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From: david.laight.linux@gmail.com
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Andre Almeida <andrealmeid@igalia.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Christian Brauner <brauner@kernel.org>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
	Darren Hart <dvhart@infradead.org>,
	David Laight <david.laight.linux@gmail.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Heiko Carstens <hca@linux.ibm.com>, Jan Kara <jack@suse.cz>,
	Julia Lawall <Julia.Lawall@inria.fr>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Madhavan Srinivasan <maddy@linux.ibm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	Nicolas Palix <nicolas.palix@imag.fr>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <pjw@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Russell King <linux@armlinux.org.uk>,
	Sven Schnelle <svens@linux.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org, Kees Cook <kees@kernel.org>,
	akpm@linux-foundation.org
Subject: [PATCH v2 4/5] uaccess: Disable -Wshadow in __scoped_user_access()
Date: Mon,  2 Mar 2026 13:27:54 +0000	[thread overview]
Message-ID: <20260302132755.1475451-5-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260302132755.1475451-1-david.laight.linux@gmail.com>

From: David Laight <david.laight.linux@gmail.com>

-Wshadow is enabled by W=2 builds and __scoped_user_access() quite
deliberately creates a 'const' shadow of the 'user' address that
references a 'guard page' when the application passes a kernel pointer.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 include/linux/uaccess.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 64bc2492eb99..445391ec5a6d 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -739,7 +739,9 @@ static __always_inline void __scoped_user_rw_access_end(const void *p)
 #define __scoped_user_access(mode, uptr, size, elbl)					\
 	with (auto _tmpptr = __scoped_user_access_begin(mode, uptr, size, elbl))	\
 		/* Force modified pointer usage within the scope */			\
-		and_with (const auto uptr __cleanup(__scoped_user_##mode##_access_end) = _tmpptr)
+		__diag_push() __diag_ignore_all("-Wshadow", "uptr is readonly copy")	\
+		and_with (const auto uptr __cleanup(__scoped_user_##mode##_access_end) = _tmpptr) \
+		__diag_pop()
 
 /**
  * scoped_user_read_access_size - Start a scoped user read access with given size
-- 
2.39.5



WARNING: multiple messages have this Message-ID (diff)
From: david.laight.linux@gmail.com
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Andre Almeida <andrealmeid@igalia.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Christian Brauner <brauner@kernel.org>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
	Darren Hart <dvhart@infradead.org>,
	David Laight <david.laight.linux@gmail.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Heiko Carstens <hca@linux.ibm.com>, Jan Kara <jack@suse.cz>,
	Julia Lawall <Julia.Lawall@inria.fr>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Madhavan Srinivasan <maddy@linux.ibm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	Nicolas Palix <nicolas.palix@imag.fr>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <pjw@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Russell King <linux@armlinux.org.uk>,
	Sven Schnelle <svens@linux.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org, Kees Cook <kees@kernel.org>,
	akpm@linux-foundation.org
Subject: [PATCH v2 4/5] uaccess: Disable -Wshadow in __scoped_user_access()
Date: Mon,  2 Mar 2026 13:27:54 +0000	[thread overview]
Message-ID: <20260302132755.1475451-5-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260302132755.1475451-1-david.laight.linux@gmail.com>

From: David Laight <david.laight.linux@gmail.com>

-Wshadow is enabled by W=2 builds and __scoped_user_access() quite
deliberately creates a 'const' shadow of the 'user' address that
references a 'guard page' when the application passes a kernel pointer.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 include/linux/uaccess.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 64bc2492eb99..445391ec5a6d 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -739,7 +739,9 @@ static __always_inline void __scoped_user_rw_access_end(const void *p)
 #define __scoped_user_access(mode, uptr, size, elbl)					\
 	with (auto _tmpptr = __scoped_user_access_begin(mode, uptr, size, elbl))	\
 		/* Force modified pointer usage within the scope */			\
-		and_with (const auto uptr __cleanup(__scoped_user_##mode##_access_end) = _tmpptr)
+		__diag_push() __diag_ignore_all("-Wshadow", "uptr is readonly copy")	\
+		and_with (const auto uptr __cleanup(__scoped_user_##mode##_access_end) = _tmpptr) \
+		__diag_pop()
 
 /**
  * scoped_user_read_access_size - Start a scoped user read access with given size
-- 
2.39.5


_______________________________________________
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  parent reply	other threads:[~2026-03-02 13:28 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-02 13:27 [PATCH v2 0/5] uaccess: Updates to scoped_user_access() david.laight.linux
2026-03-02 13:27 ` david.laight.linux
2026-03-02 13:27 ` [PATCH v2 1/5] uaccess: Fix scoped_user_read_access() for 'pointer to const' david.laight.linux
2026-03-02 13:27   ` david.laight.linux
2026-03-02 14:59   ` Christophe Leroy (CS GROUP)
2026-03-02 14:59     ` Christophe Leroy (CS GROUP)
2026-03-02 17:26     ` Linus Torvalds
2026-03-02 17:26       ` Linus Torvalds
2026-03-02 18:55       ` David Laight
2026-03-02 18:55         ` David Laight
2026-03-02 13:27 ` [PATCH v2 2/5] compiler.h: Add generic support for 'autoterminating nested for() loops' david.laight.linux
2026-03-02 13:27   ` david.laight.linux
2026-03-02 13:27 ` [PATCH v2 3/5] uaccess.h: Use with() and and_with() in __scoped_user_access() david.laight.linux
2026-03-02 13:27   ` david.laight.linux
2026-03-02 13:27 ` david.laight.linux [this message]
2026-03-02 13:27   ` [PATCH v2 4/5] uaccess: Disable -Wshadow " david.laight.linux
2026-03-02 15:00   ` Christophe Leroy (CS GROUP)
2026-03-02 15:00     ` Christophe Leroy (CS GROUP)
2026-03-03  9:12     ` David Laight
2026-03-03  9:12       ` David Laight
2026-03-02 17:17   ` Linus Torvalds
2026-03-02 17:17     ` Linus Torvalds
2026-03-05  8:10   ` kernel test robot
2026-03-05  8:10     ` kernel test robot
2026-03-02 13:27 ` [PATCH v2 next 5/5] signal: Use scoped_user_access() instead of __put/get_user() david.laight.linux
2026-03-02 13:27   ` david.laight.linux
2026-03-02 16:07   ` Christophe Leroy (CS GROUP)
2026-03-02 16:07     ` Christophe Leroy (CS GROUP)

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