diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/entry/calling.h | 42 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64.S | 20 |
2 files changed, 10 insertions, 52 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index d6a97e2..5967501 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -97,46 +97,6 @@ For 32-bit we have the following conventions - kernel is built with #define SIZEOF_PTREGS 21*8 - .macro ALLOC_PT_GPREGS_ON_STACK - addq $-(15*8), %rsp - .endm - - .macro SAVE_AND_CLEAR_REGS offset=0 - /* - * Save 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: - */ - movq %rdi, 14*8+\offset(%rsp) - movq %rsi, 13*8+\offset(%rsp) - movq %rdx, 12*8+\offset(%rsp) - movq %rcx, 11*8+\offset(%rsp) - movq %rax, 10*8+\offset(%rsp) - movq %r8, 9*8+\offset(%rsp) - xorq %r8, %r8 /* nospec r8 */ - movq %r9, 8*8+\offset(%rsp) - xorq %r9, %r9 /* nospec r9 */ - movq %r10, 7*8+\offset(%rsp) - xorq %r10, %r10 /* nospec r10 */ - movq %r11, 6*8+\offset(%rsp) - xorq %r11, %r11 /* nospec r11 */ - movq %rbx, 5*8+\offset(%rsp) - xorl %ebx, %ebx /* nospec rbx */ - movq %rbp, 4*8+\offset(%rsp) - xorl %ebp, %ebp /* nospec rbp */ - movq %r12, 3*8+\offset(%rsp) - xorq %r12, %r12 /* nospec r12 */ - movq %r13, 2*8+\offset(%rsp) - xorq %r13, %r13 /* nospec r13 */ - movq %r14, 1*8+\offset(%rsp) - xorq %r14, %r14 /* nospec r14 */ - movq %r15, 0*8+\offset(%rsp) - xorq %r15, %r15 /* nospec r15 */ - UNWIND_HINT_REGS offset=\offset - .endm - .macro PUSH_AND_CLEAR_REGS rdx=%rdx rax=%rax /* * Push registers and sanitize registers of values that a @@ -211,7 +171,7 @@ For 32-bit we have the following conventions - kernel is built with * is just setting the LSB, which makes it an invalid stack address and is also * a signal to the unwinder that it's a pt_regs pointer in disguise. * - * NOTE: This macro must be used *after* SAVE_AND_CLEAR_REGS because it corrupts + * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts * the original rbp. */ .macro ENCODE_FRAME_POINTER ptregs_offset=0 diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index b06a4b5..cfbf433 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -871,7 +871,9 @@ ENTRY(\sym) pushq $-1 /* ORIG_RAX: no syscall to restart */ .endif - ALLOC_PT_GPREGS_ON_STACK + /* Save all registers in pt_regs */ + PUSH_AND_CLEAR_REGS + ENCODE_FRAME_POINTER .if \paranoid < 2 testb $3, CS(%rsp) /* If coming from userspace, switch stacks */ @@ -1121,15 +1123,12 @@ idtentry machine_check do_mce has_error_code=0 paranoid=1 #endif /* - * Save all registers in pt_regs, and switch gs if needed. + * Switch gs if needed. * Use slow, but surefire "are we in kernel?" check. * Return: ebx=0: need swapgs on exit, ebx=1: otherwise */ ENTRY(paranoid_entry) - UNWIND_HINT_FUNC cld - SAVE_AND_CLEAR_REGS 8 - ENCODE_FRAME_POINTER 8 movl $1, %ebx movl $MSR_GS_BASE, %ecx rdmsr @@ -1142,7 +1141,7 @@ ENTRY(paranoid_entry) SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg=%rax save_reg=%r14 ret -END(paranoid_entry) +ENDPROC(paranoid_entry) /* * "Paranoid" exit path from exception stack. This is invoked @@ -1173,14 +1172,12 @@ ENTRY(paranoid_exit) END(paranoid_exit) /* - * Save all registers in pt_regs, and switch gs if needed. + * Switch gs if needed. * Return: EBX=0: came from user mode; EBX=1: otherwise */ ENTRY(error_entry) - UNWIND_HINT_FUNC + UNWIND_HINT_REGS offset=8 cld - SAVE_AND_CLEAR_REGS 8 - ENCODE_FRAME_POINTER 8 testb $3, CS+8(%rsp) jz .Lerror_kernelspace @@ -1571,7 +1568,8 @@ end_repeat_nmi: * frame to point back to repeat_nmi. */ pushq $-1 /* ORIG_RAX: no syscall to restart */ - ALLOC_PT_GPREGS_ON_STACK + PUSH_AND_CLEAR_REGS + ENCODE_FRAME_POINTER /* * Use paranoid_entry to handle SWAPGS, but no need to use paranoid_exit |
