Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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
+11
-21
+1
-1
arch/x86/include/asm/irqflags.h
+1
-1
arch/x86/include/asm/irqflags.h
+10
-18
arch/x86/kernel/entry_64.S
+10
-18
arch/x86/kernel/entry_64.S
···
830
830
RESTORE_ARGS 1,8,1
831
831
832
832
irq_return:
833
+
INTERRUPT_RETURN
834
+
835
+
ENTRY(native_iret)
833
836
/*
834
837
* Are we returning to a stack segment from the LDT? Note: in
835
838
* 64-bit mode SS:RSP on the exception stack is always valid.
836
839
*/
837
840
#ifdef CONFIG_X86_ESPFIX64
838
841
testb $4,(SS-RIP)(%rsp)
839
-
jnz irq_return_ldt
842
+
jnz native_irq_return_ldt
840
843
#endif
841
844
842
-
irq_return_iret:
843
-
INTERRUPT_RETURN
844
-
_ASM_EXTABLE(irq_return_iret, bad_iret)
845
-
846
-
#ifdef CONFIG_PARAVIRT
847
-
ENTRY(native_iret)
845
+
native_irq_return_iret:
848
846
iretq
849
-
_ASM_EXTABLE(native_iret, bad_iret)
850
-
#endif
847
+
_ASM_EXTABLE(native_irq_return_iret, bad_iret)
851
848
852
849
#ifdef CONFIG_X86_ESPFIX64
853
-
irq_return_ldt:
850
+
native_irq_return_ldt:
854
851
pushq_cfi %rax
855
852
pushq_cfi %rdi
856
853
SWAPGS
···
869
872
SWAPGS
870
873
movq %rax,%rsp
871
874
popq_cfi %rax
872
-
jmp irq_return_iret
875
+
jmp native_irq_return_iret
873
876
#endif
874
877
875
878
.section .fixup,"ax"
···
953
956
cmpl $__KERNEL_CS,CS(%rdi)
954
957
jne do_double_fault
955
958
movq RIP(%rdi),%rax
956
-
cmpq $irq_return_iret,%rax
957
-
#ifdef CONFIG_PARAVIRT
958
-
je 1f
959
-
cmpq $native_iret,%rax
960
-
#endif
959
+
cmpq $native_irq_return_iret,%rax
961
960
jne do_double_fault /* This shouldn't happen... */
962
-
1:
963
961
movq PER_CPU_VAR(kernel_stack),%rax
964
962
subq $(6*8-KERNEL_STACK_OFFSET),%rax /* Reset to original stack */
965
963
movq %rax,RSP(%rdi)
···
1420
1428
*/
1421
1429
error_kernelspace:
1422
1430
incl %ebx
1423
-
leaq irq_return_iret(%rip),%rcx
1431
+
leaq native_irq_return_iret(%rip),%rcx
1424
1432
cmpq %rcx,RIP+8(%rsp)
1425
1433
je error_swapgs
1426
1434
movl %ecx,%eax /* zero extend */
-2
arch/x86/kernel/paravirt_patch_64.c
-2
arch/x86/kernel/paravirt_patch_64.c
···
6
6
DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
7
7
DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
8
8
DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
9
-
DEF_NATIVE(pv_cpu_ops, iret, "iretq");
10
9
DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
11
10
DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
12
11
DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
···
49
50
PATCH_SITE(pv_irq_ops, save_fl);
50
51
PATCH_SITE(pv_irq_ops, irq_enable);
51
52
PATCH_SITE(pv_irq_ops, irq_disable);
52
-
PATCH_SITE(pv_cpu_ops, iret);
53
53
PATCH_SITE(pv_cpu_ops, irq_enable_sysexit);
54
54
PATCH_SITE(pv_cpu_ops, usergs_sysret32);
55
55
PATCH_SITE(pv_cpu_ops, usergs_sysret64);