diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/asm-prototypes.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 56 |
2 files changed, 15 insertions, 48 deletions
diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h index aa7585e1fe67..9bf2620ce817 100644 --- a/arch/x86/include/asm/asm-prototypes.h +++ b/arch/x86/include/asm/asm-prototypes.h @@ -21,8 +21,15 @@ extern void cmpxchg8b_emu(void); #define DECL_INDIRECT_THUNK(reg) \ extern asmlinkage void __x86_indirect_thunk_ ## reg (void); +#define DECL_RETPOLINE(reg) \ + extern asmlinkage void __x86_retpoline_ ## reg (void); + #undef GEN #define GEN(reg) DECL_INDIRECT_THUNK(reg) #include <asm/GEN-for-each-reg.h> +#undef GEN +#define GEN(reg) DECL_RETPOLINE(reg) +#include <asm/GEN-for-each-reg.h> + #endif /* CONFIG_RETPOLINE */ diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index d3269b69728a..d52d1aacdd97 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -13,15 +13,6 @@ #include <asm/unwind_hints.h> /* - * This should be used immediately before a retpoline alternative. It tells - * objtool where the retpolines are so that it can make sense of the control - * flow by just reading the original instruction(s) and ignoring the - * alternatives. - */ -#define ANNOTATE_NOSPEC_ALTERNATIVE \ - ANNOTATE_IGNORE_ALTERNATIVE - -/* * Fill the CPU return stack buffer. * * Each entry in the RSB, if used for a speculative 'ret', contains an @@ -83,44 +74,15 @@ .endm /* - * These are the bare retpoline primitives for indirect jmp and call. - * Do not use these directly; they only exist to make the ALTERNATIVE - * invocation below less ugly. - */ -.macro RETPOLINE_JMP reg:req - call .Ldo_rop_\@ -.Lspec_trap_\@: - pause - lfence - jmp .Lspec_trap_\@ -.Ldo_rop_\@: - mov \reg, (%_ASM_SP) - ret -.endm - -/* - * This is a wrapper around RETPOLINE_JMP so the called function in reg - * returns to the instruction after the macro. - */ -.macro RETPOLINE_CALL reg:req - jmp .Ldo_call_\@ -.Ldo_retpoline_jmp_\@: - RETPOLINE_JMP \reg -.Ldo_call_\@: - call .Ldo_retpoline_jmp_\@ -.endm - -/* * JMP_NOSPEC and CALL_NOSPEC macros can be used instead of a simple * indirect jmp/call which may be susceptible to the Spectre variant 2 * attack. */ .macro JMP_NOSPEC reg:req #ifdef CONFIG_RETPOLINE - ANNOTATE_NOSPEC_ALTERNATIVE - ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \ - __stringify(RETPOLINE_JMP %\reg), X86_FEATURE_RETPOLINE,\ - __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD + ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \ + __stringify(jmp __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \ + __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD #else jmp *%\reg #endif @@ -128,10 +90,9 @@ .macro CALL_NOSPEC reg:req #ifdef CONFIG_RETPOLINE - ANNOTATE_NOSPEC_ALTERNATIVE - ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg),\ - __stringify(RETPOLINE_CALL %\reg), X86_FEATURE_RETPOLINE,\ - __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_AMD + ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg), \ + __stringify(call __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \ + __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_AMD #else call *%\reg #endif @@ -165,16 +126,16 @@ * which is ensured when CONFIG_RETPOLINE is defined. */ # define CALL_NOSPEC \ - ANNOTATE_NOSPEC_ALTERNATIVE \ ALTERNATIVE_2( \ ANNOTATE_RETPOLINE_SAFE \ "call *%[thunk_target]\n", \ - "call __x86_indirect_thunk_%V[thunk_target]\n", \ + "call __x86_retpoline_%V[thunk_target]\n", \ X86_FEATURE_RETPOLINE, \ "lfence;\n" \ ANNOTATE_RETPOLINE_SAFE \ "call *%[thunk_target]\n", \ X86_FEATURE_RETPOLINE_AMD) + # define THUNK_TARGET(addr) [thunk_target] "r" (addr) #else /* CONFIG_X86_32 */ @@ -184,7 +145,6 @@ * here, anyway. */ # define CALL_NOSPEC \ - ANNOTATE_NOSPEC_ALTERNATIVE \ ALTERNATIVE_2( \ ANNOTATE_RETPOLINE_SAFE \ "call *%[thunk_target]\n", \ |