[PATCH] timekeeping: Prevent oops when GENERIC_TIME=n

Aaro Koskinen reported an issue in kernel.org bugzilla #15366, where
on non-GENERIC_TIME systems, accessing
/sys/devices/system/clocksource/clocksource0/current_clocksource
results in an oops.

It seems the timekeeper/clocksource rework missed initializing the
curr_clocksource value in the !GENERIC_TIME case.

Thanks to Aaro for reporting and diagnosing the issue as well as
testing the fix!

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
LKML-Reference: <1267475683.4216.61.camel@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Charles Wang <muming.wq@taobao.com>
[PATCH] xen: annotate functions which only call into __init at start

 of day

commit 44b46c3ef805793ab3a7730dc71c72d0f258ea8e (upstream)

Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be
called at resume time as well as at start of day but only reference
__init functions (extend_brk) at start of day. Hence annotate with
__ref.

    WARNING: arch/x86/built-in.o(.text+0x4f1): Section mismatch in reference
        from the function xen_hvm_init_shared_info() to the function
        .init.text:extend_brk()
    The function xen_hvm_init_shared_info() references
    the function __init extend_brk().
    This is often because xen_hvm_init_shared_info lacks a __init
    annotation or the annotation of extend_brk is wrong.

xen_hvm_init_shared_info calls extend_brk() iff !shared_info_page and
initialises shared_info_page with the result. This happens at start of
day only.

    WARNING: arch/x86/built-in.o(.text+0x599b): Section mismatch in reference
        from the function xen_build_mfn_list_list() to the function
        .init.text:extend_brk()
    The function xen_build_mfn_list_list() references
    the function __init extend_brk().
    This is often because xen_build_mfn_list_list lacks a __init
    annotation or the annotation of extend_brk is wrong.

(this warning occurs multiple times)

xen_build_mfn_list_list only calls extend_brk() at boot time, while
building the initial mfn list list

====
Note by Charles: 
	1. Only picked xen_build_mfn_list_list fix
	2. xen_build_mfn_list_list in our kernel is in
	   arch/x86/xen/mmu.c

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Charles Wang <muming.wq@taobao.com>
[PATCH] Revert xen handle events as edge triggered

This patch causes terminal console hanging, no respose to
keyboard. From Xen Serial console an inter-domain event channel 
with evtchn_pending and evtchn_mask masked stays always.

Revert patch xen-handle-events-as-edge-triggered.patch

 commit 487842268b22272f3388cb5a3c992cc4d3839f05

can fix this.

Signed-off-by: Charles Wang <muming.wq@taobao.com>