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Diffstat (limited to 'arch/x86/entry/calling.h')
-rw-r--r--arch/x86/entry/calling.h40
1 files changed, 21 insertions, 19 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 0789e13ece90..1c7f13bb6728 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -98,13 +98,6 @@ For 32-bit we have the following conventions - kernel is built with
#define SIZEOF_PTREGS 21*8
.macro PUSH_AND_CLEAR_REGS rdx=%rdx rax=%rax save_ret=0
- /*
- * Push registers and sanitize registers of values that a
- * speculation attack might otherwise want to exploit. The
- * lower registers are likely clobbered well before they
- * could be put to use in a speculative execution gadget.
- * Interleave XOR with PUSH for better uop scheduling:
- */
.if \save_ret
pushq %rsi /* pt_regs->si */
movq 8(%rsp), %rsi /* temporarily store the return address in %rsi */
@@ -114,34 +107,43 @@ For 32-bit we have the following conventions - kernel is built with
pushq %rsi /* pt_regs->si */
.endif
pushq \rdx /* pt_regs->dx */
- xorl %edx, %edx /* nospec dx */
pushq %rcx /* pt_regs->cx */
- xorl %ecx, %ecx /* nospec cx */
pushq \rax /* pt_regs->ax */
pushq %r8 /* pt_regs->r8 */
- xorl %r8d, %r8d /* nospec r8 */
pushq %r9 /* pt_regs->r9 */
- xorl %r9d, %r9d /* nospec r9 */
pushq %r10 /* pt_regs->r10 */
- xorl %r10d, %r10d /* nospec r10 */
pushq %r11 /* pt_regs->r11 */
- xorl %r11d, %r11d /* nospec r11*/
pushq %rbx /* pt_regs->rbx */
- xorl %ebx, %ebx /* nospec rbx*/
pushq %rbp /* pt_regs->rbp */
- xorl %ebp, %ebp /* nospec rbp*/
pushq %r12 /* pt_regs->r12 */
- xorl %r12d, %r12d /* nospec r12*/
pushq %r13 /* pt_regs->r13 */
- xorl %r13d, %r13d /* nospec r13*/
pushq %r14 /* pt_regs->r14 */
- xorl %r14d, %r14d /* nospec r14*/
pushq %r15 /* pt_regs->r15 */
- xorl %r15d, %r15d /* nospec r15*/
UNWIND_HINT_REGS
+
.if \save_ret
pushq %rsi /* return address on top of stack */
.endif
+
+ /*
+ * Sanitize registers of values that a speculation attack might
+ * otherwise want to exploit. The lower registers are likely clobbered
+ * well before they could be put to use in a speculative execution
+ * gadget.
+ */
+ xorl %edx, %edx /* nospec dx */
+ xorl %ecx, %ecx /* nospec cx */
+ xorl %r8d, %r8d /* nospec r8 */
+ xorl %r9d, %r9d /* nospec r9 */
+ xorl %r10d, %r10d /* nospec r10 */
+ xorl %r11d, %r11d /* nospec r11 */
+ xorl %ebx, %ebx /* nospec rbx */
+ xorl %ebp, %ebp /* nospec rbp */
+ xorl %r12d, %r12d /* nospec r12 */
+ xorl %r13d, %r13d /* nospec r13 */
+ xorl %r14d, %r14d /* nospec r14 */
+ xorl %r15d, %r15d /* nospec r15 */
+
.endm
.macro POP_REGS pop_rdi=1 skip_r11rcx=0