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signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
[thirdparty/linux.git] / include / linux / sched / signal.h
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b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
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2#ifndef _LINUX_SCHED_SIGNAL_H
3#define _LINUX_SCHED_SIGNAL_H
4
b2d09103 5#include <linux/rculist.h>
f361bf4a 6#include <linux/signal.h>
3f07c014 7#include <linux/sched.h>
1e4bae64 8#include <linux/sched/jobctl.h>
9164bb4a 9#include <linux/sched/task.h>
2a1f062a 10#include <linux/cred.h>
d036bda7 11#include <linux/refcount.h>
2b69942f 12#include <linux/posix-timers.h>
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13#include <linux/mm_types.h>
14#include <asm/ptrace.h>
3f07c014 15
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16/*
17 * Types defining task->signal and task->sighand and APIs using them:
18 */
19
20struct sighand_struct {
c3edc401 21 spinlock_t siglock;
e2d9018e 22 refcount_t count;
c3edc401 23 wait_queue_head_t signalfd_wqh;
e2d9018e 24 struct k_sigaction action[_NSIG];
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25};
26
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27/*
28 * Per-process accounting stats:
29 */
30struct pacct_struct {
31 int ac_flag;
32 long ac_exitcode;
33 unsigned long ac_mem;
34 u64 ac_utime, ac_stime;
35 unsigned long ac_minflt, ac_majflt;
36};
37
38struct cpu_itimer {
39 u64 expires;
40 u64 incr;
41};
42
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43/*
44 * This is the atomic variant of task_cputime, which can be used for
45 * storing and updating task_cputime statistics without locking.
46 */
47struct task_cputime_atomic {
48 atomic64_t utime;
49 atomic64_t stime;
50 atomic64_t sum_exec_runtime;
51};
52
53#define INIT_CPUTIME_ATOMIC \
54 (struct task_cputime_atomic) { \
55 .utime = ATOMIC64_INIT(0), \
56 .stime = ATOMIC64_INIT(0), \
57 .sum_exec_runtime = ATOMIC64_INIT(0), \
58 }
59/**
60 * struct thread_group_cputimer - thread group interval timer counts
61 * @cputime_atomic: atomic thread group interval timers.
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62 *
63 * This structure contains the version of task_cputime, above, that is
64 * used for thread group CPU timer calculations.
65 */
66struct thread_group_cputimer {
67 struct task_cputime_atomic cputime_atomic;
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68};
69
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70struct multiprocess_signals {
71 sigset_t signal;
72 struct hlist_node node;
73};
74
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75struct core_thread {
76 struct task_struct *task;
77 struct core_thread *next;
78};
79
80struct core_state {
81 atomic_t nr_threads;
82 struct core_thread dumper;
83 struct completion startup;
84};
85
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86/*
87 * NOTE! "signal_struct" does not have its own
88 * locking, because a shared signal_struct always
89 * implies a shared sighand_struct, so locking
90 * sighand_struct is always a proper superset of
91 * the locking of signal_struct.
92 */
93struct signal_struct {
60d4de3f 94 refcount_t sigcnt;
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95 atomic_t live;
96 int nr_threads;
d80f7d7b 97 int quick_threads;
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98 struct list_head thread_head;
99
100 wait_queue_head_t wait_chldexit; /* for wait4() */
101
102 /* current thread group signal load-balancing target: */
103 struct task_struct *curr_target;
104
105 /* shared signal handling: */
106 struct sigpending shared_pending;
107
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108 /* For collecting multiprocess signals during fork */
109 struct hlist_head multiprocess;
110
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111 /* thread group exit support */
112 int group_exit_code;
60700e38 113 /* notify group_exec_task when notify_count is less or equal to 0 */
c3edc401 114 int notify_count;
60700e38 115 struct task_struct *group_exec_task;
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116
117 /* thread group stop support, overloads group_exit_code too */
118 int group_stop_count;
119 unsigned int flags; /* see SIGNAL_* flags below */
120
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121 struct core_state *core_state; /* coredumping support */
122
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123 /*
124 * PR_SET_CHILD_SUBREAPER marks a process, like a service
125 * manager, to re-parent orphan (double-forking) child processes
126 * to this process instead of 'init'. The service manager is
127 * able to receive SIGCHLD signals and is able to investigate
128 * the process until it calls wait(). All children of this
129 * process will inherit a flag if they should look for a
130 * child_subreaper process at exit.
131 */
132 unsigned int is_child_subreaper:1;
133 unsigned int has_child_subreaper:1;
134
135#ifdef CONFIG_POSIX_TIMERS
136
137 /* POSIX.1b Interval Timers */
138 int posix_timer_id;
139 struct list_head posix_timers;
140
141 /* ITIMER_REAL timer for the process */
142 struct hrtimer real_timer;
143 ktime_t it_real_incr;
144
145 /*
146 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
147 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
148 * values are defined to 0 and 1 respectively
149 */
150 struct cpu_itimer it[2];
151
152 /*
153 * Thread group totals for process CPU timers.
154 * See thread_group_cputimer(), et al, for details.
155 */
156 struct thread_group_cputimer cputimer;
157
c3edc401 158#endif
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159 /* Empty if CONFIG_POSIX_TIMERS=n */
160 struct posix_cputimers posix_cputimers;
c3edc401 161
2c470475 162 /* PID/PID hash table linkage. */
2c470475 163 struct pid *pids[PIDTYPE_MAX];
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164
165#ifdef CONFIG_NO_HZ_FULL
166 atomic_t tick_dep_mask;
167#endif
168
169 struct pid *tty_old_pgrp;
170
171 /* boolean value for session group leader */
172 int leader;
173
174 struct tty_struct *tty; /* NULL if no tty */
175
176#ifdef CONFIG_SCHED_AUTOGROUP
177 struct autogroup *autogroup;
178#endif
179 /*
180 * Cumulative resource counters for dead threads in the group,
181 * and for reaped dead child processes forked by this group.
182 * Live threads maintain their own counters and add to these
183 * in __exit_signal, except for the group leader.
184 */
185 seqlock_t stats_lock;
186 u64 utime, stime, cutime, cstime;
187 u64 gtime;
188 u64 cgtime;
189 struct prev_cputime prev_cputime;
190 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
191 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
192 unsigned long inblock, oublock, cinblock, coublock;
193 unsigned long maxrss, cmaxrss;
194 struct task_io_accounting ioac;
195
196 /*
197 * Cumulative ns of schedule CPU time fo dead threads in the
198 * group, not including a zombie group leader, (This only differs
199 * from jiffies_to_ns(utime + stime) if sched_clock uses something
200 * other than jiffies.)
201 */
202 unsigned long long sum_sched_runtime;
203
204 /*
205 * We don't bother to synchronize most readers of this at all,
206 * because there is no reader checking a limit that actually needs
207 * to get both rlim_cur and rlim_max atomically, and either one
208 * alone is a single word that can safely be read normally.
209 * getrlimit/setrlimit use task_lock(current->group_leader) to
210 * protect this instead of the siglock, because they really
211 * have no need to disable irqs.
212 */
213 struct rlimit rlim[RLIM_NLIMITS];
214
215#ifdef CONFIG_BSD_PROCESS_ACCT
216 struct pacct_struct pacct; /* per-process accounting information */
217#endif
218#ifdef CONFIG_TASKSTATS
219 struct taskstats *stats;
220#endif
221#ifdef CONFIG_AUDIT
222 unsigned audit_tty;
223 struct tty_audit_buf *tty_audit_buf;
224#endif
225
226 /*
227 * Thread is the potential origin of an oom condition; kill first on
228 * oom
229 */
230 bool oom_flag_origin;
231 short oom_score_adj; /* OOM kill score adjustment */
232 short oom_score_adj_min; /* OOM kill score adjustment min value.
233 * Only settable by CAP_SYS_RESOURCE. */
234 struct mm_struct *oom_mm; /* recorded mm when the thread group got
235 * killed by the oom killer */
236
237 struct mutex cred_guard_mutex; /* guard against foreign influences on
238 * credential calculations
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239 * (notably. ptrace)
240 * Deprecated do not use in new code.
f7cfd871 241 * Use exec_update_lock instead.
eea96732 242 */
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243 struct rw_semaphore exec_update_lock; /* Held while task_struct is
244 * being updated during exec,
245 * and may have inconsistent
246 * permissions.
247 */
3859a271 248} __randomize_layout;
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249
250/*
251 * Bits in flags field of signal_struct.
252 */
253#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
254#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
255#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
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256/*
257 * Pending notifications to parent.
258 */
259#define SIGNAL_CLD_STOPPED 0x00000010
260#define SIGNAL_CLD_CONTINUED 0x00000020
261#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
262
263#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
264
265#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
266 SIGNAL_STOP_CONTINUED)
267
268static inline void signal_set_stop_flags(struct signal_struct *sig,
269 unsigned int flags)
270{
2f824d4d 271 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
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272 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
273}
274
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275extern void flush_signals(struct task_struct *);
276extern void ignore_signals(struct task_struct *);
277extern void flush_signal_handlers(struct task_struct *, int force_default);
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278extern int dequeue_signal(struct task_struct *task, sigset_t *mask,
279 kernel_siginfo_t *info, enum pid_type *type);
c3edc401 280
961366a0 281static inline int kernel_dequeue_signal(void)
c3edc401 282{
9e9291c7 283 struct task_struct *task = current;
ae7795bc 284 kernel_siginfo_t __info;
5768d890 285 enum pid_type __type;
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286 int ret;
287
9e9291c7 288 spin_lock_irq(&task->sighand->siglock);
5768d890 289 ret = dequeue_signal(task, &task->blocked, &__info, &__type);
9e9291c7 290 spin_unlock_irq(&task->sighand->siglock);
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291
292 return ret;
293}
294
295static inline void kernel_signal_stop(void)
296{
297 spin_lock_irq(&current->sighand->siglock);
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298 if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
299 current->jobctl |= JOBCTL_STOPPED;
b5bf9a90 300 set_special_state(TASK_STOPPED);
31cae1ea 301 }
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302 spin_unlock_irq(&current->sighand->siglock);
303
304 schedule();
305}
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306#ifdef __ia64__
307# define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3
308#else
309# define ___ARCH_SI_IA64(_a1, _a2, _a3)
310#endif
311
91ca180d 312int force_sig_fault_to_task(int sig, int code, void __user *addr
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313 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
314 , struct task_struct *t);
f8ec6601 315int force_sig_fault(int sig, int code, void __user *addr
2e1661d2 316 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
f8ec6601 317int send_sig_fault(int sig, int code, void __user *addr
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318 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
319 , struct task_struct *t);
320
f8eac901 321int force_sig_mceerr(int code, void __user *, short);
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322int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
323
324int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
325int force_sig_pkuerr(void __user *addr, u32 pkey);
78ed93d7 326int send_sig_perf(void __user *addr, u32 type, u64 sig_data);
38246735 327
f71dd7dc 328int force_sig_ptrace_errno_trap(int errno, void __user *addr);
2c9f7eaf 329int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
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330int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
331 struct task_struct *t);
307d522f 332int force_sig_seccomp(int syscall, int reason, bool force_coredump);
f71dd7dc 333
ae7795bc 334extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
cb44c9a0 335extern void force_sigsegv(int sig);
a89e9b8a 336extern int force_sig_info(struct kernel_siginfo *);
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337extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
338extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
70f1b0d3 339extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
6b4f3d01 340 const struct cred *);
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341extern int kill_pgrp(struct pid *pid, int sig, int priv);
342extern int kill_pid(struct pid *pid, int sig, int priv);
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343extern __must_check bool do_notify_parent(struct task_struct *, int);
344extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
3cf5d076 345extern void force_sig(int);
26d5badb 346extern void force_fatal_sig(int);
fcb116bc 347extern void force_exit_sig(int);
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348extern int send_sig(int, struct task_struct *, int);
349extern int zap_other_threads(struct task_struct *p);
350extern struct sigqueue *sigqueue_alloc(void);
351extern void sigqueue_free(struct sigqueue *);
24122c7f 352extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
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353extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
354
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355static inline void clear_notify_signal(void)
356{
357 clear_thread_flag(TIF_NOTIFY_SIGNAL);
358 smp_mb__after_atomic();
359}
360
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361/*
362 * Returns 'true' if kick_process() is needed to force a transition from
363 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
364 */
365static inline bool __set_notify_signal(struct task_struct *task)
366{
367 return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
368 !wake_up_state(task, TASK_INTERRUPTIBLE);
369}
370
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371/*
372 * Called to break out of interruptible wait loops, and enter the
373 * exit_to_user_mode_loop().
374 */
375static inline void set_notify_signal(struct task_struct *task)
376{
e788be95 377 if (__set_notify_signal(task))
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378 kick_process(task);
379}
380
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381static inline int restart_syscall(void)
382{
383 set_tsk_thread_flag(current, TIF_SIGPENDING);
384 return -ERESTARTNOINTR;
385}
386
5c251e9d 387static inline int task_sigpending(struct task_struct *p)
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388{
389 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
390}
391
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392static inline int signal_pending(struct task_struct *p)
393{
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394 /*
395 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
396 * behavior in terms of ensuring that we break out of wait loops
397 * so that notify signal callbacks can be processed.
398 */
399 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
400 return 1;
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401 return task_sigpending(p);
402}
403
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404static inline int __fatal_signal_pending(struct task_struct *p)
405{
406 return unlikely(sigismember(&p->pending.signal, SIGKILL));
407}
408
409static inline int fatal_signal_pending(struct task_struct *p)
410{
5c251e9d 411 return task_sigpending(p) && __fatal_signal_pending(p);
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412}
413
2f064a59 414static inline int signal_pending_state(unsigned int state, struct task_struct *p)
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415{
416 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
417 return 0;
418 if (!signal_pending(p))
419 return 0;
420
421 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
422}
423
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424/*
425 * This should only be used in fault handlers to decide whether we
426 * should stop the current fault routine to handle the signals
427 * instead, especially with the case where we've got interrupted with
428 * a VM_FAULT_RETRY.
429 */
430static inline bool fault_signal_pending(vm_fault_t fault_flags,
431 struct pt_regs *regs)
432{
433 return unlikely((fault_flags & VM_FAULT_RETRY) &&
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434 (fatal_signal_pending(current) ||
435 (user_mode(regs) && signal_pending(current))));
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436}
437
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438/*
439 * Reevaluate whether the task has signals pending delivery.
440 * Wake the task if so.
441 * This is required every time the blocked sigset_t changes.
442 * callers must hold sighand->siglock.
443 */
444extern void recalc_sigpending_and_wake(struct task_struct *t);
445extern void recalc_sigpending(void);
088fe47c 446extern void calculate_sigpending(void);
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447
448extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
449
2500ad1c 450static inline void signal_wake_up(struct task_struct *t, bool fatal)
2a1f062a 451{
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452 unsigned int state = 0;
453 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
454 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
455 state = TASK_WAKEKILL | __TASK_TRACED;
456 }
457 signal_wake_up_state(t, state);
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458}
459static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
460{
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461 unsigned int state = 0;
462 if (resume) {
463 t->jobctl &= ~JOBCTL_TRACED;
464 state = __TASK_TRACED;
465 }
466 signal_wake_up_state(t, state);
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467}
468
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469void task_join_group_stop(struct task_struct *task);
470
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471#ifdef TIF_RESTORE_SIGMASK
472/*
473 * Legacy restore_sigmask accessors. These are inefficient on
474 * SMP architectures because they require atomic operations.
475 */
476
477/**
478 * set_restore_sigmask() - make sure saved_sigmask processing gets done
479 *
480 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
481 * will run before returning to user mode, to process the flag. For
482 * all callers, TIF_SIGPENDING is already set or it's no harm to set
483 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
484 * arch code will notice on return to user mode, in case those bits
485 * are scarce. We set TIF_SIGPENDING here to ensure that the arch
486 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
487 */
488static inline void set_restore_sigmask(void)
489{
490 set_thread_flag(TIF_RESTORE_SIGMASK);
c3edc401 491}
fcfc2aa0 492
9e9291c7 493static inline void clear_tsk_restore_sigmask(struct task_struct *task)
fcfc2aa0 494{
9e9291c7 495 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
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496}
497
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498static inline void clear_restore_sigmask(void)
499{
500 clear_thread_flag(TIF_RESTORE_SIGMASK);
501}
9e9291c7 502static inline bool test_tsk_restore_sigmask(struct task_struct *task)
fcfc2aa0 503{
9e9291c7 504 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
fcfc2aa0 505}
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506static inline bool test_restore_sigmask(void)
507{
508 return test_thread_flag(TIF_RESTORE_SIGMASK);
509}
510static inline bool test_and_clear_restore_sigmask(void)
511{
512 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
513}
514
515#else /* TIF_RESTORE_SIGMASK */
516
517/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
518static inline void set_restore_sigmask(void)
519{
520 current->restore_sigmask = true;
c3edc401 521}
9e9291c7 522static inline void clear_tsk_restore_sigmask(struct task_struct *task)
fcfc2aa0 523{
9e9291c7 524 task->restore_sigmask = false;
fcfc2aa0 525}
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526static inline void clear_restore_sigmask(void)
527{
528 current->restore_sigmask = false;
529}
530static inline bool test_restore_sigmask(void)
531{
532 return current->restore_sigmask;
533}
9e9291c7 534static inline bool test_tsk_restore_sigmask(struct task_struct *task)
fcfc2aa0 535{
9e9291c7 536 return task->restore_sigmask;
fcfc2aa0 537}
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538static inline bool test_and_clear_restore_sigmask(void)
539{
540 if (!current->restore_sigmask)
541 return false;
542 current->restore_sigmask = false;
543 return true;
544}
545#endif
546
547static inline void restore_saved_sigmask(void)
548{
549 if (test_and_clear_restore_sigmask())
550 __set_current_blocked(&current->saved_sigmask);
551}
552
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553extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
554
555static inline void restore_saved_sigmask_unless(bool interrupted)
556{
557 if (interrupted)
12db8b69 558 WARN_ON(!signal_pending(current));
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559 else
560 restore_saved_sigmask();
561}
562
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563static inline sigset_t *sigmask_to_save(void)
564{
565 sigset_t *res = &current->blocked;
566 if (unlikely(test_restore_sigmask()))
567 res = &current->saved_sigmask;
568 return res;
569}
570
571static inline int kill_cad_pid(int sig, int priv)
572{
573 return kill_pid(cad_pid, sig, priv);
574}
575
576/* These can be the second arg to send_sig_info/send_group_sig_info. */
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577#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
578#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
c3edc401 579
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580static inline int __on_sig_stack(unsigned long sp)
581{
582#ifdef CONFIG_STACK_GROWSUP
583 return sp >= current->sas_ss_sp &&
584 sp - current->sas_ss_sp < current->sas_ss_size;
585#else
586 return sp > current->sas_ss_sp &&
587 sp - current->sas_ss_sp <= current->sas_ss_size;
588#endif
589}
590
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591/*
592 * True if we are on the alternate signal stack.
593 */
594static inline int on_sig_stack(unsigned long sp)
595{
596 /*
597 * If the signal stack is SS_AUTODISARM then, by construction, we
598 * can't be on the signal stack unless user code deliberately set
599 * SS_AUTODISARM when we were already on it.
600 *
601 * This improves reliability: if user state gets corrupted such that
602 * the stack pointer points very close to the end of the signal stack,
603 * then this check will enable the signal to be handled anyway.
604 */
605 if (current->sas_ss_flags & SS_AUTODISARM)
606 return 0;
607
2beb4a53 608 return __on_sig_stack(sp);
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609}
610
611static inline int sas_ss_flags(unsigned long sp)
612{
613 if (!current->sas_ss_size)
614 return SS_DISABLE;
615
616 return on_sig_stack(sp) ? SS_ONSTACK : 0;
617}
618
619static inline void sas_ss_reset(struct task_struct *p)
620{
621 p->sas_ss_sp = 0;
622 p->sas_ss_size = 0;
623 p->sas_ss_flags = SS_DISABLE;
624}
625
626static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
627{
628 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
629#ifdef CONFIG_STACK_GROWSUP
630 return current->sas_ss_sp;
631#else
632 return current->sas_ss_sp + current->sas_ss_size;
633#endif
634 return sp;
635}
636
637extern void __cleanup_sighand(struct sighand_struct *);
638extern void flush_itimer_signals(void);
639
640#define tasklist_empty() \
641 list_empty(&init_task.tasks)
642
643#define next_task(p) \
644 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
645
646#define for_each_process(p) \
647 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
648
649extern bool current_is_single_threaded(void);
650
651/*
652 * Careful: do_each_thread/while_each_thread is a double loop so
653 * 'break' will not work as expected - use goto instead.
654 */
655#define do_each_thread(g, t) \
656 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
657
658#define while_each_thread(g, t) \
659 while ((t = next_thread(t)) != g)
660
661#define __for_each_thread(signal, t) \
662 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
663
664#define for_each_thread(p, t) \
665 __for_each_thread((p)->signal, t)
666
667/* Careful: this is a double loop, 'break' won't work as expected. */
668#define for_each_process_thread(p, t) \
669 for_each_process(p) for_each_thread(p, t)
670
671typedef int (*proc_visitor)(struct task_struct *p, void *data);
672void walk_process_tree(struct task_struct *top, proc_visitor, void *);
673
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674static inline
675struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
676{
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677 struct pid *pid;
678 if (type == PIDTYPE_PID)
679 pid = task_pid(task);
680 else
681 pid = task->signal->pids[type];
682 return pid;
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683}
684
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685static inline struct pid *task_tgid(struct task_struct *task)
686{
6883f81a 687 return task->signal->pids[PIDTYPE_TGID];
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688}
689
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690/*
691 * Without tasklist or RCU lock it is not safe to dereference
692 * the result of task_pgrp/task_session even if task == current,
693 * we can race with another thread doing sys_setsid/sys_setpgid.
694 */
695static inline struct pid *task_pgrp(struct task_struct *task)
696{
697 return task->signal->pids[PIDTYPE_PGID];
698}
699
700static inline struct pid *task_session(struct task_struct *task)
701{
702 return task->signal->pids[PIDTYPE_SID];
703}
704
9e9291c7 705static inline int get_nr_threads(struct task_struct *task)
c3edc401 706{
9e9291c7 707 return task->signal->nr_threads;
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708}
709
710static inline bool thread_group_leader(struct task_struct *p)
711{
712 return p->exit_signal >= 0;
713}
714
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715static inline
716bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
717{
718 return p1->signal == p2->signal;
719}
720
721static inline struct task_struct *next_thread(const struct task_struct *p)
722{
723 return list_entry_rcu(p->thread_group.next,
724 struct task_struct, thread_group);
725}
726
727static inline int thread_group_empty(struct task_struct *p)
728{
729 return list_empty(&p->thread_group);
730}
731
732#define delay_group_leader(p) \
733 (thread_group_leader(p) && !thread_group_empty(p))
734
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735extern bool thread_group_exited(struct pid *pid);
736
9e9291c7 737extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
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738 unsigned long *flags);
739
9e9291c7 740static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
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741 unsigned long *flags)
742{
743 struct sighand_struct *ret;
744
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745 ret = __lock_task_sighand(task, flags);
746 (void)__cond_lock(&task->sighand->siglock, ret);
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747 return ret;
748}
749
9e9291c7 750static inline void unlock_task_sighand(struct task_struct *task,
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751 unsigned long *flags)
752{
9e9291c7 753 spin_unlock_irqrestore(&task->sighand->siglock, *flags);
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754}
755
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756#ifdef CONFIG_LOCKDEP
757extern void lockdep_assert_task_sighand_held(struct task_struct *task);
758#else
759static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
760#endif
761
9e9291c7 762static inline unsigned long task_rlimit(const struct task_struct *task,
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763 unsigned int limit)
764{
9e9291c7 765 return READ_ONCE(task->signal->rlim[limit].rlim_cur);
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766}
767
9e9291c7 768static inline unsigned long task_rlimit_max(const struct task_struct *task,
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769 unsigned int limit)
770{
9e9291c7 771 return READ_ONCE(task->signal->rlim[limit].rlim_max);
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772}
773
774static inline unsigned long rlimit(unsigned int limit)
775{
776 return task_rlimit(current, limit);
777}
778
779static inline unsigned long rlimit_max(unsigned int limit)
780{
781 return task_rlimit_max(current, limit);
782}
783
3f07c014 784#endif /* _LINUX_SCHED_SIGNAL_H */