January 2009 - Darwin-dev - lists.apple.com

Re: Descriptor Passing Mac OS X 10.5.4 ( X86_64 )
by Terry Lambert 07 Jan '09

07 Jan '09

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Re: generating mach-o executable files by hand
by Terry Lambert 07 Jan '09

07 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Terry, On Jan 7, 2009, at 3:33 AM, Terry Lambert wrote: You will be better off invoking the linker. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Jan 7, 2009, at 1:24 AM, Joel Reymont <joelr1(a)gmail.com> wrote: You have to use at least *a* linker; if you don't, you won't be able to import the system call stubs from libc/libsystem I hope to prove you wrong, shortly. This is a Forth so all I need is stubs for dlopen, dlclose, dlsym and dlerror. I also need to jump to an entry point. This works fine on Linux with the ELF format. I don't know how soon it will be, even with the broad strokes I'm about to outline to illustrate the complexity and fragility over updates of what you are attempting. I'm not sure if Linux uses the SVR4 trick of starting the first page of a process at a large virtual offset and always mapping ld.so into the low memory hole starting a 4k or not. I do know that there is a load command in Mach-o that causes dyld (the moral equivalent of ELF ld.so) to be loaded, and that the linker relocates things so that the default thread state struct program counter vale in another load command points to the start address of the dyld start routine, NOT the entry point for your compiled program. After that, after the segment loads (which just establish mappings), the kernel ignores all of the other load commands besides the unix thread state structure, and dyld does the rest based on the other sections. The dlopen et. al. bindings are things that know how to refernce into the dyld (unlike in Linux ELF, where they are static stubs in crt1 that are built with apriori knowledge of where ld.so gets loaded, dyld is permitted to "slide" if necessary, and do does not maintain a nrcessarily fixed location). There is no ELF-like hierarchical linking library against library to ensure visibility of pre-linked code symbols via dlsym. While you may be able to do this on the basis of bundle-style operations, rather than dlopen, you are likely not going to be happy with the results due to the dependence on a non-flat namespace. I also rather expect you aren't going to get help from the tools folks to deal with these issues, or to document how to generate a valid Mach- o. Completely apart from any correctness considerations, we don't promise we won't change all the implementation details at some point in the future, and documenting how things currently work at the level of detail you'd need would likely set certain details in stone which we'd rather not have be that static. And that's all without dealing with the vtable offsets and library preinitialized data and constructors/destructors, or the other necessary symbol relocation (even assuming you are writing PIC-only instructions and using the slightly-different-than-Linux calling conventions). This email sent to site_archiver(a)lists.apple.com

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Descriptor Passing Mac OS X 10.5.4 ( X86_64 )
by Rohitash 07 Jan '09

07 Jan '09

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Re: generating mach-o executable files by hand
by Jean-Daniel Dupas 07 Jan '09

07 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Le 7 janv. 09 à 10:24, Joel Reymont a écrit : Terry, On Jan 7, 2009, at 3:33 AM, Terry Lambert wrote: FWIW, the OS X linker is open source: http://www.opensource.apple.com/darwinsource/DevToolsOct2008/ld64-85.2.1 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… You have to use at least *a* linker; if you don't, you won't be able to import the system call stubs from libc/libsystem I hope to prove you wrong, shortly. This is a Forth so all I need is stubs for dlopen, dlclose, dlsym and dlerror. I also need to jump to an entry point. This works fine on Linux with the ELF format. Thanks, Joel But I would recommand generating mach-o objects, and link them using Apple ld. This email sent to site_archiver(a)lists.apple.com

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Re: generating mach-o executable files by hand
by Joel Reymont 07 Jan '09

07 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:cc:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-mailer; bh=xLIYkuJ0HfMPN2IXbZqushCniVXn9fsxAlUZHzGHBek=; b=oo4C4vv5QfP8tdFMCagOTqQOrPY7Iw4CeyuDyH9NCTZSnmAJoLfgFiXxCe1DQS/tt6 d7MpEJBQQhzttPPSPPEbX/DB4mHOokUR/wBV6LfcTj4T2x65EWfcUuyxISVBGVsBVbx6 jHZiqg1PAoD05eHBfOMKEEQAFQSRpH//Sq1OA= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=cc:message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-mailer; b=oULvUj+xTsY2n+qn/DbORlgp4XEtCZGGtO8WmbjvQm58NG5TGledbp/tHT938nt0N1 6EJZLVe1c2Rfj+94/BbOJH90a9BcPQYa6bf33wCWPlX7YIH+Dk9mqEw8e8D0Qf/3ANWh w1V6BkLGElOvuuDjL+k0ViD0rj1/AgpP7dE7E= Terry, On Jan 7, 2009, at 3:33 AM, Terry Lambert wrote: Thanks, Joel --- http://twitter.com/wagerlabs _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… You have to use at least *a* linker; if you don't, you won't be able to import the system call stubs from libc/libsystem I hope to prove you wrong, shortly. This is a Forth so all I need is stubs for dlopen, dlclose, dlsym and dlerror. I also need to jump to an entry point. This works fine on Linux with the ELF format. This email sent to site_archiver(a)lists.apple.com

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Has anything changed in 10.5.6 bootstrap contexts management?
by Stéphane Letz 07 Jan '09

07 Jan '09

site_archiver(a)lists.apple.com Delivered-To: Darwin-dev(a)lists.apple.com Hi, Thanks Stephane Letz _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… With OSX 10.5.6, our audio user land driver cannot be activated as default input/output device anymore. It seems that the "coreaudiod" deamon (that runs under root) cannot connect anymore to our audio server (jackd) that defines a mach port entry point in the user account bootstrap context. Is the any fundamental change in bootstrap contexts management in the system? This email sent to site_archiver(a)lists.apple.com

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Re: generating mach-o executable files by hand
by Terry Lambert 07 Jan '09

07 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Jan 6, 2009, at 1:34 PM, Joel Reymont wrote: I need to generate the Mach-O executable files by hand, without using the linker. It's for a Forth compiler that I'm porting from Linux and the headers need to be generated by hand. I'm trying to tackle "hello world" for starters. I looked at the 12K executable generated by gcc but it seems like there's too much cruft in there. Does anyone have sample code that generates Mach-O exe files without using the linker? You have to use at least *a* linker; if you don't, you won't be able to import the system call stubs from libc/libsystem (and No, you can't just statically link things, since the system call implementations are split between user and kernel space, and many times the parameter lists don't even match what's exposed to user programs). This email sent to site_archiver(a)lists.apple.com

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generating mach-o executable files by hand
by Joel Reymont 06 Jan '09

06 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(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:from:to :content-type:content-transfer-encoding:mime-version:subject:date :x-mailer; bh=jP/meA7m8HJ7iLfTsztYmRUM2GVWELcr20TIZPVj3hQ=; b=ZSny7YoHbpyFuQPiWZ0I/rYyxbBUWDu6YDpdPqyNAT3qqSwru8VwqlHtP/LnXEsyrO 20H+LiclIN2w6jyJjPNWF4AMBRTjTHmOv6CehVHQslXU/OkcyAZuxC7jczHoyaSJxwfB d8TNB1rk5eqZT6tV1MmZTkWcYdE2X0n6Qh0ug= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:content-type:content-transfer-encoding :mime-version:subject:date:x-mailer; b=KB3kkLSbxFjMBEJhpqTK/Ma35phBimtk2ejFoQ1iD+TTHJYzkDafOgc0hlx0jyDMtj pDabgiSk3fKFQSEbvyJOl43rbX5a70GlXS4cUoLXnEvik8QpFoJIJM6QPp7h4CfpSYlv aBQce3hthDqSlFdsxBPQ5tQTDQbp0NOW9Eamw= Thanks, Joel -- http://wagerlabs.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… I need to generate the Mach-O executable files by hand, without using the linker. It's for a Forth compiler that I'm porting from Linux and the headers need to be generated by hand. I'm trying to tackle "hello world" for starters. I looked at the 12K executable generated by gcc but it seems like there's too much cruft in there. Does anyone have sample code that generates Mach-O exe files without using the linker? This email sent to site_archiver(a)lists.apple.com

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.section __IMPORT,__jump_table,symbol_stubs,... with nasm
by Joel Reymont 06 Jan '09

06 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(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:from:to :content-type:content-transfer-encoding:mime-version:subject:date :x-mailer; bh=z2JWwxIovHT0cERdXc7kar8tf0l1wmOt1AxpqgZYkfs=; b=YyGF/VUF4VuveNE/Dr6k1/Rll1lQpp556y7XATE64f8CLCQjqGH2VhElaoQJNH5Fkq jk/WF+9T7rJvhs8MZMZh1qtpAEWqQr5eufXmngcpSs8dH853ONhCrdrHNENVDQOlVy8i t3ugMDNOIGL7vas77jj6mMO/BYVOE8dy0AGVI= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:content-type:content-transfer-encoding :mime-version:subject:date:x-mailer; b=X+zY7Z8Pik+ykZmy1bKEBHct7pyfl3PHdeeJemLetKv8HZx2AQFypSk34+Edi16BWE fP/WWA1oB0BTB6ODvDSDQVk8j283/1eC1EId/g2utKUdo/PFsRDUp26M4oIoYuQfBDY4 9PQq1Dafa4z5eFUKRCsKGiatj/GjQxqxD2UEg= How do I generate this bit of gas code with nasm? I do have to use nasm. Thanks in advance, Joel --- -- http://wagerlabs.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… .section __IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_ins tructions,5 L_puts$stub: .indirect_symbol _puts hlt ; hlt ; hlt ; hlt ; hlt .subsections_via_symbols This email sent to site_archiver(a)lists.apple.com

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Re: getting ACLs
by Jason Coco 06 Jan '09

06 Jan '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:cc:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-mailer; bh=sEgO3pzZ5lDISAk5jD5Cjn3lQkuXBhD9rfZ57mBz3ww=; b=a45Fx6nYWf8TQpPoX1ZnCVWrUvo5IuCJEeWHdXHed14uNGHmqyeSM5J7KNVyDkFiEk Gn6SpImibsEgR74nUphKNlXGcyg9gwWL4qvyUfOSoy/DXqlepK6TEk9qT6sGDFRFgFtD LRcI0apjPVcWwqVbOyYrxcyDmIiyg9Cp7Wffs= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=cc:message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-mailer; b=ikH4SrAaKk/TpnuRGS7h95ULgF/pBOaEfl+9F3nSEctBzv7jp/ggqZE7I7lp+q71dU lbyJXw6lIY7Wd5X0k3REa1IIqbqD3EQOxQnMFmdmUjQnwzaYwq+H4kd8VShGDVHhmlKF smDfBghhFTkwqmoL5VaFi4h2kHOQmyqyON2to= On Jan 5, 2009, at 10:45 , John Michael Zorko wrote: Hello, all ... HTH, Jason _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… I'm exploring the acl_* POSIX APIs on Leopard (and assuming the same code will work on TIger, please correct me if i'm wrong), and so far, all I get from acl_get_file() is error 22, "invalid argument". Here's my (very short) test, can someone tell me what i'm doing wrong? Two quick things about this... first of all, the only ACL_TYPE that is supported is ACL_TYPE_EXTENDED, so you have to use that on darwin. Second, just be aware that if there are no ACL entries actually on a file, you're going to get ENOENT returned, which can be quite misleading as the file actually does exist but simply doesn't have an ACL record associated with it :) I would suggest using acl_get_fd(3) instead. This way, you will know if a file doesn't exist because the call to open(2) will fail, so if acl_get_fd(3) fails and errno is ENOENT then you know that it just doesn't have any ACL record associated with it. Also, acl_get_fd(3) doesn't take an acl_type_t so it's less confusing, the only parameter is the file descriptor. This email sent to site_archiver(a)lists.apple.com

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