August 2016 - Darwin-dev - lists.apple.com

Re: Unit testing kexts
by Andrew Keller 25 Aug '16

25 Aug '16

Am 25.08.2016 um 12:35 nachm. schrieb Alastair Houghton <alastair(a)alastairs-place.net>: > > What I’d try to do is to isolate all of the kernel or userland specific bits of code somehow, such that your code doesn’t actually need lots of #ifdef UNIT_TEST blocks everywhere. I think a good way to go about this would be to put the code you think you want to test into a static library, with separate targets for your unit tests and the KEXT itself, both of which link to the static library. Then put any userland/kernel-specific stuff in source files specific to those other targets. Interesting — Good to know, then. I’ll focus my time on that approach. Thanks, - Andrew Keller _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: Unit testing kexts
by Alastair Houghton 25 Aug '16

25 Aug '16

On 25 Aug 2016, at 15:29, Andrew Keller <andrew(a)kellerfarm.com> wrote: > > For a while now, we’ve been unit testing individual pieces of our kernel extension by cross-compiling them as a standard user-space application and performing our tests there. Over time, as we have increased our code coverage of the unit tests, we’re noticing a pretty strong upward trend of the number of compiler conditionals required to support cross-compiling between a kext and a user-space app. For example: > > #ifdef UNIT_TEST > #include <stdio.h> // for snprintf > #else > #include <libkern/libkern.h> // for snprintf > #endif > > and > > #ifdef UNIT_TEST > str = (char*) malloc(sz); > #else > str = (char*) OSMalloc(sz, gOSMallocTag); > #endif > > (There are some more ugly examples, but I’m betting you can imagine how bad it can get at times) The latter one would be MUCH better written as e.g. #ifdef UNIT_TEST #define OSMalloc(sz,t) malloc(sz) #endif in a header somewhere. > Suffice it to say, we’re wondering if there’s a better way. Ideally, we would like to unit test the code that’s actually running in production. These compiler-level conditionals force us to essentially maintain two versions of our code. Worse than that, the unit tested version is not the production version. It depends what your KEXT does, but I think unit testing the code *outside* kernel mode is a good idea. Unit testing *in* kernel mode sounds like a bad plan - what if your unit test crashes? Do you really want the machine to panic?! What I’d try to do is to isolate all of the kernel or userland specific bits of code somehow, such that your code doesn’t actually need lots of #ifdef UNIT_TEST blocks everywhere. I think a good way to go about this would be to put the code you think you want to test into a static library, with separate targets for your unit tests and the KEXT itself, both of which link to the static library. Then put any userland/kernel-specific stuff in source files specific to those other targets. If you do things this way, then for example you might end up with a source file in your userland code that does this: #include <stdlib.h> void *our_malloc(size_t sz) { return malloc(sz); } while in your kernel code you’d have another one like this: #include <libkern/libkern.h> void *our_malloc(size_t sz) { return OSMalloc(sz, gOSMallocTag); } then from the rest of the program, don’t call malloc() or OSMalloc(), but instead call our_malloc(). (Equally, you could do something similar with #defines in a header file, but you get the idea.) Kind regards, Alastair. -- http://alastairs-place.net _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Unit testing kexts
by Andrew Keller 25 Aug '16

25 Aug '16

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Re: XPC, anonymous listener and endpoint: is it working?
by Stephane Sudre 21 Aug '16

21 Aug '16

Finally found the obvious issue in my code. The delegate of the listener was not set. So not setting the delegate could be added to the "Common Mistakes" chapter of the https://www.objc.io/issues/14-mac/xpc/ article. On Sun, Aug 21, 2016 at 11:21 AM, Stephane Sudre <dev.iceberg(a)gmail.com> wrote: > I'm trying to implement the type of architecture described in the > chapter "Anonymous Listeners and Endpoints" of > https://www.objc.io/issues/14-mac/xpc/ . > > Problem: > -------- > > I'm facing a problem with the endpoint of the anonymous listener. > Everything seems to work fine but calling a method of the remote proxy > object using the provided endpoint of the anonymous listener does not > work. > > I've simplified the architecture to be able to find where the problem > is but without any success: > > 1. Process A has a listener running using a mach service name. This works. > > 2. Process B connects to the mach service name and provides the > endpoint of an anonymous listener to process A. This works. > > 3. Process A creates a connection to the anonymous listener using the > provided endpoint. This works. > > 4. Process A gets a remote proxy object for the connection to B. This works. > > 5. Process A sends a message to the remote proxy object. Nothing happens. > > > I haven't found any useful piece of info on the developer forums (and > I can't post on it). > > I've checked the obvious stuff (the listeners and connections are > resumed. There are no invalidation or interruption of the connections, > the exported object is not dealloced). > > So the reason why it's not working is a mistery so far. I could still > be missing something obvious but I haven't seen it when running the > code step by step. > > > OS X 10.10.5 > > > Question: > --------- > > - Are anonymous listener working? I haven't found a single sample code > on Apple website or elsewhere. > > - Would there be some debug flags or hidden (global) defaults that > would provide more debugging info about XPC communications (or lack > thereof) -- Packaging Resources - http://s.sudre.free.fr/Packaging.html _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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XPC, anonymous listener and endpoint: is it working?
by Stephane Sudre 21 Aug '16

21 Aug '16

I'm trying to implement the type of architecture described in the chapter "Anonymous Listeners and Endpoints" of https://www.objc.io/issues/14-mac/xpc/ . Problem: -------- I'm facing a problem with the endpoint of the anonymous listener. Everything seems to work fine but calling a method of the remote proxy object using the provided endpoint of the anonymous listener does not work. I've simplified the architecture to be able to find where the problem is but without any success: 1. Process A has a listener running using a mach service name. This works. 2. Process B connects to the mach service name and provides the endpoint of an anonymous listener to process A. This works. 3. Process A creates a connection to the anonymous listener using the provided endpoint. This works. 4. Process A gets a remote proxy object for the connection to B. This works. 5. Process A sends a message to the remote proxy object. Nothing happens. I haven't found any useful piece of info on the developer forums (and I can't post on it). I've checked the obvious stuff (the listeners and connections are resumed. There are no invalidation or interruption of the connections, the exported object is not dealloced). So the reason why it's not working is a mistery so far. I could still be missing something obvious but I haven't seen it when running the code step by step. OS X 10.10.5 Question: --------- - Are anonymous listener working? I haven't found a single sample code on Apple website or elsewhere. - Would there be some debug flags or hidden (global) defaults that would provide more debugging info about XPC communications (or lack thereof) _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: XPC, launchd daemon (and NSXPCConnection)
by Stephane Sudre 12 Aug '16

12 Aug '16

Got it to work. The difficulty lied in the LaunchdDaemon .plist file which does not look like the one in the EvenBetterAuthorizationSample sample code. On Fri, Aug 12, 2016 at 5:36 AM, Jeremy Huddleston Sequoia <jeremyhu(a)apple.com> wrote: > >> On Aug 11, 2016, at 14:31, Stephane Sudre <dev.iceberg(a)gmail.com> wrote: >> >> Is there somewhere a sample project that shows how to start a launchd >> daemon using XPC through a Mach Service? > > To start the daemon, just send a message. launchd will start the process when there is a message in the port. There is no different compared to any other MachIPC in this regard. > >> The 2012 WWDC session on XPC does not seem to imply that some voodoo >> code (*) must me implemented to install a listener for a mach service >> name and receive the messages. >> >> >> * like all the launch_data_ stuff you need to do when using a MachPort. >> _______________________________________________ >> 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: >> https://lists.apple.com/mailman/options/darwin-dev/jeremyhu%40apple.com >> >> This email sent to jeremyhu(a)apple.com > -- Packaging Resources - http://s.sudre.free.fr/Packaging.html _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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XPC, launchd daemon (and NSXPCConnection)
by Stephane Sudre 11 Aug '16

11 Aug '16

Is there somewhere a sample project that shows how to start a launchd daemon using XPC through a Mach Service? The 2012 WWDC session on XPC does not seem to imply that some voodoo code (*) must me implemented to install a listener for a mach service name and receive the messages. * like all the launch_data_ stuff you need to do when using a MachPort. _______________________________________________ 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: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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