Re: [PATCH] selinux: Inode label revalidation performance fix

[Stephen Smalley <sds@xxxxxxxxxxxxx>]

On 01/05/2016 05:12 PM, Andreas Gruenbacher wrote:
> Commit 5d226df4 has introduced a performance regression of about
> 10% in the UnixBench pipe benchmark.  It turns out that the call
> to inode_security in selinux_file_permission can be moved below
> the zero-mask test and that inode_security_revalidate can be
> removed entirely, which brings us back to roughly the original
> performance.
>
> Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>

Acked-by:  Stephen Smalley <sds@xxxxxxxxxxxxx>

> ---
>   security/selinux/hooks.c | 10 ++--------
>   1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 40e071a..f8110cf 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -273,11 +273,6 @@ static int __inode_security_revalidate(struct inode *inode,
>   	return 0;
>   }
>
> -static void inode_security_revalidate(struct inode *inode)
> -{
> -	__inode_security_revalidate(inode, NULL, true);
> -}
> -
>   static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
>   {
>   	return inode->i_security;
> @@ -3277,19 +3272,19 @@ static int selinux_file_permission(struct file *file, int mask)
>   {
>   	struct inode *inode = file_inode(file);
>   	struct file_security_struct *fsec = file->f_security;
> -	struct inode_security_struct *isec = inode_security(inode);
> +	struct inode_security_struct *isec;
>   	u32 sid = current_sid();
>
>   	if (!mask)
>   		/* No permission to check.  Existence test. */
>   		return 0;
>
> +	isec = inode_security(inode);
>   	if (sid == fsec->sid && fsec->isid == isec->sid &&
>   	    fsec->pseqno == avc_policy_seqno())
>   		/* No change since file_open check. */
>   		return 0;
>
> -	inode_security_revalidate(inode);
>   	return selinux_revalidate_file_permission(file, mask);
>   }
>
> @@ -3595,7 +3590,6 @@ static int selinux_file_open(struct file *file, const struct cred *cred)
>   	 * new inode label or new policy.
>   	 * This check is not redundant - do not remove.
>   	 */
> -	inode_security_revalidate(file_inode(file));
>   	return file_path_has_perm(cred, file, open_file_to_av(file));
>   }

_______________________________________________
Selinux mailing list
Selinux@xxxxxxxxxxxxx
To unsubscribe, send email to Selinux-leave@xxxxxxxxxxxxx.
To get help, send an email containing "help" to Selinux-request@xxxxxxxxxxxxx.