From owner-freebsd-dtrace@freebsd.org Thu May 18 20:35:05 2017 Return-Path: Delivered-To: freebsd-dtrace@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 04D7AD73C07 for ; Thu, 18 May 2017 20:35:05 +0000 (UTC) (envelope-from slepetit@apple.com) Received: from mail-in6.apple.com (mail-out6.apple.com [17.151.62.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id CF8A21A69 for ; Thu, 18 May 2017 20:35:04 +0000 (UTC) (envelope-from slepetit@apple.com) DKIM-Signature: v=1; a=rsa-sha256; d=apple.com; s=mailout2048s; c=relaxed/simple; q=dns/txt; i=@apple.com; t=1495139698; h=From:Sender:Reply-To:Subject:Date:Message-id:To:Cc:MIME-version:Content-type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-reply-to:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=gQCdjA/mK2A06JjHrFUO4ieyK1NNB8wub6Dia98Wnao=; b=EVadPhzIE9wFBSX76eo5QuSIudIpNOYewx0F/bwuqpwWIQTdX1S958ztP9hFXxDe gaaZLc/dB8Yx5+2NPllV2IzSBVT2HXwUkkYsovbRLY4G1EP7duJj69XHY4qCGom8 gU1QXjWLdV36rCBvN1BvaDyYa+04tXnklgTeonypa/0n5NA1dPLQD3lpXgW+XhHt okHLTUc0GYarFE1C/XMHu7QpSpC9nSkSOm5Nr96/js+Bbc3jfXAwBL1Ity7hiHL0 lNDXonUvs41RUI6PIpI14vMhbMXyuGAhAVC1YcADFafszL0X8lm5A4+kH02FSttr bRpHZo8WpU8LwdJMXBbt4w==; Received: from relay6.apple.com (relay6.apple.com [17.128.113.90]) (using TLS with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mail-in6.apple.com (Apple Secure Mail Relay) with SMTP id 8A.70.24649.1750E195; Thu, 18 May 2017 13:34:58 -0700 (PDT) X-AuditID: 11973e15-a3fff70000006049-82-591e057101ad Received: from nwk-mmpp-sz13.apple.com (nwk-mmpp-sz13.apple.com [17.128.115.216]) by relay6.apple.com (Apple SCV relay) with SMTP id 22.B6.09762.1750E195; Thu, 18 May 2017 13:34:57 -0700 (PDT) MIME-version: 1.0 Received: from da0603a-dhcp63.apple.com (da0603a-dhcp63.apple.com [17.226.35.63]) by nwk-mmpp-sz13.apple.com (Oracle Communications Messaging Server 8.0.1.2.20170210 64bit (built Feb 10 2017)) with ESMTPSA id <0OQ600LHZ169U000@nwk-mmpp-sz13.apple.com>; Thu, 18 May 2017 13:34:57 -0700 (PDT) Sender: slepetit@apple.com From: Samuel Lepetit Message-id: <6A020677-BC76-41E1-8372-10B7962F4EDE@apple.com> Subject: Re: fbt:kernel:breadn_flags:entry): invalid address (0x0) in action #7 Date: Thu, 18 May 2017 13:34:43 -0700 In-reply-to: <591E01F5.8080208@incore.de> Cc: freebsd-dtrace@freebsd.org To: Andreas Longwitz References: <591E01F5.8080208@incore.de> X-Mailer: Apple Mail (2.3430) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrPLMWRmVeSWpSXmKPExsUi2FAYpVvEKhdpMOE6o8WGz5+YLWafXcPi wOQx49N8Fo+P++0DmKK4bFJSczLLUov07RK4Ml5MechWsECt4seyGYwNjH8Uuhg5OSQETCTO 3/jM0sXIxSEksJpJYtfMU4xdjBxgifu3NUFqhAQOMUqceQdWzysgKPFj8j0WEJtZIExi0ra5 TBC9q5gkPpxcyAqSEBaQkpg78Q2YzSagKXFz/g2wmbwCNhJv3gtClPhLHHv1hxUkzCKgKjGn TxQkzAlU3dlwGWq8nMTi07PYQWwRoPi8m5tYIM7RkHj2tYMN4nxZieZzrcwgJ0gIHGCTaP5+ hGUCo9AsJKfOQnIqhK0l8f1RK1CcA8iWlzh4XhYirCnx7N4ndghbW+LJuwusCxjZVjEK5SZm 5uhm5pnpJRYU5KTqJefnbmIExcB0O9EdjGdWWR1iFOBgVOLhfbBCNlKINbGsuDL3EKM0B4uS OG/eV6CQQHpiSWp2ampBalF8UWlOavEhRiYOTqkGxgs9TfMtuAI2GwdWlS+22MDyY0L3t8kn tv6/wpXk+Dvk6eny31HPvaV955graCX4BT74sna1zemZrGLWvUIz/59+r2Q0Y/20Xy8fNs36 dW2Rd/jLw55WavxTc5V+BE99dYkxztVxZX6Joa5j+uotqpFevqHm//2iZ4TO95uzhr3KbFuF z2+R6UosxRmJhlrMRcWJABQSF7JiAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrJIsWRmVeSWpSXmKPExsUi2FB8Q7eQVS7SYPU6BYsNnz8xW8w+u4bF gcljxqf5LB4f99sHMEVx2aSk5mSWpRbp2yVwZbyY8pCtYIFaxY9lMxgbGP8odDFycEgImEjc v63ZxcjJISRwiFHizDsFEJtXQFDix+R7LCA2s0CYxKRtc5m6GLmAalYxSXw4uZAVJCEsICUx d+IbMJtNQFPi5vwbjCAzeQVsJN68F4Qo8Zc49uoPK0iYRUBVYk6fKEiYE6i6s+Ey1Hg5icWn Z7GD2CJA8Xk3N7FAnKMh8exrBxuILSEgK9F8rpV5AiP/LCTXzUJyHYStJfH9UStQnAPIlpc4 eF4WIqwp8ezeJ3YIW1viybsLrAsY2VYxChSl5iRWmuklFhTkpOol5+duYgSHbGHUDsaG5VaH GAU4GJV4eDuWyUYKsSaWFVfmAkOIg1lJhDfoJ1CINyWxsiq1KD++qDQntfgQ40RGoB8nMkuJ JucDIyqvJN7QxMTAxNjYzNjY3MSclsJK4rw6zHKRQgLpiSWp2ampBalFMEcxcXBKNTAKuq6e /+vd7axXux3Lq9dNFvNc8VWp3HrTzJi/t7+IKLYvPlHWoaQ/s+Gdx/vXCjdO/TFJk1w9I3hF dlF/YibX4mAHEc+CkgaXZy//6K2RldSMlopcPeV00809IidnJN5bX5qRv/ZQdVyEr+XU3PbN L7pWcz/fn7Mu92n1ogaD6ayvz3SsW1uvxFKckWioxVxUnAgArdYZYMwCAAA= Content-Type: text/plain; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-dtrace@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "A discussion list for developers working on DTrace in FreeBSD." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 May 2017 20:35:05 -0000 I suspect the easiest way here is just to check that your credential in args[6] is non-null in a predicate. - Samuel Lepetit - slepetit@apple.com > On 18 May 2017, at 13:20, Andreas Longwitz wrote: > > Now running FreeBSD 10.3-STABLE #0 r317936 I try to understand the > problem described in > > https://lists.freebsd.org/pipermail/freebsd-fs/2013-November/018610.html > > using DTrace. Therefore I like to use the probe > > fbt:kernel:breadn_flags:entry > > to see what is happening in ffs_vgetf() in source ffs_vfsops.c: > > #define bread(vp, blkno, size, cred, bpp) \ > breadn_flags(vp, blkno, size, NULL, NULL, 0, cred, 0, bpp) > > /* Read in the disk contents for the inode, copy into the inode. */ > error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)), > (int)fs->fs_bsize, NOCRED, &bp); > > I get the error > > dtrace: error on enabled probe ID 22 (ID 31371: > fbt:kernel:breadn_flags:entry): invalid address (0x0) in action #6 > > probably because NOCRED is NULL: > > #define NOCRED ((struct ucred *)0) > > I like to know if this case can be handled in DTrace, the parameter > > args[6]: struct ucred * > > is sometimes a pointer and sometimes NOCRED. > > > -- > Dr. Andreas Longwitz > > _______________________________________________ > freebsd-dtrace@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-dtrace > To unsubscribe, send any mail to "freebsd-dtrace-unsubscribe@freebsd.org"