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| author | Naga Chumbalkar <nagananda.chumbalkar@hp.com> | 2011-09-14 16:22:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-09-14 18:09:38 -0700 |
| commit | e71f5cc402ecb42b407ae52add7b173bf1c53daa (patch) | |
| tree | 03e1b260a42a59e3fea1a3db4f39a9a260dd0a58 /drivers/cpufreq/pcc-cpufreq.c | |
| parent | 88cee8fd77af28d414b983798dd30c8950c71e31 (diff) | |
| download | linux-e71f5cc402ecb42b407ae52add7b173bf1c53daa.tar.gz | |
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>
Diffstat (limited to 'drivers/cpufreq/pcc-cpufreq.c')
| -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; |