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Groups > linux.kernel > #1229997
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| From | Thomas Graf <tgraf@suug.ch> |
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2] lib: fix data race in rhashtable_rehash_one |
| Date | Tue, 22 Sep 2015 11:20:02 +0200 |
| Message-ID | <qbrTY-12G-7@gated-at.bofh.it> (permalink) |
| References | <qbrAC-qV-21@gated-at.bofh.it> |
| X-Original-To | Dmitry Vyukov <dvyukov@google.com> |
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| X-Original-Cc | eric.dumazet@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kcc@google.com, andreyknvl@google.com, glider@google.com, ktsan@googlegroups.com, paulmck@linux.vnet.ibm.com |
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| Xref | csiph.com linux.kernel:1229997 |
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On 09/22/15 at 10:51am, Dmitry Vyukov wrote: > rhashtable_rehash_one() uses complex logic to update entry->next field, > after INIT_RHT_NULLS_HEAD and NULLS_MARKER expansion: > > entry->next = 1 | ((base + off) << 1) > > This can be compiled along the lines of: > > entry->next = base + off > entry->next <<= 1 > entry->next |= 1 > > Which will break concurrent readers. > > NULLS value recomputation is not needed here, so just remove > the complex logic. > > The data race was found with KernelThreadSanitizer (KTSAN). > > Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Thomas Graf <tgraf@suug.ch> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH v2] lib: fix data race in rhashtable_rehash_one Dmitry Vyukov <dvyukov@google.com> - 2015-09-22 11:00 +0200 Re: [PATCH v2] lib: fix data race in rhashtable_rehash_one Eric Dumazet <eric.dumazet@gmail.com> - 2015-09-22 11:10 +0200 Re: [PATCH v2] lib: fix data race in rhashtable_rehash_one Thomas Graf <tgraf@suug.ch> - 2015-09-22 11:20 +0200 Re: [PATCH v2] lib: fix data race in rhashtable_rehash_one Herbert Xu <herbert@gondor.apana.org.au> - 2015-09-22 17:30 +0200 Re: [PATCH v2] lib: fix data race in rhashtable_rehash_one David Miller <davem@davemloft.net> - 2015-09-23 02:40 +0200
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