Fixed
Created: Apr 8, 2013
Updated: Dec 19, 2017
Resolved Date: Jul 30, 2013
Found In Version: 5.0.1
Fix Version: 5.0.1.6
Severity: Severe
Applicable for: Wind River Linux 5
Component/s: Kernel
panic_lock is meant to ensure that panic processing takes place only on
one cpu; if any of the other cpus encounter a panic, they will spin
waiting to be shut down.
However, this causes a regression in this scenario:
1. Cpu 0 encounters a panic and acquires the panic_lock
and proceeds with the panic processing.
2. There is an interrupt on cpu 0 that also encounters
an error condition and invokes panic.
3. This second invocation fails to acquire the panic_lock
and enters the infinite while loop in panic_smp_self_stop.
Thus all panic processing is stopped, and the cpu is stuck for eternity
in the while(1) inside panic_smp_self_stop.
For full details and the upstream patch see:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/kernel/panic.c?id=190320c3b6640d4104650f55ff69611e050ea06b
unknown
