diff options
Diffstat (limited to 'arch/x86/entry/calling.h')
| -rw-r--r-- | arch/x86/entry/calling.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 3f48f695d5e6..f4b129d4af42 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -147,6 +147,25 @@ For 32-bit we have the following conventions - kernel is built with UNWIND_HINT_REGS offset=\offset .endm + /* + * 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: + */ + .macro CLEAR_REGS_NOSPEC + xorl %ebp, %ebp + xorl %ebx, %ebx + xorq %r8, %r8 + xorq %r9, %r9 + xorq %r10, %r10 + xorq %r11, %r11 + xorq %r12, %r12 + xorq %r13, %r13 + xorq %r14, %r14 + xorq %r15, %r15 + .endm + .macro POP_EXTRA_REGS popq %r15 popq %r14 |