linux-stable/arch/x86/lib/msr-reg.S
Denys Vlasenko 49db46a67b x86/asm: Introduce push/pop macros which generate CFI_REL_OFFSET and CFI_RESTORE
Sequences:

        pushl_cfi %reg
        CFI_REL_OFFSET reg, 0

and:

        popl_cfi %reg
        CFI_RESTORE reg

happen quite often. This patch adds macros which generate them.

No assembly changes (verified with objdump -dr vmlinux.o).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1421017655-25561-1-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/2202eb90f175cf45d1b2d1c64dbb5676a8ad07ad.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00

102 lines
1.9 KiB
ArmAsm

#include <linux/linkage.h>
#include <linux/errno.h>
#include <asm/dwarf2.h>
#include <asm/asm.h>
#include <asm/msr.h>
#ifdef CONFIG_X86_64
/*
* int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
*
* reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
*
*/
.macro op_safe_regs op
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushq_cfi_reg rbx
pushq_cfi_reg rbp
movq %rdi, %r10 /* Save pointer */
xorl %r11d, %r11d /* Return value */
movl (%rdi), %eax
movl 4(%rdi), %ecx
movl 8(%rdi), %edx
movl 12(%rdi), %ebx
movl 20(%rdi), %ebp
movl 24(%rdi), %esi
movl 28(%rdi), %edi
CFI_REMEMBER_STATE
1: \op
2: movl %eax, (%r10)
movl %r11d, %eax /* Return value */
movl %ecx, 4(%r10)
movl %edx, 8(%r10)
movl %ebx, 12(%r10)
movl %ebp, 20(%r10)
movl %esi, 24(%r10)
movl %edi, 28(%r10)
popq_cfi_reg rbp
popq_cfi_reg rbx
ret
3:
CFI_RESTORE_STATE
movl $-EIO, %r11d
jmp 2b
_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
ENDPROC(\op\()_safe_regs)
.endm
#else /* X86_32 */
.macro op_safe_regs op
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushl_cfi_reg ebx
pushl_cfi_reg ebp
pushl_cfi_reg esi
pushl_cfi_reg edi
pushl_cfi $0 /* Return value */
pushl_cfi %eax
movl 4(%eax), %ecx
movl 8(%eax), %edx
movl 12(%eax), %ebx
movl 20(%eax), %ebp
movl 24(%eax), %esi
movl 28(%eax), %edi
movl (%eax), %eax
CFI_REMEMBER_STATE
1: \op
2: pushl_cfi %eax
movl 4(%esp), %eax
popl_cfi (%eax)
addl $4, %esp
CFI_ADJUST_CFA_OFFSET -4
movl %ecx, 4(%eax)
movl %edx, 8(%eax)
movl %ebx, 12(%eax)
movl %ebp, 20(%eax)
movl %esi, 24(%eax)
movl %edi, 28(%eax)
popl_cfi %eax
popl_cfi_reg edi
popl_cfi_reg esi
popl_cfi_reg ebp
popl_cfi_reg ebx
ret
3:
CFI_RESTORE_STATE
movl $-EIO, 4(%esp)
jmp 2b
_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
ENDPROC(\op\()_safe_regs)
.endm
#endif
op_safe_regs rdmsr
op_safe_regs wrmsr