Messages in this thread Patch in this message | | | From | Jun Miao <> | Subject | [PATCH] irq_work: Make irq_work_queue_on() NMI-safe again | Date | Tue, 26 Apr 2022 21:49:24 +0800 |
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We should not put NMI unsafe code in irq_work_queue_on().
The KASAN of kasan_record_aux_stack_noalloc() is not NMI safe. Because which will call the spinlock. While the irq_work_queue_on() is also very carefully carafted to be exactly that. When unable CONFIG_SM or local CPU, the irq_work_queue_on() is even same to irq_work_queue(). So delete KASAN instantly.
Fixes: e2b5bcf9f5ba ("irq_work: record irq_work_queue() call stack") Suggested by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Jun Miao <jun.miao@intel.com> --- kernel/irq_work.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 7afa40fe5cc4..e7f48aa8d8af 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -20,7 +20,6 @@ #include <linux/smp.h> #include <linux/smpboot.h> #include <asm/processor.h> -#include <linux/kasan.h> static DEFINE_PER_CPU(struct llist_head, raised_list); static DEFINE_PER_CPU(struct llist_head, lazy_list); @@ -137,8 +136,6 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) if (!irq_work_claim(work)) return false; - kasan_record_aux_stack_noalloc(work); - preempt_disable(); if (cpu != smp_processor_id()) { /* Arch remote IPI send/receive backend aren't NMI safe */ -- 2.32.0
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