linux-kernel - Re: [PATCHv3 1/6] debugfs: add get/set for atomic types

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130129203509.GB27740@konrad-lan.dumpdata.com>
Date:	Tue, 29 Jan 2013 15:35:10 -0500
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	Seth Jennings <sjenning@...ux.vnet.ibm.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Nitin Gupta <ngupta@...are.org>,
	Minchan Kim <minchan@...nel.org>,
	Dan Magenheimer <dan.magenheimer@...cle.com>,
	Robert Jennings <rcj@...ux.vnet.ibm.com>,
	Jenifer Hopper <jhopper@...ibm.com>,
	Mel Gorman <mgorman@...e.de>,
	Johannes Weiner <jweiner@...hat.com>,
	Rik van Riel <riel@...hat.com>,
	Larry Woodman <lwoodman@...hat.com>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Dave Hansen <dave@...ux.vnet.ibm.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, devel@...verdev.osuosl.org
Subject: Re: [PATCHv3 1/6] debugfs: add get/set for atomic types

On Mon, Jan 28, 2013 at 03:49:22PM -0600, Seth Jennings wrote:
> debugfs currently lack the ability to create attributes
> that set/get atomic_t values.
> 
> This patch adds support for this through a new
> debugfs_create_atomic_t() function.
> 
> Signed-off-by: Seth Jennings <sjenning@...ux.vnet.ibm.com>
> Acked-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> ---
>  fs/debugfs/file.c       |   42 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/debugfs.h |    2 ++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index c5ca6ae..fa26d5b 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -21,6 +21,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
> +#include <linux/atomic.h>
>  
>  static ssize_t default_read_file(struct file *file, char __user *buf,
>  				 size_t count, loff_t *ppos)
> @@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
>  }
>  EXPORT_SYMBOL_GPL(debugfs_create_size_t);
>  
> +static int debugfs_atomic_t_set(void *data, u64 val)

Should the 'data' be 'atomic_t *' just to make sure nobody messes this
up? Or would that bring too much header changes?

> +{
> +	atomic_set((atomic_t *)data, val);
> +	return 0;
> +}
> +static int debugfs_atomic_t_get(void *data, u64 *val)
> +{
> +	*val = atomic_read((atomic_t *)data);
> +	return 0;
> +}
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
> +			debugfs_atomic_t_set, "%llu\n");
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%llu\n");
> +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%llu\n");
> +
> +/**
> + * debugfs_create_atomic_t - create a debugfs file that is used to read and
> + * write an atomic_t value
> + * @name: a pointer to a string containing the name of the file to create.
> + * @mode: the permission that the file should have
> + * @parent: a pointer to the parent dentry for this file.  This should be a
> + *          directory dentry if set.  If this parameter is %NULL, then the
> + *          file will be created in the root of the debugfs filesystem.
> + * @value: a pointer to the variable that the file should read to and write
> + *         from.
> + */
> +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
> +				 struct dentry *parent, atomic_t *value)
> +{
> +	/* if there are no write bits set, make read only */
> +	if (!(mode & S_IWUGO))
> +		return debugfs_create_file(name, mode, parent, value,
> +					&fops_atomic_t_ro);
> +	/* if there are no read bits set, make write only */
> +	if (!(mode & S_IRUGO))
> +		return debugfs_create_file(name, mode, parent, value,
> +					&fops_atomic_t_wo);
> +
> +	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
> +}
> +EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
>  
>  static ssize_t read_file_bool(struct file *file, char __user *user_buf,
>  			      size_t count, loff_t *ppos)
> diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
> index 66c434f..51fea70 100644
> --- a/include/linux/debugfs.h
> +++ b/include/linux/debugfs.h
> @@ -79,6 +79,8 @@ struct dentry *debugfs_create_x64(const char *name, umode_t mode,
>  				  struct dentry *parent, u64 *value);
>  struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
>  				     struct dentry *parent, size_t *value);
> +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
> +				     struct dentry *parent, atomic_t *value);
>  struct dentry *debugfs_create_bool(const char *name, umode_t mode,
>  				  struct dentry *parent, u32 *value);
>  
> -- 
> 1.7.9.5
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/