Add 2 macros to set and get debugreg on x86_64.  This is useful for Xen
because it will need only to redefine each macro to a hypervisor call.
Signed-off-by: NVincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fixes some !CONFIG_BUG warnings:
include/asm/mmu_context.h: I funktion `switch_mm':
include/asm/mmu_context.h:57: varning: implicit declaration of function `out_of_line_bug'
Signed-off-by: NAlexander Nyberg <alexn@telia.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Exceptions and hardware interrupts can, to a certain degree, nest, so when
attempting to follow the sequence of stacks used in order to dump their
contents this has to be accounted for.  Also, IST stacks have their tops
stored in the TSS, so there's no need to add the stack size to get to their
ends.

Minor changes from AK.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Calling a notifier three times in the debug handler does not make much sense,
because a debugger can figure out the various conditions by itself.  Remove
the additional calls to DIE_DEBUG and DIE_DEBUGSTEP completely.

This matches what i386 does now.

This also makes sure interrupts are always still disabled when calling a
debugger, which prevents:

BUG: using smp_processor_id() in preemptible [00000001] code: tpopf/1470
caller is post_kprobe_handler+0x9/0x70

Call Trace:<ffffffff8024f10f>{smp_processor_id+191} <ffffffff80120e69>{post_kpro
be_handler+9} 
<ffffffff80120f7a>{kprobe_exceptions_notify+58} 
<ffffffff80144fc0>{notifier_call_chain+32} <ffffffff80110daf>{do_debug+335} 
<ffffffff8010f513>{debug+127}  <EOE> 

on preemptible debug kernels with kprobes when single stepping in user space.

This was probably a bug even on non preempt kernels, this function was
supposed to be running with interrupts off according to a comment there.

Note to third part debugger maintainers: please double check your debugger can
still single step.

Cc: <prasanna@in.ibm.com>
Cc: <jbeulich@novell.com>
Cc: <kaos@sgi.com>
Cc: <jim.houston@ccur.com>
Cc: <jfv@bluesong.net>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There were no reports about the previous warning for FPU exceptions in the
kernel, so make it a die() now.

Also improve the error messages slightly.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fixes various issues in the return path for "paranoid"
handlers (= running on a private exception stack that act like NMIs).

Generalize previous hack to switch back to process stack for
scheduling/signal handling purposes.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Ported from i386/Linus

Be more careful with TF handling to fix some copy protection codes in Wine
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I had strange NMI watchdog timeouts running sysrq-T across 9600-baud serial.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!