diff options
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 21 | ||||
| -rw-r--r-- | arch/x86/kernel/alternative.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/x8664_ksyms_64.c | 3 | ||||
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 6 |
5 files changed, 31 insertions, 10 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 69b74a7b877f..3b5b828767b6 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 46324c6a4f6e..a78c40305447 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); diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index de7353c0ce9c..2589ea4c60ce 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -205,7 +205,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start, struct alt_instr *end) { struct alt_instr *a; - char insnbuf[MAX_PATCH_LEN]; + u8 insnbuf[MAX_PATCH_LEN]; DPRINTK("%s: alt table %p -> %p\n", __func__, start, end); for (a = start; a < end; a++) { @@ -223,6 +223,8 @@ void __init_or_module apply_alternatives(struct alt_instr *start, } #endif memcpy(insnbuf, a->replacement, a->replacementlen); + if (*insnbuf == 0xe8 && a->replacementlen == 5) + *(s32 *)(insnbuf + 1) += a->replacement - a->instr; add_nops(insnbuf + a->replacementlen, a->instrlen - a->replacementlen); text_poke_early(instr, insnbuf, a->instrlen); diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index 619f7f88b8cc..693920b22496 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -26,7 +26,8 @@ EXPORT_SYMBOL(__put_user_2); EXPORT_SYMBOL(__put_user_4); EXPORT_SYMBOL(__put_user_8); -EXPORT_SYMBOL(copy_user_generic); +EXPORT_SYMBOL(copy_user_generic_string); +EXPORT_SYMBOL(copy_user_generic_unrolled); EXPORT_SYMBOL(__copy_user_nocache); EXPORT_SYMBOL(_copy_from_user); EXPORT_SYMBOL(_copy_to_user); diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index cf889d4e076a..71100c98e337 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -90,12 +90,6 @@ ENTRY(_copy_from_user) CFI_ENDPROC ENDPROC(_copy_from_user) -ENTRY(copy_user_generic) - CFI_STARTPROC - ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string - CFI_ENDPROC -ENDPROC(copy_user_generic) - .section .fixup,"ax" /* must zero dest */ ENTRY(bad_from_user) |