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author | 2014-08-01 17:37:01 -0700 | |
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committer | 2014-08-01 17:37:01 -0700 | |
commit | f88cf230a43e08b3fb615e0520900a414f037440 (patch) | |
tree | 35dbb478d247a43c2827b634316cc65fa3cbfa4b | |
parent | Merge tag 'staging-3.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git... (diff) | |
parent | x86_64/entry/xen: Do not invoke espfix64 on Xen (diff) | |
download | linux-f88cf230a43e08b3fb615e0520900a414f037440.tar.gz linux-f88cf230a43e08b3fb615e0520900a414f037440.tar.bz2 linux-f88cf230a43e08b3fb615e0520900a414f037440.zip |
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
-rw-r--r-- | arch/x86/include/asm/irqflags.h | 2 | ||||
-rw-r--r-- | arch/x86/kernel/entry_64.S | 28 | ||||
-rw-r--r-- | arch/x86/kernel/paravirt_patch_64.c | 2 |
3 files changed, 11 insertions, 21 deletions
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index bba3cf88e624..0a8b519226b8 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -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; diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index b25ca969edd2..c844f0816ab8 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -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 */ diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c index 3f08f34f93eb..a1da6737ba5b 100644 --- a/arch/x86/kernel/paravirt_patch_64.c +++ b/arch/x86/kernel/paravirt_patch_64.c @@ -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); |