Re: Regarding select() on PPC

From: Halesh S
Date: Tue Sep 23 2008 - 00:25:38 EST


Halesh S <halesh.sadashiv <at> ap.sony.com> writes:

>
> Andreas Schwab <schwab <at> suse.de> writes:
>
> >
> > Halesh S <halesh.sadashiv <at> ap.sony.com> writes:
> >
> > > What is the purpose of Argument check only for PPC32, is ther any
specific
> > > reason?
> >
> > Probably long obsolete, it predates linux 2.2.0.
>
> Than do you mean by this is not required in later versions.
>
> >
> > Andreas.
> >
>
> Thanks,
> Halesh
>
>


Halesh S <halesh.sadashiv <at> ap.sony.com> writes:

>
> Andreas Schwab <schwab <at> suse.de> writes:
>
> >
> > Halesh S <halesh.sadashiv <at> ap.sony.com> writes:
> >
> > > What is the purpose of Argument check only for PPC32, is ther any
specific
> > > reason?
> >
> > Probably long obsolete, it predates linux 2.2.0.
>
> Than do you mean by this is not required in later versions.
>
> >
> > Andreas.
> >
>
> Thanks,
> Halesh
>
>

Please check this patch be applied for latest linux kernel??

--- arch/powerpc/kernel.old/syscalls.c 2008-09-22 20:47:06.000000000 +0530
+++ arch/powerpc/kernel/syscalls.c 2008-09-23 09:38:31.841327576 +0530
@@ -203,25 +203,13 @@

#ifdef CONFIG_PPC32
/*
- * Due to some executables calling the wrong select we sometimes
- * get wrong args. This determines how the args are being passed
- * (a single ptr to them all args passed) then calls
- * sys_select() with the appropriate args. -- Cort
+ * The argument checking is long obselete, the code was carried from
+ * kernel version 2.2.0, so removing obselete code and directly call
+ * to sys_select()
*/
int
ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user
*exp, struct timeval __user *tvp)
{
- if ( (unsigned long)n >= 4096 )
- {
- unsigned long __user *buffer = (unsigned long __user *)n;
- if (!access_ok(VERIFY_READ, buffer, 5*sizeof(unsigned long))
- || __get_user(n, buffer)
- || __get_user(inp, ((fd_set __user * __user *)(buffer+1)))
- || __get_user(outp, ((fd_set __user * __user *)(buffer+2)))
- || __get_user(exp, ((fd_set __user * __user *)(buffer+3)))
- || __get_user(tvp, ((struct timeval __user * __user *)
(buffer+4))))
- return -EFAULT;
- }
return sys_select(n, inp, outp, exp, tvp);
}
#endif

Tested on PPC32. Works fine with provided testcase.

Thanks,
Halesh

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