korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-27 06:04:23 +08:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Browse Source 
Pull x86 fix from Peter Anvin:
 "A single fix to not invoke the espfix code on Xen PV, as it turns out
  to oops the guest when invoked after all.  This patch leaves some
  amount of dead code, in particular unnecessary initialization of the
  espfix stacks when they won't be used, but in the interest of keeping
  the patch minimal that cleanup can wait for the next cycle"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_64/entry/xen: Do not invoke espfix64 on Xen
This commit is contained in:
Linus Torvalds 2014-08-01 17:37:01 -07:00
commit f88cf230a4
3 changed files with 11 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/irqflags.h
View File

@ -129,7 +129,7 @@ static inline notrace unsigned long arch_local_irq_save(void)
#define PARAVIRT_ADJUST_EXCEPTION_FRAME /* */
#define INTERRUPT_RETURN iretq
#define INTERRUPT_RETURN jmp native_iret
#define USERGS_SYSRET64 \
swapgs; \
sysretq;

28
arch/x86/kernel/entry_64.S
View File

@ -830,27 +830,24 @@ restore_args:
RESTORE_ARGS 1,8,1
irq_return:
INTERRUPT_RETURN
ENTRY(native_iret)
/*
* Are we returning to a stack segment from the LDT? Note: in
* 64-bit mode SS:RSP on the exception stack is always valid.
*/
#ifdef CONFIG_X86_ESPFIX64
testb $4,(SS-RIP)(%rsp)
jnz irq_return_ldt
jnz native_irq_return_ldt
#endif
irq_return_iret:
INTERRUPT_RETURN
_ASM_EXTABLE(irq_return_iret, bad_iret)
#ifdef CONFIG_PARAVIRT
ENTRY(native_iret)
native_irq_return_iret:
iretq
_ASM_EXTABLE(native_iret, bad_iret)
#endif
_ASM_EXTABLE(native_irq_return_iret, bad_iret)
#ifdef CONFIG_X86_ESPFIX64
irq_return_ldt:
native_irq_return_ldt:
pushq_cfi %rax
pushq_cfi %rdi
SWAPGS
@ -872,7 +869,7 @@ irq_return_ldt:
SWAPGS
movq %rax,%rsp
popq_cfi %rax
jmp irq_return_iret
jmp native_irq_return_iret
#endif
.section .fixup,"ax"
@ -956,13 +953,8 @@ __do_double_fault:
cmpl $__KERNEL_CS,CS(%rdi)
jne do_double_fault
movq RIP(%rdi),%rax
cmpq $irq_return_iret,%rax
#ifdef CONFIG_PARAVIRT
je 1f
cmpq $native_iret,%rax
#endif
cmpq $native_irq_return_iret,%rax
jne do_double_fault /* This shouldn't happen... */
1:
movq PER_CPU_VAR(kernel_stack),%rax
subq $(6*8-KERNEL_STACK_OFFSET),%rax /* Reset to original stack */
movq %rax,RSP(%rdi)
@ -1428,7 +1420,7 @@ error_sti:
*/
error_kernelspace:
incl %ebx
leaq irq_return_iret(%rip),%rcx
leaq native_irq_return_iret(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_swapgs
movl %ecx,%eax /* zero extend */

2
arch/x86/kernel/paravirt_patch_64.c
View File

@ -6,7 +6,6 @@ DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
DEF_NATIVE(pv_cpu_ops, iret, "iretq");
DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
@ -50,7 +49,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
PATCH_SITE(pv_irq_ops, save_fl);
PATCH_SITE(pv_irq_ops, irq_enable);
PATCH_SITE(pv_irq_ops, irq_disable);
PATCH_SITE(pv_cpu_ops, iret);
PATCH_SITE(pv_cpu_ops, irq_enable_sysexit);
PATCH_SITE(pv_cpu_ops, usergs_sysret32);
PATCH_SITE(pv_cpu_ops, usergs_sysret64);