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| author | H. Peter Anvin <hpa@zytor.com> | 2012-04-19 00:16:48 (GMT) |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-04-19 22:07:56 (GMT) |
| commit | ffc4bc9c6fa4eaf935d96d139bfa7443cac0b88e (patch) | |
| tree | 61296184c680a012f7d4a10deedec2caba87dc53 /arch/x86 | |
| parent | 84f4fc524eed040660bd4ebc8cba259d8afe8461 (diff) | |
| download | linux-ffc4bc9c6fa4eaf935d96d139bfa7443cac0b88e.tar.xz | |
x86, paravirt: Replace GET_CR2_INTO_RCX with GET_CR2_INTO_RAX
GET_CR2_INTO_RCX is asinine: it is only used in one place, the actual
paravirt call returns the value in %rax, not %rcx; and the one place
that wants it wants the result in %r9. We actually generate as a
result of this call:
call ...
movq %rax, %rcx
xorq %rax, %rax /* this value isn't even used... */
movq %rcx, %r9
At least make the macro do what the paravirt call does, which is put
the value into %rax.
Nevermind the fact that the macro clobbers all the volatile registers.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1334794610-5546-4-git-send-email-hpa@zytor.com
Cc: Glauber de Oliveira Costa <glommer@parallels.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/paravirt.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 6 |
2 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index aa0f913..6cbbabf 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -1023,10 +1023,8 @@ extern void default_banner(void); call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \ ) -#define GET_CR2_INTO_RCX \ - call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2); \ - movq %rax, %rcx; \ - xorq %rax, %rax; +#define GET_CR2_INTO_RAX \ + call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2) #define PARAVIRT_ADJUST_EXCEPTION_FRAME \ PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \ diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index adf52e8..d1e112c8 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -23,8 +23,9 @@ #ifdef CONFIG_PARAVIRT #include <asm/asm-offsets.h> #include <asm/paravirt.h> +#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg #else -#define GET_CR2_INTO_RCX movq %cr2, %rcx +#define GET_CR2_INTO(reg) movq %cr2, reg #endif /* we are not able to switch in one step to the final KERNEL ADDRESS SPACE @@ -286,8 +287,7 @@ ENTRY(early_idt_handler) cmpl $2,early_recursion_flag(%rip) jz 1f incl early_recursion_flag(%rip) - GET_CR2_INTO_RCX - movq %rcx,%r9 + GET_CR2_INTO(%r9) xorl %r8d,%r8d # zero for error code movl %esi,%ecx # get vector number # Test %ecx against mask of vectors that push error code. |