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selftests/mm: move uffd pagemap test to unit test

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Move it over and make it split into two tests, one for pagemap and one for
the new WP_UNPOPULATED (to be a separate one).

The thp pagemap test wasn't really working (with MADV_HUGEPAGE).  Let's
just drop it (since it never really worked anyway..) and leave that for
later.

Link: https://lkml.kernel.org/r/20230412164352.328733-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Peter Xu 2023-04-12 12:43:52 -04:00 committed by Andrew Morton
parent 16a45b57cb
commit 8bda424fca
2 changed files with 145 additions and 166 deletions
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166
tools/testing/selftests/mm/uffd-stress.c
View File

@ -670,157 +670,6 @@ static int userfaultfd_minor_test(void)
return args.missing_faults != 0 || args.minor_faults != nr_pages;
}
static int pagemap_open(void)
{
int fd = open("/proc/self/pagemap", O_RDONLY);
if (fd < 0)
err("open pagemap");
return fd;
}
/* This macro let __LINE__ works in err() */
#define pagemap_check_wp(value, wp) do { \
if (!!(value & PM_UFFD_WP) != wp) \
err("pagemap uffd-wp bit error: 0x%"PRIx64, value); \
} while (0)
static int pagemap_test_fork(bool present)
{
pid_t child = fork();
uint64_t value;
int fd, result;
if (!child) {
/* Open the pagemap fd of the child itself */
fd = pagemap_open();
value = pagemap_get_entry(fd, area_dst);
/*
* After fork() uffd-wp bit should be gone as long as we're
* without UFFD_FEATURE_EVENT_FORK
*/
pagemap_check_wp(value, false);
/* Succeed */
exit(0);
}
waitpid(child, &result, 0);
return result;
}
static void userfaultfd_wp_unpopulated_test(int pagemap_fd)
{
uint64_t value;
/* Test applying pte marker to anon unpopulated */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Test unprotect on anon pte marker */
wp_range(uffd, (uint64_t)area_dst, page_size, false);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Test zap on anon marker */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Test fault in after marker removed */
*area_dst = 1;
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Drop it to make pte none again */
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
/* Test read-zero-page upon pte marker */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
*(volatile char *)area_dst;
/* Drop it to make pte none again */
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
}
static void userfaultfd_pagemap_test(unsigned int test_pgsize)
{
int pagemap_fd;
uint64_t value;
/* Pagemap tests uffd-wp only */
if (!test_uffdio_wp)
return;
/* Not enough memory to test this page size */
if (test_pgsize > nr_pages * page_size)
return;
printf("testing uffd-wp with pagemap (pgsize=%u): ", test_pgsize);
/* Flush so it doesn't flush twice in parent/child later */
fflush(stdout);
uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED);
if (test_pgsize > page_size) {
/* This is a thp test */
if (madvise(area_dst, nr_pages * page_size, MADV_HUGEPAGE))
err("madvise(MADV_HUGEPAGE) failed");
} else if (test_pgsize == page_size) {
/* This is normal page test; force no thp */
if (madvise(area_dst, nr_pages * page_size, MADV_NOHUGEPAGE))
err("madvise(MADV_NOHUGEPAGE) failed");
}
if (uffd_register(uffd, area_dst, nr_pages * page_size,
false, true, false))
err("register failed");
pagemap_fd = pagemap_open();
/* Smoke test WP_UNPOPULATED first when it's still empty */
if (test_pgsize == page_size)
userfaultfd_wp_unpopulated_test(pagemap_fd);
/* Touch the page */
*area_dst = 1;
wp_range(uffd, (uint64_t)area_dst, test_pgsize, true);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Make sure uffd-wp bit dropped when fork */
if (pagemap_test_fork(true))
err("Detected stall uffd-wp bit in child");
/* Exclusive required or PAGEOUT won't work */
if (!(value & PM_MMAP_EXCLUSIVE))
err("multiple mapping detected: 0x%"PRIx64, value);
if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
err("madvise(MADV_PAGEOUT) failed");
/* Uffd-wp should persist even swapped out */
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Make sure uffd-wp bit dropped when fork */
if (pagemap_test_fork(false))
err("Detected stall uffd-wp bit in child");
/* Unprotect; this tests swap pte modifications */
wp_range(uffd, (uint64_t)area_dst, page_size, false);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Fault in the page from disk */
*area_dst = 2;
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
close(pagemap_fd);
printf("done\n");
}
static int userfaultfd_stress(void)
{
void *area;
@ -932,21 +781,6 @@ static int userfaultfd_stress(void)
uffd_stats_report(args, nr_cpus);
}
if (test_type == TEST_ANON) {
/*
* shmem/hugetlb won't be able to run since they have different
* behavior on fork() (file-backed memory normally drops ptes
* directly when fork), meanwhile the pagemap test will verify
* pgtable entry of fork()ed child.
*/
userfaultfd_pagemap_test(page_size);
/*
* Hard-code for x86_64 for now for 2M THP, as x86_64 is
* currently the only one that supports uffd-wp
*/
userfaultfd_pagemap_test(page_size * 512);
}
return userfaultfd_zeropage_test() || userfaultfd_sig_test()
|| userfaultfd_events_test() || userfaultfd_minor_test();
}

145
tools/testing/selftests/mm/uffd-unit-tests.c
View File

@ -197,7 +197,152 @@ static bool uffd_feature_supported(uffd_test_case_t *test)
test->uffd_feature_required;
}
static int pagemap_open(void)
{
int fd = open("/proc/self/pagemap", O_RDONLY);
if (fd < 0)
err("open pagemap");
return fd;
}
/* This macro let __LINE__ works in err() */
#define pagemap_check_wp(value, wp) do { \
if (!!(value & PM_UFFD_WP) != wp) \
err("pagemap uffd-wp bit error: 0x%"PRIx64, value); \
} while (0)
static int pagemap_test_fork(bool present)
{
pid_t child = fork();
uint64_t value;
int fd, result;
if (!child) {
/* Open the pagemap fd of the child itself */
fd = pagemap_open();
value = pagemap_get_entry(fd, area_dst);
/*
* After fork() uffd-wp bit should be gone as long as we're
* without UFFD_FEATURE_EVENT_FORK
*/
pagemap_check_wp(value, false);
/* Succeed */
exit(0);
}
waitpid(child, &result, 0);
return result;
}
static void uffd_wp_unpopulated_test(void)
{
uint64_t value;
int pagemap_fd;
if (uffd_register(uffd, area_dst, nr_pages * page_size,
false, true, false))
err("register failed");
pagemap_fd = pagemap_open();
/* Test applying pte marker to anon unpopulated */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Test unprotect on anon pte marker */
wp_range(uffd, (uint64_t)area_dst, page_size, false);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Test zap on anon marker */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Test fault in after marker removed */
*area_dst = 1;
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Drop it to make pte none again */
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
/* Test read-zero-page upon pte marker */
wp_range(uffd, (uint64_t)area_dst, page_size, true);
*(volatile char *)area_dst;
/* Drop it to make pte none again */
if (madvise(area_dst, page_size, MADV_DONTNEED))
err("madvise(MADV_DONTNEED) failed");
uffd_test_pass();
}
static void uffd_pagemap_test(void)
{
int pagemap_fd;
uint64_t value;
if (uffd_register(uffd, area_dst, nr_pages * page_size,
false, true, false))
err("register failed");
pagemap_fd = pagemap_open();
/* Touch the page */
*area_dst = 1;
wp_range(uffd, (uint64_t)area_dst, page_size, true);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Make sure uffd-wp bit dropped when fork */
if (pagemap_test_fork(true))
err("Detected stall uffd-wp bit in child");
/* Exclusive required or PAGEOUT won't work */
if (!(value & PM_MMAP_EXCLUSIVE))
err("multiple mapping detected: 0x%"PRIx64, value);
if (madvise(area_dst, page_size, MADV_PAGEOUT))
err("madvise(MADV_PAGEOUT) failed");
/* Uffd-wp should persist even swapped out */
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, true);
/* Make sure uffd-wp bit dropped when fork */
if (pagemap_test_fork(false))
err("Detected stall uffd-wp bit in child");
/* Unprotect; this tests swap pte modifications */
wp_range(uffd, (uint64_t)area_dst, page_size, false);
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
/* Fault in the page from disk */
*area_dst = 2;
value = pagemap_get_entry(pagemap_fd, area_dst);
pagemap_check_wp(value, false);
close(pagemap_fd);
uffd_test_pass();
}
uffd_test_case_t uffd_tests[] = {
{
.name = "pagemap",
.uffd_fn = uffd_pagemap_test,
.mem_targets = MEM_ANON,
.uffd_feature_required = UFFD_FEATURE_PAGEFAULT_FLAG_WP,
},
{
.name = "wp-unpopulated",
.uffd_fn = uffd_wp_unpopulated_test,
.mem_targets = MEM_ANON,
.uffd_feature_required =
UFFD_FEATURE_PAGEFAULT_FLAG_WP | UFFD_FEATURE_WP_UNPOPULATED,
},
};
int main(int argc, char *argv[])