December 2007 - Darwin-kernel

How to know given file path is part of bundle
by JanakiRam 02 Dec '07

02 Dec '07

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Re: Newbie Questions
by Michael Smith 01 Dec '07

01 Dec '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Nov 29, 2007, at 1:38 PM, Thomas Inskip wrote: Allow me to split a hair here. Resource access control is handled in a number of different ways. It's a uselessly gross oversimplification. Let me ask the usual question: What are you actually trying to do? = Mike _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I am not completely new to the darwin underpinnings, but I have been assigned a task that definitely requires pretty good knowledge of the mach kernel. First I'd like to ask what's a good introduction to the kernel (let's call it a crash course). I hate to say this, but there is no such thing. There's simply no way that you can absorb that much information and background in a 'crash course'. Amit's book is good, and will help you get your feet, but expect to spend months if not years getting comfortable. Next I'd like to explain what I need to be able to do. I basically need to be able to detect when someone is reading from a shared resource (in this case the display buffer). Do you want to know when they *are reading*, or when they are *granted permission to read*? For what I understand, any such resources are arbitrated through mach ports. The framebuffer itself is rarely accessed directly by a client; there are high-level interfaces for obtaining its contents. If a process needs access to one, it obtains either read or write rights to it (multiple reader, single writer?), and then is able to access the resource. Is this correct? If so, I should be able to determine when someone obtains read access to such a port via the kernel trace facility or something similar. At least that's my idea. Perhaps I am wayyyyyyy off. Feel free to let me know if that's so or if I am oversimplifying things. This email sent to site_archiver(a)lists.apple.com

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Re: Newbie Questions
by mm w 01 Dec '07

01 Dec '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=+BCIvzTCi+X0hM4w8YKUGT/MhJAjDj2pnoMU/9uOZLc=; b=gY8iOgGoSJ/nZvku5ttYKkQP2aszUiSJAGZNyjopPQ1KgMy+OrvxkqLc6zBJmzYmcUn6yrCKpeDA+3On6iJrxmZCwuBzpig2txc/KtsCQHcR6tmIshlCdqMGD2v/PGHoe/LreZlPKgqUkBAjcI2+q8zjl69j7i/o1pLLxp7HjCA= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=J7Fwu9HFqFPJH1Cd0fGRMZE60f61cCWh3lhtHkyhJEpDR4ipj17AiXCa1plpFqoOK0T6cF7qPrqpk4bdimep5ViIu3wJSD7nJ3ZdGMJ9MzPiiwcIzgool0JXJMFYVIe/6XYybacFd3u/9srhb9ddDp4Zz8bhRoYyx7Fu6ylMhmc= hi, it's quite tricky to propose an "history" of mach ukernel as Introduction, especially with xnu, that doesn't use mach as ukernel, it's like to propose an "history' of xnu, i think it's quite void, the Apple doc and the Amit's Book are the good tools -mmw On Nov 30, 2007 4:31 PM, Alex Nelson <pqnelson(a)gmail.com> wrote: > > I am not completely new to the darwin underpinnings, but I have been > > assigned a task that definitely requires pretty good knowledge of the > > mach kernel. First I'd like to ask what's a good introduction to the > > kernel (let's call it a crash course). > > Well, in my opinion there are a number of interesting technical papers on > the Mach 3 kernel...that is the version of the mach kernel used in the XNU > kernel. > > There is an excellent non-technical introduction that is freely available, > it is the appendix to the book "Operating System Concepts" (7th ed) by Avi > Silberschatz, Peter Baer Galvin and Greg Gagne : > http://codex.cs.yale.edu/avi/os-book/os7/online-dir/Mach.pdf > > Another excellent introductory text is "THE MACH SYSTEM": > http://library.nocrew.org/lib/os/Mach.txt > > You may wish to consult the documentation, both publications and unpublished > works, at the Carnegie Mellon University's Mach page: > > http://www.cs.cmu.edu/afs/cs/project/mach/public/www/doc/documents_top.html > > Depending on how in depth you want to get, you can always try reading up on > the Mach 3 source code directly (it's unlicensed): > > http://www.cs.cmu.edu/afs/cs/project/mach/public/www/sources/sources_top.ht… > > > > Next I'd like to explain what I need to be able to do. I basically > > need to be able to detect when someone is reading from a shared > > resource (in this case the display buffer). For what I understand, > > any such resources are arbitrated through mach ports. If a process > > needs access to one, it obtains either read or write rights to it > > (multiple reader, single writer?), and then is able to access the > > resource. Is this correct? If so, I should be able to determine > > when someone obtains read access to such a port via the kernel trace > > facility or something similar. At least that's my idea. Perhaps I > > am wayyyyyyy off. Feel free to let me know if that's so or if I am > > oversimplifying things. > > Hmm...but wouldn't the display buffer be represented by a file? And using > the freeBSD virtual file system to access it, if it's accessed wouldn't the > file be locked? > > Again, I'm purely guessing, I may be equally way off. > > But I'd use the Unix approach and try to work with the file representation > of the device. > > Cheers! > Alex Nelson > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/darwin-kernel/openspecies%40gmail.com > > This email sent to openspecies(a)gmail.com > -- echo zapydapntpd.rxltw@nzx | tr a-z@. p-za-o.@ _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Newbie Questions
by Alex Nelson 01 Dec '07

01 Dec '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:mime-version:content-type; bh=bK4XAb17qiMhDVJpmrp/jn6bN7kBf90nzdUy0u6UCzw=; b=LWeDxXhBSnbA/kNIUEqIuSDqdyJRtd3ezI6w4tBy9/PCPEhZIGbUpqScf3eC9BNmQqyWU+DBRqnbKbLB5foUZS2PdDP4O4hxLqa8zi/xNOQvKsGID+vLaOzv9NrDmXfbtfWXQrSUHr9hVAxk70bRJx8pef4I36WfWNv2Ntj9r5I= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=received:message-id:date:from:to:subject:cc:mime-version:content-type; b=szAX5Nj7pMbeGrgCu3QXSEzfDQ0nkGonHkvFbys+U3xN7RPZW54V0ITtiD33QPt2fcpJrRw6pP+Tr3yFWW+IALVftDQ4Tw3Q6v1Wo6/plvyylvSJGmBu/lS4iFErjkmiYxhFcpqqwEWr7gpBCvnSrral7BHgqmSwFd+HbmTU9i8= _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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