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 linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20071029212433.c9837c4b.zaitcev@redhat.com> Date: Mon, 29 Oct 2007 21:24:33 -0700 From: Pete Zaitcev <zaitcev@...hat.com> To: vitalivanov@...il.com Cc: Oliver Neukum <oliver@...kum.org>, linux-usb-devel@...ts.sourceforge.net, greg@...ah.com, linux-kernel@...r.kernel.org, netwiz@....id.au, zaitcev@...hat.com Subject: Re: USB: FIx locks and urb->status in adutux On Mon, 29 Oct 2007 20:04:57 +0200, Vitaliy Ivanov <vitalivanov@...il.com> wrote: > Finally had a time on my weekend to perform tests and fix Pete's patch a little. Now it seems to be correct. Great! > 1. One device per user space application. Old driver allowed many users application to work with same device which can lead to IO mess. OK. This trick was popular in UNIX. Personally I think it's in a bad taste, because good applications still need to verify if only one instance is running, and threfore can use application level locking. But if you are gunning for the maintenership I'm not going to argue your style. The busy lock-out certainly works better than "/dev/cua" :-) However, this looks wrong: > + dev->interrupt_in_endpoint->bInterval); > + dev->read_urb_finished = 0; > + retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); > + /* we ignore failure */ > + /* end of fixup for first read */ > + > + /* initialize out direction */ > + dev->out_urb_finished = 1; The finished flag is only set when URB is not in use anymore. Did you observe an anomaly with my code? Any hangs? If so, I assure you this is not the fix. As it's written, even if we ignore the failure (e.g. do not pass it to userland), we sill have to maintain the correct flag state. -- Pete - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists