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Message-Id: <20210408234327.624367-7-axelrasmussen@google.com>
Date: Thu, 8 Apr 2021 16:43:24 -0700
From: Axel Rasmussen <axelrasmussen@...gle.com>
To: Alexander Viro <viro@...iv.linux.org.uk>,
Andrea Arcangeli <aarcange@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Daniel Colascione <dancol@...gle.com>,
Hugh Dickins <hughd@...gle.com>,
Jerome Glisse <jglisse@...hat.com>,
Joe Perches <joe@...ches.com>,
Lokesh Gidra <lokeshgidra@...gle.com>,
Mike Kravetz <mike.kravetz@...cle.com>,
Mike Rapoport <rppt@...ux.vnet.ibm.com>,
Peter Xu <peterx@...hat.com>, Shaohua Li <shli@...com>,
Shuah Khan <shuah@...nel.org>,
Stephen Rothwell <sfr@...b.auug.org.au>,
Wang Qing <wangqing@...o.com>
Cc: linux-api@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
linux-mm@...ck.org, Axel Rasmussen <axelrasmussen@...gle.com>,
Brian Geffon <bgeffon@...gle.com>,
"Dr . David Alan Gilbert" <dgilbert@...hat.com>,
Mina Almasry <almasrymina@...gle.com>,
Oliver Upton <oupton@...gle.com>
Subject: [PATCH 6/9] userfaultfd/selftests: create alias mappings in the shmem test
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.
Signed-off-by: Axel Rasmussen <axelrasmussen@...gle.com>
---
tools/testing/selftests/vm/userfaultfd.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index b0af88b258d7..4b49b2cf9819 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -279,13 +279,29 @@ 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 {
@@ -315,7 +331,7 @@ 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 = {
--
2.31.1.295.g9ea45b61b8-goog
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