| #ifndef _LINUX_SCHED_SIGNAL_H |
| #define _LINUX_SCHED_SIGNAL_H |
| |
| #include <linux/rculist.h> |
| #include <linux/signal.h> |
| #include <linux/sched.h> |
| #include <linux/sched/jobctl.h> |
| #include <linux/sched/task.h> |
| #include <linux/cred.h> |
| |
| /* |
| * Types defining task->signal and task->sighand and APIs using them: |
| */ |
| |
| struct sighand_struct { |
| atomic_t count; |
| struct k_sigaction action[_NSIG]; |
| spinlock_t siglock; |
| wait_queue_head_t signalfd_wqh; |
| }; |
| |
| /* |
| * Per-process accounting stats: |
| */ |
| struct pacct_struct { |
| int ac_flag; |
| long ac_exitcode; |
| unsigned long ac_mem; |
| u64 ac_utime, ac_stime; |
| unsigned long ac_minflt, ac_majflt; |
| }; |
| |
| struct cpu_itimer { |
| u64 expires; |
| u64 incr; |
| }; |
| |
| /* |
| * This is the atomic variant of task_cputime, which can be used for |
| * storing and updating task_cputime statistics without locking. |
| */ |
| struct task_cputime_atomic { |
| atomic64_t utime; |
| atomic64_t stime; |
| atomic64_t sum_exec_runtime; |
| }; |
| |
| #define INIT_CPUTIME_ATOMIC \ |
| (struct task_cputime_atomic) { \ |
| .utime = ATOMIC64_INIT(0), \ |
| .stime = ATOMIC64_INIT(0), \ |
| .sum_exec_runtime = ATOMIC64_INIT(0), \ |
| } |
| /** |
| * struct thread_group_cputimer - thread group interval timer counts |
| * @cputime_atomic: atomic thread group interval timers. |
| * @running: true when there are timers running and |
| * @cputime_atomic receives updates. |
| * @checking_timer: true when a thread in the group is in the |
| * process of checking for thread group timers. |
| * |
| * This structure contains the version of task_cputime, above, that is |
| * used for thread group CPU timer calculations. |
| */ |
| struct thread_group_cputimer { |
| struct task_cputime_atomic cputime_atomic; |
| bool running; |
| bool checking_timer; |
| }; |
| |
| /* |
| * NOTE! "signal_struct" does not have its own |
| * locking, because a shared signal_struct always |
| * implies a shared sighand_struct, so locking |
| * sighand_struct is always a proper superset of |
| * the locking of signal_struct. |
| */ |
| struct signal_struct { |
| atomic_t sigcnt; |
| atomic_t live; |
| int nr_threads; |
| struct list_head thread_head; |
| |
| wait_queue_head_t wait_chldexit; /* for wait4() */ |
| |
| /* current thread group signal load-balancing target: */ |
| struct task_struct *curr_target; |
| |
| /* shared signal handling: */ |
| struct sigpending shared_pending; |
| |
| /* thread group exit support */ |
| int group_exit_code; |
| /* overloaded: |
| * - notify group_exit_task when ->count is equal to notify_count |
| * - everyone except group_exit_task is stopped during signal delivery |
| * of fatal signals, group_exit_task processes the signal. |
| */ |
| int notify_count; |
| struct task_struct *group_exit_task; |
| |
| /* thread group stop support, overloads group_exit_code too */ |
| int group_stop_count; |
| unsigned int flags; /* see SIGNAL_* flags below */ |
| |
| /* |
| * PR_SET_CHILD_SUBREAPER marks a process, like a service |
| * manager, to re-parent orphan (double-forking) child processes |
| * to this process instead of 'init'. The service manager is |
| * able to receive SIGCHLD signals and is able to investigate |
| * the process until it calls wait(). All children of this |
| * process will inherit a flag if they should look for a |
| * child_subreaper process at exit. |
| */ |
| unsigned int is_child_subreaper:1; |
| unsigned int has_child_subreaper:1; |
| |
| #ifdef CONFIG_POSIX_TIMERS |
| |
| /* POSIX.1b Interval Timers */ |
| int posix_timer_id; |
| struct list_head posix_timers; |
| |
| /* ITIMER_REAL timer for the process */ |
| struct hrtimer real_timer; |
| ktime_t it_real_incr; |
| |
| /* |
| * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use |
| * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these |
| * values are defined to 0 and 1 respectively |
| */ |
| struct cpu_itimer it[2]; |
| |
| /* |
| * Thread group totals for process CPU timers. |
| * See thread_group_cputimer(), et al, for details. |
| */ |
| struct thread_group_cputimer cputimer; |
| |
| /* Earliest-expiration cache. */ |
| struct task_cputime cputime_expires; |
| |
| struct list_head cpu_timers[3]; |
| |
| #endif |
| |
| struct pid *leader_pid; |
| |
| #ifdef CONFIG_NO_HZ_FULL |
| atomic_t tick_dep_mask; |
| #endif |
| |
| struct pid *tty_old_pgrp; |
| |
| /* boolean value for session group leader */ |
| int leader; |
| |
| struct tty_struct *tty; /* NULL if no tty */ |
| |
| #ifdef CONFIG_SCHED_AUTOGROUP |
| struct autogroup *autogroup; |
| #endif |
| /* |
| * Cumulative resource counters for dead threads in the group, |
| * and for reaped dead child processes forked by this group. |
| * Live threads maintain their own counters and add to these |
| * in __exit_signal, except for the group leader. |
| */ |
| seqlock_t stats_lock; |
| u64 utime, stime, cutime, cstime; |
| u64 gtime; |
| u64 cgtime; |
| struct prev_cputime prev_cputime; |
| unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; |
| unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; |
| unsigned long inblock, oublock, cinblock, coublock; |
| unsigned long maxrss, cmaxrss; |
| struct task_io_accounting ioac; |
| |
| /* |
| * Cumulative ns of schedule CPU time fo dead threads in the |
| * group, not including a zombie group leader, (This only differs |
| * from jiffies_to_ns(utime + stime) if sched_clock uses something |
| * other than jiffies.) |
| */ |
| unsigned long long sum_sched_runtime; |
| |
| /* |
| * We don't bother to synchronize most readers of this at all, |
| * because there is no reader checking a limit that actually needs |
| * to get both rlim_cur and rlim_max atomically, and either one |
| * alone is a single word that can safely be read normally. |
| * getrlimit/setrlimit use task_lock(current->group_leader) to |
| * protect this instead of the siglock, because they really |
| * have no need to disable irqs. |
| */ |
| struct rlimit rlim[RLIM_NLIMITS]; |
| |
| #ifdef CONFIG_BSD_PROCESS_ACCT |
| struct pacct_struct pacct; /* per-process accounting information */ |
| #endif |
| #ifdef CONFIG_TASKSTATS |
| struct taskstats *stats; |
| #endif |
| #ifdef CONFIG_AUDIT |
| unsigned audit_tty; |
| struct tty_audit_buf *tty_audit_buf; |
| #endif |
| |
| /* |
| * Thread is the potential origin of an oom condition; kill first on |
| * oom |
| */ |
| bool oom_flag_origin; |
| short oom_score_adj; /* OOM kill score adjustment */ |
| short oom_score_adj_min; /* OOM kill score adjustment min value. |
| * Only settable by CAP_SYS_RESOURCE. */ |
| struct mm_struct *oom_mm; /* recorded mm when the thread group got |
| * killed by the oom killer */ |
| |
| struct mutex cred_guard_mutex; /* guard against foreign influences on |
| * credential calculations |
| * (notably. ptrace) */ |
| }; |
| |
| /* |
| * Bits in flags field of signal_struct. |
| */ |
| #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ |
| #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */ |
| #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */ |
| #define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */ |
| /* |
| * Pending notifications to parent. |
| */ |
| #define SIGNAL_CLD_STOPPED 0x00000010 |
| #define SIGNAL_CLD_CONTINUED 0x00000020 |
| #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED) |
| |
| #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */ |
| |
| #define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \ |
| SIGNAL_STOP_CONTINUED) |
| |
| static inline void signal_set_stop_flags(struct signal_struct *sig, |
| unsigned int flags) |
| { |
| WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP)); |
| sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags; |
| } |
| |
| /* If true, all threads except ->group_exit_task have pending SIGKILL */ |
| static inline int signal_group_exit(const struct signal_struct *sig) |
| { |
| return (sig->flags & SIGNAL_GROUP_EXIT) || |
| (sig->group_exit_task != NULL); |
| } |
| |
| extern void flush_signals(struct task_struct *); |
| extern void ignore_signals(struct task_struct *); |
| extern void flush_signal_handlers(struct task_struct *, int force_default); |
| extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info); |
| |
| static inline int kernel_dequeue_signal(siginfo_t *info) |
| { |
| struct task_struct *tsk = current; |
| siginfo_t __info; |
| int ret; |
| |
| spin_lock_irq(&tsk->sighand->siglock); |
| ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info); |
| spin_unlock_irq(&tsk->sighand->siglock); |
| |
| return ret; |
| } |
| |
| static inline void kernel_signal_stop(void) |
| { |
| spin_lock_irq(¤t->sighand->siglock); |
| if (current->jobctl & JOBCTL_STOP_DEQUEUED) |
| __set_current_state(TASK_STOPPED); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| schedule(); |
| } |
| extern int send_sig_info(int, struct siginfo *, struct task_struct *); |
| extern int force_sigsegv(int, struct task_struct *); |
| extern int force_sig_info(int, struct siginfo *, struct task_struct *); |
| extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp); |
| extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid); |
| extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *, |
| const struct cred *, u32); |
| extern int kill_pgrp(struct pid *pid, int sig, int priv); |
| extern int kill_pid(struct pid *pid, int sig, int priv); |
| extern int kill_proc_info(int, struct siginfo *, pid_t); |
| extern __must_check bool do_notify_parent(struct task_struct *, int); |
| extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); |
| extern void force_sig(int, struct task_struct *); |
| extern int send_sig(int, struct task_struct *, int); |
| extern int zap_other_threads(struct task_struct *p); |
| extern struct sigqueue *sigqueue_alloc(void); |
| extern void sigqueue_free(struct sigqueue *); |
| extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group); |
| extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); |
| |
| static inline int restart_syscall(void) |
| { |
| set_tsk_thread_flag(current, TIF_SIGPENDING); |
| return -ERESTARTNOINTR; |
| } |
| |
| static inline int signal_pending(struct task_struct *p) |
| { |
| return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); |
| } |
| |
| static inline int __fatal_signal_pending(struct task_struct *p) |
| { |
| return unlikely(sigismember(&p->pending.signal, SIGKILL)); |
| } |
| |
| static inline int fatal_signal_pending(struct task_struct *p) |
| { |
| return signal_pending(p) && __fatal_signal_pending(p); |
| } |
| |
| static inline int signal_pending_state(long state, struct task_struct *p) |
| { |
| if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) |
| return 0; |
| if (!signal_pending(p)) |
| return 0; |
| |
| return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); |
| } |
| |
| /* |
| * Reevaluate whether the task has signals pending delivery. |
| * Wake the task if so. |
| * This is required every time the blocked sigset_t changes. |
| * callers must hold sighand->siglock. |
| */ |
| extern void recalc_sigpending_and_wake(struct task_struct *t); |
| extern void recalc_sigpending(void); |
| |
| extern void signal_wake_up_state(struct task_struct *t, unsigned int state); |
| |
| static inline void signal_wake_up(struct task_struct *t, bool resume) |
| { |
| signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0); |
| } |
| static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) |
| { |
| signal_wake_up_state(t, resume ? __TASK_TRACED : 0); |
| } |
| |
| #ifdef TIF_RESTORE_SIGMASK |
| /* |
| * Legacy restore_sigmask accessors. These are inefficient on |
| * SMP architectures because they require atomic operations. |
| */ |
| |
| /** |
| * set_restore_sigmask() - make sure saved_sigmask processing gets done |
| * |
| * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code |
| * will run before returning to user mode, to process the flag. For |
| * all callers, TIF_SIGPENDING is already set or it's no harm to set |
| * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the |
| * arch code will notice on return to user mode, in case those bits |
| * are scarce. We set TIF_SIGPENDING here to ensure that the arch |
| * signal code always gets run when TIF_RESTORE_SIGMASK is set. |
| */ |
| static inline void set_restore_sigmask(void) |
| { |
| set_thread_flag(TIF_RESTORE_SIGMASK); |
| WARN_ON(!test_thread_flag(TIF_SIGPENDING)); |
| } |
| static inline void clear_restore_sigmask(void) |
| { |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| static inline bool test_restore_sigmask(void) |
| { |
| return test_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| static inline bool test_and_clear_restore_sigmask(void) |
| { |
| return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| |
| #else /* TIF_RESTORE_SIGMASK */ |
| |
| /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ |
| static inline void set_restore_sigmask(void) |
| { |
| current->restore_sigmask = true; |
| WARN_ON(!test_thread_flag(TIF_SIGPENDING)); |
| } |
| static inline void clear_restore_sigmask(void) |
| { |
| current->restore_sigmask = false; |
| } |
| static inline bool test_restore_sigmask(void) |
| { |
| return current->restore_sigmask; |
| } |
| static inline bool test_and_clear_restore_sigmask(void) |
| { |
| if (!current->restore_sigmask) |
| return false; |
| current->restore_sigmask = false; |
| return true; |
| } |
| #endif |
| |
| static inline void restore_saved_sigmask(void) |
| { |
| if (test_and_clear_restore_sigmask()) |
| __set_current_blocked(¤t->saved_sigmask); |
| } |
| |
| static inline sigset_t *sigmask_to_save(void) |
| { |
| sigset_t *res = ¤t->blocked; |
| if (unlikely(test_restore_sigmask())) |
| res = ¤t->saved_sigmask; |
| return res; |
| } |
| |
| static inline int kill_cad_pid(int sig, int priv) |
| { |
| return kill_pid(cad_pid, sig, priv); |
| } |
| |
| /* These can be the second arg to send_sig_info/send_group_sig_info. */ |
| #define SEND_SIG_NOINFO ((struct siginfo *) 0) |
| #define SEND_SIG_PRIV ((struct siginfo *) 1) |
| #define SEND_SIG_FORCED ((struct siginfo *) 2) |
| |
| /* |
| * True if we are on the alternate signal stack. |
| */ |
| static inline int on_sig_stack(unsigned long sp) |
| { |
| /* |
| * If the signal stack is SS_AUTODISARM then, by construction, we |
| * can't be on the signal stack unless user code deliberately set |
| * SS_AUTODISARM when we were already on it. |
| * |
| * This improves reliability: if user state gets corrupted such that |
| * the stack pointer points very close to the end of the signal stack, |
| * then this check will enable the signal to be handled anyway. |
| */ |
| if (current->sas_ss_flags & SS_AUTODISARM) |
| return 0; |
| |
| #ifdef CONFIG_STACK_GROWSUP |
| return sp >= current->sas_ss_sp && |
| sp - current->sas_ss_sp < current->sas_ss_size; |
| #else |
| return sp > current->sas_ss_sp && |
| sp - current->sas_ss_sp <= current->sas_ss_size; |
| #endif |
| } |
| |
| static inline int sas_ss_flags(unsigned long sp) |
| { |
| if (!current->sas_ss_size) |
| return SS_DISABLE; |
| |
| return on_sig_stack(sp) ? SS_ONSTACK : 0; |
| } |
| |
| static inline void sas_ss_reset(struct task_struct *p) |
| { |
| p->sas_ss_sp = 0; |
| p->sas_ss_size = 0; |
| p->sas_ss_flags = SS_DISABLE; |
| } |
| |
| static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) |
| { |
| if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp)) |
| #ifdef CONFIG_STACK_GROWSUP |
| return current->sas_ss_sp; |
| #else |
| return current->sas_ss_sp + current->sas_ss_size; |
| #endif |
| return sp; |
| } |
| |
| extern void __cleanup_sighand(struct sighand_struct *); |
| extern void flush_itimer_signals(void); |
| |
| #define tasklist_empty() \ |
| list_empty(&init_task.tasks) |
| |
| #define next_task(p) \ |
| list_entry_rcu((p)->tasks.next, struct task_struct, tasks) |
| |
| #define for_each_process(p) \ |
| for (p = &init_task ; (p = next_task(p)) != &init_task ; ) |
| |
| extern bool current_is_single_threaded(void); |
| |
| /* |
| * Careful: do_each_thread/while_each_thread is a double loop so |
| * 'break' will not work as expected - use goto instead. |
| */ |
| #define do_each_thread(g, t) \ |
| for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do |
| |
| #define while_each_thread(g, t) \ |
| while ((t = next_thread(t)) != g) |
| |
| #define __for_each_thread(signal, t) \ |
| list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node) |
| |
| #define for_each_thread(p, t) \ |
| __for_each_thread((p)->signal, t) |
| |
| /* Careful: this is a double loop, 'break' won't work as expected. */ |
| #define for_each_process_thread(p, t) \ |
| for_each_process(p) for_each_thread(p, t) |
| |
| typedef int (*proc_visitor)(struct task_struct *p, void *data); |
| void walk_process_tree(struct task_struct *top, proc_visitor, void *); |
| |
| static inline int get_nr_threads(struct task_struct *tsk) |
| { |
| return tsk->signal->nr_threads; |
| } |
| |
| static inline bool thread_group_leader(struct task_struct *p) |
| { |
| return p->exit_signal >= 0; |
| } |
| |
| /* Do to the insanities of de_thread it is possible for a process |
| * to have the pid of the thread group leader without actually being |
| * the thread group leader. For iteration through the pids in proc |
| * all we care about is that we have a task with the appropriate |
| * pid, we don't actually care if we have the right task. |
| */ |
| static inline bool has_group_leader_pid(struct task_struct *p) |
| { |
| return task_pid(p) == p->signal->leader_pid; |
| } |
| |
| static inline |
| bool same_thread_group(struct task_struct *p1, struct task_struct *p2) |
| { |
| return p1->signal == p2->signal; |
| } |
| |
| static inline struct task_struct *next_thread(const struct task_struct *p) |
| { |
| return list_entry_rcu(p->thread_group.next, |
| struct task_struct, thread_group); |
| } |
| |
| static inline int thread_group_empty(struct task_struct *p) |
| { |
| return list_empty(&p->thread_group); |
| } |
| |
| #define delay_group_leader(p) \ |
| (thread_group_leader(p) && !thread_group_empty(p)) |
| |
| extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, |
| unsigned long *flags); |
| |
| static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk, |
| unsigned long *flags) |
| { |
| struct sighand_struct *ret; |
| |
| ret = __lock_task_sighand(tsk, flags); |
| (void)__cond_lock(&tsk->sighand->siglock, ret); |
| return ret; |
| } |
| |
| static inline void unlock_task_sighand(struct task_struct *tsk, |
| unsigned long *flags) |
| { |
| spin_unlock_irqrestore(&tsk->sighand->siglock, *flags); |
| } |
| |
| static inline unsigned long task_rlimit(const struct task_struct *tsk, |
| unsigned int limit) |
| { |
| return READ_ONCE(tsk->signal->rlim[limit].rlim_cur); |
| } |
| |
| static inline unsigned long task_rlimit_max(const struct task_struct *tsk, |
| unsigned int limit) |
| { |
| return READ_ONCE(tsk->signal->rlim[limit].rlim_max); |
| } |
| |
| static inline unsigned long rlimit(unsigned int limit) |
| { |
| return task_rlimit(current, limit); |
| } |
| |
| static inline unsigned long rlimit_max(unsigned int limit) |
| { |
| return task_rlimit_max(current, limit); |
| } |
| |
| #endif /* _LINUX_SCHED_SIGNAL_H */ |