diff options
Diffstat (limited to 'include/linux/signal.h')
| -rw-r--r-- | include/linux/signal.h | 492 |
1 files changed, 492 insertions, 0 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h new file mode 100644 index 000000000..3b98e7a28 --- /dev/null +++ b/include/linux/signal.h @@ -0,0 +1,492 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_SIGNAL_H +#define _LINUX_SIGNAL_H + +#include <linux/bug.h> +#include <linux/signal_types.h> +#include <linux/string.h> + +struct task_struct; + +/* for sysctl */ +extern int print_fatal_signals; + +static inline void copy_siginfo(kernel_siginfo_t *to, + const kernel_siginfo_t *from) +{ + memcpy(to, from, sizeof(*to)); +} + +static inline void clear_siginfo(kernel_siginfo_t *info) +{ + memset(info, 0, sizeof(*info)); +} + +#define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo)) + +static inline void copy_siginfo_to_external(siginfo_t *to, + const kernel_siginfo_t *from) +{ + memcpy(to, from, sizeof(*from)); + memset(((char *)to) + sizeof(struct kernel_siginfo), 0, + SI_EXPANSION_SIZE); +} + +int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from); +int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from); + +enum siginfo_layout { + SIL_KILL, + SIL_TIMER, + SIL_POLL, + SIL_FAULT, + SIL_FAULT_TRAPNO, + SIL_FAULT_MCEERR, + SIL_FAULT_BNDERR, + SIL_FAULT_PKUERR, + SIL_FAULT_PERF_EVENT, + SIL_CHLD, + SIL_RT, + SIL_SYS, +}; + +enum siginfo_layout siginfo_layout(unsigned sig, int si_code); + +/* + * Define some primitives to manipulate sigset_t. + */ + +#ifndef __HAVE_ARCH_SIG_BITOPS +#include <linux/bitops.h> + +/* We don't use <linux/bitops.h> for these because there is no need to + be atomic. */ +static inline void sigaddset(sigset_t *set, int _sig) +{ + unsigned long sig = _sig - 1; + if (_NSIG_WORDS == 1) + set->sig[0] |= 1UL << sig; + else + set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW); +} + +static inline void sigdelset(sigset_t *set, int _sig) +{ + unsigned long sig = _sig - 1; + if (_NSIG_WORDS == 1) + set->sig[0] &= ~(1UL << sig); + else + set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); +} + +static inline int sigismember(sigset_t *set, int _sig) +{ + unsigned long sig = _sig - 1; + if (_NSIG_WORDS == 1) + return 1 & (set->sig[0] >> sig); + else + return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); +} + +#endif /* __HAVE_ARCH_SIG_BITOPS */ + +static inline int sigisemptyset(sigset_t *set) +{ + switch (_NSIG_WORDS) { + case 4: + return (set->sig[3] | set->sig[2] | + set->sig[1] | set->sig[0]) == 0; + case 2: + return (set->sig[1] | set->sig[0]) == 0; + case 1: + return set->sig[0] == 0; + default: + BUILD_BUG(); + return 0; + } +} + +static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2) +{ + switch (_NSIG_WORDS) { + case 4: + return (set1->sig[3] == set2->sig[3]) && + (set1->sig[2] == set2->sig[2]) && + (set1->sig[1] == set2->sig[1]) && + (set1->sig[0] == set2->sig[0]); + case 2: + return (set1->sig[1] == set2->sig[1]) && + (set1->sig[0] == set2->sig[0]); + case 1: + return set1->sig[0] == set2->sig[0]; + } + return 0; +} + +#define sigmask(sig) (1UL << ((sig) - 1)) + +#ifndef __HAVE_ARCH_SIG_SETOPS + +#define _SIG_SET_BINOP(name, op) \ +static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ +{ \ + unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ + \ + switch (_NSIG_WORDS) { \ + case 4: \ + a3 = a->sig[3]; a2 = a->sig[2]; \ + b3 = b->sig[3]; b2 = b->sig[2]; \ + r->sig[3] = op(a3, b3); \ + r->sig[2] = op(a2, b2); \ + fallthrough; \ + case 2: \ + a1 = a->sig[1]; b1 = b->sig[1]; \ + r->sig[1] = op(a1, b1); \ + fallthrough; \ + case 1: \ + a0 = a->sig[0]; b0 = b->sig[0]; \ + r->sig[0] = op(a0, b0); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ +} + +#define _sig_or(x,y) ((x) | (y)) +_SIG_SET_BINOP(sigorsets, _sig_or) + +#define _sig_and(x,y) ((x) & (y)) +_SIG_SET_BINOP(sigandsets, _sig_and) + +#define _sig_andn(x,y) ((x) & ~(y)) +_SIG_SET_BINOP(sigandnsets, _sig_andn) + +#undef _SIG_SET_BINOP +#undef _sig_or +#undef _sig_and +#undef _sig_andn + +#define _SIG_SET_OP(name, op) \ +static inline void name(sigset_t *set) \ +{ \ + switch (_NSIG_WORDS) { \ + case 4: set->sig[3] = op(set->sig[3]); \ + set->sig[2] = op(set->sig[2]); \ + fallthrough; \ + case 2: set->sig[1] = op(set->sig[1]); \ + fallthrough; \ + case 1: set->sig[0] = op(set->sig[0]); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ +} + +#define _sig_not(x) (~(x)) +_SIG_SET_OP(signotset, _sig_not) + +#undef _SIG_SET_OP +#undef _sig_not + +static inline void sigemptyset(sigset_t *set) +{ + switch (_NSIG_WORDS) { + default: + memset(set, 0, sizeof(sigset_t)); + break; + case 2: set->sig[1] = 0; + fallthrough; + case 1: set->sig[0] = 0; + break; + } +} + +static inline void sigfillset(sigset_t *set) +{ + switch (_NSIG_WORDS) { + default: + memset(set, -1, sizeof(sigset_t)); + break; + case 2: set->sig[1] = -1; + fallthrough; + case 1: set->sig[0] = -1; + break; + } +} + +/* Some extensions for manipulating the low 32 signals in particular. */ + +static inline void sigaddsetmask(sigset_t *set, unsigned long mask) +{ + set->sig[0] |= mask; +} + +static inline void sigdelsetmask(sigset_t *set, unsigned long mask) +{ + set->sig[0] &= ~mask; +} + +static inline int sigtestsetmask(sigset_t *set, unsigned long mask) +{ + return (set->sig[0] & mask) != 0; +} + +static inline void siginitset(sigset_t *set, unsigned long mask) +{ + set->sig[0] = mask; + switch (_NSIG_WORDS) { + default: + memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); + break; + case 2: set->sig[1] = 0; + break; + case 1: ; + } +} + +static inline void siginitsetinv(sigset_t *set, unsigned long mask) +{ + set->sig[0] = ~mask; + switch (_NSIG_WORDS) { + default: + memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); + break; + case 2: set->sig[1] = -1; + break; + case 1: ; + } +} + +#endif /* __HAVE_ARCH_SIG_SETOPS */ + +static inline void init_sigpending(struct sigpending *sig) +{ + sigemptyset(&sig->signal); + INIT_LIST_HEAD(&sig->list); +} + +extern void flush_sigqueue(struct sigpending *queue); + +/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ +static inline int valid_signal(unsigned long sig) +{ + return sig <= _NSIG ? 1 : 0; +} + +struct timespec; +struct pt_regs; +enum pid_type; + +extern int next_signal(struct sigpending *pending, sigset_t *mask); +extern int do_send_sig_info(int sig, struct kernel_siginfo *info, + struct task_struct *p, enum pid_type type); +extern int group_send_sig_info(int sig, struct kernel_siginfo *info, + struct task_struct *p, enum pid_type type); +extern int send_signal_locked(int sig, struct kernel_siginfo *info, + struct task_struct *p, enum pid_type type); +extern int sigprocmask(int, sigset_t *, sigset_t *); +extern void set_current_blocked(sigset_t *); +extern void __set_current_blocked(const sigset_t *); +extern int show_unhandled_signals; + +extern bool get_signal(struct ksignal *ksig); +extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); +extern void exit_signals(struct task_struct *tsk); +extern void kernel_sigaction(int, __sighandler_t); + +#define SIG_KTHREAD ((__force __sighandler_t)2) +#define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3) + +static inline void allow_signal(int sig) +{ + /* + * Kernel threads handle their own signals. Let the signal code + * know it'll be handled, so that they don't get converted to + * SIGKILL or just silently dropped. + */ + kernel_sigaction(sig, SIG_KTHREAD); +} + +static inline void allow_kernel_signal(int sig) +{ + /* + * Kernel threads handle their own signals. Let the signal code + * know signals sent by the kernel will be handled, so that they + * don't get silently dropped. + */ + kernel_sigaction(sig, SIG_KTHREAD_KERNEL); +} + +static inline void disallow_signal(int sig) +{ + kernel_sigaction(sig, SIG_IGN); +} + +extern struct kmem_cache *sighand_cachep; + +extern bool unhandled_signal(struct task_struct *tsk, int sig); + +/* + * In POSIX a signal is sent either to a specific thread (Linux task) + * or to the process as a whole (Linux thread group). How the signal + * is sent determines whether it's to one thread or the whole group, + * which determines which signal mask(s) are involved in blocking it + * from being delivered until later. When the signal is delivered, + * either it's caught or ignored by a user handler or it has a default + * effect that applies to the whole thread group (POSIX process). + * + * The possible effects an unblocked signal set to SIG_DFL can have are: + * ignore - Nothing Happens + * terminate - kill the process, i.e. all threads in the group, + * similar to exit_group. The group leader (only) reports + * WIFSIGNALED status to its parent. + * coredump - write a core dump file describing all threads using + * the same mm and then kill all those threads + * stop - stop all the threads in the group, i.e. TASK_STOPPED state + * + * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. + * Other signals when not blocked and set to SIG_DFL behaves as follows. + * The job control signals also have other special effects. + * + * +--------------------+------------------+ + * | POSIX signal | default action | + * +--------------------+------------------+ + * | SIGHUP | terminate | + * | SIGINT | terminate | + * | SIGQUIT | coredump | + * | SIGILL | coredump | + * | SIGTRAP | coredump | + * | SIGABRT/SIGIOT | coredump | + * | SIGBUS | coredump | + * | SIGFPE | coredump | + * | SIGKILL | terminate(+) | + * | SIGUSR1 | terminate | + * | SIGSEGV | coredump | + * | SIGUSR2 | terminate | + * | SIGPIPE | terminate | + * | SIGALRM | terminate | + * | SIGTERM | terminate | + * | SIGCHLD | ignore | + * | SIGCONT | ignore(*) | + * | SIGSTOP | stop(*)(+) | + * | SIGTSTP | stop(*) | + * | SIGTTIN | stop(*) | + * | SIGTTOU | stop(*) | + * | SIGURG | ignore | + * | SIGXCPU | coredump | + * | SIGXFSZ | coredump | + * | SIGVTALRM | terminate | + * | SIGPROF | terminate | + * | SIGPOLL/SIGIO | terminate | + * | SIGSYS/SIGUNUSED | coredump | + * | SIGSTKFLT | terminate | + * | SIGWINCH | ignore | + * | SIGPWR | terminate | + * | SIGRTMIN-SIGRTMAX | terminate | + * +--------------------+------------------+ + * | non-POSIX signal | default action | + * +--------------------+------------------+ + * | SIGEMT | coredump | + * +--------------------+------------------+ + * + * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". + * (*) Special job control effects: + * When SIGCONT is sent, it resumes the process (all threads in the group) + * from TASK_STOPPED state and also clears any pending/queued stop signals + * (any of those marked with "stop(*)"). This happens regardless of blocking, + * catching, or ignoring SIGCONT. When any stop signal is sent, it clears + * any pending/queued SIGCONT signals; this happens regardless of blocking, + * catching, or ignored the stop signal, though (except for SIGSTOP) the + * default action of stopping the process may happen later or never. + */ + +#ifdef SIGEMT +#define SIGEMT_MASK rt_sigmask(SIGEMT) +#else +#define SIGEMT_MASK 0 +#endif + +#if SIGRTMIN > BITS_PER_LONG +#define rt_sigmask(sig) (1ULL << ((sig)-1)) +#else +#define rt_sigmask(sig) sigmask(sig) +#endif + +#define siginmask(sig, mask) \ + ((sig) > 0 && (sig) < SIGRTMIN && (rt_sigmask(sig) & (mask))) + +#define SIG_KERNEL_ONLY_MASK (\ + rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) + +#define SIG_KERNEL_STOP_MASK (\ + rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ + rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) + +#define SIG_KERNEL_COREDUMP_MASK (\ + rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ + rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ + rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ + rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ + rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ + SIGEMT_MASK ) + +#define SIG_KERNEL_IGNORE_MASK (\ + rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ + rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) + +#define SIG_SPECIFIC_SICODES_MASK (\ + rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \ + rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \ + rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \ + rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \ + SIGEMT_MASK ) + +#define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK) +#define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK) +#define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK) +#define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK) +#define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK) + +#define sig_fatal(t, signr) \ + (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ + (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) + +void signals_init(void); + +int restore_altstack(const stack_t __user *); +int __save_altstack(stack_t __user *, unsigned long); + +#define unsafe_save_altstack(uss, sp, label) do { \ + stack_t __user *__uss = uss; \ + struct task_struct *t = current; \ + unsafe_put_user((void __user *)t->sas_ss_sp, &__uss->ss_sp, label); \ + unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \ + unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \ +} while (0); + +#ifdef CONFIG_DYNAMIC_SIGFRAME +bool sigaltstack_size_valid(size_t ss_size); +#else +static inline bool sigaltstack_size_valid(size_t size) { return true; } +#endif /* !CONFIG_DYNAMIC_SIGFRAME */ + +#ifdef CONFIG_PROC_FS +struct seq_file; +extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); +#endif + +#ifndef arch_untagged_si_addr +/* + * Given a fault address and a signal and si_code which correspond to the + * _sigfault union member, returns the address that must appear in si_addr if + * the signal handler does not have SA_EXPOSE_TAGBITS enabled in sa_flags. + */ +static inline void __user *arch_untagged_si_addr(void __user *addr, + unsigned long sig, + unsigned long si_code) +{ + return addr; +} +#endif + +#endif /* _LINUX_SIGNAL_H */ |