April 2008 - Darwin-dev - lists.apple.com

Re: crash when throwing exception
by Boyd Waters 22 Apr '08

22 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com I suppose I should begin trimming until I reach something resembling a minimal test case. I just wanted to probe if this sounded familiar to anyone. Otherwise I will begin building the test case when I find the time. Oh boy, I feel your pain! I suspect DTrace could help... I'm getting a stack trace in real-time... _______________________________________________ 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 Apr 22, 2008, at 2:20 AM, Daniel Oberhoff wrote: Both the problem - crash in stack-unwinding code - and the prospect of creating a vetted test case. Been there. I just used /Developer/Applications/Instruments, a CPU Sampler temlate, then attached to the running process. This email sent to site_archiver(a)lists.apple.com

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mach-o digital signature segment? (was: Re: mach-o section question)
by Army Research Lab 22 Apr '08

22 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: Acikcgu5SnGXEhBlEd20BQAdT0T19A== Thread-topic: mach-o digital signature segment? (was: Re: mach-o section question) User-agent: Microsoft-Entourage/11.4.0.080122 A good point, I'll keep it in mind, although I think I'd like to test both ways. I just had a sudden, sideways thought; mach-o allows us to define new segments, right? Can we put pure data into a segment? SHA-1, MD5, etc. got me to thinking about putting in a segment that contains the digital signature of the rest of the mach-o data. Is that possible? More importantly, for signed mach-o files, can the loader be set up to check the signature prior to running the program, each time? That might help cut down on viruses, etc (which are not a problem on the mac yet, but I like to think ahead, to prevent small problems from becoming big problems) As for programs that aren't yet signed, the loader could ask the user if they want to run the program, and if the user says yes, then the loader could add a new segment that signs the mach-o file with the user's personal key. From then on, unless the program was modified, the user would not be bothered. Other programs (e.g., system libraries, etc.) would ship with signatures, and the certs for those signatures would be installed in the System keychain (or whatever is the Darwin equivalent). Also, I know there is the whole key management problem, etc. I'm not concerned with that here; I'm only asking, is it possible to embed the signature in the mach-o file? Thanks, Cem Karan On 4/21/08 5:07 PM, "Dan Markarian" <markarian(a)apple.com> wrote: > Hey Cem, > > I am not sure whether the Mach-O format requires it, but I suggest you > stick to the UUID standard documented in RFC 4122. > > http://en.wikipedia.org/wiki/UUID > http://www.ietf.org/rfc/rfc4122.txt > > uuid_generate() follows the standard. You can certainly create a UUID > out of some other namespace, per section 4.3, for which I have > provided some sample code below. > > void > uuid_generate_name(const uint8_t *name, uint32_t namelen, const uuid_t > namespc, uuid_t out) > { > SHA1_CTX c; > uint8_t md[SHA_DIGEST_LENGTH]; > > SHA1Init(&c); > SHA1Update(&c, namespc, sizeof(uuid_t)); > SHA1Update(&c, name, namelen); > SHA1Final(md, &c); > > uuid_copy(out, md); > > out[6] = (out[6] & 0x0F) | 0x50; > out[8] = (out[8] & 0x3F) | 0x80; > } > > Dan > > On 21 Apr 2008, at 4:33 PM, Army Research Lab wrote: > >> On 4/21/08 2:34 PM, "Andrew Myrick" <amyrick(a)apple.com> wrote: >> >>> I'm just not familiar enough with how UUIDs are used to be of much >>> help on this. My guess is it doesn't matter too much, as long as you >>> aren't trying to load the same binary with different UUIDs. For >>> example, in kext land, presume you have 2 kexts, A and B, where B >>> depends on A. In the following scenario: >>> >>> 1) Load kext A >>> 2) Change kext A on disk >>> 3) Load kext B >>> >>> the load will fail because we'll detect the UUID change and flag an >>> error. I would expect that userspace has some similar mechanism, >>> though probably much more complex :) >> >> OK, so would it be better to use the MD5 hash for the UUID? Its not >> perfect >> (collisions can happen), but it will detect the code has changed... _______________________________________________ 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… This email sent to site_archiver(a)lists.apple.com

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Re: crash when throwing exception
by Daniel Oberhoff 22 Apr '08

22 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Organization: Fraunhofer - FIT On Tue, 2008-04-22 at 12:18 +0530, JanakiRam wrote: > yes. > > > If you can provide the code , snippet we will get clear picture of > your problem & we can also help you out. > > Hmm, that is not straightforward. As I have mentioned before, this problem seems to only occur when an application reaches a certain level of complexity, so the "snippet" atm would be the whole app, which is a) quite large and b) not cleaned up in terms of licensing. I suppose I should begin trimming until I reach something resembling a minimal test case. I just wanted to probe if this sounded familiar to anyone. Otherwise I will begin building the test case when I find the time. Best Daniel > JanakiRam. > > On Tue, Apr 22, 2008 at 12:19 PM, Daniel Oberhoff > <daniel.oberhoff(a)fit.fraunhofer.de> wrote: > Hi, > > On Tue, 2008-04-22 at 12:02 +0530, JanakiRam wrote: > > Are you writing a kernel extension in Mac OS X ? > > > > > > Are you getting Kernel Panic or application Crash. > > > > > No, it is a regular application using c++, but it has gotten > relatively > complex. I get regular crashes, i.e. "null-pointer" signals > (invalid > access to 0x0) whenever an exception is thrown, and it seems > to happen > in the stack unwinding code (I posted a stack trace in a > nother > message). What is especially annoying: the stackframe throwing > the > exception is lost, along with the type and message of the > exception (and > the possibilty to snoop around the source of the error). > > So is this list just for kernel extensions and the like? Which > list > would be appropriate for my problem? Or should I file a bug > with this? > > > > -- > --- > Daniel Oberhoff > Fraunhofer FIT > Schloss Birlinghoven > 53754 Sankt Augustin, Germany > Tel.: +49-(0)-2241-14-3486 > Fax.:+49 (0) 2241/14-2080 > > > -- --- Daniel Oberhoff Fraunhofer FIT Schloss Birlinghoven 53754 Sankt Augustin, Germany Tel.: +49-(0)-2241-14-3486 Fax.:+49 (0) 2241/14-2080 _______________________________________________ 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… This email sent to site_archiver(a)lists.apple.com

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Re: crash when throwing exception
by Daniel Oberhoff 22 Apr '08

22 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Organization: Fraunhofer - FIT Hi, On Tue, 2008-04-22 at 12:02 +0530, JanakiRam wrote: > Are you writing a kernel extension in Mac OS X ? > > > Are you getting Kernel Panic or application Crash. > No, it is a regular application using c++, but it has gotten relatively complex. I get regular crashes, i.e. "null-pointer" signals (invalid access to 0x0) whenever an exception is thrown, and it seems to happen in the stack unwinding code (I posted a stack trace in a nother message). What is especially annoying: the stackframe throwing the exception is lost, along with the type and message of the exception (and the possibilty to snoop around the source of the error). So is this list just for kernel extensions and the like? Which list would be appropriate for my problem? Or should I file a bug with this? > -- --- Daniel Oberhoff Fraunhofer FIT Schloss Birlinghoven 53754 Sankt Augustin, Germany Tel.: +49-(0)-2241-14-3486 Fax.:+49 (0) 2241/14-2080 _______________________________________________ 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… This email sent to site_archiver(a)lists.apple.com

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Re: crash when throwing exception
by JanakiRam 22 Apr '08

22 Apr '08

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:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; bh=Yr/1IKrKtjvMXD7In1Q4+xFra1m/1VuY0dIQGZIpvgA=; b=d6N9NELDYLAy11Az3z16NXJw5ENlIzmFXTJn8UO1HfakcntUJtgkI2ZKskZPui+wtoXDx/scQ7NiDs+EKbWHmEoE+xN3KF/UrMrNmYmymx4FEk1RfxCquVN17qDWHCmgS+FGuwrZvHoqx74GbvHHozl/g0hRQ5sX5sQLLPLTwTE= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=pMBCsd0GR/GKOWHZd8Wd0rASv3NminhpBbluhZcTNWXNP+Jch7kOC5goVZxmwEAO+Dq9bspKdumQD5jvJSjsP8ZaxGiCV3JL2g/UTROgbLwgKQfCwHW22e1Q8kH7ZU/lnQywvP8o/vf0nTQrPP2mWsFOsLQTRehCXOt4SmUZV0s= _______________________________________________ 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… This email sent to site_archiver(a)lists.apple.com

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Re: crash when throwing exception
by JanakiRam 22 Apr '08

22 Apr '08

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:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; bh=i+EttrZZiXynl9T+bnzurKBO1CFNkQ4hC/NyodH/17M=; b=qveDmtrnX0iS9GGy9oH/gOlj5ptvn9vargkqPfy3ovcio2wWKgeV1KWQa6L/izIp9MrF9lhDedxOw1lF5gL4C+9uF76u175MpT5qKjGyb78Q/bi8oRPmGC0aOV148WkRsO/ZfjlubeQ10sJUUvbloEJY5zC1gnS1rqzbkPG7Cho= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=uFYpxkDcPwBj0+X+xGcrd8MN7Qv/naZviQVeFFeb2dX9L3G7hS6jD+hceZ2tozgEbc3i7ripF5/RBskLBE13mG0Z5Ntw3yEENiz6z5rFSZw0A2YBRERbQUBqYEFdTYiIJBXNP4SOy/i+L++nmDfTYiQgyyBgpDz3f39h9gJNSgg= _______________________________________________ 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… This email sent to site_archiver(a)lists.apple.com

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Re: kevent and disk eject
by Philip Aker 21 Apr '08

21 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 08-04-21, at 14:35, Chris Sarcone wrote: Thanks Chris, Philip Aker echo astwta@lvpc.dslh@nl | tr a-z@. p-za-o.@ Sent from my SE/30 _______________________________________________ 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… Since my post, I've also found that tracking /Volumes in a kevent entry is a workable substitute for my needs, so problem solved. Tracking /Volumes will not work if a network share or some other disk is mounted somewhere other than /Volumes. It would be best to use the DiskArbitration API to make sure you see all the mounts out there, regardless of where they are mounted. I will probably end up using DA. For this helper app, clients will only be mounting in /Volumes, so it seemed viable when I didn't know about the DiskArbitration utilities. This email sent to site_archiver(a)lists.apple.com

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Re: mach-o section question
by Jason Molenda 21 Apr '08

21 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Cem, On Apr 21, 2008, at 5:35 AM, Army Research Lab wrote: J _______________________________________________ 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… 5) The uuid_command referenced on page 20 uses a 128 bit UUID; is this expected to be the output of uuid_generate(), or will any 128 bit UUID generator work (in short, is there hidden info in the UUID that I need to keep straight)? The uuid_generate family of functions is fine. The content of the LC_UUID load command is primarily intended to tie an executable binary to its matching debug info dSYM bundle unambiguously. Computing some digest of the binary, like an MD5, is also fine. Using an MD5 will add time to your file generation but it does mean that two binaries with the same contents will have the same LC_UUID which may be helpful depending on your build environment. An example of how this can be useful: A Spotlight importer is included in Leopard which indexes the LC_UUIDs of all the dSYMs in its search space. When you run the debugger on an executable, it can do a Spotlight query to find the matching dSYM bundle debug info automatically. This email sent to site_archiver(a)lists.apple.com

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Re: kevent and disk eject
by Chris Sarcone 21 Apr '08

21 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.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… This email sent to site_archiver(a)lists.apple.com

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Re: kevent and disk eject
by Philip Aker 21 Apr '08

21 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 08-04-21, at 12:44, Garth Cummings wrote: Thanks Garth, Cheers, Philip Aker echo astwta@lvpc.dslh@nl | tr a-z@. p-za-o.@ Sent from my SE/30 _______________________________________________ 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 know I can use volume events in Carbon for disk insertion and eject but had hoped to keep things at the same level and eventually move this background app down to a CFRunLoop tool. DiskArbitration is the way to handle disk events at the CoreServices or UNIX layers. It's somewhat light in the documentation department but the headers in DiskArbitration.framework should get you going. The framework is also open source. The DiskArbitration.framework headers are very tastefully done. It looks like one can get by just from the info in them. Since my post, I've also found that tracking /Volumes in a kevent entry is a workable substitute for my needs, so problem solved. This email sent to site_archiver(a)lists.apple.com

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