Re: 2.6.23 regression: accessing invalid mmap'ed memory from gdb causes unkillable spinning

Linus Torvalds
2007-10-31T16:00:45Z

On Wed, 31 Oct 2007, Nick Piggin wrote:
>
> Well the patch is right, in the context of the regression I introduced
> (and so it should probably go into 2.6.23).

Yeah, it probably is fine for -stable.

And if mine (which actually changes behaviour, in that it makes ptrace get
an access error) causes regressions, I guess we'll have to use that
compatible-with-old-behaviour one for 2.6.24 too.

But I just rebooted and tested - the cleaned-up patch does seem to work
fine, and I get "Cannot access memory at address <xyz>" rather than any
reported problem.

So I think I'll commit my version asap, and see if anybody reports that
they have a situation where they use ptrace() and expect zero back from a
shared mapping past the end.. And if there are issues, we can switch back
to the old broken behaviour with your patch,

Linus