tree 20ac2e73845b0cfe0073dd8930679e18e58de1e4
parent 0df1f2487d2f0d04703f142813d53615d62a1da4
author James Custer <jcuster@sgi.com> 1414952199 -0600
committer Thomas Gleixner <tglx@linutronix.de> 1415018964 +0100

x86: UV BAU: Avoid NULL pointer reference in ptc_seq_show

In init_per_cpu(), when get_cpu_topology() fails, init_per_cpu_tunables()
is not called afterwards. This means that bau_control->statp is NULL.
If a user then reads /proc/sgi_uv/ptc_statistics ptc_seq_show() references
a NULL pointer. Therefore, since uv_bau_init calls set_bau_off when
init_per_cpu() fails, we add code that detects when the bau is off in
ptc_seq_show() to avoid referencing a NULL pointer.

Signed-off-by: James Custer <jcuster@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Link: http://lkml.kernel.org/r/1414952199-185319-2-git-send-email-jcuster@sgi.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>