linux/kernel
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
..
irq PM: Introduce functions for suspending and resuming device interrupts 2009-03-30 21:46:54 +02:00
power pm: rework includes, remove arch ifdefs 2009-04-01 08:59:16 -07:00
time Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-26 16:05:42 -07:00
trace Merge commit 'origin/master' into next 2009-03-11 17:10:07 +11:00
.gitignore
acct.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
async.c async: remove the temporary (2.6.29) "async is off by default" code 2009-03-28 13:05:30 -07:00
audit_tree.c audit: validate comparison operations, store them in sane form 2009-01-04 15:14:42 -05:00
audit.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
audit.h fixing audit rule ordering mess, part 1 2009-01-04 15:14:41 -05:00
auditfilter.c audit: validate comparison operations, store them in sane form 2009-01-04 15:14:42 -05:00
auditsc.c make sure that filterkey of task,always rules is reported 2009-01-04 15:14:42 -05:00
backtracetest.c
bounds.c
capability.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
cgroup_debug.c debug cgroup: remove unneeded cgroup_lock 2009-04-02 19:04:54 -07:00
cgroup_freezer.c freezer_cg: disable writing freezer.state of root cgroup 2008-11-12 17:17:16 -08:00
cgroup.c memcg: fix OOM killer under memcg 2009-04-02 19:04:55 -07:00
compat.c Allow times and time system calls to return small negative values 2009-01-06 15:59:13 -08:00
configs.c
cpu.c cpumask: use set_cpu_active in init/main.c 2009-03-30 22:05:12 +10:30
cpuset.c cpusets: prevent PF_THREAD_BOUND tasks from attaching to non-root cpusets 2009-04-02 19:04:57 -07:00
cred-internals.h CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-01-09 13:59:25 -08:00
delayacct.c schedstat: consolidate per-task cpu runtime stats 2008-12-18 13:54:01 +01:00
dma-coherent.c dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy. 2009-01-21 18:51:53 +09:00
dma.c
exec_domain.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
exit.c do_wait: fix waiting for the group stop with the dead leader 2009-04-02 19:04:57 -07:00
extable.c Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:10:19 -08:00
fork.c Simplify copy_thread() 2009-04-02 19:04:51 -07:00
freezer.c freezer_cg: use thaw_process() in unfreeze_cgroup() 2008-10-30 11:38:45 -07:00
futex_compat.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
futex.c futex: remove the pointer math from double_unlock_hb, fix 2009-03-13 10:32:07 +01:00
hrtimer.c hrtimer: prevent negative expiry value after clock_was_set() 2009-01-30 22:35:34 +01:00
itimer.c timers: split process wide cpu clocks/timers 2009-02-05 13:04:33 +01:00
kallsyms.c Revert "kbuild: strip generated symbols from *.ko" 2009-01-14 21:38:20 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.preempt rcu: provide RCU options on non-preempt architectures too 2008-12-25 09:31:28 +01:00
kexec.c kexec: Change kexec jump code ordering 2009-03-30 21:46:55 +02:00
kfifo.c
kgdb.c
kmod.c cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL 2009-03-30 22:05:11 +10:30
kprobes.c kprobes: check CONFIG_FREEZER instead of CONFIG_PM 2009-01-16 14:32:17 -05:00
ksysfs.c kernel/ksysfs.c:fix dependence on CONFIG_NET 2009-01-06 10:44:31 -08:00
kthread.c cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL 2009-03-30 22:05:11 +10:30
latencytop.c sched, latencytop: incorporate review feedback from Andrew Morton 2009-02-11 10:18:04 +01:00
lockdep_internals.h lockdep: get_user_chars() redo 2009-02-14 23:28:22 +01:00
lockdep_proc.c lockstat: warn about disabled lock debugging 2009-02-14 23:28:28 +01:00
lockdep_states.h lockdep: move state bit definitions around 2009-02-14 23:27:59 +01:00
lockdep.c lockdep: fix deadlock in lockdep_trace_alloc 2009-03-30 23:19:24 +02:00
Makefile PM: fix build for CONFIG_PM unset 2009-02-21 14:17:17 -08:00
marker.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
module.c Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
mutex-debug.c mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
mutex-debug.h mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
mutex.c mutex: adaptive spinnning, performance tweaks 2009-01-14 19:03:54 +01:00
mutex.h mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
notifier.c Merge commit 'v2.6.28-rc6' into core/debug 2008-11-26 08:22:50 +01:00
ns_cgroup.c cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups 2009-04-02 19:04:53 -07:00
nsproxy.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
panic.c stackprotector: update make rules 2009-02-10 00:41:54 +01:00
params.c Fix compile warning in kernel/params.c 2008-10-23 12:09:00 -07:00
pid_namespace.c
pid.c pid: generalize task_active_pid_ns 2009-01-08 08:31:12 -08:00
pm_qos_params.c
posix-cpu-timers.c posix timers: fix RLIMIT_CPU && fork() 2009-03-23 20:43:35 +01:00
posix-timers.c [CVE-2009-0029] System call wrappers part 05 2009-01-14 14:15:20 +01:00
printk.c PM: Fix suspend_console and resume_console to use only one semaphore 2009-02-21 14:17:18 -08:00
profile.c profiling: fix broken profiling regression 2009-02-10 00:50:37 +01:00
ptrace.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
rcuclassic.c rcu: Teach RCU that idle task is not quiscent state at boot 2009-02-26 04:08:14 +01:00
rcupdate.c rcu: Teach RCU that idle task is not quiscent state at boot 2009-02-26 04:08:14 +01:00
rcupreempt_trace.c "Tree RCU": scalable classic RCU implementation 2008-12-18 21:56:04 +01:00
rcupreempt.c rcu: Teach RCU that idle task is not quiscent state at boot 2009-02-26 04:08:14 +01:00
rcutorture.c cpumask: convert rcutorture.c 2009-03-30 22:05:16 +10:30
rcutree_trace.c "Tree RCU": scalable classic RCU implementation 2008-12-18 21:56:04 +01:00
rcutree.c rcu: Teach RCU that idle task is not quiscent state at boot 2009-02-26 04:08:14 +01:00
relay.c timers: add mod_timer_pending() 2009-02-18 19:26:33 +01:00
res_counter.c memcg: memory cgroup resource counters for hierarchy 2009-01-08 08:31:05 -08:00
resource.c resources: fix parameter name and kernel-doc 2009-01-15 16:39:38 -08:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c sched_clock: cleanups 2009-02-26 21:56:07 +01:00
sched_cpupri.c sched: fix section mismatch 2009-01-06 11:07:15 +01:00
sched_cpupri.h cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sched_debug.c sched: remove unused fields from struct rq 2009-03-24 23:16:51 +01:00
sched_fair.c Merge branch 'sched/urgent'; commit 'v2.6.29-rc5' into sched/core 2009-02-15 21:15:16 +01:00
sched_features.h Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-30 17:17:35 -07:00
sched_idletask.c sched: add CONFIG_SMP consistency 2008-10-22 10:01:52 +02:00
sched_rt.c Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
sched_stats.h sched: remove unused fields from struct rq 2009-03-24 23:16:51 +01:00
sched.c epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() 2009-04-01 08:59:20 -07:00
seccomp.c x86-64: seccomp: fix 32/64 syscall hole 2009-03-02 15:41:30 -08:00
semaphore.c
signal.c signals: remove 'handler' parameter to tracehook functions 2009-04-02 19:04:58 -07:00
smp.c generic-ipi: use per cpu data for single cpu ipi calls 2009-01-30 18:31:08 +01:00
softirq.c Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
softlockup.c softlock: fix false panic which can occur if softlockup_thresh is reduced 2009-01-14 11:48:07 +01:00
spinlock.c
srcu.c
stacktrace.c stacktrace: provide save_stack_trace_tsk() weak alias 2008-12-25 11:44:43 +01:00
stop_machine.c cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sys_ni.c [CVE-2009-0029] Make sys_syslog a conditional system call 2009-01-14 14:15:16 +01:00
sys.c sched: don't allow setuid to succeed if the user does not have rt bandwidth 2009-02-27 11:11:53 +01:00
sysctl_check.c net: add ARP notify option for devices 2009-02-01 01:04:33 -08:00
sysctl.c mm: fix proc_dointvec_userhz_jiffies "breakage" 2009-04-01 08:59:13 -07:00
taskstats.c cpumask: convert rest of files in kernel/ 2009-01-01 10:12:28 +10:30
test_kprobes.c kprobes: add tests for register_kprobes 2009-01-06 15:59:20 -08:00
time.c [CVE-2009-0029] System call wrappers part 01 2009-01-14 14:15:18 +01:00
timeconst.pl
timer.c Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-30 17:17:35 -07:00
tracepoint.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
tsacct.c Fix fixpoint divide exception in acct_update_integrals 2009-03-09 08:13:35 -07:00
uid16.c [CVE-2009-0029] System call wrappers part 19 2009-01-14 14:15:26 +01:00
up.c smp_call_function_single(): be slightly less stupid, fix #2 2009-01-12 16:04:37 +01:00
user_namespace.c Fix recursive lock in free_uid()/free_user_ns() 2009-02-27 16:26:21 -08:00
user.c Merge branch 'master' into next 2009-03-24 10:52:46 +11:00
utsname_sysctl.c
utsname.c
wait.c wait: prevent exclusive waiter starvation 2009-02-05 12:56:48 -08:00
workqueue.c cpumask: use new cpumask_ functions in core code. 2009-03-30 22:05:16 +10:30