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userfaultfd/selftests: create alias mappings in the shmem test

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Previously, we just allocated two shm areas: area_src and area_dst.  With
this commit, change this so we also allocate area_src_alias, and
area_dst_alias.

area_*_alias and area_* (respectively) point to the same underlying
physical pages, but are different VMAs.  In a future commit in this
series, we'll leverage this setup to exercise minor fault handling support
for shmem, just like we do in the hugetlb_shared test.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Axel Rasmussen <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Brian Geffon <[email protected]>
Cc: "Dr . David Alan Gilbert" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Lokesh Gidra <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Mina Almasry <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Wang Qing <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Axel Rasmussen
2021-06-30 20:47:27 -07:00
committed by Linus Torvalds
parent fa2c2b5818
commit 5bb23edb18
1 changed files with 19 additions and 3 deletions
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tools/testing/selftests/vm/userfaultfd.c
+19 -3
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@@ -278,13 +278,29 @@ static void shmem_release_pages(char *rel_area)
static void shmem_allocate_area(void **alloc_area)
{
unsigned long offset =
alloc_area == (void **)&area_src ? 0 : nr_pages * page_size;
void *area_alias = NULL;
bool is_src = alloc_area == (void **)&area_src;
unsigned long offset = is_src ? 0 : nr_pages * page_size;
*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
MAP_SHARED, shm_fd, offset);
if (*alloc_area == MAP_FAILED)
err("mmap of memfd failed");
area_alias = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
MAP_SHARED, shm_fd, offset);
if (area_alias == MAP_FAILED)
err("mmap of memfd alias failed");
if (is_src)
area_src_alias = area_alias;
else
area_dst_alias = area_alias;
}
static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
{
*start = (unsigned long)area_dst_alias + offset;
}
struct uffd_test_ops {
@@ -314,7 +330,7 @@ static struct uffd_test_ops shmem_uffd_test_ops = {
.expected_ioctls = SHMEM_EXPECTED_IOCTLS,
.allocate_area = shmem_allocate_area,
.release_pages = shmem_release_pages,
.alias_mapping = noop_alias_mapping,
.alias_mapping = shmem_alias_mapping,
};
static struct uffd_test_ops hugetlb_uffd_test_ops = {