[Devel] Re: utrace regressions (was: -mm merge plans for 2.6.21)

[Alexey Dobriyan]

On Sat, Feb 17, 2007 at 06:35:31PM -0800, Roland McGrath wrote:
> > Looking at mainline x86_64 ptrace code I think hole for u_debugreg[4]
> > and [5] is also needed.
>
> It's not.  The utrace_regset for the debugregs already has that behavior
> for those two words, so mapping all 8 uarea words to the regset is fine.

Sorry, I don't get it. Choosing segment from x86_64_uarea is done before
calling regset->set and regset->get as well as before zero-filling. No
segment for u_debugreg[4] and [5] means -EIO before segment handlers
will have a chance to be called.

Do you want to consolidate these two?

    {offsetof(struct user, u_debugreg[0]), offsetof(struct user, u_debugreg[4]), 3, 0},
    {offsetof(struct user, u_debugreg[6]), offsetof(struct user, u_debugreg[8]), 3, 6 * sizeof(long)},