On Tuesday 05 July 2011, Jonas Bonn wrote: > I've been looking a bit at the ptrace stuff the last couple of days. > One question that occurred to me was: is it mandatory to export the > "struct pt_regs" info in ptrace.h to userspace? I don't know, it certainly has been the case traditionally, but as far as I can tell, this was mainly used by ancient gdb ports, while newer versions just hardcode the offsets for PTRACE_PEEKUSR. > I'm not sure I like the layout of our struct pt_regs. It would be > better to lay out the registers in a way that mirrors the order that > they are saved during exception/syscall entry in order to make better > use of the cache. > > Since the registers can be exported via a regset to userspace anyway > (which doesn't necessarily need to look like pt_regs), I don't see that > userspace really needs how we lay out the registers on the stack. By > not exporting pt_regs, I am free to change the layout... if it's > exported, it becomes ABI. Yes. I think you can just change your ptrace code to not export pt_regs through PEEKUSR but only through elf_gregset_t, which you can define independently. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
