IOKit KEXT Questions

Subject: IOKit KEXT Questions

From: Matt Burnett <email@hidden>

Date: Wed, 15 Aug 2007 17:21:08 -0500

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I have 2 questions regarding IOKit KEXTs.

- How does IOMemoryDescriptor deal with memory protection (mprotect/vm_protect)? Is there a class available to check/change the protection of certain pages in memory or should i use mprotect/vm_protect?

- Why do IOKit KEXTs have issues resolving kernel symbols, and what can i do to work around it. For example if i create a KEXT in C, i can lookup the address of any symbol which is in /mach.sym, however I get unresolved symbol errors if i do the same in a IOKit KEXT.

Example HelloIOKit.cpp Code:

...

extern "C" int execve(void *, void *, int *);

...

IOLog("Found execve at %p\n",execve);

...

Example kextload output:

kextload: extension HelloIOKit.kext appears to be valid

kld(): Undefined symbols:

_execve

...

Thanks

-Matt Burnett

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Follow-Ups:

Re: IOKit KEXT Questions
- From: Andre-John Mas <email@hidden>
Re: IOKit KEXT Questions
- From: Terry Lambert <email@hidden>