[080/127] acpi-cpufreq: fix a memleak when unloading driver

From: Greg KH
Date: Tue Dec 07 2010 - 19:57:54 EST


2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Zhang Rui <rui.zhang@xxxxxxxxx>

commit dab5fff14df2cd16eb1ad4c02e83915e1063fece upstream.

We didn't free per_cpu(acfreq_data, cpu)->freq_table
when acpi_freq driver is unloaded.

Resulting in the following messages in /sys/kernel/debug/kmemleak:

unreferenced object 0xf6450e80 (size 64):
comm "modprobe", pid 1066, jiffies 4294677317 (age 19290.453s)
hex dump (first 32 bytes):
00 00 00 00 e8 a2 24 00 01 00 00 00 00 9f 24 00 ......$.......$.
02 00 00 00 00 6a 18 00 03 00 00 00 00 35 0c 00 .....j.......5..
backtrace:
[<c123ba97>] kmemleak_alloc+0x27/0x50
[<c109f96f>] __kmalloc+0xcf/0x110
[<f9da97ee>] acpi_cpufreq_cpu_init+0x1ee/0x4e4 [acpi_cpufreq]
[<c11cd8d2>] cpufreq_add_dev+0x142/0x3a0
[<c11920b7>] sysdev_driver_register+0x97/0x110
[<c11cce56>] cpufreq_register_driver+0x86/0x140
[<f9dad080>] 0xf9dad080
[<c1001130>] do_one_initcall+0x30/0x160
[<c10626e9>] sys_init_module+0x99/0x1e0
[<c1002d97>] sysenter_do_call+0x12/0x26
[<ffffffff>] 0xffffffff

https://bugzilla.kernel.org/show_bug.cgi?id=15807#c21

Tested-by: Toralf Forster <toralf.foerster@xxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 1 +
1 file changed, 1 insertion(+)

--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -741,6 +741,7 @@ static int acpi_cpufreq_cpu_exit(struct
per_cpu(drv_data, policy->cpu) = NULL;
acpi_processor_unregister_performance(data->acpi_data,
policy->cpu);
+ kfree(data->freq_table);
kfree(data);
}



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