From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 9DF373858C54 for ; Tue, 17 Oct 2023 17:47:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9DF373858C54 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 9DF373858C54 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1697564872; cv=none; b=YSJJ7PJs0fg8Mp57FTW7UmW58J1vZu2aXUan5iFLGQu0mwmZ/LpPNzOSjZWQpJsL3RDc2czioQI2CcsW7EfYrTIcYeHE+AisD7XQ7r0Zv+Ci5Y14KVsPi1xqUHXdlSJiAWxITk+Ns41O+BUYWSjypR96m3EZ4PrLM7b6ofFg7Ws= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1697564872; c=relaxed/simple; bh=dYqgbUF1yZoubQfcl9VWBgZb+cjAuaYPIASkM2hiLgw=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=XTVfouCVW6Jv2CzyUaSB51y/YkxZG5CBq8RqrGgqINnnFCGSD8QfkwzEy/jaLo5fucf3LPjZ3OqWMt6kJT1TrQkgvZeG6Py+SzlsDndk0VF47+eLPtmy8oz1siT94B4HyENJ9oNCInApqfehFVFuqMogAHcSkZS9LsQNzZzDyOA= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697564871; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to; bh=dYqgbUF1yZoubQfcl9VWBgZb+cjAuaYPIASkM2hiLgw=; b=QDzx9W5rYeinqAapIkEAihXMU34L0nEdgVJIs8fGHy3r1t8y9b3YO4Srrj1Zi1JZxAi7Gq 53XkHGF/fCvCFPjOE7xhzIa2XFcwfF7vu+prdstCXZmbdXYwsGsLs9Io1Kydyk6dxIqgge Zl4Jo7wLDixEUkEu6DZIAgGdh1WNw0I= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-57-1g2xkLDIOQed8GNjWf3Rjw-1; Tue, 17 Oct 2023 13:47:49 -0400 X-MC-Unique: 1g2xkLDIOQed8GNjWf3Rjw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6568D1052227; Tue, 17 Oct 2023 17:47:49 +0000 (UTC) Received: from greed.delorie.com (unknown [10.22.9.85]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4A78140C6F79; Tue, 17 Oct 2023 17:47:49 +0000 (UTC) Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1]) by greed.delorie.com (8.15.2/8.15.2) with ESMTP id 39HHlef92731335; Tue, 17 Oct 2023 13:47:40 -0400 From: DJ Delorie To: "Zack Weinberg" Cc: adhemerval.zanella@linaro.org, libc-alpha@sourceware.org Subject: Re: RFC: system-wide default tunables In-Reply-To: <9b118ff8-db2f-407d-858b-b526b6805467@app.fastmail.com> Date: Tue, 17 Oct 2023 13:47:40 -0400 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: "Zack Weinberg" writes: > Even better to open() unconditionally and ignore ENOENT failures. >From a security/performance perspective, which is better - open() and read a line at a time, or mmap() and parse in place? ldconfig reads a line at a time, but it also has a lot of glibc-specific helper functions (like argp_parse() and getline()) that I assume have been checked for security.