September 2002 - Darwin-kernel

Re: standard library pow function needed from kext
by Justin C. Walker 27 Sep '02

27 Sep '02

On Thursday, September 26, 2002, at 07:50 PM, Andrew Pinski wrote: On Thursday, Sep 26, 2002, at 18:28 US/Pacific, Sean Morrell wrote: Hello, I need to use the "double pow(double, double)" standard math function in a kext. Actually, the code using pow and other floating point operations is compiled into a separate library, which in turn is linked to the kext. The problem is that when loading the kext, I get an unknown symbol error for the pow function. The root cause to this problem appears to be that there is not a static libm on the system. Is this correct? Are there only dynamic versions of the math and other libs? And if so, can a dynamic library be linked to a kext? Is there a linker option to specify code from a dynamic library be pulled into a generated program/kext as would be done with a static library? Any other suggestions? why do you need pow? It is has been said before on this list and on the others you should not use floating point numbers in the kernel. What Andrew said. Plus, forget dynamic linking in the kernel. Everything must be statically linked. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | It's not whether you win or lose... | It's whether *I* win or lose. *--------------------------------------*-------------------------------* _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: standard library pow function needed from kext
by Andrew Pinski 27 Sep '02

27 Sep '02

On Thursday, Sep 26, 2002, at 18:28 US/Pacific, Sean Morrell wrote: Hello, I need to use the "double pow(double, double)" standard math function in a kext. Actually, the code using pow and other floating point operations is compiled into a separate library, which in turn is linked to the kext. The problem is that when loading the kext, I get an unknown symbol error for the pow function. The root cause to this problem appears to be that there is not a static libm on the system. Is this correct? Are there only dynamic versions of the math and other libs? And if so, can a dynamic library be linked to a kext? Is there a linker option to specify code from a dynamic library be pulled into a generated program/kext as would be done with a static library? Any other suggestions? why do you need pow? It is has been said before on this list and on the others you should not use floating point numbers in the kernel. Thanks, Andrew Pinski Thanks, Sean _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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standard library pow function needed from kext
by Sean Morrell 27 Sep '02

27 Sep '02

Hello, I need to use the "double pow(double, double)" standard math function in a kext. Actually, the code using pow and other floating point operations is compiled into a separate library, which in turn is linked to the kext. The problem is that when loading the kext, I get an unknown symbol error for the pow function. The root cause to this problem appears to be that there is not a static libm on the system. Is this correct? Are there only dynamic versions of the math and other libs? And if so, can a dynamic library be linked to a kext? Is there a linker option to specify code from a dynamic library be pulled into a generated program/kext as would be done with a static library? Any other suggestions? Thanks, Sean _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: Missing lock.h and others
by Justin C. Walker 26 Sep '02

26 Sep '02

On Thursday, September 26, 2002, at 03:23 PM, Michael Cashwell wrote: Greetings all, I'm trying to be good and not include userland headers in my NKE. I'd think that was enlightened self-interest (since doing so would likely cause problems in your NKE and the kernel). Is that not a complete setup for doing NKEs? Do I need to download something else, possibly from the Darwin repository)? If so, what (and what tag) would ensure I get files compatible with Apple's released kernels? Roughly speaking, what you need to do is check out the appropriate version of the kernel (project 'xnu', with a tag "Apple-xxxx" matching what your kernel says (uname -a) in the form "xnu-xxxx"). Then use the headers from that kernel. Your best bet is to get the missing headers from there and put them in a convenient place, and reference them with an additional "-I" flag. If you are building for the system you are running on, it's OK to put them in the "proper" place. I've also noted that KNE samples (NKEMgr, SharedIP and TCPLogger) also don't compile due to missing system headers. We're just trying to protect you from shooting yourself in the foot with the half-cocked gun we lent you :-}. You can check the archives for discussions regarding missing headers... Regards, Justin -- /~\ The ASCII Justin C. Walker, Curmudgeon-at-Large \ / Ribbon Campaign X Help cure HTML Email / \ _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Missing lock.h and others
by Michael Cashwell 26 Sep '02

26 Sep '02

Greetings all, I'm trying to be good and not include userland headers in my NKE. In the process I found in Apple's Kernel Programming pdf information about how to do locks correctly in the kernel. It says one should use mutexes and proceeds to describe functions like mutex_alloc(). That all makes sense. Except for one thing. It says these headers should be in <kern/lock.h> or xnu/osfmk/kern/lock.h. But I don't have either of these files and I'm using a standard 10.2.1, it's dev tools installed plus the August update. (I have a <sys/lock.h> but it looks much lower-level than the API described in the PDF.) Is that not a complete setup for doing NKEs? Do I need to download something else, possibly from the Darwin repository)? If so, what (and what tag) would ensure I get files compatible with Apple's released kernels? I've also noted that KNE samples (NKEMgr, SharedIP and TCPLogger) also don't compile due to missing system headers. Thanks, Mike _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: Duplicate symbols in a kext
by Justin C. Walker 24 Sep '02

24 Sep '02

On Tuesday, September 24, 2002, at 10:12 AM, Michael Cashwell wrote: Greetings all, I'm having trouble getting my kext to load. I get these errors: I recognize that they are mangled C++ function names. Does anyone recognize them as coming from a system or runtime library? Is there a tool to unmangle such names? c++filt/c++filt3. If you're using, e.g., BSD code in your extension, be aware that the kernel has prior claim on all names therefrom :-}. You have two choices if this is the case: change your variable/proc names; edit the symbol table (nmedit); or make the names "private extern". OK, that's three choices. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | If you're not confused, | You're not paying attention *--------------------------------------*-------------------------------* _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Duplicate symbols in a kext
by Michael Cashwell 24 Sep '02

24 Sep '02

Greetings all, I'm having trouble getting my kext to load. I get these errors: kld(): multiple definitions of symbol __ZdlPv /mach definition of absolute __ZdlPv (value 0x251f34) /System/Library/Extensions/netShim.kext/Contents/MacOS/netShim definition of __ZdlPv in section (__TEXT,__text) kld(): multiple definitions of symbol __Znwm /mach definition of absolute __Znwm (value 0x251ef4) /System/Library/Extensions/netShim.kext/Contents/MacOS/netShim definition of __Znwm in section (__TEXT,__text) kextload: kld_load_from_memory() failed for module /System/Library/Extensions/netShim.kext/Contents/MacOS/netShim kextload: a link/load error occured for kernel extension netShim.kext I recognize that they are mangled C++ function names. Does anyone recognize them as coming from a system or runtime library? Is there a tool to unmangle such names? Thanks, Mike _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Hotkeys question
by Iván Gómez 24 Sep '02

24 Sep '02

Hi, I have, unless I think, a very simple question. Is it possible to set an hotkey combination o however you'd like to call it so that my app receive the notification that combination have been stroke despite the app is frontmost? For example supose my app is running and my frontmost app is photoshop or the Finder, and I want to register the alt+"up arrow" for my app to change my desktop image. How can I do this?? I have been looking into the help, examples.. even the Space app (space.sourceforge.org) and I have found something similar but the functions it uses don't appear in the docs Thanks in advance. Ivan Gsmez ------> Laf _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: fork/exec performance?
by Jim Magee 23 Sep '02

23 Sep '02

On Monday, September 23, 2002, at 06:16 PM, Bill Huey (Hui) wrote: On Mon, Sep 23, 2002 at 06:06:53PM -0400, Jim Magee wrote: where appropriate appears to be the trick in your case. I don't think Linux has vfork(), so people tend to stick with just fork() in portable code. Linux has vfork(), the behavior is undefined if you modify any process data though. As it is in BSD as well. Sorry to be confusing. I know Linux has the vfork() API, but it isn't emphasized to developers like it is in BSD. Instead, they tend to emphasize their variable-weight forking technology. So people don't have vfork() on their minds as much. --Jim _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: fork/exec performance?
by Bill Huey 23 Sep '02

23 Sep '02

On Mon, Sep 23, 2002 at 06:06:53PM -0400, Jim Magee wrote: > where appropriate appears to be the trick in your case. I don't think > Linux has vfork(), so people tend to stick with just fork() in portable > code. Linux has vfork(), the behavior is undefined if you modify any process data though. bill _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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