[PATCHv2] arm: mach-omap2: smartreflex: fix another memory leak

[Aaro Koskinen]

Hi,

On Mon, 7 Feb 2011, Vishwanath Sripathy wrote:
>> Temporary strings with volt_* file names should be released after the
>> debugfs entries are created. While at it, also simplify the string
>> allocation, and use just snprintf() to create the name.
>>
>> The patch eliminates kmemleak reports with the following stack trace
>> (multiple objects depending on HW):
>>
>> unreferenced object 0xcedbc5a0 (size 64):
>>   comm "swapper", pid 1, jiffies 4294929375 (age 423.734s)
>>   hex dump (first 32 bytes):
>>     76 6f 6c 74 5f 39 37 35 30 30 30 00 00 00 00 00  volt_975000.....
>>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>   backtrace:
>>     [<c012fee0>] create_object+0x104/0x208
>>     [<c012dbc8>] kmem_cache_alloc_trace+0xf0/0x17c
>>     [<c0013f64>] omap_sr_probe+0x314/0x420
>>     [<c02a1724>] platform_drv_probe+0x18/0x1c
>>     [<c02a088c>] driver_probe_device+0xc8/0x188
>>     [<c02a09b4>] __driver_attach+0x68/0x8c
>>     [<c02a00ac>] bus_for_each_dev+0x44/0x74
>>     [<c029f9e0>] bus_add_driver+0xa0/0x228
>>     [<c02a0cac>] driver_register+0xa8/0x130
>>     [<c02a1b2c>] platform_driver_probe+0x18/0x8c
>>     [<c0013c1c>] sr_init+0x40/0x74
>>     [<c005a554>] do_one_initcall+0xc8/0x1a0
>>     [<c00084f4>] kernel_init+0x150/0x218
>>     [<c0065d64>] kernel_thread_exit+0x0/0x8
>>     [<ffffffff>] 0xffffffff
>>
>> Signed-off-by: Aaro Koskinen <aaro.koskinen at nokia.com>
>> ---
>>
>> v2: Get rid of kmalloc().
>>
>>  arch/arm/mach-omap2/smartreflex.c |   15 +++------------
>>  1 files changed, 3 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-
>> omap2/smartreflex.c
>> index 77ecebf..e54db84 100644
>> --- a/arch/arm/mach-omap2/smartreflex.c
>> +++ b/arch/arm/mach-omap2/smartreflex.c
>> @@ -927,19 +927,10 @@ static int __init omap_sr_probe(struct
>> platform_device *pdev)
>>  	}
>>
>>  	for (i = 0; i < sr_info->nvalue_count; i++) {
>> -		char *name;
>> -		char volt_name[32];
>> -
>> -		name = kzalloc(NVALUE_NAME_LEN + 1, GFP_KERNEL);
>> -		if (!name) {
>> -			dev_err(&pdev->dev, "%s: Unable to allocate
>> memory"
>> -				" for n-value directory name\n",
> __func__);
>> -			return -ENOMEM;
>> -		}
>> +		char name[NVALUE_NAME_LEN + 1];
> Is there any need to keep this inside the loop?

That's the correct place to declare it - the variable's scope should be
limited to the block where it's used.

> Defining it in the beginning of function might save a few cpu cycles.

I don't think so.

A.