Messages in this thread | | | Date | Thu, 26 Oct 2023 09:00:55 +0200 | Subject | Re: [PATCH] mm/sparsemem: fix race in accessing memory_section->usage | From | David Hildenbrand <> |
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On 25.10.23 23:35, Andrew Morton wrote: > On Tue, 17 Oct 2023 19:40:15 +0530 Charan Teja Kalla <quic_charante@quicinc.com> wrote: > >>>> * was allocated during boot. >>>> */ >>>> if (!PageReserved(virt_to_page(ms->usage))) { >>>> + synchronize_rcu(); >>>> kfree(ms->usage); >>>> ms->usage = NULL; >>>> } >>> If we add NULL checks around ms->usage, this becomes >>> >>> tmp = rcu_replace_pointer(ms->usage, NULL, hotplug_locked()); >>> syncrhonize_rcu(); >>> kfree(tmp); >> Per David input, I am working on using kfree_rcu(). > > How's it coming along? > > Given that we're at 6.6-rc7 and given that this issue is causing > daily crashes in your device farm, I'm thinking that we use the current > version of your patch for 6.6 and for -stable. We can look at the > kfree_rcu() optimization for later kernel releases?
Any particular reason we have to rush this in? It's been seen by one company in a testing farm; there were no other reports, especially not from production systems. ... and the issue seems to be quite old.
-- Cheers,
David / dhildenb
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