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| author | James Custer <jcuster@sgi.com> | 2014-11-02 21:16:39 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-11-03 15:49:24 +0300 |
| commit | fa2a79ce6aef5de35a4d50487da35deb6b634944 (patch) | |
| tree | 20ac2e73845b0cfe0073dd8930679e18e58de1e4 /arch/x86/platform/uv | |
| parent | 0df1f2487d2f0d04703f142813d53615d62a1da4 (diff) | |
| download | linux-fa2a79ce6aef5de35a4d50487da35deb6b634944.tar.xz | |
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>
Diffstat (limited to 'arch/x86/platform/uv')
| -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 3968d67d366b..570b1b14375b 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1384,6 +1384,10 @@ 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, |