diff options
author | 2021-01-31 11:37:43 -0800 | |
---|---|---|
committer | 2021-01-31 11:37:43 -0800 | |
commit | b333a99e14d133afe204f775e72cc119decda2ca (patch) | |
tree | ba442a8a3f826c9820a02c1ea7fd6d534c35b4dd | |
parent | Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
parent | powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous int... (diff) | |
download | linux-b333a99e14d133afe204f775e72cc119decda2ca.tar.gz linux-b333a99e14d133afe204f775e72cc119decda2ca.tar.bz2 linux-b333a99e14d133afe204f775e72cc119decda2ca.zip |
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
-rw-r--r-- | arch/powerpc/kernel/irq.c | 28 |
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(®s); 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(®s); @@ -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(®s); @@ -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(®s); @@ -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(®s); @@ -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. |