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From: Arnd Bergmann <arnd@kernel.org>
To: Suren Baghdasaryan <surenb@google.com>,
	Abhishek Bapat <abhishekbapat@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Hao Ge <hao.ge@linux.dev>
Cc: Arnd Bergmann <arnd@arndb.de>, SJ Park <sj@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH] [v2] alloc_tag: avoid implicit padding in uapi
Date: Wed, 16 Sep 2026 08:58:20 +0200	[thread overview]
Message-ID: <20260916065830.1619425-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

The implied padding causes a harmless warning when testing the uapi
headers with -Wpadded that could in theory indicate incompatibilities
or data leaks:

./usr/include/linux/alloc_tag.h:41:1: error: padding struct size to alignment boundary with 7 bytes [-Werror=padded]

The code here is fine, but it's better to make the padding explicit
and avoid the warning here.

Acked-by: SJ Park <sj@kernel.org>
Acked-by: Hao Ge <hao.ge@linux.dev>
Fixes: 1d581ab2348c ("alloc_tag: add ioctl to /proc/allocinfo")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2; fix changelog typos
---
 include/uapi/linux/alloc_tag.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/alloc_tag.h b/include/uapi/linux/alloc_tag.h
index e3ad94444864..7d4618bea043 100644
--- a/include/uapi/linux/alloc_tag.h
+++ b/include/uapi/linux/alloc_tag.h
@@ -38,6 +38,7 @@ struct allocinfo_counter {
 	__u64 bytes;
 	__u64 calls;
 	__u8 accurate;
+	__u8 pad[7];
 } __attribute__((aligned(8)));
 
 struct allocinfo_tag_data {
-- 
2.53.0



             reply	other threads:[~2026-09-16  6:58 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-16  6:58 Arnd Bergmann [this message]
2026-09-16 19:14 ` [PATCH] [v2] alloc_tag: avoid implicit padding in uapi Suren Baghdasaryan

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