| 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
| ||
|
Date: Thu, 07 Aug 2008 19:19:42 +0200 From: Stefan Richter <stefanr@...6.in-berlin.de> To: jmerkey@...fmountaingroup.com CC: linux-kernel@...r.kernel.org Subject: Re: [ANNOUNCE] mdb-2.6.27-rc2-ia32-08-07-08.patch jmerkey@...fmountaingroup.com wrote: >> jmerkey@...fmountaingroup.com wrote: >>> rspin locks are for these types of cases -- so if I fault on the same >>> processor I took the lock on it just bumps a counter -- yes, it is >>> atomic >>> and SMP safe to do it this way. >> Only if all contexts which take rlocks are not preemptible. [...] > check mdb-main.c -- I disable preemption before rspin_lock is attempted. > Since the only processor which sets the proc number does do inside the > spin lock, and the other processors only read it, unless memory is > corrupted or the machine is severely broken, its SMP safe to this. Then it is recommendable that you document the call context requirements at the functions. And you can and IMO should drop the _irq_save and _irq_restore from the spinlock accessors in the rlock accessors. And drop the volatile qualifier of the rlock accessor argument while you are at it. I see that you are calling save_flags/ restore_flags in mdb-main.c::mdb(). These are marked as deprecated. Would local_irq_save/ local_irq_restore be correct at these places? -- Stefan Richter -=====-==--- =--- --=== http://arcgraph.de/sr/ -- 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