[PATCH] Fix the interrupt handling for kprobes

[Steve Capper]

---
 arch/arm64/kernel/kprobes.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c
index be7c330..d39d826 100644
--- a/arch/arm64/kernel/kprobes.c
+++ b/arch/arm64/kernel/kprobes.c
@@ -229,10 +229,6 @@ skip_singlestep_missed(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
 {
 	/* set return addr to next pc to continue */
 	instruction_pointer(regs) += sizeof(kprobe_opcode_t);
-
-	if (kcb->kprobe_status != KPROBE_REENTER)
-		kprobes_restore_local_irqflag(regs);
-
 }
 
 static void __kprobes setup_singlestep(struct kprobe *p,
@@ -259,7 +255,7 @@ static void __kprobes setup_singlestep(struct kprobe *p,
 			spsr_set_debug_flag(regs, 0);
 
 		/* IRQs and single stepping do not mix well. */
-		local_irq_disable();
+		kprobes_save_local_irqflag(regs);
 		kernel_enable_single_step(regs);
 		instruction_pointer(regs) = slot;
 	} else	{
@@ -326,7 +322,6 @@ post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
 	}
 
 	reset_current_kprobe();
-	kprobes_restore_local_irqflag(regs);
 }
 
 int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr)
@@ -380,8 +375,6 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr)
 			return 1;
 
 		break;
-	default:
-		break;
 	}
 	return 0;
 }
@@ -446,7 +439,6 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
 		 * handling of this interrupt is appropriate.
 		 * Return back to original instruction, and continue.
 		 */
-		kprobes_restore_local_irqflag(regs);
 		return;
 	} else if (cur) {
 		/* We probably hit a jprobe.  Call its break handler. */
@@ -459,7 +451,6 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
 		/* breakpoint is removed, now in a race
 		 * Return back to original instruction & continue.
 		 */
-		kprobes_restore_local_irqflag(regs);
 	}
 }
 
@@ -485,6 +476,7 @@ kprobe_single_step_handler(struct pt_regs *regs, unsigned int esr)
 	retval = kprobe_ss_hit(kcb, instruction_pointer(regs));
 
 	if (retval == DBG_HOOK_HANDLED) {
+		kprobes_restore_local_irqflag(regs);
 		kernel_disable_single_step();
 
 		if (kcb->kprobe_status == KPROBE_REENTER)
@@ -499,7 +491,6 @@ kprobe_single_step_handler(struct pt_regs *regs, unsigned int esr)
 static int __kprobes
 kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr)
 {
-	kprobes_save_local_irqflag(regs);
 	kprobe_handler(regs);
 	return DBG_HOOK_HANDLED;
 }
@@ -563,7 +554,6 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
 		memcpy((void *)stack_addr, kcb->jprobes_stack,
 		       MIN_STACK_SIZE(stack_addr));
 		preempt_enable_no_resched();
-		kprobes_restore_local_irqflag(regs);
 		return 1;
 	}
 	return 0;
@@ -655,8 +645,6 @@ trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 		kfree(ri);
 	}
 
-	kprobes_restore_local_irqflag(regs);
-
 	/* return 1 so that post handlers not called */
 	return 1;
 }
-- 
1.9.3

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