tree b2deb02cec90cb18a075b3a49e6de949db374c77
parent 98ec1878cacb393975cba64f7392eece81716cb4
author Jason Wessel <jason.wessel@windriver.com> 1274407465 -0500
committer Jason Wessel <jason.wessel@windriver.com> 1274407465 -0500

x86,kgdb: Add low level debug hook

The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.

Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.

CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>