On Tuesday 09 August 2005 09:31 am, alexander wrote:
> On Tue Aug 9 05, Robert Watson wrote:
> > In general, it is much preferable that applications link against libc to
> > get the system call stubs than that they directly invoke system calls.
> > That way, if compatibility interfaces are introduced, etc, the
> > application will continue to function. For example, there was at one
> > point a migration away from explicit system calls to set certain kernel
> > parameters, such as hostname and domainname, towards using sysctl, with
> > the system calls being marked obsolete. The C library still provides a
> > sethostname() interface, which is actually a wrapper in user space around
> > sysctl(). So invoking the C function provided by libc for a system call
> > will generally be preferred, even if the originating code is assembly.
> >
> > Robert N M Watson
>
> Thx. I'll try that.
>
> Unfortunately I'm experiencing some problems right now. From time to time
> I'm getting a
>
> 'Bus error: 10 (core dumped)'
>
> This however appears randomly. One time I run the app everything works
> fine,the next time it core dumps. Are there any errors in my code?
>
> %define SYSARCH 165 ; syscall sysarch(2)
> %define I386_SET_IOPERM 4 ; i386_set_ioperm(2) number
>
> ioperm_args dd 378h
> dd 3
> dd 1
>
> OpenIO:
> push byte ioperm_args
> push dword I386_SET_IOPERM
> mov eax,SYSARCH
> Call _syscall
> lea esp,[esp+8]
> ret
Just change this to:
push byte ioperm_args ; this might be wrong, you need
; to be pushing a 32-bit pointer
; to the ioperm_args structure, not
; a byte
push dword I386_SET_IOPERM
call sysarch
addl $8,%esp
ret
To use the sysarch() function in libc.
--
John Baldwin <[EMAIL PROTECTED]> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
_______________________________________________
freebsd-hackers@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
