diff options
Diffstat (limited to 'arch/x86/entry/calling.h')
| -rw-r--r-- | arch/x86/entry/calling.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 9f1f9e3b8230..515c0ceeb4a3 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -314,6 +314,23 @@ For 32-bit we have the following conventions - kernel is built with #endif +/* + * Mitigate Spectre v1 for conditional swapgs code paths. + * + * FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to + * prevent a speculative swapgs when coming from kernel space. + * + * FENCE_SWAPGS_KERNEL_ENTRY is used in the kernel entry non-swapgs code path, + * to prevent the swapgs from getting speculatively skipped when coming from + * user space. + */ +.macro FENCE_SWAPGS_USER_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_USER +.endm +.macro FENCE_SWAPGS_KERNEL_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_KERNEL +.endm + .macro STACKLEAK_ERASE_NOCLOBBER #ifdef CONFIG_GCC_PLUGIN_STACKLEAK PUSH_AND_CLEAR_REGS @@ -343,3 +360,9 @@ For 32-bit we have the following conventions - kernel is built with .Lafter_call_\@: #endif .endm + +#ifdef CONFIG_PARAVIRT_XXL +#define GET_CR2_INTO(reg) GET_CR2_INTO_AX ; _ASM_MOV %_ASM_AX, reg +#else +#define GET_CR2_INTO(reg) _ASM_MOV %cr2, reg +#endif |