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From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [GIT PULL] x86/uaccess change for v3.13
Date: Mon, 11 Nov 2013 19:49:44 +0100	[thread overview]
Message-ID: <20131111184944.GA16606@gmail.com> (raw)

Linus,

Please pull the latest x86-uaccess-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-uaccess-for-linus

   # HEAD: ff47ab4ff3cddfa7bc1b25b990e24abe2ae474ff x86: Add 1/2/4/8 byte optimization to 64bit __copy_{from,to}_user_inatomic

It includes a single change that micro-optimizes __copy_*_user_inatomic(), 
used by the futx code.

 Thanks,

	Ingo

------------------>
Andi Kleen (1):
      x86: Add 1/2/4/8 byte optimization to 64bit __copy_{from,to}_user_inatomic


 arch/x86/include/asm/uaccess_64.h | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 4f7923d..64476bb 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -77,11 +77,10 @@ int copy_to_user(void __user *dst, const void *src, unsigned size)
 }
 
 static __always_inline __must_check
-int __copy_from_user(void *dst, const void __user *src, unsigned size)
+int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
 {
 	int ret = 0;
 
-	might_fault();
 	if (!__builtin_constant_p(size))
 		return copy_user_generic(dst, (__force void *)src, size);
 	switch (size) {
@@ -121,11 +120,17 @@ int __copy_from_user(void *dst, const void __user *src, unsigned size)
 }
 
 static __always_inline __must_check
-int __copy_to_user(void __user *dst, const void *src, unsigned size)
+int __copy_from_user(void *dst, const void __user *src, unsigned size)
+{
+	might_fault();
+	return __copy_from_user_nocheck(dst, src, size);
+}
+
+static __always_inline __must_check
+int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
 {
 	int ret = 0;
 
-	might_fault();
 	if (!__builtin_constant_p(size))
 		return copy_user_generic((__force void *)dst, src, size);
 	switch (size) {
@@ -165,6 +170,13 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
 }
 
 static __always_inline __must_check
+int __copy_to_user(void __user *dst, const void *src, unsigned size)
+{
+	might_fault();
+	return __copy_to_user_nocheck(dst, src, size);
+}
+
+static __always_inline __must_check
 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 {
 	int ret = 0;
@@ -220,13 +232,13 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 static __must_check __always_inline int
 __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
 {
-	return copy_user_generic(dst, (__force const void *)src, size);
+	return __copy_from_user_nocheck(dst, (__force const void *)src, size);
 }
 
 static __must_check __always_inline int
 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 {
-	return copy_user_generic((__force void *)dst, src, size);
+	return __copy_to_user_nocheck((__force void *)dst, src, size);
 }
 
 extern long __copy_user_nocache(void *dst, const void __user *src,

                 reply	other threads:[~2013-11-11 18:49 UTC|newest]

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