On Tue, Jun 25, 2013 at 12:26:14PM +0530, Viresh Kumar wrote: > On 24 June 2013 22:29, Tim Gardner <[email protected]> wrote: > > This is from Ubuntu Saucy based on 3.10-rc7: > > > > [ 12.911676] BUG: unable to handle kernel NULL pointer dereference at > > 0000000000000070 > > [ 12.911691] IP: [<ffffffff8156e572>] od_set_powersave_bias+0x92/0xc0 > > > > Can you please look into this bug? It occurred after your > patch... This is the boot log crash we have:
Hi, Yes, so sorry about that, it looks like I failed to test with: CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_X86_AMD_FREQ_SENSITIVITY=m The following patch fixes this, Tim, could you please test ? : ---8<--- >From 3c727b1f775448599e67c5fb2121d79448e80c90 Mon Sep 17 00:00:00 2001 From: Jacob Shin <[email protected]> Date: Tue, 25 Jun 2013 10:40:54 -0500 Subject: [PATCH 1/1] cpufreq: fix NULL pointer deference at od_set_powersave_bias() When initializing the default powersave_bias value, we need to first make sure that this policy is running the ondemand governor. Reported-by: Tim Gardner <[email protected]> Signed-off-by: Jacob Shin <[email protected]> --- drivers/cpufreq/cpufreq_ondemand.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 4b9bb5d..93eb5cb 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -47,6 +47,8 @@ static struct od_ops od_ops; static struct cpufreq_governor cpufreq_gov_ondemand; #endif +static unsigned int default_powersave_bias; + static void ondemand_powersave_bias_init_cpu(int cpu) { struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); @@ -543,7 +545,7 @@ static int od_init(struct dbs_data *dbs_data) tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; tuners->ignore_nice = 0; - tuners->powersave_bias = 0; + tuners->powersave_bias = default_powersave_bias; tuners->io_is_busy = should_io_be_busy(); dbs_data->tuners = tuners; @@ -585,6 +587,7 @@ static void od_set_powersave_bias(unsigned int powersave_bias) unsigned int cpu; cpumask_t done; + default_powersave_bias = powersave_bias; cpumask_clear(&done); get_online_cpus(); @@ -593,11 +596,17 @@ static void od_set_powersave_bias(unsigned int powersave_bias) continue; policy = per_cpu(od_cpu_dbs_info, cpu).cdbs.cur_policy; - dbs_data = policy->governor_data; - od_tuners = dbs_data->tuners; - od_tuners->powersave_bias = powersave_bias; + if (!policy) + continue; cpumask_or(&done, &done, policy->cpus); + + if (policy->governor != &cpufreq_gov_ondemand) + continue; + + dbs_data = policy->governor_data; + od_tuners = dbs_data->tuners; + od_tuners->powersave_bias = default_powersave_bias; } put_online_cpus(); } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
