Messages in this thread | | | Date | Tue, 2 Jun 2015 22:58:42 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [PATCH] livepatch: add module locking around kallsyms calls |
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On Tue, 2 Jun 2015, Josh Poimboeuf wrote:
> On Mon, Jun 01, 2015 at 05:48:37PM +0200, Miroslav Benes wrote: > > The list of loaded modules is walked through in > > module_kallsyms_on_each_symbol (called by kallsyms_on_each_symbol). The > > module_mutex lock should be acquired to prevent potential corruptions > > in the list. > > > > This was uncovered with new lockdep asserts in module code introduced by > > the commit 0be964be0d45 ("module: Sanitize RCU usage and locking") in > > recent next- trees. > > > > Signed-off-by: Miroslav Benes <mbenes@suse.cz> > > Thanks! > > Should we add a comment to kallsyms_on_each_symbol() so that others > don't make this mistake?
Yeah, the locking rules in module loader are not really crystal clear (not even after Peterz's revamp in -next), so some comment / lockdep assertion might be helpful. But let's keep that separate from this functional fix in klp.
> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
I have now queued this in for-4.1/upstream-fixes, but I don't think I'll rush this in for -final now, therefore I added Cc: stable as well. If there is -rc7, I'll push it to Linus for -final early next week.
Thanks,
-- Jiri Kosina SUSE Labs
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