arm64: traps: Add str of description to panic() in die()

Commit Message

Yue Hu Aug. 4, 2020, 8:53 a.m. UTC

From: Yue Hu <[e-mail]>

Currently, there are different description strings in die() such as
die("Oops",,), die("Oops - BUG",,). And panic() called by die() will
always show "Fatal exception" or "Fatal exception in interrupt".

Note that panic() will run any panic handler via panic_notifier_list.
And the string above will be formatted and placed in static buf[]
which will be passed to handler.

So panic handler can not distinguish which Oops it is from the buf if
we want to do some things like reserve the string in memory or panic
statistics. It's not benefit to debug. We need to add more codes to
troubleshoot. Let's utilize existing resource to make debug much simpler.

Signed-off-by: Yue Hu <[e-mail]>
---
 arch/arm64/kernel/traps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Will Deacon Sept. 7, 2020, 4:05 p.m. UTC | #1

On Tue, 4 Aug 2020 16:53:47 +0800, Yue Hu wrote:
> Currently, there are different description strings in die() such as
> die("Oops",,), die("Oops - BUG",,). And panic() called by die() will
> always show "Fatal exception" or "Fatal exception in interrupt".
> 
> Note that panic() will run any panic handler via panic_notifier_list.
> And the string above will be formatted and placed in static buf[]
> which will be passed to handler.
> 
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64: traps: Add str of description to panic() in die()
      https://git.kernel.org/arm64/c/b4c971245925

Cheers,

Patch

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 47f651d..5582d3e 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -200,9 +200,9 @@  void die(const char *str, struct pt_regs *regs, int err)
 	oops_exit();
 
 	if (in_interrupt())
-		panic("Fatal exception in interrupt");
+		panic("%s: Fatal exception in interrupt", str);
 	if (panic_on_oops)
-		panic("Fatal exception");
+		panic("%s: Fatal exception", str);
 
 	raw_spin_unlock_irqrestore(&die_lock, flags);