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Diffstat (limited to 'arch/x86/include/asm/alternative.h')
-rw-r--r--arch/x86/include/asm/alternative.h119
1 files changed, 63 insertions, 56 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index dc03a647776d..03364510d5fe 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -4,7 +4,9 @@
#include <linux/types.h>
#include <linux/stringify.h>
+#include <linux/objtool.h>
#include <asm/asm.h>
+#include <asm/bug.h>
#define ALT_FLAGS_SHIFT 16
@@ -14,7 +16,7 @@
#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__
+#ifndef __ASSEMBLER__
#include <linux/stddef.h>
@@ -47,7 +49,7 @@
".popsection\n" \
"671:"
-#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock "
#else /* ! CONFIG_SMP */
#define LOCK_PREFIX_HERE ""
@@ -55,16 +57,6 @@
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-#define ANNOTATE_IGNORE_ALTERNATIVE \
- "999:\n\t" \
- ".pushsection .discard.ignore_alts\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:
*
@@ -91,25 +83,30 @@ struct alt_instr {
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
+extern s32 __retpoline_sites[], __retpoline_sites_end[];
+extern s32 __return_sites[], __return_sites_end[];
+extern s32 __cfi_sites[], __cfi_sites_end[];
+extern s32 __ibt_endbr_seal[], __ibt_endbr_seal_end[];
+extern s32 __smp_locks[], __smp_locks_end[];
+
/*
* Debug flag that can be tested to see whether alternative
* instructions were patched in already:
*/
extern int alternatives_patched;
-struct module;
extern void alternative_instructions(void);
-extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
- struct module *mod);
-extern void apply_retpolines(s32 *start, s32 *end, struct module *mod);
-extern void apply_returns(s32 *start, s32 *end, struct module *mod);
-extern void apply_seal_endbr(s32 *start, s32 *end, struct module *mod);
+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_seal_endbr(s32 *start, s32 *end);
extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine,
- s32 *start_cfi, s32 *end_cfi, struct module *mod);
+ 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
@@ -134,6 +131,37 @@ static __always_inline int x86_call_depth_emit_accounting(u8 **pprog,
}
#endif
+#ifdef CONFIG_MITIGATION_ITS
+extern void its_init_mod(struct module *mod);
+extern void its_fini_mod(struct module *mod);
+extern void its_free_mod(struct module *mod);
+extern u8 *its_static_thunk(int reg);
+#else /* CONFIG_MITIGATION_ITS */
+static inline void its_init_mod(struct module *mod) { }
+static inline void its_fini_mod(struct module *mod) { }
+static inline void its_free_mod(struct module *mod) { }
+static inline u8 *its_static_thunk(int reg)
+{
+ WARN_ONCE(1, "ITS not compiled in");
+
+ return NULL;
+}
+#endif
+
+#if defined(CONFIG_MITIGATION_RETHUNK) && defined(CONFIG_OBJTOOL)
+extern bool cpu_wants_rethunk(void);
+extern bool cpu_wants_rethunk_at(void *addr);
+#else
+static __always_inline bool cpu_wants_rethunk(void)
+{
+ return false;
+}
+static __always_inline bool cpu_wants_rethunk_at(void *addr)
+{
+ return false;
+}
+#endif
+
#ifdef CONFIG_SMP
extern void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
@@ -169,7 +197,8 @@ static inline int alternatives_text_reserved(void *start, void *end)
"773:\n"
#define ALTINSTR_ENTRY(ft_flags) \
- ".pushsection .altinstructions,\"a\"\n" \
+ ".pushsection .altinstructions, \"aM\", @progbits, " \
+ __stringify(ALT_INSTR_SIZE) "\n" \
" .long 771b - .\n" /* label */ \
" .long 774f - .\n" /* new instruction */ \
" .4byte " __stringify(ft_flags) "\n" /* feature + flags */ \
@@ -179,6 +208,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
#define ALTINSTR_REPLACEMENT(newinstr) /* replacement */ \
".pushsection .altinstr_replacement, \"ax\"\n" \
+ ANNOTATE_DATA_SPECIAL "\n" \
"# ALT: replacement\n" \
"774:\n\t" newinstr "\n775:\n" \
".popsection\n"
@@ -246,10 +276,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
* references: i.e., if used for a function, it would add the PLT
* suffix.
*/
-#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \
+#define alternative_call(oldfunc, newfunc, ft_flags, output, input, clobbers...) \
asm_inline volatile(ALTERNATIVE("call %c[old]", "call %c[new]", ft_flags) \
: ALT_OUTPUT_SP(output) \
- : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
+ : [old] "i" (oldfunc), [new] "i" (newfunc) \
+ COMMA(input) \
+ : clobbers)
/*
* Like alternative_call, but there are two features and respective functions.
@@ -258,24 +290,14 @@ static inline int alternatives_text_reserved(void *start, void *end)
* Otherwise, old function is used.
*/
#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \
- output, input...) \
+ output, input, clobbers...) \
asm_inline volatile(ALTERNATIVE_2("call %c[old]", "call %c[new1]", ft_flags1, \
"call %c[new2]", ft_flags2) \
: ALT_OUTPUT_SP(output) \
: [old] "i" (oldfunc), [new1] "i" (newfunc1), \
- [new2] "i" (newfunc2), ## input)
-
-/*
- * use this macro(s) if you need more than one output parameter
- * in alternative_io
- */
-#define ASM_OUTPUT2(a...) a
-
-/*
- * use this macro if you need clobbers but no inputs in
- * alternative_{input,io,call}()
- */
-#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
+ [new2] "i" (newfunc2) \
+ COMMA(input) \
+ : clobbers)
#define ALT_OUTPUT_SP(...) ASM_CALL_CONSTRAINT, ## __VA_ARGS__
@@ -295,7 +317,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
void BUG_func(void);
void nop_func(void);
-#else /* __ASSEMBLY__ */
+#else /* __ASSEMBLER__ */
#ifdef CONFIG_SMP
.macro LOCK_PREFIX
@@ -311,17 +333,6 @@ void nop_func(void);
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-.macro ANNOTATE_IGNORE_ALTERNATIVE
- .Lannotate_\@:
- .pushsection .discard.ignore_alts
- .long .Lannotate_\@
- .popsection
-.endm
-
-/*
* Issue one struct alt_instr descriptor entry (need to put it into
* the section .altinstructions, see below). This entry contains
* enough information for the alternatives patching code to patch an
@@ -351,11 +362,12 @@ void nop_func(void);
741: \
.skip -(((744f-743f)-(741b-740b)) > 0) * ((744f-743f)-(741b-740b)),0x90 ;\
742: \
- .pushsection .altinstructions,"a" ; \
+ .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE ;\
altinstr_entry 740b,743f,flag,742b-740b,744f-743f ; \
.popsection ; \
.pushsection .altinstr_replacement,"ax" ; \
743: \
+ ANNOTATE_DATA_SPECIAL ; \
newinst ; \
744: \
.popsection ;
@@ -364,11 +376,6 @@ void nop_func(void);
__ALTERNATIVE(\oldinstr, \newinstr, \ft_flags)
.endm
-#define old_len 141b-140b
-#define new_len1 144f-143f
-#define new_len2 145f-144f
-#define new_len3 146f-145f
-
/*
* Same as ALTERNATIVE macro above but for two alternatives. If CPU
* has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
@@ -389,6 +396,6 @@ void nop_func(void);
ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
newinstr_yes, ft_flags
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
#endif /* _ASM_X86_ALTERNATIVE_H */
generated by cgit (git 2.34.1) at 2025-12-24 23:31:15 +0000