Re: [PATCH] powerpc/970: fix nap return address corruption on async interrupt exit

On Wed, Jul 08, 2026 at 09:57:44AM +0530, Shrikanth Hegde wrote:

Hi Mukesh.

On 7/7/26 10:54 PM, Mukesh Kumar Chaurasiya (IBM) wrote:

<... snip ...>

quoted

  		/* Can avoid a test-and-clear because NMIs do not call this */
  		clear_thread_local_flags(_TLF_NAPPING);

@@ -286,14 +293,6 @@ static inline void arch_interrupt_async_enter_prepare(struct pt_regs *regs)
  static inline void arch_interrupt_async_exit_prepare(struct pt_regs *regs)
  {
-	/*
-	 * Adjust at exit so the main handler sees the true NIA. This must
-	 * come before irq_exit() because irq_exit can enable interrupts, and
-	 * if another interrupt is taken before nap_adjust_return has run
-	 * here, then that interrupt would return directly to idle nap return.
-	 */
-	nap_adjust_return(regs);
-
  	arch_interrupt_exit_prepare(regs);
  }

This makes arch_interrupt_async_exit_prepare same as arch_interrupt_exit_prepare.
Maybe remove arch_interrupt_async_exit_prepare?

Hey,

`arch_interrupt_async_exit_prepare` and `arch_interrupt_exit_prepare`,
both are marked static inline. So the generated assembly will have no
impact. I kept it this way coz it was consistent with how we implemented
other macros like `DEFINE_INTERRUPT_HANDLER`.

Regards,
Mukesh

quoted

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index fb42a664ae54..1b45a49e9bed 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h

@@ -246,6 +246,7 @@ interrupt_handler void func(struct pt_regs *regs)			\
  	instrumentation_begin();					\
  	irq_enter_rcu();						\
  	____##func (regs);						\
+	nap_adjust_return(regs);					\
  	irq_exit_rcu();							\
  	instrumentation_end();						\
  	arch_interrupt_async_exit_prepare(regs);			\