kexec: sysrq: simplify sysrq-c handler
commitd6580a9f15238b87e618310c862231ae3f352d2d
authorNeil Horman <nhorman@tuxdriver.com>
Wed, 17 Jun 2009 23:28:17 +0000 (17 16:28 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 18 Jun 2009 20:03:59 +0000 (18 13:03 -0700)
treed7e6c1ed8a0d5fe143e4f5b90dee899be26d54f7
parentc8a06c1ef0bc45915fc45a170c7c60426971304c
kexec: sysrq: simplify sysrq-c handler

Currently the sysrq-c handler is bit over-engineered.  Its behavior is
dependent on a few compile time and run time factors that alter its
behavior which is really unnecessecary.

If CONFIG_KEXEC is not configured, sysrq-c, crashes the system with a NULL
pointer dereference.  If CONFIG_KEXEC is configured, it calls crash_kexec
directly, which implies that the kexec kernel will either be booted (if
its been previously loaded), or it will simply do nothing (the no kexec
kernel has been loaded).

It would be much easier to just simplify the whole thing to dereference a
NULL pointer all the time regardless of configuration.  That way, it will
always try to crash the system, and if a kexec kernel has been loaded into
reserved space, it will still boot from the page fault trap handler
(assuming panic_on_oops is set appropriately).

[akpm@linux-foundation.org: build fix]
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Brayan Arraes <brayan@yack.com.br>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/char/sysrq.c