diff options
Diffstat (limited to 'include/linux/sched/signal.h')
| -rw-r--r-- | include/linux/sched/signal.h | 330 |
1 files changed, 217 insertions, 113 deletions
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 13789d10a50e..7d6449982822 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -8,16 +8,21 @@ #include <linux/sched/jobctl.h> #include <linux/sched/task.h> #include <linux/cred.h> +#include <linux/refcount.h> +#include <linux/pid.h> +#include <linux/posix-timers.h> +#include <linux/mm_types.h> +#include <asm/ptrace.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; + refcount_t count; wait_queue_head_t signalfd_wqh; + struct k_sigaction action[_NSIG]; }; /* @@ -55,18 +60,12 @@ struct task_cputime_atomic { /** * 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; }; struct multiprocess_signals { @@ -74,6 +73,17 @@ struct multiprocess_signals { struct hlist_node node; }; +struct core_thread { + struct task_struct *task; + struct core_thread *next; +}; + +struct core_state { + atomic_t nr_threads; + struct core_thread dumper; + struct completion startup; +}; + /* * NOTE! "signal_struct" does not have its own * locking, because a shared signal_struct always @@ -82,9 +92,10 @@ struct multiprocess_signals { * the locking of signal_struct. */ struct signal_struct { - atomic_t sigcnt; + refcount_t sigcnt; atomic_t live; int nr_threads; + int quick_threads; struct list_head thread_head; wait_queue_head_t wait_chldexit; /* for wait4() */ @@ -100,18 +111,16 @@ struct signal_struct { /* 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. - */ + /* notify group_exec_task when notify_count is less or equal to 0 */ int notify_count; - struct task_struct *group_exit_task; + struct task_struct *group_exec_task; /* thread group stop support, overloads group_exit_code too */ int group_stop_count; unsigned int flags; /* see SIGNAL_* flags below */ + struct core_state *core_state; /* coredumping support */ + /* * PR_SET_CHILD_SUBREAPER marks a process, like a service * manager, to re-parent orphan (double-forking) child processes @@ -127,8 +136,10 @@ struct signal_struct { #ifdef CONFIG_POSIX_TIMERS /* POSIX.1b Interval Timers */ - int posix_timer_id; - struct list_head posix_timers; + unsigned int timer_create_restore_ids:1; + atomic_t next_posix_timer_id; + struct hlist_head posix_timers; + struct hlist_head ignored_posix_timers; /* ITIMER_REAL timer for the process */ struct hrtimer real_timer; @@ -147,12 +158,9 @@ struct signal_struct { */ struct thread_group_cputimer cputimer; - /* Earliest-expiration cache. */ - struct task_cputime cputime_expires; - - struct list_head cpu_timers[3]; - #endif + /* Empty if CONFIG_POSIX_TIMERS=n */ + struct posix_cputimers posix_cputimers; /* PID/PID hash table linkage. */ struct pid *pids[PIDTYPE_MAX]; @@ -218,6 +226,10 @@ struct signal_struct { struct tty_audit_buf *tty_audit_buf; #endif +#ifdef CONFIG_CGROUPS + struct rw_semaphore cgroup_threadgroup_rwsem; +#endif + /* * Thread is the potential origin of an oom condition; kill first on * oom @@ -231,7 +243,15 @@ struct signal_struct { struct mutex cred_guard_mutex; /* guard against foreign influences on * credential calculations - * (notably. ptrace) */ + * (notably. ptrace) + * Deprecated do not use in new code. + * Use exec_update_lock instead. + */ + struct rw_semaphore exec_update_lock; /* Held while task_struct is + * being updated during exec, + * and may have inconsistent + * permissions. + */ } __randomize_layout; /* @@ -240,7 +260,6 @@ struct 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. */ @@ -256,31 +275,25 @@ struct signal_struct { static inline void signal_set_stop_flags(struct signal_struct *sig, unsigned int flags) { - WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP)); + WARN_ON(sig->flags & SIGNAL_GROUP_EXIT); 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, kernel_siginfo_t *info); +extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type); static inline int kernel_dequeue_signal(void) { - struct task_struct *tsk = current; + struct task_struct *task = current; kernel_siginfo_t __info; + enum pid_type __type; int ret; - spin_lock_irq(&tsk->sighand->siglock); - ret = dequeue_signal(tsk, &tsk->blocked, &__info); - spin_unlock_irq(&tsk->sighand->siglock); + spin_lock_irq(&task->sighand->siglock); + ret = dequeue_signal(&task->blocked, &__info, &__type); + spin_unlock_irq(&task->sighand->siglock); return ret; } @@ -288,70 +301,100 @@ static inline int kernel_dequeue_signal(void) static inline void kernel_signal_stop(void) { spin_lock_irq(¤t->sighand->siglock); - if (current->jobctl & JOBCTL_STOP_DEQUEUED) + if (current->jobctl & JOBCTL_STOP_DEQUEUED) { + current->jobctl |= JOBCTL_STOPPED; set_special_state(TASK_STOPPED); + } spin_unlock_irq(¤t->sighand->siglock); schedule(); } -#ifdef __ARCH_SI_TRAPNO -# define ___ARCH_SI_TRAPNO(_a1) , _a1 -#else -# define ___ARCH_SI_TRAPNO(_a1) -#endif -#ifdef __ia64__ -# define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3 -#else -# define ___ARCH_SI_IA64(_a1, _a2, _a3) -#endif -int force_sig_fault(int sig, int code, void __user *addr - ___ARCH_SI_TRAPNO(int trapno) - ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) - , struct task_struct *t); -int send_sig_fault(int sig, int code, void __user *addr - ___ARCH_SI_TRAPNO(int trapno) - ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) - , struct task_struct *t); +int force_sig_fault_to_task(int sig, int code, void __user *addr, + struct task_struct *t); +int force_sig_fault(int sig, int code, void __user *addr); +int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t); -int force_sig_mceerr(int code, void __user *, short, struct task_struct *); +int force_sig_mceerr(int code, void __user *, short); int send_sig_mceerr(int code, void __user *, short, struct task_struct *); int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); int force_sig_pkuerr(void __user *addr, u32 pkey); +int send_sig_perf(void __user *addr, u32 type, u64 sig_data); int force_sig_ptrace_errno_trap(int errno, void __user *addr); +int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); +int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, + struct task_struct *t); +int force_sig_seccomp(int syscall, int reason, bool force_coredump); extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); -extern void force_sigsegv(int sig, struct task_struct *p); -extern int force_sig_info(int, struct kernel_siginfo *, struct task_struct *); +extern void force_sigsegv(int sig); +extern int force_sig_info(struct kernel_siginfo *); extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); -extern int kill_pid_info_as_cred(int, struct kernel_siginfo *, struct pid *, +extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, const struct cred *); extern int kill_pgrp(struct pid *pid, int sig, int priv); extern int kill_pid(struct pid *pid, int sig, int priv); 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 void force_sig(int); +extern void force_fatal_sig(int); +extern void force_exit_sig(int); 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 pid *, enum pid_type); extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); +static inline void clear_notify_signal(void) +{ + clear_thread_flag(TIF_NOTIFY_SIGNAL); + smp_mb__after_atomic(); +} + +/* + * Returns 'true' if kick_process() is needed to force a transition from + * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work. + */ +static inline bool __set_notify_signal(struct task_struct *task) +{ + return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) && + !wake_up_state(task, TASK_INTERRUPTIBLE); +} + +/* + * Called to break out of interruptible wait loops, and enter the + * exit_to_user_mode_loop(). + */ +static inline void set_notify_signal(struct task_struct *task) +{ + if (__set_notify_signal(task)) + kick_process(task); +} + static inline int restart_syscall(void) { set_tsk_thread_flag(current, TIF_SIGPENDING); return -ERESTARTNOINTR; } -static inline int signal_pending(struct task_struct *p) +static inline int task_sigpending(struct task_struct *p) { return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); } +static inline int signal_pending(struct task_struct *p) +{ + /* + * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same + * behavior in terms of ensuring that we break out of wait loops + * so that notify signal callbacks can be processed. + */ + if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) + return 1; + return task_sigpending(p); +} + static inline int __fatal_signal_pending(struct task_struct *p) { return unlikely(sigismember(&p->pending.signal, SIGKILL)); @@ -359,10 +402,10 @@ static inline int __fatal_signal_pending(struct task_struct *p) static inline int fatal_signal_pending(struct task_struct *p) { - return signal_pending(p) && __fatal_signal_pending(p); + return task_sigpending(p) && __fatal_signal_pending(p); } -static inline int signal_pending_state(long state, struct task_struct *p) +static inline int signal_pending_state(unsigned int state, struct task_struct *p) { if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) return 0; @@ -373,24 +416,47 @@ static inline int signal_pending_state(long state, struct task_struct *p) } /* + * This should only be used in fault handlers to decide whether we + * should stop the current fault routine to handle the signals + * instead, especially with the case where we've got interrupted with + * a VM_FAULT_RETRY. + */ +static inline bool fault_signal_pending(vm_fault_t fault_flags, + struct pt_regs *regs) +{ + return unlikely((fault_flags & VM_FAULT_RETRY) && + (fatal_signal_pending(current) || + (user_mode(regs) && signal_pending(current)))); +} + +/* * 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 calculate_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) +static inline void signal_wake_up(struct task_struct *t, bool fatal) { - signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0); + unsigned int state = 0; + if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) { + t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED); + state = TASK_WAKEKILL | __TASK_TRACED; + } + signal_wake_up_state(t, state); } static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) { - signal_wake_up_state(t, resume ? __TASK_TRACED : 0); + unsigned int state = 0; + if (resume) { + t->jobctl &= ~JOBCTL_TRACED; + state = __TASK_TRACED; + } + signal_wake_up_state(t, state); } void task_join_group_stop(struct task_struct *task); @@ -415,12 +481,21 @@ void task_join_group_stop(struct task_struct *task); static inline void set_restore_sigmask(void) { set_thread_flag(TIF_RESTORE_SIGMASK); - WARN_ON(!test_thread_flag(TIF_SIGPENDING)); } + +static inline void clear_tsk_restore_sigmask(struct task_struct *task) +{ + clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); +} + static inline void clear_restore_sigmask(void) { clear_thread_flag(TIF_RESTORE_SIGMASK); } +static inline bool test_tsk_restore_sigmask(struct task_struct *task) +{ + return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); +} static inline bool test_restore_sigmask(void) { return test_thread_flag(TIF_RESTORE_SIGMASK); @@ -436,7 +511,10 @@ static inline bool test_and_clear_restore_sigmask(void) static inline void set_restore_sigmask(void) { current->restore_sigmask = true; - WARN_ON(!test_thread_flag(TIF_SIGPENDING)); +} +static inline void clear_tsk_restore_sigmask(struct task_struct *task) +{ + task->restore_sigmask = false; } static inline void clear_restore_sigmask(void) { @@ -446,6 +524,10 @@ static inline bool test_restore_sigmask(void) { return current->restore_sigmask; } +static inline bool test_tsk_restore_sigmask(struct task_struct *task) +{ + return task->restore_sigmask; +} static inline bool test_and_clear_restore_sigmask(void) { if (!current->restore_sigmask) @@ -461,6 +543,16 @@ static inline void restore_saved_sigmask(void) __set_current_blocked(¤t->saved_sigmask); } +extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); + +static inline void restore_saved_sigmask_unless(bool interrupted) +{ + if (interrupted) + WARN_ON(!signal_pending(current)); + else + restore_saved_sigmask(); +} + static inline sigset_t *sigmask_to_save(void) { sigset_t *res = ¤t->blocked; @@ -478,6 +570,17 @@ static inline int kill_cad_pid(int sig, int priv) #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) #define SEND_SIG_PRIV ((struct kernel_siginfo *) 1) +static inline int __on_sig_stack(unsigned long sp) +{ +#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 +} + /* * True if we are on the alternate signal stack. */ @@ -495,13 +598,7 @@ static inline int on_sig_stack(unsigned long sp) 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 + return __on_sig_stack(sp); } static inline int sas_ss_flags(unsigned long sp) @@ -545,17 +642,18 @@ extern void flush_itimer_signals(void); 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. + * Without tasklist/siglock it is only rcu-safe if g can't exit/exec, + * otherwise next_thread(t) will never reach g after list_del_rcu(g). */ -#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_other_threads(p, t) \ + for (t = p; (t = next_thread(t)) != p; ) + #define __for_each_thread(signal, t) \ - list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node) + list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node, \ + lockdep_is_held(&tasklist_lock)) #define for_each_thread(p, t) \ __for_each_thread((p)->signal, t) @@ -598,9 +696,9 @@ static inline struct pid *task_session(struct task_struct *task) return task->signal->pids[PIDTYPE_SID]; } -static inline int get_nr_threads(struct task_struct *tsk) +static inline int get_nr_threads(struct task_struct *task) { - return tsk->signal->nr_threads; + return task->signal->nr_threads; } static inline bool thread_group_leader(struct task_struct *p) @@ -608,66 +706,72 @@ 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) == task_tgid(p); -} - 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) +/* + * returns NULL if p is the last thread in the thread group + */ +static inline struct task_struct *__next_thread(struct task_struct *p) { - return list_entry_rcu(p->thread_group.next, - struct task_struct, thread_group); + return list_next_or_null_rcu(&p->signal->thread_head, + &p->thread_node, + struct task_struct, + thread_node); +} + +static inline struct task_struct *next_thread(struct task_struct *p) +{ + return __next_thread(p) ?: p->group_leader; } static inline int thread_group_empty(struct task_struct *p) { - return list_empty(&p->thread_group); + return thread_group_leader(p) && + list_is_last(&p->thread_node, &p->signal->thread_head); } #define delay_group_leader(p) \ (thread_group_leader(p) && !thread_group_empty(p)) -extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, +extern struct sighand_struct *__lock_task_sighand(struct task_struct *task, unsigned long *flags); -static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk, +static inline struct sighand_struct *lock_task_sighand(struct task_struct *task, unsigned long *flags) { struct sighand_struct *ret; - ret = __lock_task_sighand(tsk, flags); - (void)__cond_lock(&tsk->sighand->siglock, ret); + ret = __lock_task_sighand(task, flags); + (void)__cond_lock(&task->sighand->siglock, ret); return ret; } -static inline void unlock_task_sighand(struct task_struct *tsk, +static inline void unlock_task_sighand(struct task_struct *task, unsigned long *flags) { - spin_unlock_irqrestore(&tsk->sighand->siglock, *flags); + spin_unlock_irqrestore(&task->sighand->siglock, *flags); } -static inline unsigned long task_rlimit(const struct task_struct *tsk, +#ifdef CONFIG_LOCKDEP +extern void lockdep_assert_task_sighand_held(struct task_struct *task); +#else +static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { } +#endif + +static inline unsigned long task_rlimit(const struct task_struct *task, unsigned int limit) { - return READ_ONCE(tsk->signal->rlim[limit].rlim_cur); + return READ_ONCE(task->signal->rlim[limit].rlim_cur); } -static inline unsigned long task_rlimit_max(const struct task_struct *tsk, +static inline unsigned long task_rlimit_max(const struct task_struct *task, unsigned int limit) { - return READ_ONCE(tsk->signal->rlim[limit].rlim_max); + return READ_ONCE(task->signal->rlim[limit].rlim_max); } static inline unsigned long rlimit(unsigned int limit) |