Module Name: src
Committed By: jmcneill
Date: Sat Feb 15 00:30:49 UTC 2025
Modified Files:
src/sys/arch/powerpc/pic: intr.c
Log Message:
powerpc: Fix ci_ipending corruption with cascaded pics
A cascaded pic will register pic_handle_intr as its interrupt handler,
but interrupt handlers are called with MSR[EE] = 1. This breaks
assumptions in pic callbacks and can result in eg. corrupt ci_ipending
due to a read/modify/write of the field with nested interrupts.
Fix this by always clearing MSR[EE] at the top of pic_handle_intr.
To generate a diff of this commit:
cvs rdiff -u -r1.34 -r1.35 src/sys/arch/powerpc/pic/intr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/powerpc/pic/intr.c
diff -u src/sys/arch/powerpc/pic/intr.c:1.34 src/sys/arch/powerpc/pic/intr.c:1.35
--- src/sys/arch/powerpc/pic/intr.c:1.34 Wed Feb 16 23:49:27 2022
+++ src/sys/arch/powerpc/pic/intr.c Sat Feb 15 00:30:49 2025
@@ -1,4 +1,4 @@
-/* $NetBSD: intr.c,v 1.34 2022/02/16 23:49:27 riastradh Exp $ */
+/* $NetBSD: intr.c,v 1.35 2025/02/15 00:30:49 jmcneill Exp $ */
/*-
* Copyright (c) 2007 Michael Lorenz
@@ -29,7 +29,7 @@
#define __INTR_PRIVATE
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: intr.c,v 1.34 2022/02/16 23:49:27 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: intr.c,v 1.35 2025/02/15 00:30:49 jmcneill Exp $");
#ifdef _KERNEL_OPT
#include "opt_interrupt.h"
@@ -560,13 +560,17 @@ pic_handle_intr(void *cookie)
struct cpu_info *ci = curcpu();
int picirq;
- picirq = pic->pic_get_irq(pic, PIC_GET_IRQ);
- if (picirq == 255)
- return 0;
-
const register_t msr = mfmsr();
const int pcpl = ci->ci_cpl;
+ mtmsr(msr & ~PSL_EE);
+
+ picirq = pic->pic_get_irq(pic, PIC_GET_IRQ);
+ if (picirq == 255) {
+ mtmsr(msr);
+ return 0;
+ }
+
do {
const int virq = virq_map[picirq + pic->pic_intrbase];
