Re: [PATCH v3 7/7] selftest/mm: ksm_functional_tests: Add PROT_NONE test

[David Hildenbrand]

On 03.08.23 16:32, David Hildenbrand wrote:
> Let's test whether merging and unmerging in PROT_NONE areas works as
> expected.
>
> Pass a page protection to mmap_and_merge_range(), which will trigger
> an mprotect() after writing to the pages, but before enabling merging.
>
> Make sure that unsharing works as expected, by performing a ptrace write
> (using /proc/self/mem) and by setting MADV_UNMERGEABLE.
>
> Note that this implicitly tests that ptrace writes in an inaccessible
> (PROT_NONE) mapping work as expected.
>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---

Andrew, can you squash the following?

From c2be7c02cb96b9189a52a5937821600ef4e259bd Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@xxxxxxxxxx>
Date: Mon, 7 Aug 2023 17:33:54 +0200
Subject: [PATCH] Fixup: selftest/mm: ksm_functional_tests: Add PROT_NONE test

As noted by Peter, we should be using sizeof(i) in test_prot_none().

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 tools/testing/selftests/mm/ksm_functional_tests.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index 8fa4889ab4f3..901e950f9138 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -516,7 +516,7 @@ static void test_prot_none(void)
 	/* Store a unique value in each page on one half using ptrace */
 	for (i = 0; i < size / 2; i += pagesize) {
 		lseek(mem_fd, (uintptr_t) map + i, SEEK_SET);
-		if (write(mem_fd, &i, sizeof(size)) != sizeof(size)) {
+		if (write(mem_fd, &i, sizeof(i)) != sizeof(i)) {
 			ksft_test_result_fail("ptrace write failed\n");
 			goto unmap;
 		}
--
2.41.0



--
Cheers,

David / dhildenb