Messages in this thread | | | Date | Sat, 14 Aug 2010 07:43:35 +0200 | From | Willy Tarreau <> | Subject | Re: [Stable-review] [0/3] 2.6.27.52 stable review |
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On Fri, Aug 13, 2010 at 07:53:23PM -0700, Greg KH wrote: > On Fri, Aug 13, 2010 at 05:51:56PM -0700, Linus Torvalds wrote: > > On Fri, Aug 13, 2010 at 5:11 PM, Greg KH <gregkh@suse.de> wrote: > > > > > > That's a warning that current->mm is null. I don't know enough about > > > the mm subsystem to say if this is normal or not, and I don't at first > > > glance, see how this patch could have caused this to happen. > > > > We call that whole "expand_stack()" through handle_mm_fault(), and > > that's _not_ called just for the process itself. So "current->mm" is > > sometimes simply the wrong thing to use - like when you access the VM > > of another process (during fork for the argument setup of the new VM, > > or during ptrace etc). > > > > Which is why I think commit 05fa199d45c should fix it. It makes the > > stack expansion thing use the right mm. Which it just _happened_ to do > > before, because it was always called just from the faulting code where > > current->mm happened to be the right mm. > > > > But I really don't know if there might be other issues lurking too. > > Ok, I'll go add that commit, and I unpacked my older machine that runs > the .27 kernel and will beat on it with that box tomorrow to see if > anything else pops up.
Greg, I confirm that 05fa199d45c fixes the warnings. I did not have them in .51, got them with .52-rc1 and got rid of it with the patch above.
Regards, Willy
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