Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 6 May 2003 10:01:23 -0700 | From | Jerry Cooperstein <> | Subject | Re: The disappearing sys_call_table export. |
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It's much simpler than that: Do either
nm vmlinux | grep sys_call_table or
grep sys_call_table System.map
extract the address, use the header file to get the syscall number and the offset.
Of course this all breaks the GPL, but you can get any non-exported symbol address that way.
====================================================================== Jerry Cooperstein, Senior Consultant, <coop@axian.com> Axian, Inc., Software Consulting and Training 4800 SW Griffith Dr., Ste. 202, Beaverton, OR 97005 USA http://www.axian.com/ ======================================================================
On Tue, May 06, 2003 at 11:45:41AM +0300, Yoav Weiss wrote: > > But how? When some global will not be exported, it would not be listed > > in /proc/ksyms. > > So what ? > You just find the right address (in this case by getting the addresses of > exported syscalls and finding a list in memory, containing them in the > right order), and cast it to be the syscall table. If you want it to work > with a binary-only driver, you can even insmod a small module that does > that and adds the result to the symbol table for other modules to use. > > We've been doing that for years on closed-source systems like AIX. The > above is just one way to locate a struct in memory. A faster way is to > find some exported structs which are known to point to the unexported > symbol from some offset, extract the symbol's address, and "re-export" it. > > In fact, in linux which is opensource, you can probably write a script > that extracts any unexported symbol from the source code, find a path to > it from some exported symbol, and automagically create a module that > re-exports this symbol for your legacy driver to use. > > If you write the script, don't forget to GPL it :) > > Yoav Weiss > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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