linux/include
Oleg Nesterov 43918f2bf4 signals: remove 'handler' parameter to tracehook functions
Container-init must behave like global-init to processes within the
container and hence it must be immune to unhandled fatal signals from
within the container (i.e SIG_DFL signals that terminate the process).

But the same container-init must behave like a normal process to processes
in ancestor namespaces and so if it receives the same fatal signal from a
process in ancestor namespace, the signal must be processed.

Implementing these semantics requires that send_signal() determine pid
namespace of the sender but since signals can originate from workqueues/
interrupt-handlers, determining pid namespace of sender may not always be
possible or safe.

This patchset implements the design/simplified semantics suggested by
Oleg Nesterov.  The simplified semantics for container-init are:

	- container-init must never be terminated by a signal from a
	  descendant process.

	- container-init must never be immune to SIGKILL from an ancestor
	  namespace (so a process in parent namespace must always be able
	  to terminate a descendant container).

	- container-init may be immune to unhandled fatal signals (like
	  SIGUSR1) even if they are from ancestor namespace. SIGKILL/SIGSTOP
	  are the only reliable signals to a container-init from ancestor
	  namespace.

This patch:

Based on an earlier patch submitted by Oleg Nesterov and comments from
Roland McGrath (http://lkml.org/lkml/2008/11/19/258).

The handler parameter is currently unused in the tracehook functions.
Besides, the tracehook functions are called with siglock held, so the
functions can check the handler if they later need to.

Removing the parameter simiplifies changes to sig_ignored() in a follow-on
patch.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
..
acpi acpi/x86: introduce __apci_map_table, v4 2009-02-09 13:35:07 +01:00
asm-arm S3C24XX: Move and update IIS headers 2009-03-05 12:00:59 +00:00
asm-frv mm: use debug_kmap_atomic 2009-04-01 08:59:14 -07:00
asm-generic gpiolib: allow GPIOs to be named 2009-04-02 19:04:51 -07:00
asm-h8300
asm-m32r Merge branch 'header-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-26 16:11:41 -07:00
asm-mn10300 mm: use debug_kmap_atomic 2009-04-01 08:59:14 -07:00
crypto crypto: zlib - New zlib crypto module, using pcomp 2009-03-04 15:16:19 +08:00
drm drm: detect hdmi monitor by hdmi identifier (v3) 2009-03-29 18:31:49 +10:00
keys
linux signals: remove 'handler' parameter to tracehook functions 2009-04-02 19:04:58 -07:00
math-emu
media V4L/DVB (11313): v4l2-subdev: add enum_framesizes and enum_frameintervals. 2009-03-30 12:43:49 -03:00
mtd make MTD headers use strict integer types 2009-03-26 18:14:17 +01:00
net netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections 2009-03-28 15:01:37 +11:00
pcmcia
rdma Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-03-26 15:54:36 -07:00
rxrpc
scsi [SCSI] iscsi class: remove host no argument from session creation callout 2009-03-13 15:29:39 -05:00
sound V4L/DVB (10771): tea575x-tuner: convert it to V4L2 API 2009-03-30 12:43:02 -03:00
trace net: Add dependent headers to trace/skb.h 2009-03-24 14:24:10 -07:00
video fbdev: update s1d13xxxfb to differ between revisions and production ids 2009-04-01 08:59:32 -07:00
xen
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