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selftests/mm: check that PAGEMAP_SCAN returns correct categories

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Right now, tests read page flags from /proc/pid/pagemap files.  With this
change, tests will check that PAGEMAP_SCAN return correct information too.

[colin.i.king@gmail.com: fix spelling mistake "succedded" -> "succeeded"]
  Link: https://lkml.kernel.org/r/20231121093104.1728332-1-colin.i.king@gmail.com
Link: https://lkml.kernel.org/r/20231106220959.296568-2-avagin@google.com
Signed-off-by: Andrei Vagin <avagin@google.com>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
[avagin@google.com: allow running tests on old kernels]
  Link: https://lkml.kernel.org/r/20231117181127.2574897-1-avagin@google.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrei Vagin 2023-11-06 14:09:59 -08:00 committed by Andrew Morton
parent e6a9a2cbc1
commit 600bca5805
1 changed files with 77 additions and 3 deletions
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80
tools/testing/selftests/mm/vm_util.c
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@ -4,6 +4,7 @@
#include <dirent.h>
#include <sys/ioctl.h>
#include <linux/userfaultfd.h>
#include <linux/fs.h>
#include <sys/syscall.h>
#include <unistd.h>
#include "../kselftest.h"
@ -28,19 +29,92 @@ uint64_t pagemap_get_entry(int fd, char *start)
return entry;
}
static uint64_t __pagemap_scan_get_categories(int fd, char *start, struct page_region *r)
{
struct pm_scan_arg arg;
arg.start = (uintptr_t)start;
arg.end = (uintptr_t)(start + psize());
arg.vec = (uintptr_t)r;
arg.vec_len = 1;
arg.flags = 0;
arg.size = sizeof(struct pm_scan_arg);
arg.max_pages = 0;
arg.category_inverted = 0;
arg.category_mask = 0;
arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE |
PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |
PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY;
arg.return_mask = arg.category_anyof_mask;
return ioctl(fd, PAGEMAP_SCAN, &arg);
}
static uint64_t pagemap_scan_get_categories(int fd, char *start)
{
struct page_region r;
long ret;
ret = __pagemap_scan_get_categories(fd, start, &r);
if (ret < 0)
ksft_exit_fail_msg("PAGEMAP_SCAN failed: %s\n", strerror(errno));
if (ret == 0)
return 0;
return r.categories;
}
/* `start` is any valid address. */
static bool pagemap_scan_supported(int fd, char *start)
{
static int supported = -1;
int ret;
if (supported != -1)
return supported;
/* Provide an invalid address in order to trigger EFAULT. */
ret = __pagemap_scan_get_categories(fd, start, (struct page_region *) ~0UL);
if (ret == 0)
ksft_exit_fail_msg("PAGEMAP_SCAN succeeded unexpectedly\n");
supported = errno == EFAULT;
return supported;
}
static bool page_entry_is(int fd, char *start, char *desc,
uint64_t pagemap_flags, uint64_t pagescan_flags)
{
bool m = pagemap_get_entry(fd, start) & pagemap_flags;
if (pagemap_scan_supported(fd, start)) {
bool s = pagemap_scan_get_categories(fd, start) & pagescan_flags;
if (m == s)
return m;
ksft_exit_fail_msg(
"read and ioctl return unmatched results for %s: %d %d", desc, m, s);
}
return m;
}
bool pagemap_is_softdirty(int fd, char *start)
{
return pagemap_get_entry(fd, start) & PM_SOFT_DIRTY;
return page_entry_is(fd, start, "soft-dirty",
PM_SOFT_DIRTY, PAGE_IS_SOFT_DIRTY);
}
bool pagemap_is_swapped(int fd, char *start)
{
return pagemap_get_entry(fd, start) & PM_SWAP;
return page_entry_is(fd, start, "swap", PM_SWAP, PAGE_IS_SWAPPED);
}
bool pagemap_is_populated(int fd, char *start)
{
return pagemap_get_entry(fd, start) & (PM_PRESENT | PM_SWAP);
return page_entry_is(fd, start, "populated",
PM_PRESENT | PM_SWAP,
PAGE_IS_PRESENT | PAGE_IS_SWAPPED);
}
unsigned long pagemap_get_pfn(int fd, char *start)