userfaultfd/selftests: enable hugetlb remap and remove event testing

With MADV_DONTNEED support added to hugetlb mappings, mremap testing can
also be enabled for hugetlb.

Modify the tests to use madvise MADV_DONTNEED and MADV_REMOVE instead of
fallocate hole puch for releasing hugetlb pages.

Link: https://lkml.kernel.org/r/20220215002348.128823-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index 1948098..3b265f1 100755 (executable)
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -208,14 +208,13 @@ echo "running userfaultfd_hugetlb"
 echo "---------------------------"
 # Test requires source and destination huge pages.  Size of source
 # (half_ufd_size_MB) is passed as argument to test.
-./userfaultfd hugetlb $half_ufd_size_MB 32 $mnt/ufd_test_file
+./userfaultfd hugetlb $half_ufd_size_MB 32
 if [ $? -ne 0 ]; then
        echo "[FAIL]"
        exitcode=1
 else
        echo "[PASS]"
 fi
-rm -f $mnt/ufd_test_file
 
 echo "-------------------------"
 echo "running userfaultfd_shmem"

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 39403b8..92a4516 100644 (file)
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -89,7 +89,6 @@ static bool test_uffdio_minor = false;
 static bool map_shared;
 static int shm_fd;
 static int huge_fd;
-static char *huge_fd_off0;
 static unsigned long long *count_verify;
 static int uffd = -1;
 static int uffd_flags, finished, *pipefd;
@@ -128,9 +127,9 @@ const char *examples =
     "./userfaultfd anon 100 99999\n\n"
     "# Run share memory test on 1GiB region with 99 bounces:\n"
     "./userfaultfd shmem 1000 99\n\n"
-    "# Run hugetlb memory test on 256MiB region with 50 bounces (using /dev/hugepages/hugefile):\n"
-    "./userfaultfd hugetlb 256 50 /dev/hugepages/hugefile\n\n"
-    "# Run the same hugetlb test but using shmem:\n"
+    "# Run hugetlb memory test on 256MiB region with 50 bounces:\n"
+    "./userfaultfd hugetlb 256 50\n\n"
+    "# Run the same hugetlb test but using shared file:\n"
     "./userfaultfd hugetlb_shared 256 50 /dev/hugepages/hugefile\n\n"
     "# 10MiB-~6GiB 999 bounces anonymous test, "
     "continue forever unless an error triggers\n"
@@ -227,10 +226,13 @@ static void noop_alias_mapping(__u64 *start, size_t len, unsigned long offset)
 
 static void hugetlb_release_pages(char *rel_area)
 {
-       if (fallocate(huge_fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-                     rel_area == huge_fd_off0 ? 0 : nr_pages * page_size,
-                     nr_pages * page_size))
-               err("fallocate() failed");
+       if (!map_shared) {
+               if (madvise(rel_area, nr_pages * page_size, MADV_DONTNEED))
+                       err("madvise(MADV_DONTNEED) failed");
+       } else {
+               if (madvise(rel_area, nr_pages * page_size, MADV_REMOVE))
+                       err("madvise(MADV_REMOVE) failed");
+       }
 }
 
 static void hugetlb_allocate_area(void **alloc_area)
@@ -238,26 +240,37 @@ static void hugetlb_allocate_area(void **alloc_area)
        void *area_alias = NULL;
        char **alloc_area_alias;
 
-       *alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
-                          (map_shared ? MAP_SHARED : MAP_PRIVATE) |
-                          MAP_HUGETLB |
-                          (*alloc_area == area_src ? 0 : MAP_NORESERVE),
-                          huge_fd, *alloc_area == area_src ? 0 :
-                          nr_pages * page_size);
+       if (!map_shared)
+               *alloc_area = mmap(NULL,
+                       nr_pages * page_size,
+                       PROT_READ | PROT_WRITE,
+                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB |
+                               (*alloc_area == area_src ? 0 : MAP_NORESERVE),
+                       -1,
+                       0);
+       else
+               *alloc_area = mmap(NULL,
+                       nr_pages * page_size,
+                       PROT_READ | PROT_WRITE,
+                       MAP_SHARED |
+                               (*alloc_area == area_src ? 0 : MAP_NORESERVE),
+                       huge_fd,
+                       *alloc_area == area_src ? 0 : nr_pages * page_size);
        if (*alloc_area == MAP_FAILED)
                err("mmap of hugetlbfs file failed");
 
        if (map_shared) {
-               area_alias = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
-                                 MAP_SHARED | MAP_HUGETLB,
-                                 huge_fd, *alloc_area == area_src ? 0 :
-                                 nr_pages * page_size);
+               area_alias = mmap(NULL,
+                       nr_pages * page_size,
+                       PROT_READ | PROT_WRITE,
+                       MAP_SHARED,
+                       huge_fd,
+                       *alloc_area == area_src ? 0 : nr_pages * page_size);
                if (area_alias == MAP_FAILED)
                        err("mmap of hugetlb file alias failed");
        }
 
        if (*alloc_area == area_src) {
-               huge_fd_off0 = *alloc_area;
                alloc_area_alias = &area_src_alias;
        } else {
                alloc_area_alias = &area_dst_alias;
@@ -270,12 +283,7 @@ static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset
 {
        if (!map_shared)
                return;
-       /*
-        * We can't zap just the pagetable with hugetlbfs because
-        * MADV_DONTEED won't work. So exercise -EEXIST on a alias
-        * mapping where the pagetables are not established initially,
-        * this way we'll exercise the -EEXEC at the fs level.
-        */
+
        *start = (unsigned long) area_dst_alias + offset;
 }
 
@@ -428,7 +436,6 @@ static void uffd_test_ctx_clear(void)
                uffd = -1;
        }
 
-       huge_fd_off0 = NULL;
        munmap_area((void **)&area_src);
        munmap_area((void **)&area_src_alias);
        munmap_area((void **)&area_dst);
@@ -926,10 +933,7 @@ static int faulting_process(int signal_test)
        struct sigaction act;
        unsigned long signalled = 0;
 
-       if (test_type != TEST_HUGETLB)
-               split_nr_pages = (nr_pages + 1) / 2;
-       else
-               split_nr_pages = nr_pages;
+       split_nr_pages = (nr_pages + 1) / 2;
 
        if (signal_test) {
                sigbuf = &jbuf;
@@ -986,9 +990,6 @@ static int faulting_process(int signal_test)
        if (signal_test)
                return signalled != split_nr_pages;
 
-       if (test_type == TEST_HUGETLB)
-               return 0;
-
        area_dst = mremap(area_dst, nr_pages * page_size,  nr_pages * page_size,
                          MREMAP_MAYMOVE | MREMAP_FIXED, area_src);
        if (area_dst == MAP_FAILED)
@@ -1676,7 +1677,7 @@ int main(int argc, char **argv)
        }
        nr_pages = nr_pages_per_cpu * nr_cpus;
 
-       if (test_type == TEST_HUGETLB) {
+       if (test_type == TEST_HUGETLB && map_shared) {
                if (argc < 5)
                        usage();
                huge_fd = open(argv[4], O_CREAT | O_RDWR, 0755);