FAILED: patch "[PATCH] selftests/mm: skip soft-dirty tests when" failed to apply to 6.6-stable tree

PATCH New [email protected] 2 participants 2 messages Oct 13, 2025 – Oct 14, 2025

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Stable branch Memory management Kselftest MM misc

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author maintainer

2025-10-13 11:43 UTC #0 lore raw

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 0389c305ef56cbadca4cbef44affc0ec3213ed30
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025101329-unplanted-language-2cc7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0389c305ef56cbadca4cbef44affc0ec3213ed30 Mon Sep 17 00:00:00 2001
From: Lance Yang <[email protected]>
Date: Wed, 17 Sep 2025 21:31:37 +0800
Subject: [PATCH] selftests/mm: skip soft-dirty tests when
CONFIG_MEM_SOFT_DIRTY is disabled

The madv_populate and soft-dirty kselftests currently fail on systems where CONFIG_MEM_SOFT_DIRTY is disabled.

Introduce a new helper softdirty_supported() into vm_util.c/h to ensure tests are properly skipped when the feature is not enabled.

Link https://lkml.kernel.org/r/[email protected] open here

Fixes 9f3265db6ae8 ("selftests: vm: add test for Soft-Dirty PTE bit")

Signed-off-by Lance Yang <[email protected]>

Acked-by David Hildenbrand <[email protected]>

Cc Lorenzo Stoakes <[email protected]>

Cc Shuah Khan <[email protected]>

Cc Gabriel Krisman Bertazi <[email protected]>

Cc <[email protected]>

Signed-off-by Andrew Morton <[email protected]>

tools/testing/selftests/mm/madv_populate.c +2 ~~-19~~

index b6fabd5c27ed..d8d11bc67ddc 100644
@@ -264,23 +264,6 @@ static void test_softdirty(void)
 	munmap(addr, SIZE);
 }
 
-static int system_has_softdirty(void)
-{
-	/*
-	 * There is no way to check if the kernel supports soft-dirty, other
-	 * than by writing to a page and seeing if the bit was set. But the
-	 * tests are intended to check that the bit gets set when it should, so
-	 * doing that check would turn a potentially legitimate fail into a
-	 * skip. Fortunately, we know for sure that arm64 does not support
-	 * soft-dirty. So for now, let's just use the arch as a corse guide.
-	 */
-#if defined(__aarch64__)
-	return 0;
-#else
-	return 1;
-#endif
-}
-
 int main(int argc, char **argv)
 {
 	int nr_tests = 16;

@@ -288,7 +271,7 @@ int main(int argc, char **argv)
 
 	pagesize = getpagesize();
 
-	if (system_has_softdirty())
+	if (softdirty_supported())
 		nr_tests += 5;
 
 	ksft_print_header();

@@ -300,7 +283,7 @@ int main(int argc, char **argv)
 	test_holes();
 	test_populate_read();
 	test_populate_write();
-	if (system_has_softdirty())
+	if (softdirty_supported())
 		test_softdirty();
 
 	err = ksft_get_fail_cnt();

tools/testing/selftests/mm/soft-dirty.c +4 -1

index 8a3f2b4b2186..4ee4db3750c1 100644
@@ -200,8 +200,11 @@ int main(int argc, char **argv)
 	int pagesize;
 
 	ksft_print_header();
-	ksft_set_plan(15);
 
+	if (!softdirty_supported())
+		ksft_exit_skip("soft-dirty is not support\n");
+
+	ksft_set_plan(15);
 	pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY);
 	if (pagemap_fd < 0)
 		ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH);

tools/testing/selftests/mm/vm_util.c +17 -0

index 56e9bd541edd..e33cda301dad 100644
@@ -449,6 +449,23 @@ bool check_vmflag_pfnmap(void *addr)
 	return check_vmflag(addr, "pf");
 }
 
+bool softdirty_supported(void)
+{
+	char *addr;
+	bool supported = false;
+	const size_t pagesize = getpagesize();
+
+	/* New mappings are expected to be marked with VM_SOFTDIRTY (sd). */
+	addr = mmap(0, pagesize, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (!addr)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	supported = check_vmflag(addr, "sd");
+	munmap(addr, pagesize);
+	return supported;
+}
+
 /*
  * Open an fd at /proc/$pid/maps and configure procmap_out ready for
  * PROCMAP_QUERY query. Returns 0 on success, or an error code otherwise.

tools/testing/selftests/mm/vm_util.h +1 -0

index 07c4acfd84b6..26c30fdc0241 100644
@@ -104,6 +104,7 @@ bool find_vma_procmap(struct procmap_fd *procmap, void *address);
 int close_procmap(struct procmap_fd *procmap);
 int write_sysfs(const char *file_path, unsigned long val);
 int read_sysfs(const char *file_path, unsigned long *val);
+bool softdirty_supported(void);
 
 static inline int open_self_procmap(struct procmap_fd *procmap_out)
 {

Lance Yang

2025-10-14 02:52 UTC #1 lore raw

PATCH 1/1 selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabled

From: Lance Yang <[email protected]>