Re: [patch V2 06/17] x86/entry/32: Remove redundant interrupt disable

Sean Christopherson
2019-10-23T14:17:59Z

On Wed, Oct 23, 2019 at 02:27:11PM +0200, Thomas Gleixner wrote:
> Now that the trap handlers return with interrupts disabled, the
> unconditional disabling of interrupts in the low level entry code can be
> removed along with the trace calls and the misnomed preempt_stop macro.
> As a consequence ret_from_exception and ret_from_intr collapse.
>
> Add a debug check to verify that interrupts are disabled depending on
> CONFIG_DEBUG_ENTRY.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---

One nit below.

Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>

> arch/x86/entry/entry_32.S | 21 ++++++---------------
> 1 file changed, 6 insertions(+), 15 deletions(-)
>
> --- a/arch/x86/entry/entry_32.S
> +++ b/arch/x86/entry/entry_32.S
> @@ -1207,7 +1198,7 @@ ENDPROC(common_spurious)
> TRACE_IRQS_OFF
> movl %esp, %eax
> call do_IRQ
> - jmp ret_from_intr
> + jmp ret_from_exception
> ENDPROC(common_interrupt)
>
> #define BUILD_INTERRUPT3(name, nr, fn) \
> @@ -1219,7 +1210,7 @@ ENTRY(name) \
> TRACE_IRQS_OFF \
> movl %esp, %eax; \
> call fn; \
> - jmp ret_from_intr; \
> + jmp ret_from_exception; \

This backslash is now unaligned.

> ENDPROC(name)
>
> #define BUILD_INTERRUPT(name, nr) \
> @@ -1366,7 +1357,7 @@ ENTRY(xen_do_upcall)
> #ifndef CONFIG_PREEMPTION
> call xen_maybe_preempt_hcall
> #endif
> - jmp ret_from_intr
> + jmp ret_from_exception
> ENDPROC(xen_hypervisor_callback)
>
> /*
>
>