[GIT PULL] x86/uaccess change for v3.13

From: Ingo Molnar
Date: Mon Nov 11 2013 - 13:49:57 EST


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,
--
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