lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 6 Jun 2020 00:15:03 +0300 From: Denis Efremov <efremov@...ux.com> To: Julia Lawall <julia.lawall@...ia.fr> Cc: cocci@...teme.lip6.fr, linux-kernel@...r.kernel.org Subject: Re: [Cocci] [PATCH] coccinelle: api: add kvfree script On 6/5/20 11:51 PM, Julia Lawall wrote: > Is there a strong reason for putting the choice rule first? It may make > things somewhat slower than necessary, if it matches in many places, > because the opportunity rule will have to detect that it doesn't care > about all of those places. No, I didn't know that order of rules matters. I just checked it, my PC shows no difference in exec time if I swap these rules. "choice" doesn't check the size. "opportunity" is more strict. The motivation for adding 2 rules is that we could recommend to use kvmalloc* only when there is a size condition. At the same time, we should skip all if (...) {kmalloc()} else {vmalloc()}, res = kmalloc() if (!res) {vmalloc()} cases as false positives. It seems that it's not possible to use subexpression rule "expression size <= choice.E" in this case. > Also, there is no need to exceed 80 characters here. You can put a > newline in the middle of a \( ... \) Ok, I will fix it in v2 after all comments/suggestions. Thanks, Denis
Powered by blists - more mailing lists