linux-bl808/kernel
Oleg Nesterov b79b7ba93d ptrace: ptrace_attach: check PF_KTHREAD + exit_state instead of ->mm
- Add PF_KTHREAD check to prevent attaching to the kernel thread
  with a borrowed ->mm.

  With or without this change we can race with daemonize() which
  can set PF_KTHREAD or clear ->mm after ptrace_attach() does the
  check, but this doesn't matter because reparent_to_kthreadd()
  does ptrace_unlink().

- Kill "!task->mm" check. We don't really care about ->mm != NULL,
  and the task can call exit_mm() right after we drop task_lock().
  What we need is to make sure we can't attach after exit_notify(),
  check task->exit_state != 0 instead.

Also, move the "already traced" check down for cosmetic reasons.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
..
irq
power
time
trace
.gitignore
acct.c
async.c
audit.c
audit.h
audit_tree.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup.c cgroups: forbid noprefix if mounting more than just cpuset subsystem 2009-06-18 13:03:46 -07:00
cgroup_debug.c
cgroup_freezer.c
compat.c
configs.c
cpu.c
cpuset.c
cred-internals.h
cred.c
delayacct.c
dma-coherent.c
dma.c
exec_domain.c
exit.c ptrace: do not use task->ptrace directly in core kernel 2009-06-18 13:03:51 -07:00
extable.c
fork.c
freezer.c
futex.c
futex_compat.c
groups.c
hrtimer.c
hung_task.c
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c
kfifo.c
kgdb.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile
marker.c
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
panic.c
params.c
perf_counter.c
pid.c
pid_namespace.c
pm_qos_params.c
posix-cpu-timers.c
posix-timers.c
printk.c
profile.c
ptrace.c ptrace: ptrace_attach: check PF_KTHREAD + exit_state instead of ->mm 2009-06-18 13:03:51 -07:00
rcuclassic.c
rcupdate.c
rcupreempt.c
rcupreempt_trace.c
rcutorture.c
rcutree.c
rcutree.h
rcutree_trace.c
relay.c
res_counter.c memcg: add interface to reset limits 2009-06-18 13:03:48 -07:00
resource.c
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c
sched_features.h
sched_idletask.c
sched_rt.c
sched_stats.h
seccomp.c
semaphore.c
signal.c ptrace: do not use task->ptrace directly in core kernel 2009-06-18 13:03:51 -07:00
slow-work.c
smp.c
softirq.c
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys.c
sys_ni.c
sysctl.c
sysctl_check.c
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
up.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
wait.c
workqueue.c