From: Thomas Gleixner <tglx@linutronix•de>
To: LKML <linux-kernel@vger•kernel.org>
Cc: "kernel test robot" <lkp@intel•com>,
"Russell King" <linux@armlinux•org.uk>,
linux-arm-kernel@lists•infradead.org,
"Linus Torvalds" <torvalds@linux-foundation•org>,
x86@kernel•org, "Madhavan Srinivasan" <maddy@linux•ibm.com>,
"Michael Ellerman" <mpe@ellerman•id.au>,
"Nicholas Piggin" <npiggin@gmail•com>,
"Christophe Leroy" <christophe.leroy@csgroup•eu>,
linuxppc-dev@lists•ozlabs.org, "Paul Walmsley" <pjw@kernel•org>,
"Palmer Dabbelt" <palmer@dabbelt•com>,
linux-riscv@lists•infradead.org,
"Heiko Carstens" <hca@linux•ibm.com>,
"Christian Borntraeger" <borntraeger@linux•ibm.com>,
"Sven Schnelle" <svens@linux•ibm.com>,
linux-s390@vger•kernel.org,
"Mathieu Desnoyers" <mathieu.desnoyers@efficios•com>,
"Andrew Cooper" <andrew.cooper3@citrix•com>,
"David Laight" <david.laight.linux@gmail•com>,
"Julia Lawall" <Julia.Lawall@inria•fr>,
"Nicolas Palix" <nicolas.palix@imag•fr>,
"Peter Zijlstra" <peterz@infradead•org>,
"Darren Hart" <dvhart@infradead•org>,
"Davidlohr Bueso" <dave@stgolabs•net>,
"André Almeida" <andrealmeid@igalia•com>,
"Alexander Viro" <viro@zeniv•linux.org.uk>,
"Christian Brauner" <brauner@kernel•org>,
"Jan Kara" <jack@suse•cz>,
linux-fsdevel@vger•kernel.org
Subject: [patch V5 08/12] uaccess: Provide put/get_user_inline()
Date: Mon, 27 Oct 2025 09:43:56 +0100 (CET) [thread overview]
Message-ID: <20251027083745.609031602@linutronix.de> (raw)
In-Reply-To: 20251027083700.573016505@linutronix.de
Provide conveniance wrappers around scoped user access similiar to
put/get_user(), which reduce the usage sites to:
if (!get_user_inline(val, ptr))
return -EFAULT;
Should only be used if there is a demonstrable performance benefit.
Signed-off-by: Thomas Gleixner <tglx@linutronix•de>
---
V5: Rename to inline
V4: Rename to scoped
---
include/linux/uaccess.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -825,6 +825,56 @@ for (bool done = false; !done; done = tr
#define scoped_user_rw_access(uptr, elbl) \
scoped_user_rw_access_size(uptr, sizeof(*(uptr)), elbl)
+/**
+ * get_user_inline - Read user data inlined
+ * @val: The variable to store the value read from user memory
+ * @usrc: Pointer to the user space memory to read from
+ *
+ * Return: 0 if successful, -EFAULT when faulted
+ *
+ * Inlined variant of get_user(). Only use when there is a demonstrable
+ * performance reason.
+ */
+#define get_user_inline(val, usrc) \
+({ \
+ __label__ efault; \
+ typeof(usrc) _tmpsrc = usrc; \
+ int _ret = 0; \
+ \
+ scoped_user_read_access(_tmpsrc, efault) \
+ unsafe_get_user(val, _tmpsrc, efault); \
+ if (0) { \
+ efault: \
+ _ret = -EFAULT; \
+ } \
+ _ret; \
+})
+
+/**
+ * put_user_inline - Write to user memory inlined
+ * @val: The value to write
+ * @udst: Pointer to the user space memory to write to
+ *
+ * Return: 0 if successful, -EFAULT when faulted
+ *
+ * Inlined variant of put_user(). Only use when there is a demonstrable
+ * performance reason.
+ */
+#define put_user_inline(val, udst) \
+({ \
+ __label__ efault; \
+ typeof(udst) _tmpdst = udst; \
+ int _ret = 0; \
+ \
+ scoped_user_write_access(_tmpdst, efault) \
+ unsafe_put_user(val, _tmpdst, efault); \
+ if (0) { \
+ efault: \
+ _ret = -EFAULT; \
+ } \
+ _ret; \
+})
+
#ifdef CONFIG_HARDENED_USERCOPY
void __noreturn usercopy_abort(const char *name, const char *detail,
bool to_user, unsigned long offset,
next prev parent reply other threads:[~2025-10-27 8:44 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-27 8:43 [patch V5 00/12] uaccess: Provide and use scopes for user access Thomas Gleixner
2025-10-27 8:43 ` [patch V5 01/12] ARM: uaccess: Implement missing __get_user_asm_dword() Thomas Gleixner
2025-10-28 13:35 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 02/12] uaccess: Provide ASM GOTO safe wrappers for unsafe_*_user() Thomas Gleixner
2025-10-27 12:12 ` Andrew Cooper
2025-10-28 13:44 ` Mathieu Desnoyers
2025-10-28 14:04 ` Yann Ylavic
2025-10-28 15:53 ` Thomas Gleixner
2025-10-29 9:40 ` [patch V6 " Thomas Gleixner
2025-12-19 8:10 ` patchwork-bot+linux-riscv
2025-11-04 6:11 ` [patch V5 " Christophe Leroy
2025-10-27 8:43 ` [patch V5 03/12] x86/uaccess: Use unsafe wrappers for ASM GOTO Thomas Gleixner
2025-10-28 13:50 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 04/12] powerpc/uaccess: " Thomas Gleixner
2025-10-28 13:51 ` Mathieu Desnoyers
2025-11-04 6:15 ` Christophe Leroy
2025-10-27 8:43 ` [patch V5 05/12] riscv/uaccess: " Thomas Gleixner
2025-10-28 13:52 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 06/12] s390/uaccess: " Thomas Gleixner
2025-10-28 13:54 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 07/12] uaccess: Provide scoped user access regions Thomas Gleixner
2025-10-28 14:11 ` Mathieu Desnoyers
2025-11-04 6:20 ` Christophe Leroy
2025-11-07 19:17 ` David Laight
2025-10-27 8:43 ` Thomas Gleixner [this message]
2025-10-28 14:12 ` [patch V5 08/12] uaccess: Provide put/get_user_inline() Mathieu Desnoyers
2025-11-04 6:30 ` Christophe Leroy
2025-10-27 8:43 ` [patch V5 09/12] [RFC] coccinelle: misc: Add scoped_masked_$MODE_access() checker script Thomas Gleixner
2025-10-27 8:44 ` [patch V5 10/12] futex: Convert to get/put_user_inline() Thomas Gleixner
2025-10-28 14:24 ` Mathieu Desnoyers
2025-10-28 15:56 ` Thomas Gleixner
2025-10-28 16:02 ` Mathieu Desnoyers
2025-10-28 16:13 ` Linus Torvalds
2025-11-04 6:31 ` Christophe Leroy
2025-10-27 8:44 ` [patch V5 11/12] x86/futex: Convert to scoped user access Thomas Gleixner
2025-10-27 8:44 ` [patch V5 12/12] select: " Thomas Gleixner
2025-10-28 14:42 ` Mathieu Desnoyers
2025-11-04 6:32 ` Christophe Leroy
2025-10-27 15:53 ` [patch V5 00/12] uaccess: Provide and use scopes for " Linus Torvalds
2025-10-29 10:23 ` Peter Zijlstra
2025-11-03 14:46 ` Peter Zijlstra
2025-11-04 6:35 ` Christophe Leroy
2025-12-19 8:10 ` patchwork-bot+linux-riscv
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