diff options
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 21 |
2 files changed, 26 insertions, 2 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 69b74a7b877..3b5b828767b 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -125,11 +125,16 @@ static inline void alternatives_smp_switch(int smp) {} asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ : output : "i" (0), ## input) +/* Like alternative_io, but for replacing a direct call with another one. */ +#define alternative_call(oldfunc, newfunc, feature, output, input...) \ + asm volatile (ALTERNATIVE("call %P[old]", "call %P[new]", feature) \ + : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input) + /* * use this macro(s) if you need more than one output parameter * in alternative_io */ -#define ASM_OUTPUT2(a, b) a, b +#define ASM_OUTPUT2(a...) a struct paravirt_patch_site; #ifdef CONFIG_PARAVIRT diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 46324c6a4f6..a78c4030544 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -8,6 +8,8 @@ #include <linux/errno.h> #include <linux/prefetch.h> #include <linux/lockdep.h> +#include <asm/alternative.h> +#include <asm/cpufeature.h> #include <asm/page.h> /* @@ -16,7 +18,24 @@ /* Handles exceptions in both to and from, but doesn't do access_ok */ __must_check unsigned long -copy_user_generic(void *to, const void *from, unsigned len); +copy_user_generic_string(void *to, const void *from, unsigned len); +__must_check unsigned long +copy_user_generic_unrolled(void *to, const void *from, unsigned len); + +static __always_inline __must_check unsigned long +copy_user_generic(void *to, const void *from, unsigned len) +{ + unsigned ret; + + alternative_call(copy_user_generic_unrolled, + copy_user_generic_string, + X86_FEATURE_REP_GOOD, + ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from), + "=d" (len)), + "1" (to), "2" (from), "3" (len) + : "memory", "rcx", "r8", "r9", "r10", "r11"); + return ret; +} __must_check unsigned long _copy_to_user(void __user *to, const void *from, unsigned len); |