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Commit 79c5dca3 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, msr: CFI annotations, cleanups for msr-reg.S 



Add CFI annotations for native_{rd,wr}msr_safe_regs().
Simplify the 64-bit implementation: we don't allow the upper half
registers to be set, and so we can use them to carry state across the
operation.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <petkovbb@gmail.com>
LKML-Reference: <1251705011-18636-1-git-send-email-petkovbb@gmail.com>
parent 709972b1

arch/x86/lib/msr-reg.S

+42 −38
Original line number Original line Diff line number Diff line 
#include <linux/linkage.h>

#include <linux/linkage.h>

#include <linux/errno.h>

#include <linux/errno.h>

#include <asm/dwarf2.h>

#include <asm/asm.h>

#include <asm/asm.h>

#include <asm/msr.h>

#include <asm/msr.h>
@@ -12,10 +13,11 @@ 
 */

 */

.macro op_safe_regs op:req

.macro op_safe_regs op:req

ENTRY(native_\op\()_safe_regs)

ENTRY(native_\op\()_safe_regs)

	push    %rbx

	CFI_STARTPROC

	push    %rbp

	pushq_cfi %rbx

	push    $0              /* Return value */

	pushq_cfi %rbp

	push    %rdi

	movq	%rdi, %r10	/* Save pointer */

	xorl	%r11d, %r11d	/* Return value */

	movl    (%rdi), %eax

	movl    (%rdi), %eax

	movl    4(%rdi), %ecx

	movl    4(%rdi), %ecx

	movl    8(%rdi), %edx

	movl    8(%rdi), %edx
@@ -23,27 +25,26 @@ ENTRY(native_\op\()_safe_regs) 
	movl    20(%rdi), %ebp

	movl    20(%rdi), %ebp

	movl    24(%rdi), %esi

	movl    24(%rdi), %esi

	movl    28(%rdi), %edi

	movl    28(%rdi), %edi

	CFI_REMEMBER_STATE

1:	\op

1:	\op

2:	movl    %edi, %r10d

2:	movl    %eax, (%r10)

	pop     %rdi

	movl	%r11d, %eax	/* Return value */

	movl    %eax, (%rdi)

	movl    %ecx, 4(%r10)

	movl    %ecx, 4(%rdi)

	movl    %edx, 8(%r10)

	movl    %edx, 8(%rdi)

	movl    %ebx, 12(%r10)

	movl    %ebx, 12(%rdi)

	movl    %ebp, 20(%r10)

	movl    %ebp, 20(%rdi)

	movl    %esi, 24(%r10)

	movl    %esi, 24(%rdi)

	movl    %edi, 28(%r10)

	movl    %r10d, 28(%rdi)

	popq_cfi %rbp

	pop     %rax

	popq_cfi %rbx

	pop     %rbp

	pop     %rbx

	ret

	ret

3:

3:

	movq    $-EIO, 8(%rsp)

	CFI_RESTORE_STATE

	movl    $-EIO, %r11d

	jmp     2b

	jmp     2b

	.section __ex_table,"ax"



	.balign 4

	_ASM_EXTABLE(1b, 3b)

	.quad   1b, 3b

	CFI_ENDPROC

	.previous

ENDPROC(native_\op\()_safe_regs)

ENDPROC(native_\op\()_safe_regs)

.endm

.endm
@@ -51,12 +52,13 @@ ENDPROC(native_\op\()_safe_regs) 




.macro op_safe_regs op:req

.macro op_safe_regs op:req

ENTRY(native_\op\()_safe_regs)

ENTRY(native_\op\()_safe_regs)

	push    %ebx

	CFI_STARTPROC

	push    %ebp

	pushl_cfi %ebx

	push    %esi

	pushl_cfi %ebp

	push    %edi

	pushl_cfi %esi

	push    $0              /* Return value */

	pushl_cfi %edi

	push    %eax

	pushl_cfi $0              /* Return value */

	pushl_cfi %eax

	movl    4(%eax), %ecx

	movl    4(%eax), %ecx

	movl    8(%eax), %edx

	movl    8(%eax), %edx

	movl    12(%eax), %ebx

	movl    12(%eax), %ebx
@@ -64,30 +66,32 @@ ENTRY(native_\op\()_safe_regs) 
	movl    24(%eax), %esi

	movl    24(%eax), %esi

	movl    28(%eax), %edi

	movl    28(%eax), %edi

	movl    (%eax), %eax

	movl    (%eax), %eax

	CFI_REMEMBER_STATE

1:	\op

1:	\op

2:	push    %eax

2:	pushl_cfi %eax

	movl    4(%esp), %eax

	movl    4(%esp), %eax

	pop     (%eax)

	popl_cfi (%eax)

	addl    $4, %esp

	addl    $4, %esp

	CFI_ADJUST_CFA_OFFSET -4

	movl    %ecx, 4(%eax)

	movl    %ecx, 4(%eax)

	movl    %edx, 8(%eax)

	movl    %edx, 8(%eax)

	movl    %ebx, 12(%eax)

	movl    %ebx, 12(%eax)

	movl    %ebp, 20(%eax)

	movl    %ebp, 20(%eax)

	movl    %esi, 24(%eax)

	movl    %esi, 24(%eax)

	movl    %edi, 28(%eax)

	movl    %edi, 28(%eax)

	pop     %eax

	popl_cfi %eax

	pop     %edi

	popl_cfi %edi

	pop     %esi

	popl_cfi %esi

	pop     %ebp

	popl_cfi %ebp

	pop     %ebx

	popl_cfi %ebx

	ret

	ret

3:

3:

	CFI_RESTORE_STATE

	movl    $-EIO, 4(%esp)

	movl    $-EIO, 4(%esp)

	jmp     2b

	jmp     2b

	.section __ex_table,"ax"



	.balign 4

	_ASM_EXTABLE(1b, 3b)

	.long   1b, 3b

	CFI_ENDPROC

	.previous

ENDPROC(native_\op\()_safe_regs)

ENDPROC(native_\op\()_safe_regs)

.endm

.endm