The patch titled
Subject: selftests/mm: virtual_address_range: mmap() without PROT_WRITE
has been added to the -mm mm-unstable branch. Its filename is
selftests-mm-virtual_address_range-mmap-without-prot_write.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-virtual_address_range-mmap-without-prot_write.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Thomas WeiÃ?schuh <thomas.weissschuh@xxxxxxxxxxxxx>
Subject: selftests/mm: virtual_address_range: mmap() without PROT_WRITE
Date: Mon, 13 Jan 2025 14:15:35 +0100
Patch series "selftests/mm: virtual_address_range: Reduce memory", v3.
The selftest started failing since commit e93d2521b27f ("x86/vdso: Split
virtual clock pages into dedicated mapping") was merged. While debugging
I stumbled upon some memory usage optimizations.
With these test now runs on a VM with only 60MiB of memory.
This patch (of 4):
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.
Link: https://lkml.kernel.org/r/20250113-virtual_address_range-tests-v3-0-f4a8e6b7feed@xxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20250113-virtual_address_range-tests-v3-1-f4a8e6b7feed@xxxxxxxxxxxxx
Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()")
Signed-off-by: Thomas WeiÃ?schuh <thomas.weissschuh@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Dev Jain <dev.jain@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Shuah Khan (Samsung OSG) <shuah@xxxxxxxxxx>
Cc: kernel test robot <oliver.sang@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/virtual_address_range.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/mm/virtual_address_range.c~selftests-mm-virtual_address_range-mmap-without-prot_write
+++ a/tools/testing/selftests/mm/virtual_address_range.c
@@ -166,7 +166,7 @@ int main(void)
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(void)
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)
_
Patches currently in -mm which might be from thomas.weissschuh@xxxxxxxxxxxxx are
selftests-mm-virtual_address_range-mmap-without-prot_write.patch
selftests-mm-virtual_address_range-unmap-chunks-after-validation.patch
selftests-mm-vm_util-split-up-proc-self-smaps-parsing.patch
selftests-mm-virtual_address_range-avoid-reading-from-vm_io-mappings.patch
