On Thu, Jan 12, 2012 at 11:23 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > On 01/12, Will Drewry wrote: >> >> On Thu, Jan 12, 2012 at 10:22 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: >> >> + */ >> >> + regs = seccomp_get_regs(regs_tmp, ®s_size); >> > >> > Stupid question. I am sure you know what are you doing ;) and I know >> > nothing about !x86 arches. >> > >> > But could you explain why it is designed to use user_regs_struct ? >> > Why we can't simply use task_pt_regs() and avoid the (costly) regsets? >> >> So on x86 32, it would work since user_regs_struct == task_pt_regs >> (iirc), but on x86-64 >> and others, that's not true. > > Yes sure, I meant that userpace should use pt_regs too. > >> If it would be appropriate to expose pt_regs to userspace, then I'd >> happily do so :) > > Ah, so that was the reason. But it is already exported? At least I see > the "#ifndef __KERNEL__" definition in arch/x86/include/asm/ptrace.h. > > Once again, I am not arguing, just trying to understand. And I do not > know if this definition is part of abi. I don't either :/ My original idea was to operate on task_pt_regs(current), but I noticed that PTRACE_GETREGS/SETREGS only uses the user_regs_struct. So I went that route. I'd love for pt_regs to be fair game to cut down on the copying! will -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
