diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-01-15 17:46:08 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-20 02:17:01 +0300 |
| commit | bfa318ad52a23f1e303d176b44366cdd2bb71ad2 (patch) | |
| tree | bf58fe12825bfebdc02f1acce0cd79f246491e7b | |
| parent | 72859081851af2bda04117ca3d64206ffa199e5e (diff) | |
| download | linux-bfa318ad52a23f1e303d176b44366cdd2bb71ad2.tar.xz | |
fix: crash: IP: __bitmap_intersects+0x48/0x73
-tip testing found this crash:
> [ 35.258515] calling acpi_cpufreq_init+0x0/0x127 @ 1
> [ 35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [ 35.267554] PGD 0
> [ 35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...
Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 5bf2c834a236..4b1c319d30c3 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -145,7 +145,7 @@ typedef union { struct drv_cmd { unsigned int type; - cpumask_var_t mask; + const struct cpumask *mask; drv_addr_union addr; u32 val; }; @@ -231,6 +231,7 @@ static u32 get_cur_val(const struct cpumask *mask) return 0; } + cmd.mask = mask; drv_read(&cmd); dprintk("get_cur_val = %u\n", cmd.val); @@ -397,9 +398,6 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, return -ENODEV; } - if (unlikely(!alloc_cpumask_var(&cmd.mask, GFP_KERNEL))) - return -ENOMEM; - perf = data->acpi_data; result = cpufreq_frequency_table_target(policy, data->freq_table, @@ -444,9 +442,9 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, /* cpufreq holds the hotplug lock, so we are safe from here on */ if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY) - cpumask_and(cmd.mask, cpu_online_mask, policy->cpus); + cmd.mask = policy->cpus; else - cpumask_copy(cmd.mask, cpumask_of(policy->cpu)); + cmd.mask = cpumask_of(policy->cpu); freqs.old = perf->states[perf->state].core_frequency * 1000; freqs.new = data->freq_table[next_state].frequency; @@ -473,7 +471,6 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, perf->state = next_perf_state; out: - free_cpumask_var(cmd.mask); return result; } |