Audit: remove unused audit_log_secctx function

The function audit_log_secctx() is unused in the upstream kernel.
All it does is wrap another function that doesn't need wrapping.
It claims to give you the SELinux context, but that is not true if
you are using a different security module.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

include/linux/audit.h

@@ -149,12 +149,6 @@ extern void		    audit_log_key(struct audit_buffer *ab,
 extern void		    audit_log_link_denied(const char *operation,
 						  const struct path *link);
 extern void		    audit_log_lost(const char *message);
-#ifdef CONFIG_SECURITY
-extern void 		    audit_log_secctx(struct audit_buffer *ab, u32 secid);
-#else
-static inline void	    audit_log_secctx(struct audit_buffer *ab, u32 secid)
-{ }
-#endif
 
 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab,
@@ -203,8 +197,6 @@ static inline void audit_log_key(struct audit_buffer *ab, char *key)
 static inline void audit_log_link_denied(const char *string,
 					 const struct path *link)
 { }
-static inline void audit_log_secctx(struct audit_buffer *ab, u32 secid)
-{ }
 static inline int audit_log_task_context(struct audit_buffer *ab)
 {
 	return 0;

kernel/audit.c

@@ -2345,32 +2345,6 @@ void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
 	}
 }
 
-#ifdef CONFIG_SECURITY
-/**
- * audit_log_secctx - Converts and logs SELinux context
- * @ab: audit_buffer
- * @secid: security number
- *
- * This is a helper function that calls security_secid_to_secctx to convert
- * secid to secctx and then adds the (converted) SELinux context to the audit
- * log by calling audit_log_format, thus also preventing leak of internal secid
- * to userspace. If secid cannot be converted audit_panic is called.
- */
-void audit_log_secctx(struct audit_buffer *ab, u32 secid)
-{
-	u32 len;
-	char *secctx;
-
-	if (security_secid_to_secctx(secid, &secctx, &len)) {
-		audit_panic("Cannot convert secid to context");
-	} else {
-		audit_log_format(ab, " obj=%s", secctx);
-		security_release_secctx(secctx, len);
-	}
-}
-EXPORT_SYMBOL(audit_log_secctx);
-#endif
-
 EXPORT_SYMBOL(audit_log_start);
 EXPORT_SYMBOL(audit_log_end);
 EXPORT_SYMBOL(audit_log_format);