Re: [v2][PATCH] Revert "mfd: syscon: Don't free allocated name for regmap_config"

[Marc Zyngier]

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@xxxxxxxxxxxxx>
> > Sent: Friday, January 15, 2021 9:51 AM
> > To: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: maz@xxxxxxxxxx; lee.jones@xxxxxxxxxx; arnd@xxxxxxxx; Hao, Kexin
> > <Kexin.Hao@xxxxxxxxxxxxx>; Li, Meng <Meng.Li@xxxxxxxxxxxxx>
> > Subject: [v2][PATCH] Revert "mfd: syscon: Don't free allocated name 
> > for
> > regmap_config"
> >
> > From: Limeng <Meng.Li@xxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Meng Li <Meng.Li@xxxxxxxxxxxxx>
> > ---
> >  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

--
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