/* $NetBSD: linux_signal.c,v 1.80.8.2 2022/08/03 11:11:32 martin Exp $ */ /*- * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Frank van der Linden and Eric Haszlakiewicz. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * heavily from: svr4_signal.c,v 1.7 1995/01/09 01:04:21 christos Exp */ /* * Functions in multiarch: * linux_sys_signal : linux_sig_notalpha.c * linux_sys_siggetmask : linux_sig_notalpha.c * linux_sys_sigsetmask : linux_sig_notalpha.c * linux_sys_pause : linux_sig_notalpha.c * linux_sys_sigaction : linux_sigaction.c * */ /* * Unimplemented: * linux_sys_rt_sigtimedwait : sigsuspend w/timeout. */ #include __KERNEL_RCSID(0, "$NetBSD: linux_signal.c,v 1.80.8.2 2022/08/03 11:11:32 martin Exp $"); #define COMPAT_LINUX 1 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Locally used defines (in bsd<->linux conversion functions): */ #define linux_sigemptyset(s) memset((s), 0, sizeof(*(s))) #define linux_sigismember(s, n) ((s)->sig[((n) - 1) / LINUX__NSIG_BPW] \ & (1L << ((n) - 1) % LINUX__NSIG_BPW)) #define linux_sigaddset(s, n) ((s)->sig[((n) - 1) / LINUX__NSIG_BPW] \ |= (1L << ((n) - 1) % LINUX__NSIG_BPW)) #ifdef DEBUG_LINUX #define DPRINTF(a) uprintf a #else #define DPRINTF(a) #endif extern const int native_to_linux_signo[]; extern const int linux_to_native_signo[]; /* * Convert between Linux and BSD signal sets. */ #if LINUX__NSIG_WORDS > 1 void linux_old_extra_to_native_sigset(sigset_t *bss, const linux_old_sigset_t *lss, const unsigned long *extra) { linux_sigset_t lsnew; /* convert old sigset to new sigset */ linux_sigemptyset(&lsnew); lsnew.sig[0] = *lss; if (extra) memcpy(&lsnew.sig[1], extra, sizeof(linux_sigset_t) - sizeof(linux_old_sigset_t)); linux_to_native_sigset(bss, &lsnew); } void native_to_linux_old_extra_sigset(linux_old_sigset_t *lss, unsigned long *extra, const sigset_t *bss) { linux_sigset_t lsnew; native_to_linux_sigset(&lsnew, bss); /* convert new sigset to old sigset */ *lss = lsnew.sig[0]; if (extra) memcpy(extra, &lsnew.sig[1], sizeof(linux_sigset_t) - sizeof(linux_old_sigset_t)); } #endif /* LINUX__NSIG_WORDS > 1 */ void linux_to_native_sigset(sigset_t *bss, const linux_sigset_t *lss) { int i, newsig; sigemptyset(bss); for (i = 1; i < LINUX__NSIG; i++) { if (linux_sigismember(lss, i)) { newsig = linux_to_native_signo[i]; if (newsig) sigaddset(bss, newsig); } } } void native_to_linux_sigset(linux_sigset_t *lss, const sigset_t *bss) { int i, newsig; linux_sigemptyset(lss); for (i = 1; i < NSIG; i++) { if (sigismember(bss, i)) { newsig = native_to_linux_signo[i]; if (newsig) linux_sigaddset(lss, newsig); } } } void native_to_linux_siginfo(linux_siginfo_t *lsi, const struct _ksiginfo *ksi) { memset(lsi, 0, sizeof(*lsi)); lsi->lsi_signo = native_to_linux_signo[ksi->_signo]; lsi->lsi_errno = native_to_linux_errno[ksi->_errno]; lsi->lsi_code = native_to_linux_si_code(ksi->_code); switch (ksi->_code) { case SI_NOINFO: break; case SI_USER: lsi->lsi_pid = ksi->_reason._rt._pid; lsi->lsi_uid = ksi->_reason._rt._uid; if (lsi->lsi_signo == LINUX_SIGALRM || lsi->lsi_signo >= LINUX_SIGRTMIN) lsi->lsi_value.sival_ptr = ksi->_reason._rt._value.sival_ptr; break; case SI_TIMER: case SI_QUEUE: lsi->lsi_uid = ksi->_reason._rt._uid; lsi->lsi_uid = ksi->_reason._rt._uid; lsi->lsi_value.sival_ptr = ksi->_reason._rt._value.sival_ptr; break; case SI_ASYNCIO: case SI_MESGQ: lsi->lsi_value.sival_ptr = ksi->_reason._rt._value.sival_ptr; break; default: switch (ksi->_signo) { case SIGCHLD: lsi->lsi_uid = ksi->_reason._child._uid; lsi->lsi_pid = ksi->_reason._child._pid; lsi->lsi_status = native_to_linux_si_status( ksi->_code, ksi->_reason._child._status); lsi->lsi_utime = ksi->_reason._child._utime; lsi->lsi_stime = ksi->_reason._child._stime; break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGTRAP: lsi->lsi_addr = ksi->_reason._fault._addr; break; case SIGIO: lsi->lsi_fd = ksi->_reason._poll._fd; lsi->lsi_band = ksi->_reason._poll._band; break; default: break; } } } unsigned int native_to_linux_sigflags(const int bsf) { unsigned int lsf = 0; if ((bsf & SA_NOCLDSTOP) != 0) lsf |= LINUX_SA_NOCLDSTOP; if ((bsf & SA_NOCLDWAIT) != 0) lsf |= LINUX_SA_NOCLDWAIT; if ((bsf & SA_ONSTACK) != 0) lsf |= LINUX_SA_ONSTACK; if ((bsf & SA_RESTART) != 0) lsf |= LINUX_SA_RESTART; if ((bsf & SA_NODEFER) != 0) lsf |= LINUX_SA_NOMASK; if ((bsf & SA_RESETHAND) != 0) lsf |= LINUX_SA_ONESHOT; if ((bsf & SA_SIGINFO) != 0) lsf |= LINUX_SA_SIGINFO; return lsf; } int linux_to_native_sigflags(const unsigned long lsf) { int bsf = 0; if ((lsf & LINUX_SA_NOCLDSTOP) != 0) bsf |= SA_NOCLDSTOP; if ((lsf & LINUX_SA_NOCLDWAIT) != 0) bsf |= SA_NOCLDWAIT; if ((lsf & LINUX_SA_ONSTACK) != 0) bsf |= SA_ONSTACK; if ((lsf & LINUX_SA_RESTART) != 0) bsf |= SA_RESTART; if ((lsf & LINUX_SA_ONESHOT) != 0) bsf |= SA_RESETHAND; if ((lsf & LINUX_SA_NOMASK) != 0) bsf |= SA_NODEFER; if ((lsf & LINUX_SA_SIGINFO) != 0) bsf |= SA_SIGINFO; if ((lsf & ~LINUX_SA_ALLBITS) != 0) { DPRINTF(("linux_old_to_native_sigflags: " "%lx extra bits ignored\n", lsf)); } return bsf; } /* * Convert between Linux and BSD sigaction structures. */ void linux_old_to_native_sigaction(struct sigaction *bsa, const struct linux_old_sigaction *lsa) { memset(bsa, 0, sizeof(*bsa)); bsa->sa_handler = lsa->linux_sa_handler; linux_old_to_native_sigset(&bsa->sa_mask, &lsa->linux_sa_mask); bsa->sa_flags = linux_to_native_sigflags(lsa->linux_sa_flags); } void native_to_linux_old_sigaction(struct linux_old_sigaction *lsa, const struct sigaction *bsa) { memset(lsa, 0, sizeof(*lsa)); lsa->linux_sa_handler = bsa->sa_handler; native_to_linux_old_sigset(&lsa->linux_sa_mask, &bsa->sa_mask); lsa->linux_sa_flags = native_to_linux_sigflags(bsa->sa_flags); #ifndef __alpha__ lsa->linux_sa_restorer = NULL; #endif } /* ...and the new sigaction conversion funcs. */ void linux_to_native_sigaction(struct sigaction *bsa, const struct linux_sigaction *lsa) { memset(bsa, 0, sizeof(*bsa)); bsa->sa_handler = lsa->linux_sa_handler; linux_to_native_sigset(&bsa->sa_mask, &lsa->linux_sa_mask); bsa->sa_flags = linux_to_native_sigflags(lsa->linux_sa_flags); } void native_to_linux_sigaction(struct linux_sigaction *lsa, const struct sigaction *bsa) { memset(lsa, 0, sizeof(*lsa)); lsa->linux_sa_handler = bsa->sa_handler; native_to_linux_sigset(&lsa->linux_sa_mask, &bsa->sa_mask); lsa->linux_sa_flags = native_to_linux_sigflags(bsa->sa_flags); #ifndef __alpha__ lsa->linux_sa_restorer = NULL; #endif } /* ----------------------------------------------------------------------- */ /* * The Linux sigaction() system call. Do the usual conversions, * and just call sigaction(). Some flags and values are silently * ignored (see above). */ int linux_sys_rt_sigaction(struct lwp *l, const struct linux_sys_rt_sigaction_args *uap, register_t *retval) { /* { syscallarg(int) signum; syscallarg(const struct linux_sigaction *) nsa; syscallarg(struct linux_sigaction *) osa; syscallarg(size_t) sigsetsize; } */ struct linux_sigaction nlsa, olsa; struct sigaction nbsa, obsa; int error, sig; void *tramp = NULL; int vers = 0; #ifdef LINUX_SA_RESTORER struct sigacts *ps = l->l_proc->p_sigacts; #endif if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t)) return EINVAL; if (SCARG(uap, nsa)) { error = copyin(SCARG(uap, nsa), &nlsa, sizeof(nlsa)); if (error) return error; linux_to_native_sigaction(&nbsa, &nlsa); } sig = SCARG(uap, signum); /* * XXX: Linux has 33 realtime signals, the go binary wants to * reset all of them; nothing else uses the last RT signal, so for * now ignore it. */ if (sig == LINUX__NSIG) { uprintf("%s: setting signal %d ignored\n", __func__, sig); sig--; /* back to 63 which is ignored */ } if (sig < 0 || sig >= LINUX__NSIG) return EINVAL; if (sig > 0 && !linux_to_native_signo[sig]) { /* Pretend that we did something useful for unknown signals. */ obsa.sa_handler = SIG_IGN; sigemptyset(&obsa.sa_mask); obsa.sa_flags = 0; } else { #ifdef LINUX_SA_RESTORER if (SCARG(uap, nsa) && (nlsa.linux_sa_flags & LINUX_SA_RESTORER) && (tramp = nlsa.linux_sa_restorer) != NULL) vers = 2; #endif error = sigaction1(l, linux_to_native_signo[sig], SCARG(uap, nsa) ? &nbsa : NULL, SCARG(uap, osa) ? &obsa : NULL, tramp, vers); if (error) return error; } if (SCARG(uap, osa)) { native_to_linux_sigaction(&olsa, &obsa); #ifdef LINUX_SA_RESTORER if (ps->sa_sigdesc[sig].sd_vers != 0) { olsa.linux_sa_restorer = ps->sa_sigdesc[sig].sd_tramp; olsa.linux_sa_flags |= LINUX_SA_RESTORER; } #endif error = copyout(&olsa, SCARG(uap, osa), sizeof(olsa)); if (error) return error; } return 0; } int linux_sigprocmask1(struct lwp *l, int how, const linux_old_sigset_t *set, linux_old_sigset_t *oset) { struct proc *p = l->l_proc; linux_old_sigset_t nlss, olss; sigset_t nbss, obss; int error; switch (how) { case LINUX_SIG_BLOCK: how = SIG_BLOCK; break; case LINUX_SIG_UNBLOCK: how = SIG_UNBLOCK; break; case LINUX_SIG_SETMASK: how = SIG_SETMASK; break; default: return EINVAL; } if (set) { error = copyin(set, &nlss, sizeof(nlss)); if (error) return error; linux_old_to_native_sigset(&nbss, &nlss); } mutex_enter(p->p_lock); error = sigprocmask1(l, how, set ? &nbss : NULL, oset ? &obss : NULL); mutex_exit(p->p_lock); if (error) return error; if (oset) { native_to_linux_old_sigset(&olss, &obss); error = copyout(&olss, oset, sizeof(olss)); if (error) return error; } return error; } int linux_sys_rt_sigprocmask(struct lwp *l, const struct linux_sys_rt_sigprocmask_args *uap, register_t *retval) { /* { syscallarg(int) how; syscallarg(const linux_sigset_t *) set; syscallarg(linux_sigset_t *) oset; syscallarg(size_t) sigsetsize; } */ linux_sigset_t nlss, olss, *oset; const linux_sigset_t *set; struct proc *p = l->l_proc; sigset_t nbss, obss; int error, how; if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t)) return EINVAL; switch (SCARG(uap, how)) { case LINUX_SIG_BLOCK: how = SIG_BLOCK; break; case LINUX_SIG_UNBLOCK: how = SIG_UNBLOCK; break; case LINUX_SIG_SETMASK: how = SIG_SETMASK; break; default: return EINVAL; } set = SCARG(uap, set); oset = SCARG(uap, oset); if (set) { error = copyin(set, &nlss, sizeof(nlss)); if (error) return error; linux_to_native_sigset(&nbss, &nlss); } mutex_enter(p->p_lock); error = sigprocmask1(l, how, set ? &nbss : NULL, oset ? &obss : NULL); mutex_exit(p->p_lock); if (!error && oset) { native_to_linux_sigset(&olss, &obss); error = copyout(&olss, oset, sizeof(olss)); } return error; } int linux_sys_rt_sigpending(struct lwp *l, const struct linux_sys_rt_sigpending_args *uap, register_t *retval) { /* { syscallarg(linux_sigset_t *) set; syscallarg(size_t) sigsetsize; } */ sigset_t bss; linux_sigset_t lss; if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t)) return EINVAL; sigpending1(l, &bss); native_to_linux_sigset(&lss, &bss); return copyout(&lss, SCARG(uap, set), sizeof(lss)); } #ifndef __amd64__ int linux_sys_sigpending(struct lwp *l, const struct linux_sys_sigpending_args *uap, register_t *retval) { /* { syscallarg(linux_old_sigset_t *) mask; } */ sigset_t bss; linux_old_sigset_t lss; sigpending1(l, &bss); native_to_linux_old_sigset(&lss, &bss); return copyout(&lss, SCARG(uap, set), sizeof(lss)); } int linux_sys_sigsuspend(struct lwp *l, const struct linux_sys_sigsuspend_args *uap, register_t *retval) { /* { syscallarg(void *) restart; syscallarg(int) oldmask; syscallarg(int) mask; } */ linux_old_sigset_t lss; sigset_t bss; lss = SCARG(uap, mask); linux_old_to_native_sigset(&bss, &lss); return sigsuspend1(l, &bss); } #endif /* __amd64__ */ int linux_sys_rt_sigsuspend(struct lwp *l, const struct linux_sys_rt_sigsuspend_args *uap, register_t *retval) { /* { syscallarg(linux_sigset_t *) unewset; syscallarg(size_t) sigsetsize; } */ linux_sigset_t lss; sigset_t bss; int error; if (SCARG(uap, sigsetsize) != sizeof(linux_sigset_t)) return EINVAL; error = copyin(SCARG(uap, unewset), &lss, sizeof(linux_sigset_t)); if (error) return error; linux_to_native_sigset(&bss, &lss); return sigsuspend1(l, &bss); } static int fetchss(const void *u, void *s, size_t len) { int error; linux_sigset_t lss; if ((error = copyin(u, &lss, sizeof(lss))) != 0) return error; linux_to_native_sigset(s, &lss); return 0; } static int fetchts(const void *u, void *s, size_t len) { int error; struct linux_timespec lts; if ((error = copyin(u, <s, sizeof(lts))) != 0) return error; linux_to_native_timespec(s, <s); return 0; } static int fakestorets(const void *u, void *s, size_t len) { /* Do nothing, sigtimedwait does not alter timeout like ours */ return 0; } static int storeinfo(const void *s, void *u, size_t len) { struct linux_siginfo lsi; native_to_linux_siginfo(&lsi, &((const siginfo_t *)s)->_info); return copyout(&lsi, u, sizeof(lsi)); } int linux_sys_rt_sigtimedwait(struct lwp *l, const struct linux_sys_rt_sigtimedwait_args *uap, register_t *retval) { /* { syscallarg(const linux_sigset_t *) set; syscallarg(linux_siginfo_t *) info); syscallarg(const struct linux_timespec *) timeout; } */ return sigtimedwait1(l, (const struct sys_____sigtimedwait50_args *)uap, retval, fetchss, storeinfo, fetchts, fakestorets); } /* * Once more: only a signal conversion is needed. * Note: also used as sys_rt_queueinfo. The info field is ignored. */ int linux_sys_rt_queueinfo(struct lwp *l, const struct linux_sys_rt_queueinfo_args *uap, register_t *retval) { /* syscallarg(int) pid; syscallarg(int) signum; syscallarg(linix_siginfo_t *) uinfo; */ int error; linux_siginfo_t info; error = copyin(SCARG(uap, uinfo), &info, sizeof(info)); if (error) return error; if (info.lsi_code >= 0) return EPERM; /* XXX To really implement this we need to */ /* XXX keep a list of queued signals somewhere. */ return linux_sys_kill(l, (const void *)uap, retval); } int linux_sys_kill(struct lwp *l, const struct linux_sys_kill_args *uap, register_t *retval) { /* { syscallarg(int) pid; syscallarg(int) signum; } */ struct sys_kill_args ka; int sig; SCARG(&ka, pid) = SCARG(uap, pid); sig = SCARG(uap, signum); if (sig < 0 || sig >= LINUX__NSIG) return EINVAL; SCARG(&ka, signum) = linux_to_native_signo[sig]; return sys_kill(l, &ka, retval); } #ifdef LINUX_SS_ONSTACK static void linux_to_native_sigaltstack(struct sigaltstack *, const struct linux_sigaltstack *); static void linux_to_native_sigaltstack(struct sigaltstack *bss, const struct linux_sigaltstack *lss) { bss->ss_sp = lss->ss_sp; bss->ss_size = lss->ss_size; if (lss->ss_flags & LINUX_SS_ONSTACK) bss->ss_flags = SS_ONSTACK; else if (lss->ss_flags & LINUX_SS_DISABLE) bss->ss_flags = SS_DISABLE; else bss->ss_flags = 0; } void native_to_linux_sigaltstack(struct linux_sigaltstack *lss, const struct sigaltstack *bss) { memset(lss, 0, sizeof(*lss)); lss->ss_sp = bss->ss_sp; lss->ss_size = bss->ss_size; if (bss->ss_flags & SS_ONSTACK) lss->ss_flags = LINUX_SS_ONSTACK; else if (bss->ss_flags & SS_DISABLE) lss->ss_flags = LINUX_SS_DISABLE; else lss->ss_flags = 0; } int linux_sys_sigaltstack(struct lwp *l, const struct linux_sys_sigaltstack_args *uap, register_t *retval) { /* { syscallarg(const struct linux_sigaltstack *) ss; syscallarg(struct linux_sigaltstack *) oss; } */ struct linux_sigaltstack ss; struct sigaltstack nss; struct proc *p = l->l_proc; int error = 0; if (SCARG(uap, oss)) { native_to_linux_sigaltstack(&ss, &l->l_sigstk); if ((error = copyout(&ss, SCARG(uap, oss), sizeof(ss))) != 0) return error; } if (SCARG(uap, ss) != NULL) { if ((error = copyin(SCARG(uap, ss), &ss, sizeof(ss))) != 0) return error; linux_to_native_sigaltstack(&nss, &ss); mutex_enter(p->p_lock); if (nss.ss_flags & ~SS_ALLBITS) error = EINVAL; else if (nss.ss_flags & SS_DISABLE) { if (l->l_sigstk.ss_flags & SS_ONSTACK) error = EINVAL; } else if (nss.ss_size < LINUX_MINSIGSTKSZ) error = ENOMEM; if (error == 0) l->l_sigstk = nss; mutex_exit(p->p_lock); } return error; } #endif /* LINUX_SS_ONSTACK */ static int linux_do_tkill(struct lwp *l, int tgid, int tid, int signum) { struct proc *p; struct lwp *t; ksiginfo_t ksi; int error; if (signum < 0 || signum >= LINUX__NSIG) return EINVAL; signum = linux_to_native_signo[signum]; if (tgid == -1) { tgid = tid; } KSI_INIT(&ksi); ksi.ksi_signo = signum; ksi.ksi_code = SI_LWP; ksi.ksi_pid = l->l_proc->p_pid; ksi.ksi_uid = kauth_cred_geteuid(l->l_cred); ksi.ksi_lid = tid; mutex_enter(proc_lock); p = proc_find(tgid); if (p == NULL) { mutex_exit(proc_lock); return ESRCH; } mutex_enter(p->p_lock); error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(signum), NULL, NULL); if ((t = lwp_find(p, ksi.ksi_lid)) == NULL) error = ESRCH; else if (signum != 0) kpsignal2(p, &ksi); mutex_exit(p->p_lock); mutex_exit(proc_lock); return error; } int linux_sys_tkill(struct lwp *l, const struct linux_sys_tkill_args *uap, register_t *retval) { /* { syscallarg(int) tid; syscallarg(int) sig; } */ if (SCARG(uap, tid) <= 0) return EINVAL; return linux_do_tkill(l, -1, SCARG(uap, tid), SCARG(uap, sig)); } int linux_sys_tgkill(struct lwp *l, const struct linux_sys_tgkill_args *uap, register_t *retval) { /* { syscallarg(int) tgid; syscallarg(int) tid; syscallarg(int) sig; } */ if (SCARG(uap, tid) <= 0 || SCARG(uap, tgid) < -1) return EINVAL; return linux_do_tkill(l, SCARG(uap, tgid), SCARG(uap, tid), SCARG(uap, sig)); } int native_to_linux_si_code(int code) { int si_codes[] = { LINUX_SI_USER, LINUX_SI_QUEUE, LINUX_SI_TIMER, LINUX_SI_ASYNCIO, LINUX_SI_MESGQ, LINUX_SI_TKILL /* SI_LWP */ }; if (code <= 0 && -code < __arraycount(si_codes)) return si_codes[-code]; return code; } int native_to_linux_si_status(int code, int status) { int sts; switch (code) { case CLD_CONTINUED: sts = LINUX_SIGCONT; break; case CLD_EXITED: sts = WEXITSTATUS(status); break; case CLD_STOPPED: case CLD_TRAPPED: case CLD_DUMPED: case CLD_KILLED: default: sts = native_to_linux_signo[WTERMSIG(status)]; break; } return sts; }