-
- /*
- * "Paranoid" exit path from exception stack.
- * Paranoid because this is used by NMIs and cannot take
- * any kernel state for granted.
- * We don't do kernel preemption checks here, because only
- * NMI should be common and it does not enable IRQs and
- * cannot get reschedule ticks.
- *
- * "trace" is 0 for the NMI handler only, because irq-tracing
- * is fundamentally NMI-unsafe. (we cannot change the soft and
- * hard flags at once, atomically)
- */
- .macro paranoidexit trace=1
- /* ebx: no swapgs flag */
-paranoid_exit\trace:
- testl %ebx,%ebx /* swapgs needed? */
- jnz paranoid_restore\trace
- testl $3,CS(%rsp)
- jnz paranoid_userspace\trace
-paranoid_swapgs\trace:
- TRACE_IRQS_IRETQ 0
- swapgs
-paranoid_restore\trace:
- RESTORE_ALL 8
- iretq
-paranoid_userspace\trace:
- GET_THREAD_INFO(%rcx)
- movl threadinfo_flags(%rcx),%ebx
- andl $_TIF_WORK_MASK,%ebx
- jz paranoid_swapgs\trace
- movq %rsp,%rdi /* &pt_regs */
- call sync_regs
- movq %rax,%rsp /* switch stack for scheduling */
- testl $_TIF_NEED_RESCHED,%ebx
- jnz paranoid_schedule\trace
- movl %ebx,%edx /* arg3: thread flags */
- .if \trace
- TRACE_IRQS_ON
- .endif
- sti
- xorl %esi,%esi /* arg2: oldset */
- movq %rsp,%rdi /* arg1: &pt_regs */
- call do_notify_resume
- cli
- .if \trace
- TRACE_IRQS_OFF
- .endif
- jmp paranoid_userspace\trace
-paranoid_schedule\trace:
- .if \trace
- TRACE_IRQS_ON
- .endif
- sti
- call schedule
- cli
- .if \trace
- TRACE_IRQS_OFF
- .endif
- jmp paranoid_userspace\trace
- CFI_ENDPROC
- .endm
-