signed-off-by: Jiaqi Yan <jiaqiyan@...gle.com>
---
tools/testing/selftests/mm/hugetlb-hgm.c | 194 +++++++++++++++++++----
1 file changed, 167 insertions(+), 27 deletions(-)
diff --git a/tools/testing/selftests/mm/hugetlb-hgm.c b/tools/testing/selftests/mm/hugetlb-hgm.c
index c0ba6ad44005..bc9529986b66 100644
--- a/tools/testing/selftests/mm/hugetlb-hgm.c
+++ b/tools/testing/selftests/mm/hugetlb-hgm.c
@@ -39,6 +39,10 @@
#define MADV_SPLIT 26
#endif
+#ifndef NUM_HWPOISON_PAGES
+#define NUM_HWPOISON_PAGES 3UL
+#endif
+
#define PREFIX " ... "
#define ERROR_PREFIX " !!! "
@@ -241,6 +245,9 @@ static int test_sigbus(char *addr, bool poison)
sigbus_addr, addr);
else if (poison && !was_mceerr)
printf(ERROR_PREFIX "didn't get an MCEERR?\n");
+ else if (!poison && was_mceerr)
+ printf(ERROR_PREFIX "got BUS_MCEERR_AR sigbus on expected healthy address: %p\n",
+ sigbus_addr);
else
ret = 0;
out:
@@ -272,43 +279,176 @@ static int read_event_from_uffd(int *uffd, pthread_t *pthread)
return 0;
}
-static int test_sigbus_range(char *primary_map, size_t len, bool hwpoison)
+struct range_exclude_pages {
+ /* Starting address of the buffer. */
+ char *mapping;
+ /* Length of the buffer in bytes. */
+ size_t length;
+ /* The value that each byte in buffer should equal to. */
+ char value;
+ /*
+ * PAGESIZE aligned addresses excluded from the checking,
+ * e.g. if PAGE_SIZE=4k, for each addr in excludes,
+ * skips checking on [addr, addr + 4096).
+ */
+ unsigned long excluded[NUM_HWPOISON_PAGES];
+};
+
+static int check_range_exclude_pages(struct range_exclude_pages *range)
+{
+ const unsigned long pagesize = getpagesize();
+ unsigned long excluded_index;
+ unsigned long page_index;
+ bool should_skip;
+ size_t i = 0;
+ size_t j = 0;
+
+ while (i < range->length) {
+ page_index = ((unsigned long)(range->mapping + i)) / pagesize;
+ should_skip = false;
+ for (j = 0; j < NUM_HWPOISON_PAGES; ++j) {
+ excluded_index = range->excluded[j] / pagesize;
+ if (page_index == excluded_index) {
+ should_skip = true;
+ break;
+ }
+ }
+ if (should_skip) {
+ printf(PREFIX "skip excluded addr range [%#lx, %#lx)\n",
+ (unsigned long)(range->mapping + i),
+ (unsigned long)(range->mapping + i + pagesize));
+ i += pagesize;
+ continue;
+ }
+ if (range->mapping[i] != range->value) {
+ printf(ERROR_PREFIX "mismatch at %p (%d != %d)\n",
+ &range->mapping[i], range->mapping[i], range->value);
+ return -1;
+ }
+ ++i;
+ }
+
+ return 0;
+}
+
+enum test_status verify_raw_pages(char *map, size_t len,
+ unsigned long excluded[NUM_HWPOISON_PAGES])
{
const unsigned long pagesize = getpagesize();
- const int num_checks = 512;
- unsigned long bytes_per_check = len/num_checks;
- int i;
+ unsigned long size, offset, value;
+ size_t j = 0;
+
+ for (size = len / 2, offset = 0, value = 1; size > pagesize;
+ offset += size, size /= 2, ++value) {
+ struct range_exclude_pages range = {
+ .mapping = map + offset,
+ .length = size,
+ .value = value,
+ };
+ for (j = 0; j < NUM_HWPOISON_PAGES; ++j)
+ range.excluded[j] = excluded[j];
+
+ printf(PREFIX "checking non-poisoned range [%p, %p) "
+ "(len=%#lx) per-byte value=%lu\n",
+ range.mapping, range.mapping + range.length,
+ range.length, value);
+ if (check_range_exclude_pages(&range))
+ return TEST_FAILED;
+
+ printf(PREFIX PREFIX "good\n");
+ }
- printf(PREFIX "checking that we can't access "
- "(%d addresses within %p -> %p)\n",
- num_checks, primary_map, primary_map + len);
+ return TEST_PASSED;
+}
- if (pagesize > bytes_per_check)
- bytes_per_check = pagesize;
+static int read_hwpoison_pages(unsigned long *nr_hwp_pages)
+{
+ const unsigned long pagesize = getpagesize();
+ char buffer[256] = {0};
+ char *cmd = "cat /proc/meminfo | grep -i HardwareCorrupted | grep -o '[0-9]*'";
+ FILE *cmdfile = popen(cmd, "r");
- for (i = 0; i < len; i += bytes_per_check)
- if (test_sigbus(primary_map + i, hwpoison) < 0)
- return 1;
- /* check very last byte, because we left it unmapped */
- if (test_sigbus(primary_map + len - 1, hwpoison))
- return 1;
+ if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
+ perror("failed to read HardwareCorrupted from /proc/meminfo\n");
+ return -1;
+ }
+ pclose(cmdfile);
+ *nr_hwp_pages = atoll(buffer) * 1024 / pagesize;
return 0;
}
-static enum test_status test_hwpoison(char *primary_map, size_t len)
+static enum test_status test_hwpoison_one_raw_page(char *hwpoison_addr)
{
- printf(PREFIX "poisoning %p -> %p\n", primary_map, primary_map + len);
- if (madvise(primary_map, len, MADV_HWPOISON) < 0) {
+ const unsigned long pagesize = getpagesize();
+
+ printf(PREFIX "poisoning [%p, %p) (len=%#lx)\n",
+ hwpoison_addr, hwpoison_addr + pagesize, pagesize);
+ if (madvise(hwpoison_addr, pagesize, MADV_HWPOISON) < 0) {
perror(ERROR_PREFIX "MADV_HWPOISON failed");
return TEST_SKIPPED;
}
- return test_sigbus_range(primary_map, len, true)
- ? TEST_FAILED : TEST_PASSED;
+ printf(PREFIX "checking poisoned range [%p, %p) (len=%#lx)\n",
+ hwpoison_addr, hwpoison_addr + pagesize, pagesize);
+ if (test_sigbus(hwpoison_addr, true) < 0)
+ return TEST_FAILED;
+
+ return TEST_PASSED;
}
-static int test_fork(int uffd, char *primary_map, size_t len)
+static enum test_status test_hwpoison_present(char *map, size_t len,
+ bool already_injected)
+{
+ const unsigned long pagesize = getpagesize();
+ const unsigned long hwpoison_next = 128;
+ unsigned long nr_hwpoison_pages_before, nr_hwpoison_pages_after;
+ enum test_status ret;
+ size_t i;
+ char *hwpoison_addr = map;
+ unsigned long hwpoison_addrs[NUM_HWPOISON_PAGES];
+
+ if (hwpoison_next * (NUM_HWPOISON_PAGES - 1) >= (len / pagesize)) {
+ printf(ERROR_PREFIX "max hwpoison_addr out of range");
+ return TEST_SKIPPED;
+ }
+
+ for (i = 0; i < NUM_HWPOISON_PAGES; ++i) {
+ hwpoison_addrs[i] = (unsigned long)hwpoison_addr;
+ hwpoison_addr += hwpoison_next * pagesize;
+ }
+
+ if (already_injected)
+ return verify_raw_pages(map, len, hwpoison_addrs);
+
+ if (read_hwpoison_pages(&nr_hwpoison_pages_before)) {
+ printf(ERROR_PREFIX "check #HWPOISON pages\n");
+ return TEST_SKIPPED;
+ }
+ printf(PREFIX "Before injections, #HWPOISON pages = %ld\n", nr_hwpoison_pages_before);
+
+ for (i = 0; i < NUM_HWPOISON_PAGES; ++i) {
+ ret = test_hwpoison_one_raw_page((char *)hwpoison_addrs[i]);
+ if (ret != TEST_PASSED)
+ return ret;
+ }
+
+ if (read_hwpoison_pages(&nr_hwpoison_pages_after)) {
+ printf(ERROR_PREFIX "check #HWPOISON pages\n");
+ return TEST_SKIPPED;
+ }
+ printf(PREFIX "After injections, #HWPOISON pages = %ld\n", nr_hwpoison_pages_after);
+
+ if (nr_hwpoison_pages_after - nr_hwpoison_pages_before != NUM_HWPOISON_PAGES) {
+ printf(ERROR_PREFIX "delta #HWPOISON pages != %ld",
+ NUM_HWPOISON_PAGES);
+ return TEST_FAILED;
+ }
+
+ return verify_raw_pages(map, len, hwpoison_addrs);
+}
+
+int test_fork(int uffd, char *primary_map, size_t len)
{
int status;
int ret = 0;
@@ -360,7 +500,6 @@ static int test_fork(int uffd, char *primary_map, size_t len)
pthread_join(uffd_thd, NULL);
return ret;
-
}
static int uffd_register(int uffd, char *primary_map, unsigned long len,
@@ -394,6 +533,7 @@ test_hgm(int fd, size_t hugepagesize, size_t len, enum test_type type)
bool uffd_wp = type == TEST_UFFDWP;
bool verify = type == TEST_DEFAULT;
int register_args;
+ enum test_status hwp_status = TEST_SKIPPED;
if (ftruncate(fd, len) < 0) {
perror(ERROR_PREFIX "ftruncate failed");
@@ -489,10 +629,10 @@ test_hgm(int fd, size_t hugepagesize, size_t len, enum test_type type)
* mapping.
*/
if (hwpoison) {
- enum test_status new_status = test_hwpoison(primary_map, len);
-
- if (new_status != TEST_PASSED) {
- status = new_status;
+ /* test_hwpoison can fail with TEST_SKIPPED. */
+ hwp_status = test_hwpoison_present(primary_map, len, false);
+ if (hwp_status != TEST_PASSED) {
+ status = hwp_status;
goto done;
}
}
@@ -539,7 +679,7 @@ test_hgm(int fd, size_t hugepagesize, size_t len, enum test_type type)
/*
* Verify that memory is still poisoned.
*/
- if (hwpoison && test_sigbus_range(primary_map, len, true))
+ if (hwpoison && test_hwpoison_present(primary_map, len, true))
goto done;
status = TEST_PASSED;
--
2.40.1.495.gc816e09b53d-goog
Powered by blists - more mailing lists