diff options
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 219 |
1 files changed, 161 insertions, 58 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 9542c582d546..fcd20c6dc7f9 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -6,8 +6,13 @@ #include <linux/stringify.h> #include <asm/asm.h> -#define ALTINSTR_FLAG_INV (1 << 15) -#define ALT_NOT(feat) ((feat) | ALTINSTR_FLAG_INV) +#define ALT_FLAGS_SHIFT 16 + +#define ALT_FLAG_NOT (1 << 0) +#define ALT_NOT(feature) ((ALT_FLAG_NOT << ALT_FLAGS_SHIFT) | (feature)) +#define ALT_FLAG_DIRECT_CALL (1 << 1) +#define ALT_DIRECT_CALL(feature) ((ALT_FLAG_DIRECT_CALL << ALT_FLAGS_SHIFT) | (feature)) +#define ALT_CALL_ALWAYS ALT_DIRECT_CALL(X86_FEATURE_ALWAYS) #ifndef __ASSEMBLY__ @@ -56,17 +61,36 @@ #define ANNOTATE_IGNORE_ALTERNATIVE \ "999:\n\t" \ ".pushsection .discard.ignore_alts\n\t" \ - ".long 999b - .\n\t" \ + ".long 999b\n\t" \ ".popsection\n\t" +/* + * The patching flags are part of the upper bits of the @ft_flags parameter when + * specifying them. The split is currently like this: + * + * [31... flags ...16][15... CPUID feature bit ...0] + * + * but since this is all hidden in the macros argument being split, those fields can be + * extended in the future to fit in a u64 or however the need arises. + */ struct alt_instr { s32 instr_offset; /* original instruction */ s32 repl_offset; /* offset to replacement instruction */ - u16 cpuid; /* cpuid bit set for replacement */ + + union { + struct { + u32 cpuid: 16; /* CPUID bit set for replacement */ + u32 flags: 16; /* patching control flags */ + }; + u32 ft_flags; + }; + u8 instrlen; /* length of original instruction */ u8 replacementlen; /* length of new instruction */ } __packed; +extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; + /* * Debug flag that can be tested to see whether alternative * instructions were patched in already: @@ -77,10 +101,39 @@ extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); extern void apply_retpolines(s32 *start, s32 *end); extern void apply_returns(s32 *start, s32 *end); -extern void apply_ibt_endbr(s32 *start, s32 *end); +extern void apply_seal_endbr(s32 *start, s32 *end); +extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine, + s32 *start_cfi, s32 *end_cfi); struct module; +struct callthunk_sites { + s32 *call_start, *call_end; + struct alt_instr *alt_start, *alt_end; +}; + +#ifdef CONFIG_CALL_THUNKS +extern void callthunks_patch_builtin_calls(void); +extern void callthunks_patch_module_calls(struct callthunk_sites *sites, + struct module *mod); +extern void *callthunks_translate_call_dest(void *dest); +extern int x86_call_depth_emit_accounting(u8 **pprog, void *func); +#else +static __always_inline void callthunks_patch_builtin_calls(void) {} +static __always_inline void +callthunks_patch_module_calls(struct callthunk_sites *sites, + struct module *mod) {} +static __always_inline void *callthunks_translate_call_dest(void *dest) +{ + return dest; +} +static __always_inline int x86_call_depth_emit_accounting(u8 **pprog, + void *func) +{ + return 0; +} +#endif + #ifdef CONFIG_SMP extern void alternatives_smp_module_add(struct module *mod, char *name, void *locks, void *locks_end, @@ -101,6 +154,8 @@ static inline int alternatives_text_reserved(void *start, void *end) } #endif /* CONFIG_SMP */ +#define ALT_CALL_INSTR "call BUG_func" + #define b_replacement(num) "664"#num #define e_replacement(num) "665"#num @@ -147,10 +202,10 @@ static inline int alternatives_text_reserved(void *start, void *end) " - (" alt_slen ")), 0x90\n" \ alt_end_marker ":\n" -#define ALTINSTR_ENTRY(feature, num) \ +#define ALTINSTR_ENTRY(ft_flags, num) \ " .long 661b - .\n" /* label */ \ " .long " b_replacement(num)"f - .\n" /* new instruction */ \ - " .word " __stringify(feature) "\n" /* feature bit */ \ + " .4byte " __stringify(ft_flags) "\n" /* feature + flags */ \ " .byte " alt_total_slen "\n" /* source len */ \ " .byte " alt_rlen(num) "\n" /* replacement len */ @@ -159,20 +214,20 @@ static inline int alternatives_text_reserved(void *start, void *end) b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n" /* alternative assembly primitive: */ -#define ALTERNATIVE(oldinstr, newinstr, feature) \ +#define ALTERNATIVE(oldinstr, newinstr, ft_flags) \ OLDINSTR(oldinstr, 1) \ ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(feature, 1) \ + ALTINSTR_ENTRY(ft_flags, 1) \ ".popsection\n" \ ".pushsection .altinstr_replacement, \"ax\"\n" \ ALTINSTR_REPLACEMENT(newinstr, 1) \ ".popsection\n" -#define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\ +#define ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \ OLDINSTR_2(oldinstr, 1, 2) \ ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(feature1, 1) \ - ALTINSTR_ENTRY(feature2, 2) \ + ALTINSTR_ENTRY(ft_flags1, 1) \ + ALTINSTR_ENTRY(ft_flags2, 2) \ ".popsection\n" \ ".pushsection .altinstr_replacement, \"ax\"\n" \ ALTINSTR_REPLACEMENT(newinstr1, 1) \ @@ -180,21 +235,22 @@ static inline int alternatives_text_reserved(void *start, void *end) ".popsection\n" /* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ -#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \ +#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ - newinstr_yes, feature) - -#define ALTERNATIVE_3(oldinsn, newinsn1, feat1, newinsn2, feat2, newinsn3, feat3) \ - OLDINSTR_3(oldinsn, 1, 2, 3) \ - ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(feat1, 1) \ - ALTINSTR_ENTRY(feat2, 2) \ - ALTINSTR_ENTRY(feat3, 3) \ - ".popsection\n" \ - ".pushsection .altinstr_replacement, \"ax\"\n" \ - ALTINSTR_REPLACEMENT(newinsn1, 1) \ - ALTINSTR_REPLACEMENT(newinsn2, 2) \ - ALTINSTR_REPLACEMENT(newinsn3, 3) \ + newinstr_yes, ft_flags) + +#define ALTERNATIVE_3(oldinsn, newinsn1, ft_flags1, newinsn2, ft_flags2, \ + newinsn3, ft_flags3) \ + OLDINSTR_3(oldinsn, 1, 2, 3) \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY(ft_flags1, 1) \ + ALTINSTR_ENTRY(ft_flags2, 2) \ + ALTINSTR_ENTRY(ft_flags3, 3) \ + ".popsection\n" \ + ".pushsection .altinstr_replacement, \"ax\"\n" \ + ALTINSTR_REPLACEMENT(newinsn1, 1) \ + ALTINSTR_REPLACEMENT(newinsn2, 2) \ + ALTINSTR_REPLACEMENT(newinsn3, 3) \ ".popsection\n" /* @@ -209,14 +265,14 @@ static inline int alternatives_text_reserved(void *start, void *end) * For non barrier like inlines please define new variants * without volatile and memory clobber. */ -#define alternative(oldinstr, newinstr, feature) \ - asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory") +#define alternative(oldinstr, newinstr, ft_flags) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) : : : "memory") -#define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \ - asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "memory") +#define alternative_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \ + asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory") -#define alternative_ternary(oldinstr, feature, newinstr_yes, newinstr_no) \ - asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) ::: "memory") +#define alternative_ternary(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ + asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) ::: "memory") /* * Alternative inline assembly with input. @@ -226,8 +282,8 @@ static inline int alternatives_text_reserved(void *start, void *end) * Argument numbers start with 1. * Leaving an unused argument 0 to keep API compatibility. */ -#define alternative_input(oldinstr, newinstr, feature, input...) \ - asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ +#define alternative_input(oldinstr, newinstr, ft_flags, input...) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) \ : : "i" (0), ## input) /* @@ -238,20 +294,20 @@ static inline int alternatives_text_reserved(void *start, void *end) * Otherwise, if CPU has feature1, newinstr1 is used. * Otherwise, oldinstr is used. */ -#define alternative_input_2(oldinstr, newinstr1, feature1, newinstr2, \ - feature2, input...) \ - asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, \ - newinstr2, feature2) \ +#define alternative_input_2(oldinstr, newinstr1, ft_flags1, newinstr2, \ + ft_flags2, input...) \ + asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, \ + newinstr2, ft_flags2) \ : : "i" (0), ## input) /* Like alternative_input, but with a single output argument */ -#define alternative_io(oldinstr, newinstr, feature, output, input...) \ - asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ +#define alternative_io(oldinstr, newinstr, ft_flags, output, input...) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) \ : 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_inline volatile (ALTERNATIVE("call %P[old]", "call %P[new]", feature) \ +#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \ + asm_inline volatile (ALTERNATIVE("call %P[old]", "call %P[new]", ft_flags) \ : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input) /* @@ -260,10 +316,10 @@ static inline int alternatives_text_reserved(void *start, void *end) * Otherwise, if CPU has feature1, function1 is used. * Otherwise, old function is used. */ -#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2, \ +#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \ output, input...) \ - asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\ - "call %P[new2]", feature2) \ + asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", ft_flags1,\ + "call %P[new2]", ft_flags2) \ : output, ASM_CALL_CONSTRAINT \ : [old] "i" (oldfunc), [new1] "i" (newfunc1), \ [new2] "i" (newfunc2), ## input) @@ -280,6 +336,22 @@ static inline int alternatives_text_reserved(void *start, void *end) */ #define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr +/* Macro for creating assembler functions avoiding any C magic. */ +#define DEFINE_ASM_FUNC(func, instr, sec) \ + asm (".pushsection " #sec ", \"ax\"\n" \ + ".global " #func "\n\t" \ + ".type " #func ", @function\n\t" \ + ASM_FUNC_ALIGN "\n" \ + #func ":\n\t" \ + ASM_ENDBR \ + instr "\n\t" \ + ASM_RET \ + ".size " #func ", . - " #func "\n\t" \ + ".popsection") + +void BUG_func(void); +void nop_func(void); + #else /* __ASSEMBLY__ */ #ifdef CONFIG_SMP @@ -302,7 +374,7 @@ static inline int alternatives_text_reserved(void *start, void *end) .macro ANNOTATE_IGNORE_ALTERNATIVE .Lannotate_\@: .pushsection .discard.ignore_alts - .long .Lannotate_\@ - . + .long .Lannotate_\@ .popsection .endm @@ -312,21 +384,25 @@ static inline int alternatives_text_reserved(void *start, void *end) * enough information for the alternatives patching code to patch an * instruction. See apply_alternatives(). */ -.macro altinstruction_entry orig alt feature orig_len alt_len +.macro altinstr_entry orig alt ft_flags orig_len alt_len .long \orig - . .long \alt - . - .word \feature + .4byte \ft_flags .byte \orig_len .byte \alt_len .endm +.macro ALT_CALL_INSTR + call BUG_func +.endm + /* * Define an alternative between two instructions. If @feature is * present, early code in apply_alternatives() replaces @oldinstr with * @newinstr. ".skip" directive takes care of proper instruction padding * in case @newinstr is longer than @oldinstr. */ -.macro ALTERNATIVE oldinstr, newinstr, feature +.macro ALTERNATIVE oldinstr, newinstr, ft_flags 140: \oldinstr 141: @@ -334,7 +410,7 @@ static inline int alternatives_text_reserved(void *start, void *end) 142: .pushsection .altinstructions,"a" - altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f + altinstr_entry 140b,143f,\ft_flags,142b-140b,144f-143f .popsection .pushsection .altinstr_replacement,"ax" @@ -347,6 +423,7 @@ static inline int alternatives_text_reserved(void *start, void *end) #define old_len 141b-140b #define new_len1 144f-143f #define new_len2 145f-144f +#define new_len3 146f-145f /* * gas compatible max based on the idea from: @@ -354,7 +431,8 @@ static inline int alternatives_text_reserved(void *start, void *end) * * The additional "-" is needed because gas uses a "true" value of -1. */ -#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b))))) +#define alt_max_2(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b))))) +#define alt_max_3(a, b, c) (alt_max_2(alt_max_2(a, b), c)) /* @@ -362,17 +440,40 @@ static inline int alternatives_text_reserved(void *start, void *end) * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has * @feature2, it replaces @oldinstr with @feature2. */ -.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2 +.macro ALTERNATIVE_2 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2 +140: + \oldinstr +141: + .skip -((alt_max_2(new_len1, new_len2) - (old_len)) > 0) * \ + (alt_max_2(new_len1, new_len2) - (old_len)),0x90 +142: + + .pushsection .altinstructions,"a" + altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f + altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f + .popsection + + .pushsection .altinstr_replacement,"ax" +143: + \newinstr1 +144: + \newinstr2 +145: + .popsection +.endm + +.macro ALTERNATIVE_3 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, newinstr3, ft_flags3 140: \oldinstr 141: - .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \ - (alt_max_short(new_len1, new_len2) - (old_len)),0x90 + .skip -((alt_max_3(new_len1, new_len2, new_len3) - (old_len)) > 0) * \ + (alt_max_3(new_len1, new_len2, new_len3) - (old_len)),0x90 142: .pushsection .altinstructions,"a" - altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f - altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f + altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f + altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f + altinstr_entry 140b,145f,\ft_flags3,142b-140b,146f-145f .popsection .pushsection .altinstr_replacement,"ax" @@ -381,13 +482,15 @@ static inline int alternatives_text_reserved(void *start, void *end) 144: \newinstr2 145: + \newinstr3 +146: .popsection .endm /* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ -#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \ +#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ - newinstr_yes, feature + newinstr_yes, ft_flags #endif /* __ASSEMBLY__ */ |