linux-kernel - Re: [v2][PATCH] Revert "mfd: syscon: Don't free allocated name for regmap

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Date:   Mon, 22 Feb 2021 09:12:22 +0000
From:   Marc Zyngier <maz@...nel.org>
To:     "Li, Meng" <Meng.Li@...driver.com>
Cc:     linux-kernel@...r.kernel.org, lee.jones@...aro.org, arnd@...db.de,
        "Hao, Kexin" <Kexin.Hao@...driver.com>
Subject: Re: [v2][PATCH] Revert "mfd: syscon: Don't free allocated name for
 regmap_config"

Hi Limeng,

On 2021-02-22 03:45, Li, Meng wrote:
> Hi Marc&Lee,
> 
> Is there any comment on this patch?
> Could you please help to review this patch so that I can improve it if
> it still has weakness?

If you are confident that the root issue has been fixed, no objection
from me, but I'm not in a position to test it at the moment (the board
I found the problem on is in a bit of a state).

Thanks,

         M.

> 
> Thanks,
> Limeng
> 
>> -----Original Message-----
>> From: Li, Meng <Meng.Li@...driver.com>
>> Sent: Friday, January 15, 2021 9:51 AM
>> To: linux-kernel@...r.kernel.org
>> Cc: maz@...nel.org; lee.jones@...aro.org; arnd@...db.de; Hao, Kexin
>> <Kexin.Hao@...driver.com>; Li, Meng <Meng.Li@...driver.com>
>> Subject: [v2][PATCH] Revert "mfd: syscon: Don't free allocated name 
>> for
>> regmap_config"
>> 
>> From: Limeng <Meng.Li@...driver.com>
>> 
>> This reverts commit 529a1101212a785c5df92c314b0e718287150c3b.
>> 
>> The reverted patch moves the memory free to error path, but introduce 
>> a
>> memory leak. There is another commit 94cc89eb8fa5("regmap: debugfs:
>> Fix handling of name string for debugfs init delays") fixing this 
>> debugfs init
>> issue from root cause. With this fixing, the name field in struct
>> regmap_debugfs_node is removed. When initialize debugfs for syscon 
>> driver,
>> the name field of struct regmap_config is not used anymore. So, revert 
>> this
>> patch directly to avoid memory leak.
>> 
>> v2:
>> Notify the author of the reverted commit by adding Cc:
>> 
>> Fixes: 529a1101212a("mfd: syscon: Don't free allocated name for
>> regmap_config")
>> Cc: Marc Zyngier <maz@...nel.org>
>> Cc: stable@...r.kernel.org
>> Signed-off-by: Meng Li <Meng.Li@...driver.com>
>> ---
>>  drivers/mfd/syscon.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index
>> ca465794ea9c..df5cebb372a5 100644
>> --- a/drivers/mfd/syscon.c
>> +++ b/drivers/mfd/syscon.c
>> @@ -108,6 +108,7 @@ static struct syscon *of_syscon_register(struct
>> device_node *np, bool check_clk)
>>  	syscon_config.max_register = resource_size(&res) - reg_io_width;
>> 
>>  	regmap = regmap_init_mmio(NULL, base, &syscon_config);
>> +	kfree(syscon_config.name);
>>  	if (IS_ERR(regmap)) {
>>  		pr_err("regmap init failed\n");
>>  		ret = PTR_ERR(regmap);
>> @@ -144,7 +145,6 @@ static struct syscon *of_syscon_register(struct
>> device_node *np, bool check_clk)
>>  	regmap_exit(regmap);
>>  err_regmap:
>>  	iounmap(base);
>> -	kfree(syscon_config.name);
>>  err_map:
>>  	kfree(syscon);
>>  	return ERR_PTR(ret);
>> --
>> 2.17.1

-- 
Jazz is not dead. It just smells funny...