[PATCH 0/7] Serialise oopses, BUGs, WARNs, dump_stack, soft lockups and hard lockups

From: Anton Blanchard
Date: Mon Feb 23 2015 - 22:30:42 EST

Every now and then I end up with an undebuggable issue because multiple
CPUs hit something at the same time and everything is interleaved:

CR: 48000082 XER: 00000000
Instruction dump:
MSR: 8000000100029033

Very annoying.

Some architectures already have their own recursive locking for oopses
and we have another version for serialising dump_stack.

Create a common version and use it everywhere (oopses, BUGs, WARNs,
dump_stack, soft lockups and hard lockups). A few testcases were
used to verify the series:

A trivial module to create concurrent WARNs, BUGs and oopses:


And one to create concurrent soft and hard lockups:


Anton Blanchard (7):
Add die_spin_lock_{irqsave,irqrestore}
powerpc: Use die_spin_lock_{irqsave,irqrestore}
arm: Use die_spin_lock_{irqsave,irqrestore}
x86: Use die_spin_lock_{irqsave,irqrestore}
watchdog: Serialise soft lockup errors with
dump_stack: Serialise dump_stack with
powerpc: Serialise BUG and WARNs with

arch/arm/kernel/traps.c | 26 ++---------------
arch/powerpc/kernel/traps.c | 68 ++++++++++++++++++++++++++-------------------
arch/x86/kernel/dumpstack.c | 26 ++---------------
include/linux/die_lock.h | 23 +++++++++++++++
kernel/watchdog.c | 4 +++
lib/Makefile | 1 +
lib/die_lock.c | 43 ++++++++++++++++++++++++++++
lib/dump_stack.c | 40 +++-----------------------
8 files changed, 120 insertions(+), 111 deletions(-)
create mode 100644 include/linux/die_lock.h
create mode 100644 lib/die_lock.c


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