[PATCH] alloc_tag: add ioctl to /proc/allocinfo -fix

Abhishek Bapat <[email protected]> Tue, 4 Aug 2026 18:24:14 +0000
Newsgroups org.kvack.linux-mm,org.kernel.vger.linux-kernel
Message-ID <e4e49ec4a5960292aeeb9e196526c18dc95228a2.1785867739.git.abhishekbapat@google.com>
Move the `inaccurate` filtering criteria from `struct allocinfo_tag` to
`struct allocinfo_filter`. Also fix a typo in the selftest added to
validate the introduced feature.

This is a fixup patch to resolve a pending comment left by sashiko on
the patch series starting with Commit bc3da70ba4d9 ("alloc_tag: add ioctl
to /proc/allocinfo").

Note, sashiko also left a valid comment on the selftest about the sscanf
in the test skipping loaded modules, however, it was a deliberate design
choice. The modules were kept out of the test baseline on purpose as
dunamic module loading/unloading can trigger content_id mismatches
(which can cause flakiness). Since the IOCTL logic itself function
regardless of whether the codetag is in vmlinux or a loadable module,
stocking to stable built-in targets keeps the tests robust.

Fixes: b011dfc9f8d6 ("alloc_tag: add accuracy based filtering to ioctl")
Fixes: 359316c50445 ("kselftest: alloc_tag: add kselftest for ioctl interface")
Closes: https://sashiko.dev/#/patchset/[email protected]
Signed-off-by: Abhishek Bapat <[email protected]>
---
 include/uapi/linux/alloc_tag.h                           | 4 ++--
 mm/alloc_tag.c                                           | 2 +-
 tools/testing/selftests/alloc_tag/allocinfo_ioctl_test.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/alloc_tag.h b/include/uapi/linux/alloc_tag.h
index 270f693b1822..e3ad94444864 100644
--- a/include/uapi/linux/alloc_tag.h
+++ b/include/uapi/linux/alloc_tag.h
@@ -31,8 +31,6 @@ struct allocinfo_tag {
 	char function[ALLOCINFO_STR_SIZE];
 	char filename[ALLOCINFO_STR_SIZE];
 	__u64 lineno;
-	/* filter criteria only; see allocinfo_counter.accurate for actual accuracy */
-	__u64 inaccurate;
 };
 
 /* The alignment ensures 32-bit compatible interfaces are not broken */
@@ -74,6 +72,8 @@ struct allocinfo_filter {
 	struct allocinfo_tag fields;
 	__u64 min_size;
 	__u64 max_size;
+	/* filter criteria only; see allocinfo_counter.accurate for actual accuracy */
+	__u64 inaccurate;
 };
 
 struct allocinfo_get_at {
diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c
index 52aece27b00e..84c5c3783ca4 100644
--- a/mm/alloc_tag.c
+++ b/mm/alloc_tag.c
@@ -291,7 +291,7 @@ static bool matches_filter(struct codetag *ct, struct allocinfo_filter *filter,
 
 	if (filter->mask & ALLOCINFO_FILTER_MASK_INACCURATE) {
 		inaccurate = !!(ct->flags & CODETAG_FLAG_INACCURATE);
-		if (inaccurate != !!(filter->fields.inaccurate))
+		if (inaccurate != !!(filter->inaccurate))
 			return false;
 	}
 
diff --git a/tools/testing/selftests/alloc_tag/allocinfo_ioctl_test.c b/tools/testing/selftests/alloc_tag/allocinfo_ioctl_test.c
index 7d94abb785a1..74fd64b2370c 100644
--- a/tools/testing/selftests/alloc_tag/allocinfo_ioctl_test.c
+++ b/tools/testing/selftests/alloc_tag/allocinfo_ioctl_test.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
 /* kselftest for allocinfo ioctl
- * allocinfo ioctl retrives allocinfo data through ioctl
+ * allocinfo ioctl retrieves allocinfo data through ioctl
  * Copyright (C) 2026 Google, Inc.
  */
 

base-commit: 486855239e38a91d3eae26618ccb7845c1764625
-- 
2.55.0.508.g3f0d502094-goog