diff options
Diffstat (limited to 'arch/i386/kernel/entry.S')
| -rw-r--r-- | arch/i386/kernel/entry.S | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index 0220bc8cbb4..d274612e05c 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -62,13 +62,6 @@ DF_MASK = 0x00000400 NT_MASK = 0x00004000 VM_MASK = 0x00020000 -/* These are replaces for paravirtualization */ -#define DISABLE_INTERRUPTS cli -#define ENABLE_INTERRUPTS sti -#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit -#define INTERRUPT_RETURN iret -#define GET_CR0_INTO_EAX movl %cr0, %eax - #ifdef CONFIG_PREEMPT #define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF #else @@ -416,6 +409,20 @@ ldt_ss: jnz restore_nocheck testl $0x00400000, %eax # returning to 32bit stack? jnz restore_nocheck # allright, normal return + +#ifdef CONFIG_PARAVIRT + /* + * The kernel can't run on a non-flat stack if paravirt mode + * is active. Rather than try to fixup the high bits of + * ESP, bypass this code entirely. This may break DOSemu + * and/or Wine support in a paravirt VM, although the option + * is still available to implement the setting of the high + * 16-bits in the INTERRUPT_RETURN paravirt-op. + */ + cmpl $0, paravirt_ops+PARAVIRT_enabled + jne restore_nocheck +#endif + /* If returning to userspace with 16bit stack, * try to fix the higher word of ESP, as the CPU * won't restore it. @@ -833,6 +840,19 @@ nmi_espfix_stack: .previous KPROBE_END(nmi) +#ifdef CONFIG_PARAVIRT +ENTRY(native_iret) +1: iret +.section __ex_table,"a" + .align 4 + .long 1b,iret_exc +.previous + +ENTRY(native_irq_enable_sysexit) + sti + sysexit +#endif + KPROBE_ENTRY(int3) RING0_INT_FRAME pushl $-1 # mark this as an int |