linux_dsm_epyc7002/kernel
hongfeng 6c0c0d4d10 poweroff: fix bug in orderly_poweroff()
orderly_poweroff is trying to poweroff platform in two steps:

step 1: Call user space application to poweroff
step 2: If user space poweroff fail, then do a force power off if force param
        is set.

The bug here is, step 1 is always successful with param UMH_NO_WAIT, which obey
the design goal of orderly_poweroff.

We have two choices here:
UMH_WAIT_EXEC which means wait for the exec, but not the process;
UMH_WAIT_PROC which means wait for the process to complete.
we need to trade off the two choices:

If using UMH_WAIT_EXEC, there is potential issue comments by Serge E.
Hallyn: The exec will have started, but may for whatever (very unlikely)
reason fail.

If using UMH_WAIT_PROC, there is potential issue comments by Eric W.
Biederman: If the caller is not running in a kernel thread then we can
easily get into a case where the user space caller will block waiting for
us when we are waiting for the user space caller.

Thanks for their excellent ideas, based on the above discussion, we
finally choose UMH_WAIT_EXEC, which is much more safe, if the user
application really fails, we just complain the application itself, it
seems a better choice here.

Signed-off-by: Feng Hong <hongfeng@marvell.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:48 +09:00
..
debug
events Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
gcov
irq
power
sched
time Power management updates for 3.7-rc1 2012-10-02 18:32:35 -07:00
trace
.gitignore
acct.c
async.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-10-02 21:38:48 -07:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup.c
compat.c
configs.c
cpu_pm.c
cpu.c
cpuset.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
extable.c
fork.c
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c
hung_task.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kfifo.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
lglock.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
posix-cpu-timers.c
posix-timers.c
printk.c
profile.c
ptrace.c
range.c
rcu.h
rcupdate.c
rcutiny_plugin.h
rcutiny.c
rcutorture.c
rcutree_plugin.h
rcutree_trace.c
rcutree.c
rcutree.h
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
seccomp.c
semaphore.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c poweroff: fix bug in orderly_poweroff() 2012-10-06 03:04:48 +09:00
sysctl_binary.c
sysctl.c
task_work.c
taskstats.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c
workqueue_sched.h
workqueue.c