linux-kernel - [tip: timers/urgent] vdso: Address variable shadowing in macros

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <174427635228.31282.10735746636221422010.tip-bot2@tip-bot2>
Date: Thu, 10 Apr 2025 09:12:32 -0000
From: "tip-bot2 for Peng Jiang" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Peng Jiang <jiang.peng9@....com.cn>,
 Shao Mingyin <shao.mingyin@....com.cn>, Thomas Gleixner <tglx@...utronix.de>,
 x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: timers/urgent] vdso: Address variable shadowing in macros

The following commit has been merged into the timers/urgent branch of tip:

Commit-ID:     acea9943271b62905033f2f8ca571cdd52d6ea7b
Gitweb:        https://git.kernel.org/tip/acea9943271b62905033f2f8ca571cdd52d6ea7b
Author:        Peng Jiang <jiang.peng9@....com.cn>
AuthorDate:    Mon, 24 Mar 2025 19:12:30 +08:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Thu, 10 Apr 2025 11:07:10 +02:00

vdso: Address variable shadowing in macros

Compiling the kernel with gcc12.3 W=2 results in shadowing warnings:

warning: declaration of '__pptr' shadows a previous local [-Wshadow]
  const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);

note: in definition of macro '__put_unaligned_t'
  __pptr->x = (val);

note: in expansion of macro '__get_unaligned_t'
  __put_unaligned_t(type, __get_unaligned_t(type, src), dst);

__get_unaligned_t() and __put_unaligned_t() use a local variable named
'__pptr', which can lead to variable shadowing when these macros are used in
the same scope. This results in a -Wshadow warning during compilation.

To address this issue, rename the local variables within the macros to
ensure uniqueness.

Signed-off-by: Peng Jiang <jiang.peng9@....com.cn>
Signed-off-by: Shao Mingyin <shao.mingyin@....com.cn>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Link: https://lore.kernel.org/all/20250324191230477zpGtgIRSH4mEHdtxGtgx9@zte.com.cn
---
 include/vdso/unaligned.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/vdso/unaligned.h b/include/vdso/unaligned.h
index eee3d2a..ff0c06b 100644
--- a/include/vdso/unaligned.h
+++ b/include/vdso/unaligned.h
@@ -2,14 +2,14 @@
 #ifndef __VDSO_UNALIGNED_H
 #define __VDSO_UNALIGNED_H
 
-#define __get_unaligned_t(type, ptr) ({						\
-	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
-	__pptr->x;								\
+#define __get_unaligned_t(type, ptr) ({							\
+	const struct { type x; } __packed * __get_pptr = (typeof(__get_pptr))(ptr);	\
+	__get_pptr->x;									\
 })
 
-#define __put_unaligned_t(type, val, ptr) do {					\
-	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
-	__pptr->x = (val);							\
+#define __put_unaligned_t(type, val, ptr) do {						\
+	struct { type x; } __packed * __put_pptr = (typeof(__put_pptr))(ptr);		\
+	__put_pptr->x = (val);								\
 } while (0)
 
 #endif /* __VDSO_UNALIGNED_H */