From a8f072c1d624a627b67f2ace2f0c25d856ef4e54 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Jun 2011 11:13:59 +0200 Subject: [PATCH] job control: rename signal->group_stop and flags to jobctl and update them signal->group_stop currently hosts mostly group stop related flags; however, it's gonna be used for wider purposes and the GROUP_STOP_ flag prefix becomes confusing. Rename signal->group_stop to signal->jobctl and rename all GROUP_STOP_* flags to JOBCTL_*. Bit position macros JOBCTL_*_BIT are defined and JOBCTL_* flags are defined in terms of them to allow using bitops later. While at it, reassign JOBCTL_TRAPPING to bit 22 to better accomodate future additions. This doesn't cause any functional change. -v2: JOBCTL_*_BIT macros added as suggested by Linus. Signed-off-by: Tejun Heo Cc: Linus Torvalds Signed-off-by: Oleg Nesterov --- fs/exec.c | 2 +- include/linux/sched.h | 22 +++++++---- kernel/ptrace.c | 12 +++--- kernel/signal.c | 91 ++++++++++++++++++++++--------------------- 4 files changed, 67 insertions(+), 60 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index ea5f748906a8..8986bb0f9dc2 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1772,7 +1772,7 @@ static int zap_process(struct task_struct *start, int exit_code) t = start; do { - task_clear_group_stop_pending(t); + task_clear_jobctl_stop_pending(t); if (t != current && t->mm) { sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); diff --git a/include/linux/sched.h b/include/linux/sched.h index 2a8621c4be1e..b0dd064eb4fc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1282,7 +1282,7 @@ struct task_struct { int exit_state; int exit_code, exit_signal; int pdeath_signal; /* The signal sent when the parent dies */ - unsigned int group_stop; /* GROUP_STOP_*, siglock protected */ + unsigned int jobctl; /* JOBCTL_*, siglock protected */ /* ??? */ unsigned int personality; unsigned did_exec:1; @@ -1803,15 +1803,21 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t * #define used_math() tsk_used_math(current) /* - * task->group_stop flags + * task->jobctl flags */ -#define GROUP_STOP_SIGMASK 0xffff /* signr of the last group stop */ -#define GROUP_STOP_PENDING (1 << 16) /* task should stop for group stop */ -#define GROUP_STOP_CONSUME (1 << 17) /* consume group stop count */ -#define GROUP_STOP_TRAPPING (1 << 18) /* switching from STOPPED to TRACED */ -#define GROUP_STOP_DEQUEUED (1 << 19) /* stop signal dequeued */ +#define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */ -extern void task_clear_group_stop_pending(struct task_struct *task); +#define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */ +#define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */ +#define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */ +#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */ + +#define JOBCTL_STOP_DEQUEUED (1 << JOBCTL_STOP_DEQUEUED_BIT) +#define JOBCTL_STOP_PENDING (1 << JOBCTL_STOP_PENDING_BIT) +#define JOBCTL_STOP_CONSUME (1 << JOBCTL_STOP_CONSUME_BIT) +#define JOBCTL_TRAPPING (1 << JOBCTL_TRAPPING_BIT) + +extern void task_clear_jobctl_stop_pending(struct task_struct *task); #ifdef CONFIG_PREEMPT_RCU diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 4f689cb739a3..134f34cb142b 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -77,13 +77,13 @@ void __ptrace_unlink(struct task_struct *child) spin_lock(&child->sighand->siglock); /* - * Reinstate GROUP_STOP_PENDING if group stop is in effect and + * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and * @child isn't dead. */ if (!(child->flags & PF_EXITING) && (child->signal->flags & SIGNAL_STOP_STOPPED || child->signal->group_stop_count)) - child->group_stop |= GROUP_STOP_PENDING; + child->jobctl |= JOBCTL_STOP_PENDING; /* * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick @@ -91,7 +91,7 @@ void __ptrace_unlink(struct task_struct *child) * is in TASK_TRACED; otherwise, we might unduly disrupt * TASK_KILLABLE sleeps. */ - if (child->group_stop & GROUP_STOP_PENDING || task_is_traced(child)) + if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) signal_wake_up(child, task_is_traced(child)); spin_unlock(&child->sighand->siglock); @@ -226,7 +226,7 @@ static int ptrace_attach(struct task_struct *task) spin_lock(&task->sighand->siglock); /* - * If the task is already STOPPED, set GROUP_STOP_PENDING and + * If the task is already STOPPED, set JOBCTL_STOP_PENDING and * TRAPPING, and kick it so that it transits to TRACED. TRAPPING * will be cleared if the child completes the transition or any * event which clears the group stop states happens. We'll wait @@ -243,7 +243,7 @@ static int ptrace_attach(struct task_struct *task) * in and out of STOPPED are protected by siglock. */ if (task_is_stopped(task)) { - task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING; + task->jobctl |= JOBCTL_STOP_PENDING | JOBCTL_TRAPPING; signal_wake_up(task, 1); } @@ -257,7 +257,7 @@ unlock_creds: out: if (!retval) wait_event(current->signal->wait_chldexit, - !(task->group_stop & GROUP_STOP_TRAPPING)); + !(task->jobctl & JOBCTL_TRAPPING)); return retval; } diff --git a/kernel/signal.c b/kernel/signal.c index 86c32b884f8e..ab6851c06461 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -124,7 +124,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) static int recalc_sigpending_tsk(struct task_struct *t) { - if ((t->group_stop & GROUP_STOP_PENDING) || + if ((t->jobctl & JOBCTL_STOP_PENDING) || PENDING(&t->pending, &t->blocked) || PENDING(&t->signal->shared_pending, &t->blocked)) { set_tsk_thread_flag(t, TIF_SIGPENDING); @@ -224,27 +224,28 @@ static inline void print_dropped_signal(int sig) } /** - * task_clear_group_stop_trapping - clear group stop trapping bit + * task_clear_jobctl_trapping - clear jobctl trapping bit * @task: target task * - * If GROUP_STOP_TRAPPING is set, a ptracer is waiting for us. Clear it - * and wake up the ptracer. Note that we don't need any further locking. - * @task->siglock guarantees that @task->parent points to the ptracer. + * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED. + * Clear it and wake up the ptracer. Note that we don't need any further + * locking. @task->siglock guarantees that @task->parent points to the + * ptracer. * * CONTEXT: * Must be called with @task->sighand->siglock held. */ -static void task_clear_group_stop_trapping(struct task_struct *task) +static void task_clear_jobctl_trapping(struct task_struct *task) { - if (unlikely(task->group_stop & GROUP_STOP_TRAPPING)) { - task->group_stop &= ~GROUP_STOP_TRAPPING; + if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { + task->jobctl &= ~JOBCTL_TRAPPING; __wake_up_sync_key(&task->parent->signal->wait_chldexit, TASK_UNINTERRUPTIBLE, 1, task); } } /** - * task_clear_group_stop_pending - clear pending group stop + * task_clear_jobctl_stop_pending - clear pending group stop * @task: target task * * Clear group stop states for @task. @@ -252,19 +253,19 @@ static void task_clear_group_stop_trapping(struct task_struct *task) * CONTEXT: * Must be called with @task->sighand->siglock held. */ -void task_clear_group_stop_pending(struct task_struct *task) +void task_clear_jobctl_stop_pending(struct task_struct *task) { - task->group_stop &= ~(GROUP_STOP_PENDING | GROUP_STOP_CONSUME | - GROUP_STOP_DEQUEUED); + task->jobctl &= ~(JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME | + JOBCTL_STOP_DEQUEUED); } /** * task_participate_group_stop - participate in a group stop * @task: task participating in a group stop * - * @task has GROUP_STOP_PENDING set and is participating in a group stop. + * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop. * Group stop states are cleared and the group stop count is consumed if - * %GROUP_STOP_CONSUME was set. If the consumption completes the group + * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group * stop, the appropriate %SIGNAL_* flags are set. * * CONTEXT: @@ -277,11 +278,11 @@ void task_clear_group_stop_pending(struct task_struct *task) static bool task_participate_group_stop(struct task_struct *task) { struct signal_struct *sig = task->signal; - bool consume = task->group_stop & GROUP_STOP_CONSUME; + bool consume = task->jobctl & JOBCTL_STOP_CONSUME; - WARN_ON_ONCE(!(task->group_stop & GROUP_STOP_PENDING)); + WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)); - task_clear_group_stop_pending(task); + task_clear_jobctl_stop_pending(task); if (!consume) return false; @@ -604,7 +605,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) * is to alert stop-signal processing code when another * processor has come along and cleared the flag. */ - current->group_stop |= GROUP_STOP_DEQUEUED; + current->jobctl |= JOBCTL_STOP_DEQUEUED; } if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { /* @@ -809,7 +810,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); t = p; do { - task_clear_group_stop_pending(t); + task_clear_jobctl_stop_pending(t); rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); wake_up_state(t, __TASK_STOPPED); } while_each_thread(p, t); @@ -925,7 +926,7 @@ static void complete_signal(int sig, struct task_struct *p, int group) signal->group_stop_count = 0; t = p; do { - task_clear_group_stop_pending(t); + task_clear_jobctl_stop_pending(t); sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); } while_each_thread(p, t); @@ -1160,7 +1161,7 @@ int zap_other_threads(struct task_struct *p) p->signal->group_stop_count = 0; while_each_thread(p, t) { - task_clear_group_stop_pending(t); + task_clear_jobctl_stop_pending(t); count++; /* Don't bother with already dead threads */ @@ -1738,7 +1739,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) * clear now. We act as if SIGCONT is received after TASK_TRACED * is entered - ignore it. */ - if (why == CLD_STOPPED && (current->group_stop & GROUP_STOP_PENDING)) + if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING)) gstop_done = task_participate_group_stop(current); current->last_siginfo = info; @@ -1751,12 +1752,12 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) set_current_state(TASK_TRACED); /* - * We're committing to trapping. Clearing GROUP_STOP_TRAPPING and + * We're committing to trapping. Clearing JOBCTL_TRAPPING and * transition to TASK_TRACED should be atomic with respect to - * siglock. This hsould be done after the arch hook as siglock is + * siglock. This should be done after the arch hook as siglock is * released and regrabbed across it. */ - task_clear_group_stop_trapping(current); + task_clear_jobctl_trapping(current); spin_unlock_irq(¤t->sighand->siglock); read_lock(&tasklist_lock); @@ -1792,9 +1793,9 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) * * If @gstop_done, the ptracer went away between group stop * completion and here. During detach, it would have set - * GROUP_STOP_PENDING on us and we'll re-enter TASK_STOPPED - * in do_signal_stop() on return, so notifying the real - * parent of the group stop completion is enough. + * JOBCTL_STOP_PENDING on us and we'll re-enter + * TASK_STOPPED in do_signal_stop() on return, so notifying + * the real parent of the group stop completion is enough. */ if (gstop_done) do_notify_parent_cldstop(current, false, why); @@ -1856,14 +1857,14 @@ static int do_signal_stop(int signr) { struct signal_struct *sig = current->signal; - if (!(current->group_stop & GROUP_STOP_PENDING)) { - unsigned int gstop = GROUP_STOP_PENDING | GROUP_STOP_CONSUME; + if (!(current->jobctl & JOBCTL_STOP_PENDING)) { + unsigned int gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME; struct task_struct *t; - /* signr will be recorded in task->group_stop for retries */ - WARN_ON_ONCE(signr & ~GROUP_STOP_SIGMASK); + /* signr will be recorded in task->jobctl for retries */ + WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK); - if (!likely(current->group_stop & GROUP_STOP_DEQUEUED) || + if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) || unlikely(signal_group_exit(sig))) return 0; /* @@ -1890,19 +1891,19 @@ static int do_signal_stop(int signr) else WARN_ON_ONCE(!task_ptrace(current)); - current->group_stop &= ~GROUP_STOP_SIGMASK; - current->group_stop |= signr | gstop; + current->jobctl &= ~JOBCTL_STOP_SIGMASK; + current->jobctl |= signr | gstop; sig->group_stop_count = 1; for (t = next_thread(current); t != current; t = next_thread(t)) { - t->group_stop &= ~GROUP_STOP_SIGMASK; + t->jobctl &= ~JOBCTL_STOP_SIGMASK; /* * Setting state to TASK_STOPPED for a group * stop is always done with the siglock held, * so this check has no races. */ if (!(t->flags & PF_EXITING) && !task_is_stopped(t)) { - t->group_stop |= signr | gstop; + t->jobctl |= signr | gstop; sig->group_stop_count++; signal_wake_up(t, 0); } @@ -1943,23 +1944,23 @@ retry: spin_lock_irq(¤t->sighand->siglock); } else { - ptrace_stop(current->group_stop & GROUP_STOP_SIGMASK, + ptrace_stop(current->jobctl & JOBCTL_STOP_SIGMASK, CLD_STOPPED, 0, NULL); current->exit_code = 0; } /* - * GROUP_STOP_PENDING could be set if another group stop has + * JOBCTL_STOP_PENDING could be set if another group stop has * started since being woken up or ptrace wants us to transit * between TASK_STOPPED and TRACED. Retry group stop. */ - if (current->group_stop & GROUP_STOP_PENDING) { - WARN_ON_ONCE(!(current->group_stop & GROUP_STOP_SIGMASK)); + if (current->jobctl & JOBCTL_STOP_PENDING) { + WARN_ON_ONCE(!(current->jobctl & JOBCTL_STOP_SIGMASK)); goto retry; } /* PTRACE_ATTACH might have raced with task killing, clear trapping */ - task_clear_group_stop_trapping(current); + task_clear_jobctl_trapping(current); spin_unlock_irq(¤t->sighand->siglock); @@ -2078,8 +2079,8 @@ relock: if (unlikely(signr != 0)) ka = return_ka; else { - if (unlikely(current->group_stop & - GROUP_STOP_PENDING) && do_signal_stop(0)) + if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) && + do_signal_stop(0)) goto relock; signr = dequeue_signal(current, ¤t->blocked, @@ -2253,7 +2254,7 @@ void exit_signals(struct task_struct *tsk) signotset(&unblocked); retarget_shared_pending(tsk, &unblocked); - if (unlikely(tsk->group_stop & GROUP_STOP_PENDING) && + if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) && task_participate_group_stop(tsk)) group_stop = CLD_STOPPED; out: -- 2.34.1