diff options
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index f928ad9b143f..2cd344d1a6e5 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -291,16 +291,20 @@ do { \ * lfence * jmp spec_trap * do_rop: - * mov %rax,(%rsp) + * mov %rax,(%rsp) for x86_64 + * mov %edx,(%esp) for x86_32 * retq * * Without retpolines configured: * - * jmp *%rax + * jmp *%rax for x86_64 + * jmp *%edx for x86_32 */ #ifdef CONFIG_RETPOLINE +#ifdef CONFIG_X86_64 # define RETPOLINE_RAX_BPF_JIT_SIZE 17 # define RETPOLINE_RAX_BPF_JIT() \ +do { \ EMIT1_off32(0xE8, 7); /* callq do_rop */ \ /* spec_trap: */ \ EMIT2(0xF3, 0x90); /* pause */ \ @@ -308,11 +312,31 @@ do { \ EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ /* do_rop: */ \ EMIT4(0x48, 0x89, 0x04, 0x24); /* mov %rax,(%rsp) */ \ - EMIT1(0xC3); /* retq */ + EMIT1(0xC3); /* retq */ \ +} while (0) #else +# define RETPOLINE_EDX_BPF_JIT() \ +do { \ + EMIT1_off32(0xE8, 7); /* call do_rop */ \ + /* spec_trap: */ \ + EMIT2(0xF3, 0x90); /* pause */ \ + EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \ + EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ + /* do_rop: */ \ + EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \ + EMIT1(0xC3); /* ret */ \ +} while (0) +#endif +#else /* !CONFIG_RETPOLINE */ + +#ifdef CONFIG_X86_64 # define RETPOLINE_RAX_BPF_JIT_SIZE 2 # define RETPOLINE_RAX_BPF_JIT() \ EMIT2(0xFF, 0xE0); /* jmp *%rax */ +#else +# define RETPOLINE_EDX_BPF_JIT() \ + EMIT2(0xFF, 0xE2) /* jmp *%edx */ +#endif #endif #endif /* _ASM_X86_NOSPEC_BRANCH_H_ */ |