On Fri, Feb 21, 2020 at 11:22:44AM -0800, David Miller wrote:
> From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Date: Fri, 21 Feb 2020 18:59:03 +0000
>
> > Again, a couple of copy_regset_to_user(), but there's an additional
> > twist - GETREGSET of 32bit task on sparc64 will use access_process_vm()
> > when trying to fetch L0..L7/I0..I7 of other task, using copy_from_user()
> > only when the target is equal to current. For sparc32 this is not
> > true - it's always copy_from_user() there, so the values it reports
> > for those registers have nothing to do with the target process. That
> > part smells like a bug; by the time GETREGSET had been introduced
> > sparc32 was not getting much attention, GETREGS worked just fine
> > (not reporting L*/I* anyway) and for coredump it was accessing the
> > caller's memory. Not sure if anyone cares at that point...
>
> That's definitely a bug and sparc64 is doing it correctly.
OK... What does the comment in
case PTRACE_GETREGS64:
ret = copy_regset_to_user(child, view, REGSET_GENERAL,
1 * sizeof(u64),
15 * sizeof(u64),
&pregs->u_regs[0]);
if (!ret) {
/* XXX doesn't handle 'y' register correctly XXX */
ret = copy_regset_to_user(child, view, REGSET_GENERAL,
32 * sizeof(u64),
4 * sizeof(u64),
&pregs->tstate);
}
break;
refer to? The fact that you end up with 0 in pregs->y and Y in pregs->magic?
In that case it's probably too late to do anything about that...
Or is that something different?
