[PATCH] eventfs: Use kcalloc() instead of kzalloc()

Erick Archer posted 1 patch 1 year, 11 months ago
There is a newer version of this series
fs/tracefs/event_inode.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
[PATCH] eventfs: Use kcalloc() instead of kzalloc()
Posted by Erick Archer 1 year, 11 months ago
Use 2-factor multiplication argument form kcalloc() instead
of kzalloc().

Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Erick Archer <erick.archer@gmx.com>
---
 fs/tracefs/event_inode.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index fdff53d5a1f8..f8196289692c 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -93,7 +93,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
 	/* Preallocate the children mode array if necessary */
 	if (!(dentry->d_inode->i_mode & S_IFDIR)) {
 		if (!ei->entry_attrs) {
-			ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries,
+			ei->entry_attrs = kcalloc(ei->nr_entries, sizeof(*ei->entry_attrs),
 						  GFP_NOFS);
 			if (!ei->entry_attrs) {
 				ret = -ENOMEM;
@@ -874,7 +874,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode
 	}

 	if (size) {
-		ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
+		ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
 		if (!ei->d_children) {
 			kfree_const(ei->name);
 			kfree(ei);
@@ -941,7 +941,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
 		goto fail;

 	if (size) {
-		ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
+		ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
 		if (!ei->d_children)
 			goto fail;
 	}
--
2.25.1
Re: [PATCH] eventfs: Use kcalloc() instead of kzalloc()
Posted by Mark Rutland 1 year, 11 months ago
On Sun, Jan 14, 2024 at 11:53:40AM +0100, Erick Archer wrote:
> Use 2-factor multiplication argument form kcalloc() instead
> of kzalloc().
> 
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <erick.archer@gmx.com>

Could you put something in the commit message explaining *why* this change
should be made?

I assume that this is so that overflows during multiplication can be caught and
handled in some way, but the commit message doesn't say that, and nor does the
linked github page.

The patch itself looks fine.

Thanks,
Mark.

> ---
>  fs/tracefs/event_inode.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
> index fdff53d5a1f8..f8196289692c 100644
> --- a/fs/tracefs/event_inode.c
> +++ b/fs/tracefs/event_inode.c
> @@ -93,7 +93,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
>  	/* Preallocate the children mode array if necessary */
>  	if (!(dentry->d_inode->i_mode & S_IFDIR)) {
>  		if (!ei->entry_attrs) {
> -			ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries,
> +			ei->entry_attrs = kcalloc(ei->nr_entries, sizeof(*ei->entry_attrs),
>  						  GFP_NOFS);
>  			if (!ei->entry_attrs) {
>  				ret = -ENOMEM;
> @@ -874,7 +874,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode
>  	}
> 
>  	if (size) {
> -		ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
> +		ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
>  		if (!ei->d_children) {
>  			kfree_const(ei->name);
>  			kfree(ei);
> @@ -941,7 +941,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
>  		goto fail;
> 
>  	if (size) {
> -		ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
> +		ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
>  		if (!ei->d_children)
>  			goto fail;
>  	}
> --
> 2.25.1
> 
>