};
bool other_cpu_in_panic(void);
-bool this_cpu_in_panic(void);
bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
bool is_extended, bool may_supress);
*/
asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
{
+ bool in_panic = this_cpu_in_panic();
unsigned long flags;
/*
* Permit this cpu to perform nested stack dumps while serialising
- * against other CPUs
+ * against other CPUs, unless this CPU is in panic.
+ *
+ * When in panic, non-panic CPUs are not permitted to store new
+ * printk messages so there is no need to synchronize the output.
+ * This avoids potential deadlock in panic() if another CPU is
+ * holding and unable to release the printk_cpu_sync.
*/
- printk_cpu_sync_get_irqsave(flags);
+ if (!in_panic)
+ printk_cpu_sync_get_irqsave(flags);
+
__dump_stack(log_lvl);
- printk_cpu_sync_put_irqrestore(flags);
+
+ if (!in_panic)
+ printk_cpu_sync_put_irqrestore(flags);
}
EXPORT_SYMBOL(dump_stack_lvl);