/* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. * Copyright (c) 2020-2022 Huawei Device Co., Ltd. All rights reserved. * * 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. * * 3. Neither the name of the copyright holder nor the names of its contributors may be used * to endorse or promote products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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. */ #include "los_signal.h" #include "pthread.h" #include "los_process_pri.h" #include "los_sched_pri.h" #include "los_hw_pri.h" #include "user_copy.h" #ifdef LOSCFG_SECURITY_CAPABILITY #include "capability_api.h" #endif #include "los_atomic.h" #ifdef LOSCFG_KERNEL_VM int raise(int sig) { (VOID)sig; PRINT_ERR("%s NOT SUPPORT\n", __FUNCTION__); errno = ENOSYS; return -1; } #define GETUNMASKSET(procmask, pendFlag) ((~(procmask)) & (sigset_t)(pendFlag)) #define UINT64_BIT_SIZE 64 int OsSigIsMember(const sigset_t *set, int signo) { int ret = LOS_NOK; /* In musl, sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ signo -= 1; /* Verify the signal */ if (GOOD_SIGNO(signo)) { /* Check if the signal is in the set */ ret = ((*set & SIGNO2SET((unsigned int)signo)) != 0); } return ret; } STATIC VOID OsMoveTmpInfoToUnbInfo(sig_cb *sigcb, INT32 signo) { SigInfoListNode *tmpInfoNode = sigcb->tmpInfoListHead; SigInfoListNode **prevHook = &sigcb->tmpInfoListHead; while (tmpInfoNode != NULL) { if (tmpInfoNode->info.si_signo == signo) { /* copy tmpinfo to unbinfo. */ (VOID)memcpy_s(&sigcb->sigunbinfo, sizeof(siginfo_t), &tmpInfoNode->info, sizeof(siginfo_t)); /* delete tmpinfo from tmpList. */ *prevHook = tmpInfoNode->next; (VOID)LOS_MemFree(m_aucSysMem0, tmpInfoNode); tmpInfoNode = *prevHook; break; } prevHook = &tmpInfoNode->next; tmpInfoNode = tmpInfoNode->next; } } STATIC INT32 OsAddSigInfoToTmpList(sig_cb *sigcb, siginfo_t *info) { /* try to find the old siginfo */ SigInfoListNode *tmp = sigcb->tmpInfoListHead; while (tmp != NULL) { if (tmp->info.si_signo == info->si_signo) { /* found it, break. */ break; } tmp = tmp->next; } if (tmp == NULL) { /* none, alloc new one */ tmp = (SigInfoListNode *)LOS_MemAlloc(m_aucSysMem0, sizeof(SigInfoListNode)); if (tmp == NULL) { return LOS_NOK; } tmp->next = sigcb->tmpInfoListHead; sigcb->tmpInfoListHead = tmp; } (VOID)memcpy_s(&tmp->info, sizeof(siginfo_t), info, sizeof(siginfo_t)); return LOS_OK; } VOID OsClearSigInfoTmpList(sig_cb *sigcb) { while (sigcb->tmpInfoListHead != NULL) { SigInfoListNode *tmpInfoNode = sigcb->tmpInfoListHead; sigcb->tmpInfoListHead = sigcb->tmpInfoListHead->next; (VOID)LOS_MemFree(m_aucSysMem0, tmpInfoNode); } } STATIC INLINE VOID OsSigWaitTaskWake(LosTaskCB *taskCB, INT32 signo) { sig_cb *sigcb = &taskCB->sig; if (!LOS_ListEmpty(&sigcb->waitList) && OsSigIsMember(&sigcb->sigwaitmask, signo)) { OsMoveTmpInfoToUnbInfo(sigcb, signo); OsTaskWakeClearPendMask(taskCB); taskCB->ops->wake(taskCB); OsSigEmptySet(&sigcb->sigwaitmask); } } STATIC UINT32 OsPendingTaskWake(LosTaskCB *taskCB, INT32 signo) { if (!OsTaskIsPending(taskCB) || !OsProcessIsUserMode(OS_PCB_FROM_PID(taskCB->processID))) { return 0; } if ((signo != SIGKILL) && (taskCB->waitFlag != OS_TASK_WAIT_SIGNAL)) { return 0; } switch (taskCB->waitFlag) { case OS_TASK_WAIT_PROCESS: case OS_TASK_WAIT_GID: case OS_TASK_WAIT_ANYPROCESS: OsWaitWakeTask(taskCB, OS_INVALID_VALUE); break; case OS_TASK_WAIT_JOIN: OsTaskWakeClearPendMask(taskCB); taskCB->ops->wake(taskCB); break; case OS_TASK_WAIT_SIGNAL: OsSigWaitTaskWake(taskCB, signo); break; case OS_TASK_WAIT_LITEIPC: OsTaskWakeClearPendMask(taskCB); taskCB->ops->wake(taskCB); break; case OS_TASK_WAIT_FUTEX: OsFutexNodeDeleteFromFutexHash(&taskCB->futex, TRUE, NULL, NULL); OsTaskWakeClearPendMask(taskCB); taskCB->ops->wake(taskCB); break; default: break; } return 0; } int OsTcbDispatch(LosTaskCB *stcb, siginfo_t *info) { bool masked = FALSE; sig_cb *sigcb = &stcb->sig; OS_RETURN_IF_NULL(sigcb); /* If signo is 0, not send signal, just check process or pthread exist */ if (info->si_signo == 0) { return 0; } masked = (bool)OsSigIsMember(&sigcb->sigprocmask, info->si_signo); if (masked) { /* If signal is in wait list and mask list, need unblock it */ if (LOS_ListEmpty(&sigcb->waitList) || (!LOS_ListEmpty(&sigcb->waitList) && !OsSigIsMember(&sigcb->sigwaitmask, info->si_signo))) { OsSigAddSet(&sigcb->sigPendFlag, info->si_signo); } } else { /* unmasked signal actions */ OsSigAddSet(&sigcb->sigFlag, info->si_signo); } if (OsAddSigInfoToTmpList(sigcb, info) == LOS_NOK) { return -ENOMEM; } return OsPendingTaskWake(stcb, info->si_signo); } void OsSigMaskSwitch(LosTaskCB * const rtcb, sigset_t set) { sigset_t unmaskset; rtcb->sig.sigprocmask = set; unmaskset = GETUNMASKSET(rtcb->sig.sigprocmask, rtcb->sig.sigPendFlag); if (unmaskset != NULL_SIGNAL_SET) { /* pendlist do */ rtcb->sig.sigFlag |= unmaskset; rtcb->sig.sigPendFlag ^= unmaskset; } } int OsSigprocMask(int how, const sigset_t_l *setl, sigset_t_l *oldsetl) { LosTaskCB *spcb = NULL; int ret = LOS_OK; unsigned int intSave; sigset_t set; SCHEDULER_LOCK(intSave); spcb = OsCurrTaskGet(); /* If requested, copy the old mask to user. */ if (oldsetl != NULL) { *(sigset_t *)oldsetl = spcb->sig.sigprocmask; } /* If requested, modify the current signal mask. */ if (setl != NULL) { set = *(sigset_t *)setl; /* Okay, determine what we are supposed to do */ switch (how) { /* Set the union of the current set and the signal * set pointed to by set as the new sigprocmask. */ case SIG_BLOCK: spcb->sig.sigprocmask |= set; break; /* Set the intersection of the current set and the * signal set pointed to by set as the new sigprocmask. */ case SIG_UNBLOCK: spcb->sig.sigprocmask &= ~(set); break; /* Set the signal set pointed to by set as the new sigprocmask. */ case SIG_SETMASK: spcb->sig.sigprocmask = set; break; default: ret = -EINVAL; break; } /* If pending mask not in sigmask, need set sigflag. */ OsSigMaskSwitch(spcb, spcb->sig.sigprocmask); } SCHEDULER_UNLOCK(intSave); return ret; } int OsSigProcessForeachChild(LosProcessCB *spcb, ForEachTaskCB handler, void *arg) { int ret; /* Visit the main thread last (if present) */ LosTaskCB *taskCB = NULL; LOS_DL_LIST_FOR_EACH_ENTRY(taskCB, &(spcb->threadSiblingList), LosTaskCB, threadList) { ret = handler(taskCB, arg); OS_RETURN_IF(ret != 0, ret); } return LOS_OK; } static int SigProcessSignalHandler(LosTaskCB *tcb, void *arg) { struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg; int ret; int isMember; if (tcb == NULL) { return 0; } /* If the default tcb is not setted, then set this one as default. */ if (!info->defaultTcb) { info->defaultTcb = tcb; } isMember = OsSigIsMember(&tcb->sig.sigwaitmask, info->sigInfo->si_signo); if (isMember && (!info->awakenedTcb)) { /* This means the task is waiting for this signal. Stop looking for it and use this tcb. * The requirement is: if more than one task in this task group is waiting for the signal, * then only one indeterminate task in the group will receive the signal. */ ret = OsTcbDispatch(tcb, info->sigInfo); OS_RETURN_IF(ret < 0, ret); /* set this tcb as awakenedTcb */ info->awakenedTcb = tcb; OS_RETURN_IF(info->receivedTcb != NULL, SIG_STOP_VISIT); /* Stop search */ } /* Is this signal unblocked on this thread? */ isMember = OsSigIsMember(&tcb->sig.sigprocmask, info->sigInfo->si_signo); if ((!isMember) && (!info->receivedTcb) && (tcb != info->awakenedTcb)) { /* if unblockedTcb of this signal is not setted, then set it. */ if (!info->unblockedTcb) { info->unblockedTcb = tcb; } ret = OsTcbDispatch(tcb, info->sigInfo); OS_RETURN_IF(ret < 0, ret); /* set this tcb as receivedTcb */ info->receivedTcb = tcb; OS_RETURN_IF(info->awakenedTcb != NULL, SIG_STOP_VISIT); /* Stop search */ } return 0; /* Keep searching */ } static int SigProcessKillSigHandler(LosTaskCB *tcb, void *arg) { struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg; return OsPendingTaskWake(tcb, info->sigInfo->si_signo); } static void SigProcessLoadTcb(struct ProcessSignalInfo *info, siginfo_t *sigInfo) { LosTaskCB *tcb = NULL; if (info->awakenedTcb == NULL && info->receivedTcb == NULL) { if (info->unblockedTcb) { tcb = info->unblockedTcb; } else if (info->defaultTcb) { tcb = info->defaultTcb; } else { return; } /* Deliver the signal to the selected task */ (void)OsTcbDispatch(tcb, sigInfo); } } int OsSigProcessSend(LosProcessCB *spcb, siginfo_t *sigInfo) { int ret; struct ProcessSignalInfo info = { .sigInfo = sigInfo, .defaultTcb = NULL, .unblockedTcb = NULL, .awakenedTcb = NULL, .receivedTcb = NULL }; if (info.sigInfo == NULL) { return -EFAULT; } /* visit all taskcb and dispatch signal */ if (info.sigInfo->si_signo == SIGKILL) { OsSigAddSet(&spcb->sigShare, info.sigInfo->si_signo); (void)OsSigProcessForeachChild(spcb, SigProcessKillSigHandler, &info); return 0; } else { ret = OsSigProcessForeachChild(spcb, SigProcessSignalHandler, &info); } if (ret < 0) { return ret; } SigProcessLoadTcb(&info, sigInfo); return 0; } int OsSigEmptySet(sigset_t *set) { *set = NULL_SIGNAL_SET; return 0; } /* Privilege process can't send to kernel and privilege process */ static int OsSignalPermissionToCheck(const LosProcessCB *spcb) { UINT32 gid = spcb->group->groupID; if (gid == OS_KERNEL_PROCESS_GROUP) { return -EPERM; } else if (gid == OS_USER_PRIVILEGE_PROCESS_GROUP) { return -EPERM; } return 0; } int OsDispatch(pid_t pid, siginfo_t *info, int permission) { if (OsProcessIDUserCheckInvalid(pid) || pid < 0) { return -ESRCH; } LosProcessCB *spcb = OS_PCB_FROM_PID(pid); if (OsProcessIsUnused(spcb)) { return -ESRCH; } /* If the process you want to kill had been inactive, but still exist. should return LOS_OK */ if (OsProcessIsInactive(spcb)) { return LOS_OK; } #ifdef LOSCFG_SECURITY_CAPABILITY LosProcessCB *current = OsCurrProcessGet(); /* Kernel process always has kill permission and user process should check permission */ if (OsProcessIsUserMode(current) && !(current->processStatus & OS_PROCESS_FLAG_EXIT)) { if ((current != spcb) && (!IsCapPermit(CAP_KILL)) && (current->user->userID != spcb->user->userID)) { return -EPERM; } } #endif if ((permission == OS_USER_KILL_PERMISSION) && (OsSignalPermissionToCheck(spcb) < 0)) { return -EPERM; } return OsSigProcessSend(spcb, info); } int OsKill(pid_t pid, int sig, int permission) { siginfo_t info; int ret; /* Make sure that the para is valid */ if (!GOOD_SIGNO(sig)) { return -EINVAL; } /* Create the siginfo structure */ info.si_signo = sig; info.si_code = SI_USER; info.si_value.sival_ptr = NULL; if (pid > 0) { /* Send the signal to the specify process */ ret = OsDispatch(pid, &info, permission); } else if (pid == -1) { /* Send SIG to all processes */ ret = OsSendSignalToAllProcess(&info, permission); } else { /* Send SIG to all processes in process group PGRP. If PGRP is zero, send SIG to all processes in the current process's process group. */ ret = OsSendSignalToProcessGroup(pid, &info, permission); } return ret; } int OsKillLock(pid_t pid, int sig) { int ret; unsigned int intSave; SCHEDULER_LOCK(intSave); ret = OsKill(pid, sig, OS_USER_KILL_PERMISSION); SCHEDULER_UNLOCK(intSave); return ret; } INT32 OsTaskKillUnsafe(UINT32 taskID, INT32 signo) { siginfo_t info; LosTaskCB *taskCB = OsGetTaskCB(taskID); INT32 ret = OsUserTaskOperatePermissionsCheck(taskCB); if (ret != LOS_OK) { return -ret; } /* Create the siginfo structure */ info.si_signo = signo; info.si_code = SI_USER; info.si_value.sival_ptr = NULL; /* Dispatch the signal to thread, bypassing normal task group thread * dispatch rules. */ return OsTcbDispatch(taskCB, &info); } int OsPthreadKill(UINT32 tid, int signo) { int ret; UINT32 intSave; /* Make sure that the signal is valid */ OS_RETURN_IF(!GOOD_SIGNO(signo), -EINVAL); if (OS_TID_CHECK_INVALID(tid)) { return -ESRCH; } /* Keep things stationary through the following */ SCHEDULER_LOCK(intSave); ret = OsTaskKillUnsafe(tid, signo); SCHEDULER_UNLOCK(intSave); return ret; } int OsSigAddSet(sigset_t *set, int signo) { /* Verify the signal */ if (!GOOD_SIGNO(signo)) { return -EINVAL; } else { /* In musl, sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ signo -= 1; /* Add the signal to the set */ *set |= SIGNO2SET((unsigned int)signo); return LOS_OK; } } int OsSigPending(sigset_t *set) { LosTaskCB *tcb = NULL; unsigned int intSave; if (set == NULL) { return -EFAULT; } SCHEDULER_LOCK(intSave); tcb = OsCurrTaskGet(); *set = tcb->sig.sigPendFlag; SCHEDULER_UNLOCK(intSave); return LOS_OK; } STATIC int FindFirstSetedBit(UINT64 n) { int count; if (n == 0) { return -1; } for (count = 0; (count < UINT64_BIT_SIZE) && (n ^ 1ULL); n >>= 1, count++) {} return (count < UINT64_BIT_SIZE) ? count : (-1); } int OsSigTimedWaitNoLock(sigset_t *set, siginfo_t *info, unsigned int timeout) { LosTaskCB *task = NULL; sig_cb *sigcb = NULL; int ret; task = OsCurrTaskGet(); sigcb = &task->sig; if (sigcb->waitList.pstNext == NULL) { LOS_ListInit(&sigcb->waitList); } /* If pendingflag & set > 0, should clear pending flag */ sigset_t clear = sigcb->sigPendFlag & *set; if (clear) { sigcb->sigPendFlag ^= clear; ret = FindFirstSetedBit((UINT64)clear) + 1; OsMoveTmpInfoToUnbInfo(sigcb, ret); } else { OsSigAddSet(set, SIGKILL); OsSigAddSet(set, SIGSTOP); sigcb->sigwaitmask |= *set; OsTaskWaitSetPendMask(OS_TASK_WAIT_SIGNAL, sigcb->sigwaitmask, timeout); ret = task->ops->wait(task, &sigcb->waitList, timeout); if (ret == LOS_ERRNO_TSK_TIMEOUT) { ret = -EAGAIN; } sigcb->sigwaitmask = NULL_SIGNAL_SET; } if (info != NULL) { (VOID)memcpy_s(info, sizeof(siginfo_t), &sigcb->sigunbinfo, sizeof(siginfo_t)); } return ret; } int OsSigTimedWait(sigset_t *set, siginfo_t *info, unsigned int timeout) { int ret; unsigned int intSave; SCHEDULER_LOCK(intSave); ret = OsSigTimedWaitNoLock(set, info, timeout); SCHEDULER_UNLOCK(intSave); return ret; } int OsPause(void) { LosTaskCB *spcb = NULL; sigset_t oldSigprocmask; spcb = OsCurrTaskGet(); oldSigprocmask = spcb->sig.sigprocmask; return OsSigSuspend(&oldSigprocmask); } int OsSigSuspend(const sigset_t *set) { unsigned int intSave; LosTaskCB *rtcb = NULL; sigset_t setSuspend; int ret; if (set == NULL) { return -EINVAL; } SCHEDULER_LOCK(intSave); rtcb = OsCurrTaskGet(); /* Wait signal calc */ setSuspend = FULL_SIGNAL_SET & (~(*set)); /* If pending mask not in sigmask, need set sigflag */ OsSigMaskSwitch(rtcb, *set); if (rtcb->sig.sigFlag > 0) { SCHEDULER_UNLOCK(intSave); /* * If rtcb->sig.sigFlag > 0, it means that some signal have been * received, and we need to do schedule to handle the signal directly. */ LOS_Schedule(); return -EINTR; } else { ret = OsSigTimedWaitNoLock(&setSuspend, NULL, LOS_WAIT_FOREVER); if (ret < 0) { PRINT_ERR("FUNC %s LINE = %d, ret = %x\n", __FUNCTION__, __LINE__, ret); } } SCHEDULER_UNLOCK(intSave); return -EINTR; } int OsSigAction(int sig, const sigaction_t *act, sigaction_t *oact) { UINTPTR addr; sigaction_t action; if (!GOOD_SIGNO(sig) || sig < 1 || act == NULL) { return -EINVAL; } if (LOS_ArchCopyFromUser(&action, act, sizeof(sigaction_t)) != LOS_OK) { return -EFAULT; } if (sig == SIGSYS) { addr = OsGetSigHandler(); if (addr == 0) { OsSetSigHandler((unsigned long)(UINTPTR)action.sa_handler); return LOS_OK; } return -EINVAL; } return LOS_OK; } VOID OsSigIntLock(VOID) { LosTaskCB *task = OsCurrTaskGet(); sig_cb *sigcb = &task->sig; (VOID)LOS_AtomicAdd((Atomic *)&sigcb->sigIntLock, 1); } VOID OsSigIntUnlock(VOID) { LosTaskCB *task = OsCurrTaskGet(); sig_cb *sigcb = &task->sig; (VOID)LOS_AtomicSub((Atomic *)&sigcb->sigIntLock, 1); } VOID *OsSaveSignalContext(VOID *sp, VOID *newSp) { UINTPTR sigHandler; UINT32 intSave; LosTaskCB *task = OsCurrTaskGet(); LosProcessCB *process = OsCurrProcessGet(); sig_cb *sigcb = &task->sig; /* A thread is not allowed to interrupt the processing of its signals during a system call */ if (sigcb->sigIntLock > 0) { return sp; } if (OsTaskIsKilled(task)) { OsRunningTaskToExit(task, 0); return sp; } SCHEDULER_LOCK(intSave); if ((sigcb->count == 0) && ((sigcb->sigFlag != 0) || (process->sigShare != 0))) { sigHandler = OsGetSigHandler(); if (sigHandler == 0) { sigcb->sigFlag = 0; process->sigShare = 0; SCHEDULER_UNLOCK(intSave); PRINT_ERR("The signal processing function for the current process pid =%d is NULL!\n", task->processID); return sp; } /* One pthread do the share signal */ sigcb->sigFlag |= process->sigShare; UINT32 signo = (UINT32)FindFirstSetedBit(sigcb->sigFlag) + 1; UINT32 sigVal = (UINT32)(UINTPTR)(sigcb->sigunbinfo.si_value.sival_ptr); OsMoveTmpInfoToUnbInfo(sigcb, signo); OsProcessExitCodeSignalSet(process, signo); sigcb->sigContext = sp; OsInitSignalContext(sp, newSp, sigHandler, signo, sigVal); /* sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ sigcb->sigFlag ^= 1ULL << (signo - 1); sigcb->count++; SCHEDULER_UNLOCK(intSave); return newSp; } SCHEDULER_UNLOCK(intSave); return sp; } VOID *OsRestorSignalContext(VOID *sp) { UINT32 intSave; LosTaskCB *task = OsCurrTaskGet(); sig_cb *sigcb = &task->sig; SCHEDULER_LOCK(intSave); if (sigcb->count != 1) { SCHEDULER_UNLOCK(intSave); PRINT_ERR("sig error count : %d\n", sigcb->count); return sp; } LosProcessCB *process = OsCurrProcessGet(); VOID *saveContext = sigcb->sigContext; sigcb->sigContext = NULL; sigcb->count--; process->sigShare = 0; OsProcessExitCodeSignalClear(process); SCHEDULER_UNLOCK(intSave); return saveContext; } #endif