dect
/
linux-2.6
Archived
13
0
Fork 0
This repository has been archived on 2022-02-17. You can view files and clone it, but cannot push or open issues or pull requests.
linux-2.6/kernel
Oleg Nesterov ee77f07592 signal: Turn SIGNAL_STOP_DEQUEUED into GROUP_STOP_DEQUEUED
This patch moves SIGNAL_STOP_DEQUEUED from signal_struct->flags to
task_struct->group_stop, and thus makes it per-thread.

Like SIGNAL_STOP_DEQUEUED, GROUP_STOP_DEQUEUED can be false-positive
after return from get_signal_to_deliver(), this is fine. The only
purpose of this bit is: we can drop ->siglock after __dequeue_signal()
returns the sig_kernel_stop() signal and before we call
do_signal_stop(), in this case we must not miss SIGCONT if it comes in
between.

But, unlike SIGNAL_STOP_DEQUEUED, GROUP_STOP_DEQUEUED can not be
false-positive in do_signal_stop() if multiple threads dequeue the
sig_kernel_stop() signal at the same time.

Consider two threads T1 and T2, SIGTTIN has a hanlder.

	- T1 dequeues SIGTSTP and sets SIGNAL_STOP_DEQUEUED, then
	  it drops ->siglock

	- SIGCONT comes and clears SIGNAL_STOP_DEQUEUED, SIGTSTP
	  should be cancelled.

	- T2 dequeues SIGTTIN and sets SIGNAL_STOP_DEQUEUED again.
	  Since we have a handler we should not stop, T2 returns
	  to usermode to run the handler.

	- T1 continues, calls do_signal_stop() and wrongly starts
	  the group stop because SIGNAL_STOP_DEQUEUED was restored
	  in between.

With or without this change:

	- we need to do something with ptrace_signal() which can
	  return SIGSTOP, but this needs another discussion

	- SIGSTOP can be lost if it races with the mt exec, will
	  be fixed later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2011-04-04 02:11:05 +02:00
..
debug Merge branch 'master' into for-next 2010-12-22 18:57:02 +01:00
gcov Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2011-03-20 18:14:55 -07:00
irq genirq: Fix incorrect unlock in __setup_irq() 2011-03-17 15:52:30 +01:00
power Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2011-03-20 18:14:55 -07:00
time Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 18:53:35 -07:00
trace Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-18 10:38:34 -07:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
Makefile kernel: clean up USE_GENERIC_SMP_HELPERS 2011-01-13 08:03:08 -08:00
acct.c pass a struct path to vfs_statfs 2010-08-09 16:48:42 -04:00
async.c async: use workqueue for worker pool 2010-07-14 11:29:46 +02:00
audit.c netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms 2011-03-03 10:55:40 -08:00
audit.h audit: make functions static 2010-10-30 01:42:19 -04:00
audit_tree.c in untag_chunk() we need to do alloc_chunk() a bit earlier 2010-10-30 02:18:32 -04:00
audit_watch.c kill path_lookup() 2011-03-14 09:15:23 -04:00
auditfilter.c netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms 2011-03-03 10:55:40 -08:00
auditsc.c audit mmap 2010-10-30 08:45:43 -04:00
backtracetest.c
bounds.c
capability.c security: add cred argument to security_capable() 2011-02-11 17:41:58 +11:00
cgroup.c cgroups: if you list_empty() a head then don't list_del() it 2011-03-22 17:43:58 -07:00
cgroup_freezer.c cgroup_freezer: update_freezer_state() does incorrect state transitions 2010-10-27 18:03:08 -07:00
compat.c posix-timers: Introduce a syscall for clock tuning. 2011-02-02 15:28:19 +01:00
configs.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
cpu.c kernel/cpu.c: fix many errors related to style. 2011-03-22 17:44:11 -07:00
cpuset.c cpuset: add a missing unlock in cpuset_write_resmask() 2011-03-04 17:53:38 -08:00
cred.c Merge commit 'v2.6.38-rc5' into core/locking 2011-02-16 13:33:41 +01:00
delayacct.c
dma.c
elfcore.c
exec_domain.c sys_personality: remove the bogus checks in sys_personality()->__set_personality() path 2010-08-09 20:45:05 -07:00
exit.c job control: Allow access to job control events through ptracees 2011-03-23 10:37:01 +01:00
extable.c
fork.c sys_unshare: remove the dead CLONE_THREAD/SIGHAND/VM code 2011-03-22 17:44:11 -07:00
freezer.c Freezer: Fix a race during freezing of TASK_STOPPED tasks 2010-12-24 15:02:40 +01:00
futex.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 18:28:30 -07:00
futex_compat.c futex: Address compiler warnings in exit_robust_list 2010-11-10 13:27:50 +01:00
groups.c kernel/groups.c: fix integer overflow in groups_search 2010-09-09 18:57:24 -07:00
hrtimer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 18:53:35 -07:00
hung_task.c lockup detector: Fix grammar by adding a missing "to" in the comments 2010-08-17 09:11:52 +02:00
hw_breakpoint.c perf: Dynamic pmu types 2010-12-16 11:36:43 +01:00
irq_work.c irq_work: Use per cpu atomics instead of regular atomics 2010-12-18 15:54:48 +01:00
itimer.c
jump_label.c jump label: Make arch_jump_label_text_poke_early() optional 2010-10-29 12:56:13 -04:00
kallsyms.c printk: use %pK for /proc/kallsyms and /proc/modules 2011-03-22 17:44:12 -07:00
kexec.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
kfifo.c kfifo: fix scatterlist usage 2010-10-01 10:50:58 -07:00
kmod.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
kprobes.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
ksysfs.c
kthread.c kthread: NUMA aware kthread_create_on_node() 2011-03-22 17:44:01 -07:00
latencytop.c fs/proc/base.c, kernel/latencytop.c: convert sprintf_symbol() to %ps 2011-01-13 08:03:16 -08:00
lockdep.c lockdep: Move early boot local IRQ enable/disable status to init/main.c 2011-01-20 13:32:33 +01:00
lockdep_internals.h
lockdep_proc.c locking, lockdep: Convert sprintf_symbol to %pS 2010-11-10 10:23:58 +01:00
lockdep_states.h
module.c printk: use %pK for /proc/kallsyms and /proc/modules 2011-03-22 17:44:12 -07:00
mutex-debug.c
mutex-debug.h
mutex.c mutexes, sched: Introduce arch_mutex_cpu_relax() 2010-11-26 15:05:34 +01:00
mutex.h
notifier.c
ns_cgroup.c cgroup: notify ns_cgroup deprecated 2010-10-27 18:03:09 -07:00
nsproxy.c
padata.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2010-08-04 15:23:14 -07:00
panic.c move x86 specific oops=panic to generic code 2011-03-22 17:44:11 -07:00
params.c module: show version information for built-in modules in sysfs 2011-01-24 14:32:51 +10:30
perf_event.c perf: Fix tear-down of inherited group events 2011-03-16 14:04:14 +01:00
pid.c export pid symbols needed for kvm_vcpu_on_spin 2011-03-17 13:08:28 -03:00
pid_namespace.c
pm_qos_params.c PM QoS: Make pm_qos settings readable 2011-03-15 00:43:18 +01:00
posix-cpu-timers.c posix-timers: Cleanup namespace 2011-02-02 15:28:19 +01:00
posix-timers.c timers: Export CLOCK_BOOTTIME via the posix timers interface 2011-02-21 12:53:09 -08:00
printk.c printk: allow setting DEFAULT_MESSAGE_LEVEL via Kconfig 2011-03-22 17:44:13 -07:00
profile.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ptrace.c ptrace: Always put ptracee into appropriate execution state 2011-03-23 10:37:01 +01:00
range.c kernel/range.c: fix clean_sort_range() for the case of full array 2010-11-12 07:55:31 -08:00
rcupdate.c rcu: add comment saying why DEBUG_OBJECTS_RCU_HEAD depends on PREEMPT. 2011-03-04 08:05:41 -08:00
rcutiny.c rcu: avoid pointless blocked-task warnings 2011-01-14 04:58:08 -08:00
rcutiny_plugin.h rcu: call __rcu_read_unlock() in exit_rcu for tiny RCU 2011-03-04 08:05:08 -08:00
rcutorture.c rcutorture: Get rid of duplicate sched.h include 2011-03-04 08:05:17 -08:00
rcutree.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
rcutree.h rcu: limit rcu_node leaf-level fanout 2010-12-17 12:34:20 -08:00
rcutree_plugin.h rcu: increase synchronize_sched_expedited() batching 2010-12-17 12:34:08 -08:00
rcutree_trace.c rcu,cleanup: simplify the code when cpu is dying 2010-11-29 22:01:58 -08:00
relay.c Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset 2010-11-05 08:21:34 -07:00
res_counter.c
resource.c resources: add arch hook for preventing allocation in reserved areas 2010-12-17 10:01:09 -08:00
rtmutex-debug.c rtmutex: Simplify PI algorithm and make highest prio task get lock 2011-01-27 21:13:51 -05:00
rtmutex-debug.h
rtmutex-tester.c rtmutex: tester: Remove the remaining BKL leftovers 2011-02-22 22:07:22 +01:00
rtmutex.c rtmutex: Simplify PI algorithm and make highest prio task get lock 2011-01-27 21:13:51 -05:00
rtmutex.h
rtmutex_common.h rtmutex: Simplify PI algorithm and make highest prio task get lock 2011-01-27 21:13:51 -05:00
rwsem.c
sched.c Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2011-03-16 17:21:00 -07:00
sched_autogroup.c sched, autogroup: Stop claiming ownership of the root task group 2011-02-23 11:34:03 +01:00
sched_autogroup.h sched, autogroup: Stop going ahead if autogroup is disabled 2011-02-23 11:33:59 +01:00
sched_clock.c sched: Add some clock info to sched_debug 2010-11-23 10:29:08 +01:00
sched_cpupri.c sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_cpupri.h sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_debug.c sched: Use a buddy to implement yield_task_fair() 2011-02-03 14:20:33 +01:00
sched_fair.c sched: Resched proper CPU on yield_to() 2011-03-04 11:14:31 +01:00
sched_features.h sched: Rewrite tg_shares_up) 2010-11-18 13:27:46 +01:00
sched_idletask.c sched: Fix switch_from_fair() 2011-01-26 12:33:22 +01:00
sched_rt.c Merge branch 'sched/urgent' into sched/core 2011-03-04 11:12:26 +01:00
sched_stats.h sched_stat: Update sched_info_queue/dequeue() code comments 2010-10-24 13:29:01 +02:00
sched_stoptask.c sched: Fix switch_from_fair() 2011-01-26 12:33:22 +01:00
seccomp.c
semaphore.c
signal.c signal: Turn SIGNAL_STOP_DEQUEUED into GROUP_STOP_DEQUEUED 2011-04-04 02:11:05 +02:00
smp.c smp: move smp setup functions to kernel/smp.c 2011-03-22 17:44:11 -07:00
softirq.c kthread: use kthread_create_on_node() 2011-03-22 17:44:01 -07:00
spinlock.c
srcu.c rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status 2011-01-14 04:56:49 -08:00
stacktrace.c
stop_machine.c kthread: use kthread_create_on_node() 2011-03-22 17:44:01 -07:00
sys.c PM / Core: Introduce struct syscore_ops for core subsystems PM 2011-03-15 00:43:46 +01:00
sys_ni.c vfs: Add open by file handle support 2011-03-15 02:21:44 -04:00
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2011-03-16 09:15:43 -07:00
sysctl_binary.c open-style analog of vfs_path_lookup() 2011-03-14 09:15:28 -04:00
sysctl_check.c sysctl: min/max bounds are optional 2010-10-15 14:42:24 -07:00
taskstats.c taskstats: use better ifdef for alignment 2011-01-13 08:03:19 -08:00
test_kprobes.c kprobes: Fix selftest to clear flags field for reusing probes 2010-10-14 08:55:27 +02:00
time.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 18:53:35 -07:00
timeconst.pl
timer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 18:53:35 -07:00
tracepoint.c tracepoints: Fix section alignment using pointer array 2011-02-03 09:28:46 -05:00
tsacct.c taskstats: use real microsecond granularity for CPU times 2010-10-27 18:03:17 -07:00
uid16.c
up.c
user-return-notifier.c
user.c fix freeing user_struct in user cache 2010-12-29 11:31:38 -08:00
user_namespace.c user_ns: improve the user_ns on-the-slab packaging 2011-01-13 08:03:18 -08:00
utsname.c
utsname_sysctl.c
wait.c docbook: add more wait/wake/completion to device-drivers docbook 2010-10-26 17:32:41 -07:00
watchdog.c kernel/watchdog.c: always return NOTIFY_OK during cpu up/down events 2011-03-22 17:44:12 -07:00
workqueue.c kthread: use kthread_create_on_node() 2011-03-22 17:44:01 -07:00
workqueue_sched.h workqueue: implement concurrency managed dynamic worker pool 2010-06-29 10:07:14 +02:00