Re: maps2-add-proc-pid-pagemap-interface.patch

[Rusty Russell <rusty@rustcorp.com.au>]

On Mon, 2007-07-09 at 17:31 -0500, Matt Mackall wrote:
> > And how about "cpu_to_le16(1) == 1" instead of "ntohl(1) != 1"?
> 
> Why?

Using a networking macro to detect endianness is old school: we have the
nice explicit macros these days...

> > > +	while (pm.count > 0 && vma) {
> > > +		if (!ptrace_may_attach(task)) {
> > > +			ret = -EIO;
> > > +			goto out_mm;
> > > +		}
> > 
> > You already checked ptrace_may_attach() earlier in this function; do you
> > need to do that again?
> 
> I think so. Consider exec(). This whole area is full of interesting
> traps and it pays to be paranoid.

I don't think normal ptraces get cut on exec, so I'm not sure why this
should be different.  You could argue it would be more correct to check
at the open, in fact.

Cheers,
Rusty.