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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=1TmLUW6hPremyHfH02mI1sZyfyvVZyCwA3fX+FOaBXI=; b=WI18pH9VTFb5u6FN/Yrc+1r1styV1bPnXmerMw2Thyflmb2SVRF4GHWstt/iArxNUL ap7k/MNkBVPDOby0gB7o3CWjASMSHIvE3aWkkgWIxLGtCj6JE/KAzcFd4fRKoGmWtwYJ Cab9FPxbrsDdw22vp4EpIUMYzLkyxKCWG0Cun4vq+QWrHYATLAFxWbXRY/vekAu0LYBa RQXMrmxEbAvcMoUKqhR/eXHEOi3tHlxdKgEG2L6UOAKE8HtXNq4iUBBacxnvYHHZkfNA 6osQkb2uTZK7cBoBbtL/f99tCulra3eVkO9MnDq0Tx1luBUG72blt5kZ2DAwedbr8rEs Kwrw== X-Gm-Message-State: AO0yUKV3fQNgXqGr1pbkyaCZ7/SBcTpvVAa+LM1cCPuL/JlrKpHsFJTM tMlCuqVWlOo5sErjd+wZfrqvTbGt8WUhd5ld5IEabQ== X-Google-Smtp-Source: AK7set+Jv4HZl0nSf1uZg7MOawEojcn8ISEv4W9PIqKYmccB/VLVVt+9l+W+zQuslLejUuemhSR18qAuVCNghXpzs0I= X-Received: by 2002:a92:8e43:0:b0:30f:5797:2c71 with SMTP id k3-20020a928e43000000b0030f57972c71mr13118156ilh.51.1676289171334; Mon, 13 Feb 2023 03:52:51 -0800 (PST) MIME-Version: 1.0 References: <359ac9c13cd0869c56740fb2029f505e41593830.1676063693.git.andreyknvl@google.com> In-Reply-To: <359ac9c13cd0869c56740fb2029f505e41593830.1676063693.git.andreyknvl@google.com> From: Alexander Potapenko Date: Mon, 13 Feb 2023 12:52:12 +0100 Message-ID: Subject: Re: [PATCH v2 16/18] lib/stackdepot: annotate racy pool_index accesses To: andrey.konovalov@linux.dev Cc: Marco Elver , Andrey Konovalov , Vlastimil Babka , kasan-dev@googlegroups.com, Evgenii Stepanov , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Queue-Id: 5F30C40024 X-Rspamd-Server: rspam01 X-Stat-Signature: m8s5jhiznerk3ibt6sgsugmsrnjsyb18 X-HE-Tag: 1676289172-546917 X-HE-Meta: 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 5+RkkHRx +cqu9Z954ARuNr2GyErop+W5Eeai3xPS6Wb2ZU7h7ki+lNfJIg6BclUi9fYr5mkrfQUrwoZBZ+tKiBSOyS2BmcsTv5+tPADOqXaoRSSV5qvA196V0ESDrbttN++3NiDCB7I+kENJr+Ly9gqvulOATJMl+2vOnXJnimT85+xxPkkd7PQdlTc0GBLdmAXI1qfjWrN//lLSKpPiyOTIQ/9Rs5dx9wlL+JJ+ss+NHggwV9St+pr2NLkVKGblTv+sne31dhgbcXQ8CfpZdu/DUIRLeOc62EuUZdDfO3LahZC/tO26wzWkFmCV78DDSTfVF0kkQUysS77X4e7AYi1m+HLK5biU9ciHfzLdMRcHC X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Feb 10, 2023 at 10:18 PM wrote: > > From: Andrey Konovalov > > Accesses to pool_index are protected by pool_lock everywhere except > in a sanity check in stack_depot_fetch. The read access there can race > with the write access in depot_alloc_stack. > > Use WRITE/READ_ONCE() to annotate the racy accesses. > > As the sanity check is only used to print a warning in case of a > violation of the stack depot interface usage, it does not make a lot > of sense to use proper synchronization. > > Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko