diff options
| author | Naga Chumbalkar <nagananda.chumbalkar@hp.com> | 2011-09-15 03:22:23 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-09-15 05:09:38 +0400 |
| commit | e71f5cc402ecb42b407ae52add7b173bf1c53daa (patch) | |
| tree | 03e1b260a42a59e3fea1a3db4f39a9a260dd0a58 | |
| parent | 88cee8fd77af28d414b983798dd30c8950c71e31 (diff) | |
| download | linux-e71f5cc402ecb42b407ae52add7b173bf1c53daa.tar.xz | |
drivers/cpufreq/pcc-cpufreq.c: avoid NULL pointer dereference
per_cpu(processors, n) can be NULL, resulting in:
Loading CPUFreq modules[ 437.661360] BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa0434314>] pcc_cpufreq_cpu_init+0x74/0x220 [pcc_cpufreq]
It's better to avoid the oops by failing the driver, and allowing the
system to boot.
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/cpufreq/pcc-cpufreq.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c index 7b0603eb0129..cdc02ac8f41a 100644 --- a/drivers/cpufreq/pcc-cpufreq.c +++ b/drivers/cpufreq/pcc-cpufreq.c @@ -261,6 +261,9 @@ static int pcc_get_offset(int cpu) pr = per_cpu(processors, cpu); pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu); + if (!pr) + return -ENODEV; + status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer); if (ACPI_FAILURE(status)) return -ENODEV; |