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Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
-rw-r--r--arch/x86/include/asm/nospec-branch.h41
1 files changed, 32 insertions, 9 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 8b38df98548e..f6f6c63da62f 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -308,16 +308,20 @@ 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
-# define RETPOLINE_RAX_BPF_JIT_SIZE 17
-# define RETPOLINE_RAX_BPF_JIT() \
+# 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 */ \
@@ -325,11 +329,30 @@ do { \
EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \
/* do_rop: */ \
EMIT4(0x48, 0x89, 0x04, 0x24); /* mov %rax,(%rsp) */ \
- EMIT1(0xC3); /* retq */
-#else
-# define RETPOLINE_RAX_BPF_JIT_SIZE 2
-# define RETPOLINE_RAX_BPF_JIT() \
- EMIT2(0xFF, 0xE0); /* jmp *%rax */
+ EMIT1(0xC3); /* retq */ \
+} while (0)
+# else /* !CONFIG_X86_64 */
+# 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 /* !CONFIG_X86_64 */
+# define RETPOLINE_EDX_BPF_JIT() \
+ EMIT2(0xFF, 0xE2) /* jmp *%edx */
+# endif
#endif
#endif /* _ASM_X86_NOSPEC_BRANCH_H_ */