linux-kernel - Re: [PATCH 1/2] cpu: fix "crash_notes" leak in register

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Message-ID: <20130514131611.GD5558@phenom.dumpdata.com>
Date:	Tue, 14 May 2013 09:16:11 -0400
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	Igor Mammedov <imammedo@...hat.com>
Cc:	linux-kernel@...r.kernel.org, gregkh@...uxfoundation.org,
	chuck.anderson@...cle.com
Subject: Re: [PATCH 1/2] cpu: fix "crash_notes" leak in register_cpu()

On Tue, May 14, 2013 at 12:05:31AM +0200, Igor Mammedov wrote:
> "crash_notes" is dinamically created with device_create_file() but
                   ^^^^^^^^^^^-dynamically
> isn't anywhere deleted.
> Define "crash_notes" statically via attribute groups so that
> device_register would create it automatically and file would be
> destroyed when CPU is destroyed.

I had to modify it a bit to work with v3.10-rc1 (It is missing
the dev_attr_crash_notes_size), but otherwise it worked nicely.
> 
> Signed-off-by: Igor Mammedov <imammedo@...hat.com>
> ---
>  drivers/base/cpu.c |   21 +++++++++++++++++----
>  1 files changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
> index fb10728..02e4d73 100644
> --- a/drivers/base/cpu.c
> +++ b/drivers/base/cpu.c
> @@ -132,8 +132,24 @@ static ssize_t show_crash_notes(struct device *dev, struct device_attribute *att
>  	return rc;
>  }
>  static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
> +
> +static struct attribute *crash_note_cpu_attrs[] = {
> +	&dev_attr_crash_notes.attr,
> +	NULL
> +};
> +
> +static struct attribute_group crash_note_cpu_attr_group = {
> +	.attrs = crash_note_cpu_attrs,
> +};
>  #endif
>  
> +static const struct attribute_group *common_cpu_attr_groups[] = {
> +#ifdef CONFIG_KEXEC
> +	&crash_note_cpu_attr_group,
> +#endif
> +	NULL
> +};
> +
>  /*
>   * Print cpu online, possible, present, and system maps
>   */
> @@ -248,6 +264,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
>  #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
>  	cpu->dev.bus->uevent = arch_cpu_uevent;
>  #endif
> +	cpu->dev.groups = common_cpu_attr_groups;
>  	error = device_register(&cpu->dev);
>  	if (!error && cpu->hotpluggable)
>  		register_cpu_control(cpu);
> @@ -256,10 +273,6 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
>  	if (!error)
>  		register_cpu_under_node(num, cpu_to_node(num));
>  
> -#ifdef CONFIG_KEXEC
> -	if (!error)
> -		error = device_create_file(&cpu->dev, &dev_attr_crash_notes);
> -#endif
>  	return error;
>  }
>  
> -- 
> 1.7.1
> 
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