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author | Ingo Molnar <mingo@kernel.org> | 2024-02-14 12:45:07 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2024-02-14 12:45:07 +0300 |
commit | 03c11eb3b16dc0058589751dfd91f254be2be613 (patch) | |
tree | e5f2889212fec0bb0babdce9abd781ab487e246a /arch/x86/include/asm/nospec-branch.h | |
parent | de8c6a352131f642b82474abe0cbb5dd26a7e081 (diff) | |
parent | 841c35169323cd833294798e58b9bf63fa4fa1de (diff) | |
download | linux-03c11eb3b16dc0058589751dfd91f254be2be613.tar.xz |
Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch
Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
-rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 75 |
1 files changed, 33 insertions, 42 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 65fbf6b853af..691ff1ef701b 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -49,7 +49,7 @@ * but there is still a cushion vs. the RSB depth. The algorithm does not * claim to be perfect and it can be speculated around by the CPU, but it * is considered that it obfuscates the problem enough to make exploitation - * extremly difficult. + * extremely difficult. */ #define RET_DEPTH_SHIFT 5 #define RSB_RET_STUFF_LOOPS 16 @@ -187,7 +187,7 @@ .macro ANNOTATE_RETPOLINE_SAFE .Lhere_\@: .pushsection .discard.retpoline_safe - .long .Lhere_\@ - . + .long .Lhere_\@ .popsection .endm @@ -199,7 +199,7 @@ /* * Abuse ANNOTATE_RETPOLINE_SAFE on a NOP to indicate UNRET_END, should - * eventually turn into it's own annotation. + * eventually turn into its own annotation. */ .macro VALIDATE_UNRET_END #if defined(CONFIG_NOINSTR_VALIDATION) && \ @@ -262,7 +262,7 @@ .Lskip_rsb_\@: .endm -#ifdef CONFIG_CPU_UNRET_ENTRY +#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_SRSO) #define CALL_UNTRAIN_RET "call entry_untrain_ret" #else #define CALL_UNTRAIN_RET "" @@ -279,38 +279,24 @@ * As such, this must be placed after every *SWITCH_TO_KERNEL_CR3 at a point * where we have a stack but before any RET instruction. */ -.macro UNTRAIN_RET -#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \ - defined(CONFIG_CALL_DEPTH_TRACKING) || defined(CONFIG_CPU_SRSO) +.macro __UNTRAIN_RET ibpb_feature, call_depth_insns +#if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY) VALIDATE_UNRET_END ALTERNATIVE_3 "", \ CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \ - "call entry_ibpb", X86_FEATURE_ENTRY_IBPB, \ - __stringify(RESET_CALL_DEPTH), X86_FEATURE_CALL_DEPTH + "call entry_ibpb", \ibpb_feature, \ + __stringify(\call_depth_insns), X86_FEATURE_CALL_DEPTH #endif .endm -.macro UNTRAIN_RET_VM -#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \ - defined(CONFIG_CALL_DEPTH_TRACKING) || defined(CONFIG_CPU_SRSO) - VALIDATE_UNRET_END - ALTERNATIVE_3 "", \ - CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \ - "call entry_ibpb", X86_FEATURE_IBPB_ON_VMEXIT, \ - __stringify(RESET_CALL_DEPTH), X86_FEATURE_CALL_DEPTH -#endif -.endm +#define UNTRAIN_RET \ + __UNTRAIN_RET X86_FEATURE_ENTRY_IBPB, __stringify(RESET_CALL_DEPTH) -.macro UNTRAIN_RET_FROM_CALL -#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \ - defined(CONFIG_CALL_DEPTH_TRACKING) - VALIDATE_UNRET_END - ALTERNATIVE_3 "", \ - CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \ - "call entry_ibpb", X86_FEATURE_ENTRY_IBPB, \ - __stringify(RESET_CALL_DEPTH_FROM_CALL), X86_FEATURE_CALL_DEPTH -#endif -.endm +#define UNTRAIN_RET_VM \ + __UNTRAIN_RET X86_FEATURE_IBPB_ON_VMEXIT, __stringify(RESET_CALL_DEPTH) + +#define UNTRAIN_RET_FROM_CALL \ + __UNTRAIN_RET X86_FEATURE_ENTRY_IBPB, __stringify(RESET_CALL_DEPTH_FROM_CALL) .macro CALL_DEPTH_ACCOUNT @@ -325,7 +311,7 @@ #define ANNOTATE_RETPOLINE_SAFE \ "999:\n\t" \ ".pushsection .discard.retpoline_safe\n\t" \ - ".long 999b - .\n\t" \ + ".long 999b\n\t" \ ".popsection\n\t" typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE]; @@ -339,13 +325,23 @@ extern void __x86_return_thunk(void); static inline void __x86_return_thunk(void) {} #endif +#ifdef CONFIG_CPU_UNRET_ENTRY extern void retbleed_return_thunk(void); +#else +static inline void retbleed_return_thunk(void) {} +#endif + +#ifdef CONFIG_CPU_SRSO extern void srso_return_thunk(void); extern void srso_alias_return_thunk(void); +#else +static inline void srso_return_thunk(void) {} +static inline void srso_alias_return_thunk(void) {} +#endif -extern void retbleed_untrain_ret(void); -extern void srso_untrain_ret(void); -extern void srso_alias_untrain_ret(void); +extern void retbleed_return_thunk(void); +extern void srso_return_thunk(void); +extern void srso_alias_return_thunk(void); extern void entry_untrain_ret(void); extern void entry_ibpb(void); @@ -353,12 +349,7 @@ extern void entry_ibpb(void); extern void (*x86_return_thunk)(void); #ifdef CONFIG_CALL_DEPTH_TRACKING -extern void __x86_return_skl(void); - -static inline void x86_set_skl_return_thunk(void) -{ - x86_return_thunk = &__x86_return_skl; -} +extern void call_depth_return_thunk(void); #define CALL_DEPTH_ACCOUNT \ ALTERNATIVE("", \ @@ -371,12 +362,12 @@ DECLARE_PER_CPU(u64, __x86_ret_count); DECLARE_PER_CPU(u64, __x86_stuffs_count); DECLARE_PER_CPU(u64, __x86_ctxsw_count); #endif -#else -static inline void x86_set_skl_return_thunk(void) {} +#else /* !CONFIG_CALL_DEPTH_TRACKING */ +static inline void call_depth_return_thunk(void) {} #define CALL_DEPTH_ACCOUNT "" -#endif +#endif /* CONFIG_CALL_DEPTH_TRACKING */ #ifdef CONFIG_RETPOLINE |