May 2007 - Darwin-dev - lists.apple.com

Fuse
by Andre-John Mas 13 May '07

13 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hi, Andre _______________________________________________ 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… The MacFuse project ( http://code.google.com/p/macfuse/ ) has come a long way to making user-space filesystems accessible to Darwin/MacOS X. Would making MacFuse part of the core Darwin feature set, along with having file systems such as DAV being based on this, be considered an advantage to the system? This email sent to site_archiver(a)lists.apple.com

1 0

Re: dependency checks
by Graham J Lee 12 May '07

12 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 11 May 2007, at 22:50, Dave Zarzycki wrote: #!/bin/sh while [ ! -d /Volumes/NAS ] do sleep 1 done exec /usr/sbin/my_favorite_daemon Dude - wait4path :-) Cheers, Graham. _______________________________________________ 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

1 0

how to get the info like "vmmap"?
by 周章林 12 May '07

12 May '07

site_archiver(a)lists.apple.com Delivered-To: Darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type; b=k5kRPad7jO50BwZ1IGQ6xtmlSpZ7KbRjtA4XT7c9T5pK93/FOgBfys9ibtpIKDhFHeUlIVplovdRsq1VG1pUHLBv9UyAnXZjY7UF5xIBiOCsT5MgBWxbGleLrq8UzofWjlpbskZ+HKw5KsNORHp74VSuGFHf8CSs2H6QPDY3f7I= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:mime-version:content-type; b=i0t8CMPL7g8cK7dzIpUIpormcel7ljFDzIss/oroxh7p91Lja315Sn9giBPB0FWgwagzdWLGXBCuCsweXqT9WG5MjsukShOicUW8zzgwg0NVK61XATg8KssgLvMRS9A2Pb7w/aRe3Ari1DpCCTX+EsWTMZY3prPRgBonGWveakw= _______________________________________________ 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

1 0

Re: dependency checks
by seebs＠seebs.net 11 May '07

11 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com In message <EEB16D29-C90A-4BD3-AF0F-C98393B3AAE4(a)apple.com>, Dave Zarzycki writes: >We've actually discussed this a few times within Apple. We all agree >that it would be a great idea to provide system administrators this >kind of crutch so they can workaround software bugs or design flaws. >Unfortunately, we all have higher priorities for the foreseeable >future. For whatever it may be worth, you can already fake a lot of >this stuff up with a shell script right now. The problem is knowing >what tools to run and how. For example: >#!/bin/sh >while [ ! -d /Volumes/NAS ] >do > sleep 1 >done >exec /usr/sbin/my_favorite_daemon Yup. >I'm sure a semi-smart person could probably use the same trick >outlined above with the 'nc' tool to check for port/host reach-ability. Seems reasonable. It seems to me that a moderately complete program like this would be an afternoon's work, and might be generally useful. I know that, at one point, I had a program somewhat like the above, which had the interesting trait that Finder wouldn't launch until my program terminated. I never did get around to a careful debugging of that one, though. -s _______________________________________________ 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

1 0

Re: dependency checks
by Dave Zarzycki 11 May '07

11 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com #!/bin/sh while [ ! -d /Volumes/NAS ] do sleep 1 done exec /usr/sbin/my_favorite_daemon davez On May 11, 2007, at 2:14 PM, Peter Seebach wrote: Example usage: /usr/local/bin/depends -p 80 run_me_after_apapche /usr/local/bin/depends -d /Volumes/NAS run_me_after_network_mounts Obviously, this program could then be used in launchd jobs. (It would probably want options to distinguish between "wait forever" and "error out if the dependency isn't met") Are there obvious problems that real launchd-based systems face, which cannot be addressed reasonably well by the use of such a program? -s _______________________________________________ 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/zarzycki%40apple.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… We've actually discussed this a few times within Apple. We all agree that it would be a great idea to provide system administrators this kind of crutch so they can workaround software bugs or design flaws. Unfortunately, we all have higher priorities for the foreseeable future. For whatever it may be worth, you can already fake a lot of this stuff up with a shell script right now. The problem is knowing what tools to run and how. For example: I'm sure a semi-smart person could probably use the same trick outlined above with the 'nc' tool to check for port/host reach-ability. So, as we all know, for reasonably sound reasons, launchd does not have any support for dependency checking. And, as many of us know, there are some programs out there that must be run, cannot run without certain dependencies, and cannot be modified. (Whether that's "cannot" as in company policy, or "cannot" as in "we only have binaries" doesn't matter much.) Imagine, if you will, a program that does exactly one thing: Check for one or more requirements, and launch a specified program when they are met. No attempt is made to solve the abstract/general problem of deadlock; rather, this program leaves it to the admin to figure out what the deadlock risks are. This email sent to zarzycki(a)apple.com This email sent to site_archiver(a)lists.apple.com

1 0

dependency checks
by seebs＠seebs.net 11 May '07

11 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com So, as we all know, for reasonably sound reasons, launchd does not have any support for dependency checking. And, as many of us know, there are some programs out there that must be run, cannot run without certain dependencies, and cannot be modified. (Whether that's "cannot" as in company policy, or "cannot" as in "we only have binaries" doesn't matter much.) Imagine, if you will, a program that does exactly one thing: Check for one or more requirements, and launch a specified program when they are met. No attempt is made to solve the abstract/general problem of deadlock; rather, this program leaves it to the admin to figure out what the deadlock risks are. Example usage: /usr/local/bin/depends -p 80 run_me_after_apapche /usr/local/bin/depends -d /Volumes/NAS run_me_after_network_mounts Obviously, this program could then be used in launchd jobs. (It would probably want options to distinguish between "wait forever" and "error out if the dependency isn't met") Are there obvious problems that real launchd-based systems face, which cannot be addressed reasonably well by the use of such a program? -s _______________________________________________ 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

1 0

Re: catching floating point exception on OS X Intel
by Jonas Maebe 11 May '07

11 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 11 mei 2007, at 01:44, Kristoffer Eriksen wrote: Program received signal EXC_ARITHMETIC, Arithmetic exception. 0x00001f2f in main (argc=1, argv=0xbfffe708) at fpasm.c:14 14 x = -1.0/0.0; Jonas _______________________________________________ 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 not using long doubles, so for simplicity I've disabled 387 instruction generation with the -mfpmath=sse compiler switch, and therefore only have to deal with the SSE XMCSR. For clarity's sake: -mfpmath=sse is the default on Mac OS X. If you use long doubles, it will nevertheless still use the 387 because they are not supported by the sse units. It's not a SIGFPE, which is a little puzzling, and I don't know what an EXC_ARITHMETIC, is but it's effective. As Andrew Pinski mentioned, gdb catches the exceptions at the Mach rather than at the Unix level. This is quite annoying, because it cannot step into Unix signal handlers because of this. This has been the case forever afaik, and there is a long standing bug report open about this with Apple (rdar://problem/2818847) This email sent to site_archiver(a)lists.apple.com

1 0

Re: pci config space
by Andrew Gallatin 11 May '07

11 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Andrew Gallatin writes: > > > My suggestion would be to write a simple driver and communicate with > > it. That will free you from the availability of the CHUD API. > > The problem with this is that the only thing I can visualize will work > only on x86 (io port access). I can't seem to figure out a way to get > "random access" to the PCI bus. Eg, I don't see a way specify a > bus/slot/function and access its PCI config space, even in the kernel. FWIW, I wrote a trivial kernel extension to allow in/out{b,w,l}, and our tools are working fine on Intel. Powerpc is still a problem, but since ppc seems to be pretty much dead, I guess I'll have to not worry about it. I would still be interested to know if it is possible somehow to access PCI device classes on a bus/slot/function bases so I could use the iokit IOPCIDevice::configRead functions.. Drew _______________________________________________ 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

1 0

Re: catching floating point exception on OS X Intel
by Andrew Pinski 10 May '07

10 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; 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; b=qoNpxAoGhcV2HcsPM9u452kOspWamjPoQqWuXqcOMzi90gtyPh/OJcovkZcivrmDtVnwbD+1MXTmXnjqsZYLtOM3VFvqxMCsPc8kC+Ar/1TLezX5j5Z3Es7KPunZ79tX2cgEOmwF6UCnJlEd4aPIRanwkLz2dxzVeidQmFyXzNw= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=triHdJwcj+fX8pmwyqZciFWbpOIbzLX/me3smWlLkKYyTOOv38yDGM/KYu92MpG6W5iuKB0eT1aG8XxGbK2s9tcPE628IPlyTN2BLNEh1w2QAVwcaJTbxkICzUK99JAFCYapMJhAX+9wT7G2UzxTyoxo7DfuRny1f8WN01gMzrw= When I run it in gdb I get: Program received signal EXC_ARITHMETIC, Arithmetic exception. 0x00001f2f in main (argc=1, argv=0xbfffe708) at fpasm.c:14 14 x = -1.0/0.0; It's not a SIGFPE, which is a little puzzling, and I don't know what an EXC_ARITHMETIC, is but it's effective. gdb uses mach signals. The mach signals are converted to UNIX signals latter on. Thanks, Andrew Pinski _______________________________________________ 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 5/10/07, Kristoffer Eriksen <keriksen(a)as.arizona.edu> wrote: This email sent to site_archiver(a)lists.apple.com

1 0

Re: catching floating point exception on OS X Intel
by Kristoffer Eriksen 10 May '07

10 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thanks for all your responses. Specific replies below: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <Accelerate/Accelerate.h> #include <xmmintrin.h> int main(int argc, char *argv[]){ double x; _mm_setcsr( _MM_MASK_MASK &~ (_MM_MASK_OVERFLOW|_MM_MASK_INVALID|_MM_MASK_DIV_ZERO) ); x = -1.0/0.0; printf("%f\n",x); exit(0); } When I run it in gdb I get: Program received signal EXC_ARITHMETIC, Arithmetic exception. 0x00001f2f in main (argc=1, argv=0xbfffe708) at fpasm.c:14 14 x = -1.0/0.0; /* This will set the FE_INVALID flag */ x = sqrt(-x); retval = fetestexcept(FE_ALL_EXCEPT); if (retval != 0) raise(SIGFPE); thanks, Kris _______________________________________________ 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… Jonas (thank you!) posted some code involving assembly instructions to directly change the control words for both the 387 FPU and SSE. I think this is generally the right way to go, though I think I've found a more concise solution. I'm not using long doubles, so for simplicity I've disabled 387 instruction generation with the - mfpmath=sse compiler switch, and therefore only have to deal with the SSE XMCSR. There are library functions in the Accelerate framework to deal with SSE intrinsics. The following code crashes before the print statement, and gives a floating exception, which is the desired behavior: Similarly, if I try something like sqrt(-1.0), that crashes as well. (good!) It's not a SIGFPE, which is a little puzzling, and I don't know what an EXC_ARITHMETIC, is but it's effective. Thanks also to Axel for explaining why the example code from my original post didn't crash and suggested something like: I'm doing a ton of floating point operations, so it's not practical for me check the feflags after each operation. I went back through the Mac OS X Numerics guide that Axel referred me to, and was puzzled by this paragraph: "By enabling (setting) bits in the Floating Point Status and Control Register (FPSCR), the application can cause the PowerPC microprocessor to generate hardware interupt signals when a floating- point exception occurs. These bits are set through the use of the fesetenvd [sic] call. The Mac OS X will deliver that interrupt to your application by raising the UNIX signal SIGFPE" So clearly there is at least supposed to be an interface above the assembly instructions to convince the OS to generate a SIGFPE on a fp exception. At least there was for PPC. In the PPC fenv.h the fenv_t type is just an unsigned int, so it's easy to do the right bitwise OR and pass fesetenv() the correct flags. However, on i386, fenv_t is a struct (i.e. it can't be OR'd), and OR'ing the apparently appropriate struct member has no effect. It seems like fenv.h is missing a necessary macro or the like to manipulate the floating point environment. To make a very long story short, thanks to the help here I found a solution to my problem, I think. However, some examples from Apple on how to generate SIGFPE's on floating exception traps would be most appreciated. This email sent to site_archiver(a)lists.apple.com

1 0