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

From: Li, Meng
Date: Sun Feb 21 2021 - 22:46:28 EST


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?

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