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| author |   Thomas Zimmermann <tzimmermann@suse.de> | 2024-03-25 21:11:58 +0100 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2024-03-25 21:11:58 +0100 |
| commit | 36a1818f5a1e50b805317ba13f827067d50f6970 (patch) | |
| tree | b9414b9509bea9f006c292a46a7632ffb57d18ee /lib/dump_stack.c | |
| parent | dma-buf: Fix NULL pointer dereference in sanitycheck() (diff) | |
| parent | Linux 6.9-rc1 (diff) | |
| download | wireguard-linux-36a1818f5a1e50b805317ba13f827067d50f6970.tar.xz wireguard-linux-36a1818f5a1e50b805317ba13f827067d50f6970.zip | |
Merge drm/drm-fixes into drm-misc-fixes
Backmerging to get drm-misc-fixes to the state of v6.9-rc1.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Diffstat (limited to '')
| -rw-r--r-- | lib/dump_stack.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/dump_stack.c b/lib/dump_stack.c index 83471e81501a..222c6d6c8281 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -96,15 +96,25 @@ static void __dump_stack(const char *log_lvl) */ 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); |