When mapping a larger chunk than physical memory is available with
PROT_WRITE and overcommit is disabled, the mapping will fail.
This will prevent the test from running on systems with less then ~1GiB
of memory and triggering an inscrutinable test failure.
As the mappings are never written to anyways, the flag can be removed.
Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
---
I went with dropping PROT_WRITE instead of adding MAP_NORESERVE as this
works even in the face of OVERCOMMIT_NEVER.
---
tools/testing/selftests/mm/virtual_address_range.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c
index 2a2b69e91950a37999f606847c9c8328d79890c2..ea6ccf49ef4c552f26317c2a40b09bca1a677f8f 100644
--- a/tools/testing/selftests/mm/virtual_address_range.c
+++ b/tools/testing/selftests/mm/virtual_address_range.c
@@ -166,7 +166,7 @@ int main(int argc, char *argv[])
ksft_set_plan(1);
for (i = 0; i < NR_CHUNKS_LOW; i++) {
- ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
+ ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (ptr[i] == MAP_FAILED) {
@@ -186,7 +186,7 @@ int main(int argc, char *argv[])
for (i = 0; i < NR_CHUNKS_HIGH; i++) {
hint = hint_addr();
- hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
+ hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (hptr[i] == MAP_FAILED)
--
2.47.1
