From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Tue, 17 May 2016 09:53:31 +0300 Subject: [lustre-devel] [PATCH v2] staging/lustre/ptlrpc: Removes potential null dereference In-Reply-To: <8AEE9006-6CF8-4BB7-A236-808ACE3AB302@intel.com> References: <1463408271-18079-1-git-send-email-lidza.louina@oracle.com> <573A0A23.2010705@cray.com> <8AEE9006-6CF8-4BB7-A236-808ACE3AB302@intel.com> Message-ID: <20160517065330.GA10957@mwanda> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org When I read the code, I just assumed desc was a pointer and it should have been: if (!desc) return NULL; For me, "if (rc) " is way more readable than "if (rc != 0) ". So readability could go either way depending on what you're used to, I suppose. It should definitely == 0 and != 0 if you are talking about the actual number zero instead of success/fail like we are here. Also it helps to use == 0 with strcmp() and friends (although half of the kernel does not know that trick yet). The other thing which I have noticed recently is that a lot of subsystems use a mix of "if (rc) " and "if (rc < 0) ". It's annoying for Smatch because say a function only returns zero but the some of the callers check for < 0 and some check for != 0. We can't know for sure that they are equivalent. regards, dan carpenter