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From: Arnd Bergmann <arnd@arndb.de>
To: =?iso-8859-1?q?Am=E9rico_Wang?= <xiyou.wangcong@gmail.com>
Subject: Re: interpreting semantics of ipc system call
Date: Thu, 30 Sep 2010 13:37:55 +0200
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On Thursday 30 September 2010, Américo Wang wrote:
> On Wed, Sep 29, 2010 at 03:03:11PM -0700, Andreas Saebjoernsen wrote:
> >We are developing a simulator that can simulate any specimen x86 linux program.
> >Our simulator has a simulated memory, unlike the concrete memory state of
> >tools like Valgrind, so that we can do concrete symbolic execution. Instead of
> >reimplementing the system calls we marshal the system calls called by
> >the specimen.
> >
> >I am currently working on marshaling calls to the ipc system call (system
> >call 117) which has the following signature
> >
> >int ipc(unsigned int call, int first, int second, int third, void
> >*ptr, long fifth)
> >
> >I have a problem interpreting what the size is of the data structure
> >pointed to by
> >the 'void*', and I have been unable to locate good documentation or code on the
> >semantics of this system call.
> 
> 
> Take a look at ipc/syscall.c, that pointer will be interpreted to different
> data structures when you pass different arguments to 'call'.

Right. Note that you can ignore the version field for all practical
purposes and consider it constant.

	Arnd