On Fri, Feb 24, 2012 at 10:43:25PM +0000, Russell King - ARM Linux wrote:

On Fri, Feb 24, 2012 at 10:12:06PM +0000, Catalin Marinas wrote:

quoted

Just to reply to Russell - yes, this part needs changing (could be the
pt_regs saving or just the signal and trace code that copies them to
user so that we preserve the ABI).

It's more than just that.  What about the various exception handling
code which needs to look up registers by numerical index?  That
encompasses kprobes, alignment fixup, swp emulation, fp exception
fixup, and so forth.

Some of these don't apply to the M profile, like swp emulation (Thumb-2
only core). Anyway, it's not difficult to get the pt_regs structure back
to the standard layout.

Catalin