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authorLinus Torvalds <torvalds@linux-foundation.org>2021-01-31 11:37:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-01-31 11:37:43 -0800
commitb333a99e14d133afe204f775e72cc119decda2ca (patch)
treeba442a8a3f826c9820a02c1ea7fd6d534c35b4dd /arch/powerpc
parent1188866d9cec4987ee465b7a0815f0bcb946641e (diff)
parent4025c784c573cab7e3f84746cc82b8033923ec62 (diff)
downloadlinux-b333a99e14d133afe204f775e72cc119decda2ca.tar.bz2
Merge tag 'powerpc-5.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fix from Michael Ellerman: "One fix for a bug in our soft interrupt masking, which could lead to interrupt replaying recursing, causing spurious interrupts. Thanks to Nicholas Piggin" * tag 'powerpc-5.11-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/irq.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 6b1eca53e36c..cc7a6271b6b4 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -180,13 +180,18 @@ void notrace restore_interrupts(void)
void replay_soft_interrupts(void)
{
+ struct pt_regs regs;
+
/*
- * We use local_paca rather than get_paca() to avoid all
- * the debug_smp_processor_id() business in this low level
- * function
+ * Be careful here, calling these interrupt handlers can cause
+ * softirqs to be raised, which they may run when calling irq_exit,
+ * which will cause local_irq_enable() to be run, which can then
+ * recurse into this function. Don't keep any state across
+ * interrupt handler calls which may change underneath us.
+ *
+ * We use local_paca rather than get_paca() to avoid all the
+ * debug_smp_processor_id() business in this low level function.
*/
- unsigned char happened = local_paca->irq_happened;
- struct pt_regs regs;
ppc_save_regs(&regs);
regs.softe = IRQS_ENABLED;
@@ -209,7 +214,7 @@ again:
* This is a higher priority interrupt than the others, so
* replay it first.
*/
- if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_HMI)) {
+ if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_HMI)) {
local_paca->irq_happened &= ~PACA_IRQ_HMI;
regs.trap = 0xe60;
handle_hmi_exception(&regs);
@@ -217,7 +222,7 @@ again:
hard_irq_disable();
}
- if (happened & PACA_IRQ_DEC) {
+ if (local_paca->irq_happened & PACA_IRQ_DEC) {
local_paca->irq_happened &= ~PACA_IRQ_DEC;
regs.trap = 0x900;
timer_interrupt(&regs);
@@ -225,7 +230,7 @@ again:
hard_irq_disable();
}
- if (happened & PACA_IRQ_EE) {
+ if (local_paca->irq_happened & PACA_IRQ_EE) {
local_paca->irq_happened &= ~PACA_IRQ_EE;
regs.trap = 0x500;
do_IRQ(&regs);
@@ -233,7 +238,7 @@ again:
hard_irq_disable();
}
- if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (happened & PACA_IRQ_DBELL)) {
+ if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (local_paca->irq_happened & PACA_IRQ_DBELL)) {
local_paca->irq_happened &= ~PACA_IRQ_DBELL;
if (IS_ENABLED(CONFIG_PPC_BOOK3E))
regs.trap = 0x280;
@@ -245,7 +250,7 @@ again:
}
/* Book3E does not support soft-masking PMI interrupts */
- if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_PMI)) {
+ if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_PMI)) {
local_paca->irq_happened &= ~PACA_IRQ_PMI;
regs.trap = 0xf00;
performance_monitor_exception(&regs);
@@ -253,8 +258,7 @@ again:
hard_irq_disable();
}
- happened = local_paca->irq_happened;
- if (happened & ~PACA_IRQ_HARD_DIS) {
+ if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS) {
/*
* We are responding to the next interrupt, so interrupt-off
* latencies should be reset here.