Re: [PATCH 2/3] smack: call WARN_ONCE() instead of calling audit_log_start()

Casey Schaufler
2013-12-06T18:40:59Z

On 12/4/2013 6:45 PM, Richard Guy Briggs wrote:
> Remove the call to audit_log() (which call audit_log_start()) and deal with
> the errors in the caller, logging only once if the condition is met. Calling
> audit_log_start() in this location makes buffer allocation and locking more
> complicated in the calling tree (audit_filter_user()).
>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

I'm not opposed to this change, but have you actually tried it?

> ---
> security/smack/smack_lsm.c | 5 ++---
> 1 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 8825375..185e2e7 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3615,9 +3615,8 @@ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
> struct smack_known *skp;
> char *rule = vrule;
>
> - if (!rule) {
> - audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
> - "Smack: missing rule\n");
> + if (unlikely(!rule)) {
> + WARN_ONCE(1, "Smack: missing rule\n");
> return -ENOENT;
> }
>