mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 14:51:00 +07:00
selftests: add MREMAP_DONTUNMAP selftest
Add a few simple self tests for the new flag MREMAP_DONTUNMAP, they are simple smoke tests which also demonstrate the behavior. [akpm@linux-foundation.org: convert eight-spaces to hard tabs] [bgeffon@google.com: v7] Link: http://lkml.kernel.org/r/20200221174248.244748-2-bgeffon@google.com [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Brian Geffon <bgeffon@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Deacon <will@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Yu Zhao <yuzhao@google.com> Cc: Jesse Barnes <jsbarnes@google.com> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Lokesh Gidra <lokeshgidra@google.com> Link: http://lkml.kernel.org/r/20200218173221.237674-2-bgeffon@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Brian Geffon
Linus Torvalds
parent
e346b38130
commit
0c28759ee3
@ -14,6 +14,7 @@ TEST_GEN_FILES += map_fixed_noreplace
|
||||
TEST_GEN_FILES += map_populate
|
||||
TEST_GEN_FILES += mlock-random-test
|
||||
TEST_GEN_FILES += mlock2-tests
|
||||
TEST_GEN_FILES += mremap_dontunmap
|
||||
TEST_GEN_FILES += on-fault-limit
|
||||
TEST_GEN_FILES += thuge-gen
|
||||
TEST_GEN_FILES += transhuge-stress
|
||||
|
||||
313
tools/testing/selftests/vm/mremap_dontunmap.c
Normal file
313
tools/testing/selftests/vm/mremap_dontunmap.c
Normal file
@ -0,0 +1,313 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
/*
|
||||
* Tests for mremap w/ MREMAP_DONTUNMAP.
|
||||
*
|
||||
* Copyright 2020, Brian Geffon <bgeffon@google.com>
|
||||
*/
|
||||
#define _GNU_SOURCE
|
||||
#include <sys/mman.h>
|
||||
#include <errno.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "../kselftest.h"
|
||||
|
||||
#ifndef MREMAP_DONTUNMAP
|
||||
#define MREMAP_DONTUNMAP 4
|
||||
#endif
|
||||
|
||||
unsigned long page_size;
|
||||
char *page_buffer;
|
||||
|
||||
static void dump_maps(void)
|
||||
{
|
||||
char cmd[32];
|
||||
|
||||
snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps", getpid());
|
||||
system(cmd);
|
||||
}
|
||||
|
||||
#define BUG_ON(condition, description) \
|
||||
do { \
|
||||
if (condition) { \
|
||||
fprintf(stderr, "[FAIL]\t%s():%d\t%s:%s\n", __func__, \
|
||||
__LINE__, (description), strerror(errno)); \
|
||||
dump_maps(); \
|
||||
exit(1); \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
// Try a simple operation for to "test" for kernel support this prevents
|
||||
// reporting tests as failed when it's run on an older kernel.
|
||||
static int kernel_support_for_mremap_dontunmap()
|
||||
{
|
||||
int ret = 0;
|
||||
unsigned long num_pages = 1;
|
||||
void *source_mapping = mmap(NULL, num_pages * page_size, PROT_NONE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(source_mapping == MAP_FAILED, "mmap");
|
||||
|
||||
// This simple remap should only fail if MREMAP_DONTUNMAP isn't
|
||||
// supported.
|
||||
void *dest_mapping =
|
||||
mremap(source_mapping, num_pages * page_size, num_pages * page_size,
|
||||
MREMAP_DONTUNMAP | MREMAP_MAYMOVE, 0);
|
||||
if (dest_mapping == MAP_FAILED) {
|
||||
ret = errno;
|
||||
} else {
|
||||
BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap destination mapping");
|
||||
}
|
||||
|
||||
BUG_ON(munmap(source_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap source mapping");
|
||||
return ret;
|
||||
}
|
||||
|
||||
// This helper will just validate that an entire mapping contains the expected
|
||||
// byte.
|
||||
static int check_region_contains_byte(void *addr, unsigned long size, char byte)
|
||||
{
|
||||
BUG_ON(size & (page_size - 1),
|
||||
"check_region_contains_byte expects page multiples");
|
||||
BUG_ON((unsigned long)addr & (page_size - 1),
|
||||
"check_region_contains_byte expects page alignment");
|
||||
|
||||
memset(page_buffer, byte, page_size);
|
||||
|
||||
unsigned long num_pages = size / page_size;
|
||||
unsigned long i;
|
||||
|
||||
// Compare each page checking that it contains our expected byte.
|
||||
for (i = 0; i < num_pages; ++i) {
|
||||
int ret =
|
||||
memcmp(addr + (i * page_size), page_buffer, page_size);
|
||||
if (ret) {
|
||||
return ret;
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
// this test validates that MREMAP_DONTUNMAP moves the pagetables while leaving
|
||||
// the source mapping mapped.
|
||||
static void mremap_dontunmap_simple()
|
||||
{
|
||||
unsigned long num_pages = 5;
|
||||
|
||||
void *source_mapping =
|
||||
mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(source_mapping == MAP_FAILED, "mmap");
|
||||
|
||||
memset(source_mapping, 'a', num_pages * page_size);
|
||||
|
||||
// Try to just move the whole mapping anywhere (not fixed).
|
||||
void *dest_mapping =
|
||||
mremap(source_mapping, num_pages * page_size, num_pages * page_size,
|
||||
MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL);
|
||||
BUG_ON(dest_mapping == MAP_FAILED, "mremap");
|
||||
|
||||
// Validate that the pages have been moved, we know they were moved if
|
||||
// the dest_mapping contains a's.
|
||||
BUG_ON(check_region_contains_byte
|
||||
(dest_mapping, num_pages * page_size, 'a') != 0,
|
||||
"pages did not migrate");
|
||||
BUG_ON(check_region_contains_byte
|
||||
(source_mapping, num_pages * page_size, 0) != 0,
|
||||
"source should have no ptes");
|
||||
|
||||
BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap destination mapping");
|
||||
BUG_ON(munmap(source_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap source mapping");
|
||||
}
|
||||
|
||||
// This test validates MREMAP_DONTUNMAP will move page tables to a specific
|
||||
// destination using MREMAP_FIXED, also while validating that the source
|
||||
// remains intact.
|
||||
static void mremap_dontunmap_simple_fixed()
|
||||
{
|
||||
unsigned long num_pages = 5;
|
||||
|
||||
// Since we want to guarantee that we can remap to a point, we will
|
||||
// create a mapping up front.
|
||||
void *dest_mapping =
|
||||
mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(dest_mapping == MAP_FAILED, "mmap");
|
||||
memset(dest_mapping, 'X', num_pages * page_size);
|
||||
|
||||
void *source_mapping =
|
||||
mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(source_mapping == MAP_FAILED, "mmap");
|
||||
memset(source_mapping, 'a', num_pages * page_size);
|
||||
|
||||
void *remapped_mapping =
|
||||
mremap(source_mapping, num_pages * page_size, num_pages * page_size,
|
||||
MREMAP_FIXED | MREMAP_DONTUNMAP | MREMAP_MAYMOVE,
|
||||
dest_mapping);
|
||||
BUG_ON(remapped_mapping == MAP_FAILED, "mremap");
|
||||
BUG_ON(remapped_mapping != dest_mapping,
|
||||
"mremap should have placed the remapped mapping at dest_mapping");
|
||||
|
||||
// The dest mapping will have been unmap by mremap so we expect the Xs
|
||||
// to be gone and replaced with a's.
|
||||
BUG_ON(check_region_contains_byte
|
||||
(dest_mapping, num_pages * page_size, 'a') != 0,
|
||||
"pages did not migrate");
|
||||
|
||||
// And the source mapping will have had its ptes dropped.
|
||||
BUG_ON(check_region_contains_byte
|
||||
(source_mapping, num_pages * page_size, 0) != 0,
|
||||
"source should have no ptes");
|
||||
|
||||
BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap destination mapping");
|
||||
BUG_ON(munmap(source_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap source mapping");
|
||||
}
|
||||
|
||||
// This test validates that we can MREMAP_DONTUNMAP for a portion of an
|
||||
// existing mapping.
|
||||
static void mremap_dontunmap_partial_mapping()
|
||||
{
|
||||
/*
|
||||
* source mapping:
|
||||
* --------------
|
||||
* | aaaaaaaaaa |
|
||||
* --------------
|
||||
* to become:
|
||||
* --------------
|
||||
* | aaaaa00000 |
|
||||
* --------------
|
||||
* With the destination mapping containing 5 pages of As.
|
||||
* ---------
|
||||
* | aaaaa |
|
||||
* ---------
|
||||
*/
|
||||
unsigned long num_pages = 10;
|
||||
void *source_mapping =
|
||||
mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(source_mapping == MAP_FAILED, "mmap");
|
||||
memset(source_mapping, 'a', num_pages * page_size);
|
||||
|
||||
// We will grab the last 5 pages of the source and move them.
|
||||
void *dest_mapping =
|
||||
mremap(source_mapping + (5 * page_size), 5 * page_size,
|
||||
5 * page_size,
|
||||
MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL);
|
||||
BUG_ON(dest_mapping == MAP_FAILED, "mremap");
|
||||
|
||||
// We expect the first 5 pages of the source to contain a's and the
|
||||
// final 5 pages to contain zeros.
|
||||
BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 'a') !=
|
||||
0, "first 5 pages of source should have original pages");
|
||||
BUG_ON(check_region_contains_byte
|
||||
(source_mapping + (5 * page_size), 5 * page_size, 0) != 0,
|
||||
"final 5 pages of source should have no ptes");
|
||||
|
||||
// Finally we expect the destination to have 5 pages worth of a's.
|
||||
BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') !=
|
||||
0, "dest mapping should contain ptes from the source");
|
||||
|
||||
BUG_ON(munmap(dest_mapping, 5 * page_size) == -1,
|
||||
"unable to unmap destination mapping");
|
||||
BUG_ON(munmap(source_mapping, num_pages * page_size) == -1,
|
||||
"unable to unmap source mapping");
|
||||
}
|
||||
|
||||
// This test validates that we can remap over only a portion of a mapping.
|
||||
static void mremap_dontunmap_partial_mapping_overwrite(void)
|
||||
{
|
||||
/*
|
||||
* source mapping:
|
||||
* ---------
|
||||
* |aaaaa|
|
||||
* ---------
|
||||
* dest mapping initially:
|
||||
* -----------
|
||||
* |XXXXXXXXXX|
|
||||
* ------------
|
||||
* Source to become:
|
||||
* ---------
|
||||
* |00000|
|
||||
* ---------
|
||||
* With the destination mapping containing 5 pages of As.
|
||||
* ------------
|
||||
* |aaaaaXXXXX|
|
||||
* ------------
|
||||
*/
|
||||
void *source_mapping =
|
||||
mmap(NULL, 5 * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(source_mapping == MAP_FAILED, "mmap");
|
||||
memset(source_mapping, 'a', 5 * page_size);
|
||||
|
||||
void *dest_mapping =
|
||||
mmap(NULL, 10 * page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(dest_mapping == MAP_FAILED, "mmap");
|
||||
memset(dest_mapping, 'X', 10 * page_size);
|
||||
|
||||
// We will grab the last 5 pages of the source and move them.
|
||||
void *remapped_mapping =
|
||||
mremap(source_mapping, 5 * page_size,
|
||||
5 * page_size,
|
||||
MREMAP_DONTUNMAP | MREMAP_MAYMOVE | MREMAP_FIXED, dest_mapping);
|
||||
BUG_ON(dest_mapping == MAP_FAILED, "mremap");
|
||||
BUG_ON(dest_mapping != remapped_mapping, "expected to remap to dest_mapping");
|
||||
|
||||
BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 0) !=
|
||||
0, "first 5 pages of source should have no ptes");
|
||||
|
||||
// Finally we expect the destination to have 5 pages worth of a's.
|
||||
BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') != 0,
|
||||
"dest mapping should contain ptes from the source");
|
||||
|
||||
// Finally the last 5 pages shouldn't have been touched.
|
||||
BUG_ON(check_region_contains_byte(dest_mapping + (5 * page_size),
|
||||
5 * page_size, 'X') != 0,
|
||||
"dest mapping should have retained the last 5 pages");
|
||||
|
||||
BUG_ON(munmap(dest_mapping, 10 * page_size) == -1,
|
||||
"unable to unmap destination mapping");
|
||||
BUG_ON(munmap(source_mapping, 5 * page_size) == -1,
|
||||
"unable to unmap source mapping");
|
||||
}
|
||||
|
||||
int main(void)
|
||||
{
|
||||
page_size = sysconf(_SC_PAGE_SIZE);
|
||||
|
||||
// test for kernel support for MREMAP_DONTUNMAP skipping the test if
|
||||
// not.
|
||||
if (kernel_support_for_mremap_dontunmap() != 0) {
|
||||
printf("No kernel support for MREMAP_DONTUNMAP\n");
|
||||
return KSFT_SKIP;
|
||||
}
|
||||
|
||||
// Keep a page sized buffer around for when we need it.
|
||||
page_buffer =
|
||||
mmap(NULL, page_size, PROT_READ | PROT_WRITE,
|
||||
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
||||
BUG_ON(page_buffer == MAP_FAILED, "unable to mmap a page.");
|
||||
|
||||
mremap_dontunmap_simple();
|
||||
mremap_dontunmap_simple_fixed();
|
||||
mremap_dontunmap_partial_mapping();
|
||||
mremap_dontunmap_partial_mapping_overwrite();
|
||||
|
||||
BUG_ON(munmap(page_buffer, page_size) == -1,
|
||||
"unable to unmap page buffer");
|
||||
|
||||
printf("OK\n");
|
||||
return 0;
|
||||
}
|
||||
@ -292,4 +292,19 @@ else
|
||||
exitcode=1
|
||||
fi
|
||||
|
||||
echo "------------------------------------"
|
||||
echo "running MREMAP_DONTUNMAP smoke test"
|
||||
echo "------------------------------------"
|
||||
./mremap_dontunmap
|
||||
ret_val=$?
|
||||
|
||||
if [ $ret_val -eq 0 ]; then
|
||||
echo "[PASS]"
|
||||
elif [ $ret_val -eq $ksft_skip ]; then
|
||||
echo "[SKIP]"
|
||||
exitcode=$ksft_skip
|
||||
else
|
||||
echo "[FAIL]"
|
||||
exitcode=1
|
||||
fi
|
||||
exit $exitcode
|
||||
|
||||
Loading…
Reference in New Issue
Block a user