Re: [PATCH] audit: grab a reference to context->pwd when it's cached

Hi Al, Any word on a less unpleasant fix? Also, do you know if/how I could measure the impact of the cacheline bouncing? I haven't been able to notice anything anecdotally on the machine running this patch, but I'm not pushing it incredibly hard. Cheers, peter On Wed, Aug 15, 2012 at 6:41 PM, Peter Moody <pmoody(a)google.com&gt; wrote: > On Wed, Aug 15, 2012 at 6:26 PM, Alexander Viro <aviro(a)redhat.com&gt; wrote: >> On Wed, Aug 15, 2012 at 06:13:33PM -0700, Peter Moody wrote: >>> On certain systems, in certain pathalogical cases, current's cwd can >>> be deleted while we're still processing a syscall. This should prevent >>> the system from evicting the inode while we're still referencing it. >>> >>> This seems to fix the bug I reported here: >>> https://www.redhat.com/archives/linux-audit/2012-August/msg00017.html >> >> Sigh... The bug is real, but I really don't like the fix. Among other >> things, it's going to cause cacheline bouncing from hell and not everyone >> runs with audit sensibly disabled... Let me think for a while and see >> if I can come up with something less unpleasant, OK? > > Works for me. I have a set of machines that I can very easily test a fix on. > > Cheers, > peter > > -- > Peter Moody Google 1.650.253.7306 > Security Engineer pgp:0xC3410038 -- Peter Moody Google 1.650.253.7306 Security Engineer pgp:0xC3410038