diff options
| author | James Custer <jcuster@sgi.com> | 2014-11-02 12:16:39 -0600 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-02-16 16:10:59 +0100 |
| commit | 18f12cbe86a5d6d4afc710cd3e3e064898808738 (patch) | |
| tree | c46c943638cebe21ca74a391fcacf7021155ee03 | |
| parent | ebf1059f4bc4e12a6878c44137f95fafc1fe55b3 (diff) | |
x86: UV BAU: Avoid NULL pointer reference in ptc_seq_show
commit fa2a79ce6aef5de35a4d50487da35deb6b634944 upstream.
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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | arch/x86/platform/uv/tlb_uv.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index efe4d7220397..a6b5affb024a 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1367,6 +1367,10 @@ static int ptc_seq_show(struct seq_file *file, void *data) } if (cpu < num_possible_cpus() && cpu_online(cpu)) { bcp = &per_cpu(bau_control, cpu); + if (bcp->nobau) { + seq_printf(file, "cpu %d bau disabled\n", cpu); + return 0; + } stat = bcp->statp; /* source side statistics */ seq_printf(file, |