From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 610D1C433FE for ; Wed, 26 Oct 2022 23:03:37 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MyPVv3gyVz3cBM for ; Thu, 27 Oct 2022 10:03:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=dB7SmPQa; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linaro.org (client-ip=2607:f8b0:4864:20::336; helo=mail-ot1-x336.google.com; envelope-from=adhemerval.zanella@linaro.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=dB7SmPQa; dkim-atps=neutral Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4My68B59Gdz2ywV for ; Wed, 26 Oct 2022 22:31:19 +1100 (AEDT) Received: by mail-ot1-x336.google.com with SMTP id t4-20020a9d7f84000000b00661c3d864f9so9642255otp.10 for ; Wed, 26 Oct 2022 04:31:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=i5n4oiK3s1rDEvpalpOgnJbA6yOfd99CxCaeDt2OpzQ=; b=dB7SmPQa5RaGySX3MXp5jzUgLT7CsWbeb4V7XMAjnLeZSz6pbG84SqjNM5oMh2eFhy /cXOzEtlWqJMSdml3q0x4r9+vwHY23wReHXZm+VJjCXf9vCjgngpuNxKoVifOb1NMLpq grvM9DKvMw0jhXs9+RKXIjncW36w/atSWST5tL0iWKx3YNmk6UYuXq+Bpfx6FLjahQVL kIp6n41iYLKUer0bC2oRbGeLr/yj0e4LqKR/wygADFHOQgF5r4/9qFmsh38cmqr/nLVl rTCuK6Bng2Oi65VUhv5iGvv4mj3Namx0zp+HuNjwSZbC359nTZgLE64zTHz4hMsBvNLz wJrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=i5n4oiK3s1rDEvpalpOgnJbA6yOfd99CxCaeDt2OpzQ=; b=KOziMNETO7u0kxJx5osnqcXbCDdt3AsAw/vMGU7ZY2Xw3j15R17BexGuGAUVPEcAyi GG6LiLGSgjETvyf62WJYR9CiCCXpQnNlzcF7FJounG5gDqHdCt4pukHM5mc421gx7Gz1 7TmaKw6Ueqb4rjRGIvQh6MyYFLipZ6yx9OVDaCrrdD+5+UWZIsNyOjUzxhz2Z/AZUH8Q ljKWQ+Kq/8RSpWw/Ok6wCnyDKLF3mWEGdi0BZWGz+ccRoaz3J123r5BNMAmgxSDeKBPF rNSzvb4qYOpi3CgGqPL2BO0JVf3vsSiP+INeKIO5paGbOIf5kKGu2MDkPUDEf6NjSLMr 74Zg== X-Gm-Message-State: ACrzQf152serOoM4ogAQgIaErAODBTPVmJco79MjGE95fimgYXMnMgLo 8GH3mFeX97lHS/mhj4QAQ25cZg== X-Google-Smtp-Source: AMsMyM7nBq+ZoRETnfRKRTqgw9DfHET03EP+jmHYxEwag9S3pSnQMIjCDEwLFextjAg1E/Qo4yxNeA== X-Received: by 2002:a05:6830:6303:b0:65c:5bcd:c2d0 with SMTP id cg3-20020a056830630300b0065c5bcdc2d0mr20828925otb.115.1666783876186; Wed, 26 Oct 2022 04:31:16 -0700 (PDT) Received: from ?IPV6:2804:1b3:a7c0:17c8:3978:9d2:1936:95b? ([2804:1b3:a7c0:17c8:3978:9d2:1936:95b]) by smtp.gmail.com with ESMTPSA id r6-20020a05687080c600b0013bc95650c8sm2915372oab.54.2022.10.26.04.31.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 26 Oct 2022 04:31:15 -0700 (PDT) Message-ID: <55cc0d33-b468-de1f-58f2-9016bf40566d@linaro.org> Date: Wed, 26 Oct 2022 08:31:12 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.4.0 Subject: Re: nscd time_t size mismatch problem Content-Language: en-US To: Zev Weiss References: <72f37987-5f8a-99c5-bd36-5153343dcf75@linaro.org> From: Adhemerval Zanella Netto Organization: Linaro In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Thu, 27 Oct 2022 10:02:41 +1100 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: openbmc@lists.ozlabs.org, libc-alpha@sourceware.org, Wayne Tung Errors-To: openbmc-bounces+openbmc=archiver.kernel.org@lists.ozlabs.org Sender: "openbmc" On 25/10/22 22:04, Zev Weiss wrote: > On Tue, Oct 25, 2022 at 02:13:23PM PDT, Adhemerval Zanella Netto wrote: >> >> >> On 25/10/22 16:54, Zev Weiss via Libc-alpha wrote: >>> Hello glibc devs, >>> >>> We've recently been seeing some misbehavior from nscd in OpenBMC. It >>> manifests as lots of log messages like: >>> >>> disabled inotify-based monitoring for file /passwd': No such file or directory >>> stat failed for file /passwd'; will try again later: No such file or directory >>> disabled inotify-based monitoring for file /group': No such file or directory >>> stat failed for file /group'; will try again later: No such file or directory >>> disabled inotify-based monitoring for file /hosts': No such file or directory >>> stat failed for file /hosts'; will try again later: No such file or directory >>> disabled inotify-based monitoring for file /resolv.conf': No such file or directory >>> stat failed for file /resolv.conf'; will try again later: No such file or directory >>> >>> and so forth. I initially assumed it was a configure-time --sysconfdir mixup, but after digging into it I found that it actually stems from a time_t size mismatch (this is a 32-bit ARM gnueabi target): >>> >>> $ gdb -batch -ex 'pt time_t' -ex 'p sizeof(time_t)' time/time.o >>> type = long >>> $1 = 4 >>> $ gdb -batch -ex 'pt time_t' -ex 'p sizeof(time_t)' nscd/nscd.o >>> type = long long >>> $1 = 8 >>> >>> The confusing log messages are thus just the result of the coincidence that sizeof(long long) - sizeof(long) == strlen("/etc"), which causes the disagreement in the layout of struct traced_file to make it look like the 'fname' member just had its directory prefix chopped off. >>> >>> In the discussion of the bug in the OpenBMC issue tracker [0], Wayne Tung (CCed) came up with the patch below, which does seem to solve the immediate problem, but if I'm understanding things right does so by just reverting nscd to a 32-bit time_t, and so I'd expect probably wouldn't be considered the "right" fix -- however I don't presently know enough about the 32/64-bit time_t transition and ensuing compatibility concerns to know what the right fix really is. Should nscd perhaps be using __time64_t or something instead of time_t? >> >> Reverting to 32 bits time_t only means that we are postponing some potential >> failure to y2038, we really move everything to 64 bit time_t. Could you check >> if the following patch fix it? >> >> The issue is we do build nss modules with 64 time_t, however some features >> are built on libc.so itself and in such cases we need to explicit use the >> internal __time64_t type. >> >> diff --git a/nscd/nscd.h b/nscd/nscd.h >> index 368091aef8..f15321585b 100644 >> --- a/nscd/nscd.h >> +++ b/nscd/nscd.h >> @@ -65,7 +65,7 @@ typedef enum >> struct traced_file >> { >> /* Tracks the last modified time of the traced file. */ >> - time_t mtime; >> + __time64_t mtime; >> /* Support multiple registered files per database. */ >> struct traced_file *next; >> int call_res_init; >> > > Ah, great -- after testing that out I can confirm that it appears to fix the problem. Thanks! > > Also, after sending that email I discovered that there's an existing bugzilla issue for this same problem (https://sourceware.org/bugzilla/show_bug.cgi?id=29402), so that can presumably be closed once a fix is committed. I will send a proper path and I will check if there are any other instance of time_t that is used internally as this.