/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* hash function for the lwpid hash table, p->p_tidhash[] */ #define TIDHASH(tid, hash_sz) ((tid) & ((hash_sz) - 1)) void *segkp_lwp; /* cookie for pool of segkp resources */ extern void reapq_move_lq_to_tq(kthread_t *); extern void freectx_ctx(struct ctxop *); /* * Create a kernel thread associated with a particular system process. Give * it an LWP so that microstate accounting will be available for it. */ kthread_t * lwp_kernel_create(proc_t *p, void (*proc)(), void *arg, int state, pri_t pri) { klwp_t *lwp; VERIFY((p->p_flag & SSYS) != 0); lwp = lwp_create(proc, arg, 0, p, state, pri, &t0.t_hold, syscid, 0); VERIFY(lwp != NULL); return (lwptot(lwp)); } /* * Create a thread that appears to be stopped at sys_rtt. */ klwp_t * lwp_create(void (*proc)(), caddr_t arg, size_t len, proc_t *p, int state, int pri, const k_sigset_t *smask, int cid, id_t lwpid) { klwp_t *lwp = NULL; kthread_t *t; kthread_t *tx; cpupart_t *oldpart = NULL; size_t stksize; caddr_t lwpdata = NULL; processorid_t binding; int err = 0; kproject_t *oldkpj, *newkpj; void *bufp = NULL; klwp_t *curlwp; lwpent_t *lep; lwpdir_t *old_dir = NULL; uint_t old_dirsz = 0; tidhash_t *old_hash = NULL; uint_t old_hashsz = 0; ret_tidhash_t *ret_tidhash = NULL; int i; int rctlfail = 0; boolean_t branded = 0; struct ctxop *ctx = NULL; ASSERT(cid != sysdccid); /* system threads must start in SYS */ ASSERT(p != &p0); /* No new LWPs in p0. */ mutex_enter(&p->p_lock); mutex_enter(&p->p_zone->zone_nlwps_lock); /* * don't enforce rctl limits on system processes */ if (!CLASS_KERNEL(cid)) { if (p->p_task->tk_nlwps >= p->p_task->tk_nlwps_ctl) if (rctl_test(rc_task_lwps, p->p_task->tk_rctls, p, 1, 0) & RCT_DENY) rctlfail = 1; if (p->p_task->tk_proj->kpj_nlwps >= p->p_task->tk_proj->kpj_nlwps_ctl) if (rctl_test(rc_project_nlwps, p->p_task->tk_proj->kpj_rctls, p, 1, 0) & RCT_DENY) rctlfail = 1; if (p->p_zone->zone_nlwps >= p->p_zone->zone_nlwps_ctl) if (rctl_test(rc_zone_nlwps, p->p_zone->zone_rctls, p, 1, 0) & RCT_DENY) rctlfail = 1; } if (rctlfail) { mutex_exit(&p->p_zone->zone_nlwps_lock); mutex_exit(&p->p_lock); return (NULL); } p->p_task->tk_nlwps++; p->p_task->tk_proj->kpj_nlwps++; p->p_zone->zone_nlwps++; mutex_exit(&p->p_zone->zone_nlwps_lock); mutex_exit(&p->p_lock); if (CLASS_KERNEL(cid)) { curlwp = NULL; /* don't inherit from curlwp */ stksize = lwp_default_stksize; } else { curlwp = ttolwp(curthread); if (curlwp == NULL || (stksize = curlwp->lwp_childstksz) == 0) stksize = lwp_default_stksize; } /* * For system threads, we sleep for our swap reservation, and the * thread stack can't be swapped. * * Otherwise, try to reclaim a from 'deathrow' */ if (CLASS_KERNEL(cid)) { lwpdata = (caddr_t)segkp_get(segkp, stksize, (KPD_NO_ANON | KPD_HASREDZONE | KPD_LOCKED)); } else if (stksize == lwp_default_stksize) { if (lwp_reapcnt > 0) { mutex_enter(&reaplock); if ((t = lwp_deathrow) != NULL) { ASSERT(t->t_swap); lwp_deathrow = t->t_forw; lwp_reapcnt--; lwpdata = t->t_swap; lwp = t->t_lwp; ctx = t->t_ctx; t->t_swap = NULL; t->t_lwp = NULL; t->t_ctx = NULL; reapq_move_lq_to_tq(t); } mutex_exit(&reaplock); if (lwp != NULL) { lwp_stk_fini(lwp); } if (ctx != NULL) { freectx_ctx(ctx); } } if (lwpdata == NULL && (lwpdata = (caddr_t)segkp_cache_get(segkp_lwp)) == NULL) { mutex_enter(&p->p_lock); mutex_enter(&p->p_zone->zone_nlwps_lock); p->p_task->tk_nlwps--; p->p_task->tk_proj->kpj_nlwps--; p->p_zone->zone_nlwps--; mutex_exit(&p->p_zone->zone_nlwps_lock); mutex_exit(&p->p_lock); return (NULL); } } else { stksize = roundup(stksize, PAGESIZE); if ((lwpdata = (caddr_t)segkp_get(segkp, stksize, (KPD_NOWAIT | KPD_HASREDZONE | KPD_LOCKED))) == NULL) { mutex_enter(&p->p_lock); mutex_enter(&p->p_zone->zone_nlwps_lock); p->p_task->tk_nlwps--; p->p_task->tk_proj->kpj_nlwps--; p->p_zone->zone_nlwps--; mutex_exit(&p->p_zone->zone_nlwps_lock); mutex_exit(&p->p_lock); return (NULL); } } /* * Create a thread, initializing the stack pointer */ t = thread_create(lwpdata, stksize, NULL, NULL, 0, p, TS_STOPPED, pri); t->t_swap = lwpdata; /* Start of page-able data */ if (lwp == NULL) lwp = kmem_cache_alloc(lwp_cache, KM_SLEEP); bzero(lwp, sizeof (*lwp)); t->t_lwp = lwp; t->t_hold = *smask; lwp->lwp_thread = t; lwp->lwp_procp = p; lwp->lwp_sigaltstack.ss_flags = SS_DISABLE; if (curlwp != NULL && curlwp->lwp_childstksz != 0) lwp->lwp_childstksz = curlwp->lwp_childstksz; t->t_stk = lwp_stk_init(lwp, t->t_stk); thread_load(t, proc, arg, len); /* * Allocate the SIGPROF buffer if ITIMER_REALPROF is in effect. */ if (p->p_rprof_cyclic != CYCLIC_NONE) t->t_rprof = kmem_zalloc(sizeof (struct rprof), KM_SLEEP); if (cid != NOCLASS) (void) CL_ALLOC(&bufp, cid, KM_SLEEP); /* * Allocate an lwp directory entry for the new lwp. */ lep = kmem_zalloc(sizeof (*lep), KM_SLEEP); mutex_enter(&p->p_lock); grow: /* * Grow the lwp (thread) directory and lwpid hash table if necessary. * A note on the growth algorithm: * The new lwp directory size is computed as: * new = 2 * old + 2 * Starting with an initial size of 2 (see exec_common()), * this yields numbers that are a power of two minus 2: * 2, 6, 14, 30, 62, 126, 254, 510, 1022, ... * The size of the lwpid hash table must be a power of two * and must be commensurate in size with the lwp directory * so that hash bucket chains remain short. Therefore, * the lwpid hash table size is computed as: * hashsz = (dirsz + 2) / 2 * which leads to these hash table sizes corresponding to * the above directory sizes: * 2, 4, 8, 16, 32, 64, 128, 256, 512, ... * A note on growing the hash table: * For performance reasons, code in lwp_unpark() does not * acquire curproc->p_lock when searching the hash table. * Rather, it calls lwp_hash_lookup_and_lock() which * acquires only the individual hash bucket lock, taking * care to deal with reallocation of the hash table * during the time it takes to acquire the lock. * * This is sufficient to protect the integrity of the * hash table, but it requires us to acquire all of the * old hash bucket locks before growing the hash table * and to release them afterwards. It also requires us * not to free the old hash table because some thread * in lwp_hash_lookup_and_lock() might still be trying * to acquire the old bucket lock. * * So we adopt the tactic of keeping all of the retired * hash tables on a linked list, so they can be safely * freed when the process exits or execs. * * Because the hash table grows in powers of two, the * total size of all of the hash tables will be slightly * less than twice the size of the largest hash table. */ while (p->p_lwpfree == NULL) { uint_t dirsz = p->p_lwpdir_sz; lwpdir_t *new_dir; uint_t new_dirsz; lwpdir_t *ldp; tidhash_t *new_hash; uint_t new_hashsz; mutex_exit(&p->p_lock); /* * Prepare to remember the old p_tidhash for later * kmem_free()ing when the process exits or execs. */ if (ret_tidhash == NULL) ret_tidhash = kmem_zalloc(sizeof (ret_tidhash_t), KM_SLEEP); if (old_dir != NULL) kmem_free(old_dir, old_dirsz * sizeof (*old_dir)); if (old_hash != NULL) kmem_free(old_hash, old_hashsz * sizeof (*old_hash)); new_dirsz = 2 * dirsz + 2; new_dir = kmem_zalloc(new_dirsz * sizeof (lwpdir_t), KM_SLEEP); for (ldp = new_dir, i = 1; i < new_dirsz; i++, ldp++) ldp->ld_next = ldp + 1; new_hashsz = (new_dirsz + 2) / 2; new_hash = kmem_zalloc(new_hashsz * sizeof (tidhash_t), KM_SLEEP); mutex_enter(&p->p_lock); if (p == curproc) prbarrier(p); if (dirsz != p->p_lwpdir_sz || p->p_lwpfree != NULL) { /* * Someone else beat us to it or some lwp exited. * Set up to free our memory and take a lap. */ old_dir = new_dir; old_dirsz = new_dirsz; old_hash = new_hash; old_hashsz = new_hashsz; } else { /* * For the benefit of lwp_hash_lookup_and_lock(), * called from lwp_unpark(), which searches the * tid hash table without acquiring p->p_lock, * we must acquire all of the tid hash table * locks before replacing p->p_tidhash. */ old_hash = p->p_tidhash; old_hashsz = p->p_tidhash_sz; for (i = 0; i < old_hashsz; i++) { mutex_enter(&old_hash[i].th_lock); mutex_enter(&new_hash[i].th_lock); } /* * We simply hash in all of the old directory entries. * This works because the old directory has no empty * slots and the new hash table starts out empty. * This reproduces the original directory ordering * (required for /proc directory semantics). */ old_dir = p->p_lwpdir; old_dirsz = p->p_lwpdir_sz; p->p_lwpdir = new_dir; p->p_lwpfree = new_dir; p->p_lwpdir_sz = new_dirsz; for (ldp = old_dir, i = 0; i < old_dirsz; i++, ldp++) lwp_hash_in(p, ldp->ld_entry, new_hash, new_hashsz, 0); /* * Remember the old hash table along with all * of the previously-remembered hash tables. * We will free them at process exit or exec. */ ret_tidhash->rth_tidhash = old_hash; ret_tidhash->rth_tidhash_sz = old_hashsz; ret_tidhash->rth_next = p->p_ret_tidhash; p->p_ret_tidhash = ret_tidhash; /* * Now establish the new tid hash table. * As soon as we assign p->p_tidhash, * code in lwp_unpark() can start using it. */ membar_producer(); p->p_tidhash = new_hash; /* * It is necessary that p_tidhash reach global * visibility before p_tidhash_sz. Otherwise, * code in lwp_hash_lookup_and_lock() could * index into the old p_tidhash using the new * p_tidhash_sz and thereby access invalid data. */ membar_producer(); p->p_tidhash_sz = new_hashsz; /* * Release the locks; allow lwp_unpark() to carry on. */ for (i = 0; i < old_hashsz; i++) { mutex_exit(&old_hash[i].th_lock); mutex_exit(&new_hash[i].th_lock); } /* * Avoid freeing these objects below. */ ret_tidhash = NULL; old_hash = NULL; old_hashsz = 0; } } /* * Block the process against /proc while we manipulate p->p_tlist, * unless lwp_create() was called by /proc for the PCAGENT operation. * We want to do this early enough so that we don't drop p->p_lock * until the thread is put on the p->p_tlist. */ if (p == curproc) { prbarrier(p); /* * If the current lwp has been requested to stop, do so now. * Otherwise we have a race condition between /proc attempting * to stop the process and this thread creating a new lwp * that was not seen when the /proc PCSTOP request was issued. * We rely on stop() to call prbarrier(p) before returning. */ while ((curthread->t_proc_flag & TP_PRSTOP) && !ttolwp(curthread)->lwp_nostop) { /* * We called pool_barrier_enter() before calling * here to lwp_create(). We have to call * pool_barrier_exit() before stopping. */ pool_barrier_exit(); prbarrier(p); stop(PR_REQUESTED, 0); /* * And we have to repeat the call to * pool_barrier_enter after stopping. */ pool_barrier_enter(); prbarrier(p); } /* * If process is exiting, there could be a race between * the agent lwp creation and the new lwp currently being * created. So to prevent this race lwp creation is failed * if the process is exiting. */ if (p->p_flag & (SEXITLWPS|SKILLED)) { err = 1; goto error; } /* * Since we might have dropped p->p_lock, the * lwp directory free list might have changed. */ if (p->p_lwpfree == NULL) goto grow; } kpreempt_disable(); /* can't grab cpu_lock here */ /* * Inherit processor and processor set bindings from curthread. * * For kernel LWPs, we do not inherit processor set bindings at * process creation time (i.e. when p != curproc). After the * kernel process is created, any subsequent LWPs must be created * by threads in the kernel process, at which point we *will* * inherit processor set bindings. */ if (CLASS_KERNEL(cid) && p != curproc) { t->t_bind_cpu = binding = PBIND_NONE; t->t_cpupart = oldpart = &cp_default; t->t_bind_pset = PS_NONE; t->t_bindflag = (uchar_t)default_binding_mode; } else { binding = curthread->t_bind_cpu; t->t_bind_cpu = binding; oldpart = t->t_cpupart; t->t_cpupart = curthread->t_cpupart; t->t_bind_pset = curthread->t_bind_pset; t->t_bindflag = curthread->t_bindflag | (uchar_t)default_binding_mode; } /* * thread_create() initializes this thread's home lgroup to the root. * Choose a more suitable lgroup, since this thread is associated * with an lwp. */ ASSERT(oldpart != NULL); if (binding != PBIND_NONE && t->t_affinitycnt == 0) { t->t_bound_cpu = cpu[binding]; if (t->t_lpl != t->t_bound_cpu->cpu_lpl) lgrp_move_thread(t, t->t_bound_cpu->cpu_lpl, 1); } else { lgrp_move_thread(t, lgrp_choose(t, t->t_cpupart), 1); } kpreempt_enable(); /* * make sure lpl points to our own partition */ ASSERT(t->t_lpl >= t->t_cpupart->cp_lgrploads); ASSERT(t->t_lpl < t->t_cpupart->cp_lgrploads + t->t_cpupart->cp_nlgrploads); /* * If we're creating a new process, then inherit the project from our * parent. If we're only creating an additional lwp then use the * project pointer of the target process. */ if (p->p_task == NULL) newkpj = ttoproj(curthread); else newkpj = p->p_task->tk_proj; /* * It is safe to point the thread to the new project without holding it * since we're holding the target process' p_lock here and therefore * we're guaranteed that it will not move to another project. */ oldkpj = ttoproj(t); if (newkpj != oldkpj) { t->t_proj = newkpj; (void) project_hold(newkpj); project_rele(oldkpj); } if (cid != NOCLASS) { /* * If the lwp is being created in the current process * and matches the current thread's scheduling class, * we should propagate the current thread's scheduling * parameters by calling CL_FORK. Otherwise just use * the defaults by calling CL_ENTERCLASS. */ if (p != curproc || curthread->t_cid != cid) { err = CL_ENTERCLASS(t, cid, NULL, NULL, bufp); t->t_pri = pri; /* CL_ENTERCLASS may have changed it */ /* * We don't call schedctl_set_cidpri(t) here * because the schedctl data is not yet set * up for the newly-created lwp. */ } else { t->t_clfuncs = &(sclass[cid].cl_funcs->thread); err = CL_FORK(curthread, t, bufp); t->t_cid = cid; } if (err) goto error; else bufp = NULL; } /* * If we were given an lwpid then use it, else allocate one. */ if (lwpid != 0) t->t_tid = lwpid; else { /* * lwp/thread id 0 is never valid; reserved for special checks. * lwp/thread id 1 is reserved for the main thread. * Start again at 2 when INT_MAX has been reached * (id_t is a signed 32-bit integer). */ id_t prev_id = p->p_lwpid; /* last allocated tid */ do { /* avoid lwpid duplication */ if (p->p_lwpid == INT_MAX) { p->p_flag |= SLWPWRAP; p->p_lwpid = 1; } if ((t->t_tid = ++p->p_lwpid) == prev_id) { /* * All lwpids are allocated; fail the request. */ err = 1; goto error; } /* * We only need to worry about colliding with an id * that's already in use if this process has * cycled through all available lwp ids. */ if ((p->p_flag & SLWPWRAP) == 0) break; } while (lwp_hash_lookup(p, t->t_tid) != NULL); } /* * If this is a branded process, let the brand do any necessary lwp * initialization. */ if (PROC_IS_BRANDED(p)) { if (BROP(p)->b_initlwp(lwp)) { err = 1; goto error; } branded = 1; } if (t->t_tid == 1) { kpreempt_disable(); ASSERT(t->t_lpl != NULL); p->p_t1_lgrpid = t->t_lpl->lpl_lgrpid; kpreempt_enable(); if (p->p_tr_lgrpid != LGRP_NONE && p->p_tr_lgrpid != p->p_t1_lgrpid) { lgrp_update_trthr_migrations(1); } } p->p_lwpcnt++; t->t_waitfor = -1; /* * Turn microstate accounting on for thread if on for process. */ if (p->p_flag & SMSACCT) t->t_proc_flag |= TP_MSACCT; /* * If the process has watchpoints, mark the new thread as such. */ if (pr_watch_active(p)) watch_enable(t); /* * The lwp is being created in the stopped state. * We set all the necessary flags to indicate that fact here. * We omit the TS_CREATE flag from t_schedflag so that the lwp * cannot be set running until the caller is finished with it, * even if lwp_continue() is called on it after we drop p->p_lock. * When the caller is finished with the newly-created lwp, * the caller must call lwp_create_done() to allow the lwp * to be set running. If the TP_HOLDLWP is left set, the * lwp will suspend itself after reaching system call exit. */ init_mstate(t, LMS_STOPPED); t->t_proc_flag |= TP_HOLDLWP; t->t_schedflag |= (TS_ALLSTART & ~(TS_CSTART | TS_CREATE)); t->t_whystop = PR_SUSPENDED; t->t_whatstop = SUSPEND_NORMAL; t->t_sig_check = 1; /* ensure that TP_HOLDLWP is honored */ /* * Set system call processing flags in case tracing or profiling * is set. The first system call will evaluate these and turn * them off if they aren't needed. */ t->t_pre_sys = 1; t->t_post_sys = 1; /* * Insert the new thread into the list of all threads. */ if ((tx = p->p_tlist) == NULL) { t->t_back = t; t->t_forw = t; p->p_tlist = t; } else { t->t_forw = tx; t->t_back = tx->t_back; tx->t_back->t_forw = t; tx->t_back = t; } /* * Insert the new lwp into an lwp directory slot position * and into the lwpid hash table. */ lep->le_thread = t; lep->le_lwpid = t->t_tid; lep->le_start = t->t_start; lwp_hash_in(p, lep, p->p_tidhash, p->p_tidhash_sz, 1); if (state == TS_RUN) { /* * We set the new lwp running immediately. */ t->t_proc_flag &= ~TP_HOLDLWP; lwp_create_done(t); } error: if (err) { if (CLASS_KERNEL(cid)) { /* * This should only happen if a system process runs * out of lwpids, which shouldn't occur. */ panic("Failed to create a system LWP"); } /* * We have failed to create an lwp, so decrement the number * of lwps in the task and let the lgroup load averages know * that this thread isn't going to show up. */ kpreempt_disable(); lgrp_move_thread(t, NULL, 1); kpreempt_enable(); ASSERT(MUTEX_HELD(&p->p_lock)); mutex_enter(&p->p_zone->zone_nlwps_lock); p->p_task->tk_nlwps--; p->p_task->tk_proj->kpj_nlwps--; p->p_zone->zone_nlwps--; mutex_exit(&p->p_zone->zone_nlwps_lock); if (cid != NOCLASS && bufp != NULL) CL_FREE(cid, bufp); if (branded) BROP(p)->b_freelwp(lwp); mutex_exit(&p->p_lock); t->t_state = TS_FREE; thread_rele(t); /* * We need to remove t from the list of all threads * because thread_exit()/lwp_exit() isn't called on t. */ mutex_enter(&pidlock); ASSERT(t != t->t_next); /* t0 never exits */ t->t_next->t_prev = t->t_prev; t->t_prev->t_next = t->t_next; mutex_exit(&pidlock); thread_free(t); kmem_free(lep, sizeof (*lep)); lwp = NULL; } else { mutex_exit(&p->p_lock); } if (old_dir != NULL) kmem_free(old_dir, old_dirsz * sizeof (*old_dir)); if (old_hash != NULL) kmem_free(old_hash, old_hashsz * sizeof (*old_hash)); if (ret_tidhash != NULL) kmem_free(ret_tidhash, sizeof (ret_tidhash_t)); DTRACE_PROC1(lwp__create, kthread_t *, t); return (lwp); } /* * lwp_create_done() is called by the caller of lwp_create() to set the * newly-created lwp running after the caller has finished manipulating it. */ void lwp_create_done(kthread_t *t) { proc_t *p = ttoproc(t); ASSERT(MUTEX_HELD(&p->p_lock)); /* * We set the TS_CREATE and TS_CSTART flags and call setrun_locked(). * (The absence of the TS_CREATE flag prevents the lwp from running * until we are finished with it, even if lwp_continue() is called on * it by some other lwp in the process or elsewhere in the kernel.) */ thread_lock(t); ASSERT(t->t_state == TS_STOPPED && !(t->t_schedflag & TS_CREATE)); /* * If TS_CSTART is set, lwp_continue(t) has been called and * has already incremented p_lwprcnt; avoid doing this twice. */ if (!(t->t_schedflag & TS_CSTART)) p->p_lwprcnt++; t->t_schedflag |= (TS_CSTART | TS_CREATE); setrun_locked(t); thread_unlock(t); } /* * Copy an LWP's active templates, and clear the latest contracts. */ void lwp_ctmpl_copy(klwp_t *dst, klwp_t *src) { int i; for (i = 0; i < ct_ntypes; i++) { dst->lwp_ct_active[i] = ctmpl_dup(src->lwp_ct_active[i]); dst->lwp_ct_latest[i] = NULL; } } /* * Clear an LWP's contract template state. */ void lwp_ctmpl_clear(klwp_t *lwp) { ct_template_t *tmpl; int i; for (i = 0; i < ct_ntypes; i++) { if ((tmpl = lwp->lwp_ct_active[i]) != NULL) { ctmpl_free(tmpl); lwp->lwp_ct_active[i] = NULL; } if (lwp->lwp_ct_latest[i] != NULL) { contract_rele(lwp->lwp_ct_latest[i]); lwp->lwp_ct_latest[i] = NULL; } } } /* * Individual lwp exit. * If this is the last lwp, exit the whole process. */ void lwp_exit(void) { kthread_t *t = curthread; klwp_t *lwp = ttolwp(t); proc_t *p = ttoproc(t); ASSERT(MUTEX_HELD(&p->p_lock)); mutex_exit(&p->p_lock); #if defined(__sparc) /* * Ensure that the user stack is fully abandoned.. */ trash_user_windows(); #endif tsd_exit(); /* free thread specific data */ kcpc_passivate(); /* Clean up performance counter state */ pollcleanup(); if (t->t_door) door_slam(); if (t->t_schedctl != NULL) schedctl_lwp_cleanup(t); if (t->t_upimutex != NULL) upimutex_cleanup(); /* * Perform any brand specific exit processing, then release any * brand data associated with the lwp */ if (PROC_IS_BRANDED(p)) BROP(p)->b_lwpexit(lwp); mutex_enter(&p->p_lock); lwp_cleanup(); /* * When this process is dumping core, its lwps are held here * until the core dump is finished. Then exitlwps() is called * again to release these lwps so that they can finish exiting. */ if (p->p_flag & SCOREDUMP) stop(PR_SUSPENDED, SUSPEND_NORMAL); /* * Block the process against /proc now that we have really acquired * p->p_lock (to decrement p_lwpcnt and manipulate p_tlist at least). */ prbarrier(p); /* * Call proc_exit() if this is the last non-daemon lwp in the process. */ if (!(t->t_proc_flag & TP_DAEMON) && p->p_lwpcnt == p->p_lwpdaemon + 1) { mutex_exit(&p->p_lock); if (proc_exit(CLD_EXITED, 0) == 0) { /* Restarting init. */ return; } /* * proc_exit() returns a non-zero value when some other * lwp got there first. We just have to continue in * lwp_exit(). */ mutex_enter(&p->p_lock); ASSERT(curproc->p_flag & SEXITLWPS); prbarrier(p); } DTRACE_PROC(lwp__exit); /* * If the lwp is a detached lwp or if the process is exiting, * remove (lwp_hash_out()) the lwp from the lwp directory. * Otherwise null out the lwp's le_thread pointer in the lwp * directory so that other threads will see it as a zombie lwp. */ prlwpexit(t); /* notify /proc */ if (!(t->t_proc_flag & TP_TWAIT) || (p->p_flag & SEXITLWPS)) lwp_hash_out(p, t->t_tid); else { ASSERT(!(t->t_proc_flag & TP_DAEMON)); p->p_lwpdir[t->t_dslot].ld_entry->le_thread = NULL; p->p_zombcnt++; cv_broadcast(&p->p_lwpexit); } if (t->t_proc_flag & TP_DAEMON) { p->p_lwpdaemon--; t->t_proc_flag &= ~TP_DAEMON; } t->t_proc_flag &= ~TP_TWAIT; /* * Maintain accurate lwp count for task.max-lwps resource control. */ mutex_enter(&p->p_zone->zone_nlwps_lock); p->p_task->tk_nlwps--; p->p_task->tk_proj->kpj_nlwps--; p->p_zone->zone_nlwps--; mutex_exit(&p->p_zone->zone_nlwps_lock); CL_EXIT(t); /* tell the scheduler that t is exiting */ ASSERT(p->p_lwpcnt != 0); p->p_lwpcnt--; /* * If all remaining non-daemon lwps are waiting in lwp_wait(), * wake them up so someone can return EDEADLK. * (See the block comment preceeding lwp_wait().) */ if (p->p_lwpcnt == p->p_lwpdaemon + (p->p_lwpwait - p->p_lwpdwait)) cv_broadcast(&p->p_lwpexit); t->t_proc_flag |= TP_LWPEXIT; term_mstate(t); #ifndef NPROBE /* Kernel probe */ if (t->t_tnf_tpdp) tnf_thread_exit(); #endif /* NPROBE */ t->t_forw->t_back = t->t_back; t->t_back->t_forw = t->t_forw; if (t == p->p_tlist) p->p_tlist = t->t_forw; /* * Clean up the signal state. */ if (t->t_sigqueue != NULL) sigdelq(p, t, 0); if (lwp->lwp_curinfo != NULL) { siginfofree(lwp->lwp_curinfo); lwp->lwp_curinfo = NULL; } thread_rele(t); /* * Terminated lwps are associated with process zero and are put onto * death-row by resume(). Avoid preemption after resetting t->t_procp. */ t->t_preempt++; if (t->t_ctx != NULL) exitctx(t); if (p->p_pctx != NULL) exitpctx(p); t->t_procp = &p0; /* * Notify the HAT about the change of address space */ hat_thread_exit(t); /* * When this is the last running lwp in this process and some lwp is * waiting for this condition to become true, or this thread was being * suspended, then the waiting lwp is awakened. * * Also, if the process is exiting, we may have a thread waiting in * exitlwps() that needs to be notified. */ if (--p->p_lwprcnt == 0 || (t->t_proc_flag & TP_HOLDLWP) || (p->p_flag & SEXITLWPS)) cv_broadcast(&p->p_holdlwps); /* * Need to drop p_lock so we can reacquire pidlock. */ mutex_exit(&p->p_lock); mutex_enter(&pidlock); ASSERT(t != t->t_next); /* t0 never exits */ t->t_next->t_prev = t->t_prev; t->t_prev->t_next = t->t_next; cv_broadcast(&t->t_joincv); /* wake up anyone in thread_join */ mutex_exit(&pidlock); lwp_pcb_exit(); t->t_state = TS_ZOMB; swtch_from_zombie(); /* never returns */ } /* * Cleanup function for an exiting lwp. * Called both from lwp_exit() and from proc_exit(). * p->p_lock is repeatedly released and grabbed in this function. */ void lwp_cleanup(void) { kthread_t *t = curthread; proc_t *p = ttoproc(t); ASSERT(MUTEX_HELD(&p->p_lock)); /* untimeout any lwp-bound realtime timers */ if (p->p_itimer != NULL) timer_lwpexit(); /* * If this is the /proc agent lwp that is exiting, readjust p_lwpid * so it appears that the agent never existed, and clear p_agenttp. */ if (t == p->p_agenttp) { ASSERT(t->t_tid == p->p_lwpid); p->p_lwpid--; p->p_agenttp = NULL; } /* * Do lgroup bookkeeping to account for thread exiting. */ kpreempt_disable(); lgrp_move_thread(t, NULL, 1); if (t->t_tid == 1) { p->p_t1_lgrpid = LGRP_NONE; } kpreempt_enable(); lwp_ctmpl_clear(ttolwp(t)); } int lwp_suspend(kthread_t *t) { int tid; proc_t *p = ttoproc(t); ASSERT(MUTEX_HELD(&p->p_lock)); /* * Set the thread's TP_HOLDLWP flag so it will stop in holdlwp(). * If an lwp is stopping itself, there is no need to wait. */ top: t->t_proc_flag |= TP_HOLDLWP; if (t == curthread) { t->t_sig_check = 1; } else { /* * Make sure the lwp stops promptly. */ thread_lock(t); t->t_sig_check = 1; /* * XXX Should use virtual stop like /proc does instead of * XXX waking the thread to get it to stop. */ if (ISWAKEABLE(t) || ISWAITING(t)) { setrun_locked(t); } else if (t->t_state == TS_ONPROC && t->t_cpu != CPU) { poke_cpu(t->t_cpu->cpu_id); } tid = t->t_tid; /* remember thread ID */ /* * Wait for lwp to stop */ while (!SUSPENDED(t)) { /* * Drop the thread lock before waiting and reacquire it * afterwards, so the thread can change its t_state * field. */ thread_unlock(t); /* * Check if aborted by exitlwps(). */ if (p->p_flag & SEXITLWPS) lwp_exit(); /* * Cooperate with jobcontrol signals and /proc stopping * by calling cv_wait_sig() to wait for the target * lwp to stop. Just using cv_wait() can lead to * deadlock because, if some other lwp has stopped * by either of these mechanisms, then p_lwprcnt will * never become zero if we do a cv_wait(). */ if (!cv_wait_sig(&p->p_holdlwps, &p->p_lock)) return (EINTR); /* * Check to see if thread died while we were * waiting for it to suspend. */ if (idtot(p, tid) == NULL) return (ESRCH); thread_lock(t); /* * If the TP_HOLDLWP flag went away, lwp_continue() * or vfork() must have been called while we were * waiting, so start over again. */ if ((t->t_proc_flag & TP_HOLDLWP) == 0) { thread_unlock(t); goto top; } } thread_unlock(t); } return (0); } /* * continue a lwp that's been stopped by lwp_suspend(). */ void lwp_continue(kthread_t *t) { proc_t *p = ttoproc(t); int was_suspended = t->t_proc_flag & TP_HOLDLWP; ASSERT(MUTEX_HELD(&p->p_lock)); t->t_proc_flag &= ~TP_HOLDLWP; thread_lock(t); if (SUSPENDED(t) && !(p->p_flag & (SHOLDFORK | SHOLDFORK1 | SHOLDWATCH))) { p->p_lwprcnt++; t->t_schedflag |= TS_CSTART; setrun_locked(t); } thread_unlock(t); /* * Wakeup anyone waiting for this thread to be suspended */ if (was_suspended) cv_broadcast(&p->p_holdlwps); } /* * ******************************** * Miscellaneous lwp routines * * ******************************** */ /* * When a process is undergoing a forkall(), its p_flag is set to SHOLDFORK. * This will cause the process's lwps to stop at a hold point. A hold * point is where a kernel thread has a flat stack. This is at the * return from a system call and at the return from a user level trap. * * When a process is undergoing a fork1() or vfork(), its p_flag is set to * SHOLDFORK1. This will cause the process's lwps to stop at a modified * hold point. The lwps in the process are not being cloned, so they * are held at the usual hold points and also within issig_forreal(). * This has the side-effect that their system calls do not return * showing EINTR. * * An lwp can also be held. This is identified by the TP_HOLDLWP flag on * the thread. The TP_HOLDLWP flag is set in lwp_suspend(), where the active * lwp is waiting for the target lwp to be stopped. */ void holdlwp(void) { proc_t *p = curproc; kthread_t *t = curthread; mutex_enter(&p->p_lock); /* * Don't terminate immediately if the process is dumping core. * Once the process has dumped core, all lwps are terminated. */ if (!(p->p_flag & SCOREDUMP)) { if ((p->p_flag & SEXITLWPS) || (t->t_proc_flag & TP_EXITLWP)) lwp_exit(); } if (!(ISHOLD(p)) && !(p->p_flag & (SHOLDFORK1 | SHOLDWATCH))) { mutex_exit(&p->p_lock); return; } /* * stop() decrements p->p_lwprcnt and cv_signal()s &p->p_holdlwps * when p->p_lwprcnt becomes zero. */ stop(PR_SUSPENDED, SUSPEND_NORMAL); if (p->p_flag & SEXITLWPS) lwp_exit(); mutex_exit(&p->p_lock); } /* * Have all lwps within the process hold at a point where they are * cloneable (SHOLDFORK) or just safe w.r.t. fork1 (SHOLDFORK1). */ int holdlwps(int holdflag) { proc_t *p = curproc; ASSERT(holdflag == SHOLDFORK || holdflag == SHOLDFORK1); mutex_enter(&p->p_lock); schedctl_finish_sigblock(curthread); again: while (p->p_flag & (SEXITLWPS | SHOLDFORK | SHOLDFORK1 | SHOLDWATCH)) { /* * If another lwp is doing a forkall() or proc_exit(), bail out. */ if (p->p_flag & (SEXITLWPS | SHOLDFORK)) { mutex_exit(&p->p_lock); return (0); } /* * Another lwp is doing a fork1() or is undergoing * watchpoint activity. We hold here for it to complete. */ stop(PR_SUSPENDED, SUSPEND_NORMAL); } p->p_flag |= holdflag; pokelwps(p); --p->p_lwprcnt; /* * Wait for the process to become quiescent (p->p_lwprcnt == 0). */ while (p->p_lwprcnt > 0) { /* * Check if aborted by exitlwps(). * Also check if SHOLDWATCH is set; it takes precedence. */ if (p->p_flag & (SEXITLWPS | SHOLDWATCH)) { p->p_lwprcnt++; p->p_flag &= ~holdflag; cv_broadcast(&p->p_holdlwps); goto again; } /* * Cooperate with jobcontrol signals and /proc stopping. * If some other lwp has stopped by either of these * mechanisms, then p_lwprcnt will never become zero * and the process will appear deadlocked unless we * stop here in sympathy with the other lwp before * doing the cv_wait() below. * * If the other lwp stops after we do the cv_wait(), it * will wake us up to loop around and do the sympathy stop. * * Since stop() drops p->p_lock, we must start from * the top again on returning from stop(). */ if (p->p_stopsig | (curthread->t_proc_flag & TP_PRSTOP)) { int whystop = p->p_stopsig? PR_JOBCONTROL : PR_REQUESTED; p->p_lwprcnt++; p->p_flag &= ~holdflag; stop(whystop, p->p_stopsig); goto again; } cv_wait(&p->p_holdlwps, &p->p_lock); } p->p_lwprcnt++; p->p_flag &= ~holdflag; mutex_exit(&p->p_lock); return (1); } /* * See comments for holdwatch(), below. */ static int holdcheck(int clearflags) { proc_t *p = curproc; /* * If we are trying to exit, that takes precedence over anything else. */ if (p->p_flag & SEXITLWPS) { p->p_lwprcnt++; p->p_flag &= ~clearflags; lwp_exit(); } /* * If another thread is calling fork1(), stop the current thread so the * other can complete. */ if (p->p_flag & SHOLDFORK1) { p->p_lwprcnt++; stop(PR_SUSPENDED, SUSPEND_NORMAL); if (p->p_flag & SEXITLWPS) { p->p_flag &= ~clearflags; lwp_exit(); } return (-1); } /* * If another thread is calling fork(), then indicate we are doing * watchpoint activity. This will cause holdlwps() above to stop the * forking thread, at which point we can continue with watchpoint * activity. */ if (p->p_flag & SHOLDFORK) { p->p_lwprcnt++; while (p->p_flag & SHOLDFORK) { p->p_flag |= SHOLDWATCH; cv_broadcast(&p->p_holdlwps); cv_wait(&p->p_holdlwps, &p->p_lock); p->p_flag &= ~SHOLDWATCH; } return (-1); } return (0); } /* * Stop all lwps within the process, holding themselves in the kernel while the * active lwp undergoes watchpoint activity. This is more complicated than * expected because stop() relies on calling holdwatch() in order to copyin data * from the user's address space. A double barrier is used to prevent an * infinite loop. * * o The first thread into holdwatch() is the 'master' thread and does * the following: * * - Sets SHOLDWATCH on the current process * - Sets TP_WATCHSTOP on the current thread * - Waits for all threads to be either stopped or have * TP_WATCHSTOP set. * - Sets the SWATCHOK flag on the process * - Unsets TP_WATCHSTOP * - Waits for the other threads to completely stop * - Unsets SWATCHOK * * o If SHOLDWATCH is already set when we enter this function, then another * thread is already trying to stop this thread. This 'slave' thread * does the following: * * - Sets TP_WATCHSTOP on the current thread * - Waits for SWATCHOK flag to be set * - Calls stop() * * o If SWATCHOK is set on the process, then this function immediately * returns, as we must have been called via stop(). * * In addition, there are other flags that take precedence over SHOLDWATCH: * * o If SEXITLWPS is set, exit immediately. * * o If SHOLDFORK1 is set, wait for fork1() to complete. * * o If SHOLDFORK is set, then watchpoint activity takes precedence In this * case, set SHOLDWATCH, signalling the forking thread to stop first. * * o If the process is being stopped via /proc (TP_PRSTOP is set), then we * stop the current thread. * * Returns 0 if all threads have been quiesced. Returns non-zero if not all * threads were stopped, or the list of watched pages has changed. */ int holdwatch(void) { proc_t *p = curproc; kthread_t *t = curthread; int ret = 0; mutex_enter(&p->p_lock); p->p_lwprcnt--; /* * Check for bail-out conditions as outlined above. */ if (holdcheck(0) != 0) { mutex_exit(&p->p_lock); return (-1); } if (!(p->p_flag & SHOLDWATCH)) { /* * We are the master watchpoint thread. Set SHOLDWATCH and poke * the other threads. */ p->p_flag |= SHOLDWATCH; pokelwps(p); /* * Wait for all threads to be stopped or have TP_WATCHSTOP set. */ while (pr_allstopped(p, 1) > 0) { if (holdcheck(SHOLDWATCH) != 0) { p->p_flag &= ~SHOLDWATCH; mutex_exit(&p->p_lock); return (-1); } cv_wait(&p->p_holdlwps, &p->p_lock); } /* * All threads are now stopped or in the process of stopping. * Set SWATCHOK and let them stop completely. */ p->p_flag |= SWATCHOK; t->t_proc_flag &= ~TP_WATCHSTOP; cv_broadcast(&p->p_holdlwps); while (pr_allstopped(p, 0) > 0) { /* * At first glance, it may appear that we don't need a * call to holdcheck() here. But if the process gets a * SIGKILL signal, one of our stopped threads may have * been awakened and is waiting in exitlwps(), which * takes precedence over watchpoints. */ if (holdcheck(SHOLDWATCH | SWATCHOK) != 0) { p->p_flag &= ~(SHOLDWATCH | SWATCHOK); mutex_exit(&p->p_lock); return (-1); } cv_wait(&p->p_holdlwps, &p->p_lock); } /* * All threads are now completely stopped. */ p->p_flag &= ~SWATCHOK; p->p_flag &= ~SHOLDWATCH; p->p_lwprcnt++; } else if (!(p->p_flag & SWATCHOK)) { /* * SHOLDWATCH is set, so another thread is trying to do * watchpoint activity. Indicate this thread is stopping, and * wait for the OK from the master thread. */ t->t_proc_flag |= TP_WATCHSTOP; cv_broadcast(&p->p_holdlwps); while (!(p->p_flag & SWATCHOK)) { if (holdcheck(0) != 0) { t->t_proc_flag &= ~TP_WATCHSTOP; mutex_exit(&p->p_lock); return (-1); } cv_wait(&p->p_holdlwps, &p->p_lock); } /* * Once the master thread has given the OK, this thread can * actually call stop(). */ t->t_proc_flag &= ~TP_WATCHSTOP; p->p_lwprcnt++; stop(PR_SUSPENDED, SUSPEND_NORMAL); /* * It's not OK to do watchpoint activity, notify caller to * retry. */ ret = -1; } else { /* * The only way we can hit the case where SHOLDWATCH is set and * SWATCHOK is set is if we are triggering this from within a * stop() call. Assert that this is the case. */ ASSERT(t->t_proc_flag & TP_STOPPING); p->p_lwprcnt++; } mutex_exit(&p->p_lock); return (ret); } /* * force all interruptible lwps to trap into the kernel. */ void pokelwps(proc_t *p) { kthread_t *t; ASSERT(MUTEX_HELD(&p->p_lock)); t = p->p_tlist; do { if (t == curthread) continue; thread_lock(t); aston(t); /* make thread trap or do post_syscall */ if (ISWAKEABLE(t) || ISWAITING(t)) { setrun_locked(t); } else if (t->t_state == TS_STOPPED) { /* * Ensure that proc_exit() is not blocked by lwps * that were stopped via jobcontrol or /proc. */ if (p->p_flag & SEXITLWPS) { p->p_stopsig = 0; t->t_schedflag |= (TS_XSTART | TS_PSTART); setrun_locked(t); } /* * If we are holding lwps for a forkall(), * force lwps that have been suspended via * lwp_suspend() and are suspended inside * of a system call to proceed to their * holdlwp() points where they are clonable. */ if ((p->p_flag & SHOLDFORK) && SUSPENDED(t)) { if ((t->t_schedflag & TS_CSTART) == 0) { p->p_lwprcnt++; t->t_schedflag |= TS_CSTART; setrun_locked(t); } } } else if (t->t_state == TS_ONPROC) { if (t->t_cpu != CPU) poke_cpu(t->t_cpu->cpu_id); } thread_unlock(t); } while ((t = t->t_forw) != p->p_tlist); } /* * undo the effects of holdlwps() or holdwatch(). */ void continuelwps(proc_t *p) { kthread_t *t; /* * If this flag is set, then the original holdwatch() didn't actually * stop the process. See comments for holdwatch(). */ if (p->p_flag & SWATCHOK) { ASSERT(curthread->t_proc_flag & TP_STOPPING); return; } ASSERT(MUTEX_HELD(&p->p_lock)); ASSERT((p->p_flag & (SHOLDFORK | SHOLDFORK1 | SHOLDWATCH)) == 0); t = p->p_tlist; do { thread_lock(t); /* SUSPENDED looks at t_schedflag */ if (SUSPENDED(t) && !(t->t_proc_flag & TP_HOLDLWP)) { p->p_lwprcnt++; t->t_schedflag |= TS_CSTART; setrun_locked(t); } thread_unlock(t); } while ((t = t->t_forw) != p->p_tlist); } /* * Force all other LWPs in the current process other than the caller to exit, * and then cv_wait() on p_holdlwps for them to exit. The exitlwps() function * is typically used in these situations: * * (a) prior to an exec() system call * (b) prior to dumping a core file * (c) prior to a uadmin() shutdown * * If the 'coredump' flag is set, other LWPs are quiesced but not destroyed. * Multiple threads in the process can call this function at one time by * triggering execs or core dumps simultaneously, so the SEXITLWPS bit is used * to declare one particular thread the winner who gets to kill the others. * If a thread wins the exitlwps() dance, zero is returned; otherwise an * appropriate errno value is returned to caller for its system call to return. */ int exitlwps(int coredump) { proc_t *p = curproc; int heldcnt; if (curthread->t_door) door_slam(); if (p->p_door_list) door_revoke_all(); if (curthread->t_schedctl != NULL) schedctl_lwp_cleanup(curthread); /* * Ensure that before starting to wait for other lwps to exit, * cleanup all upimutexes held by curthread. Otherwise, some other * lwp could be waiting (uninterruptibly) for a upimutex held by * curthread, and the call to pokelwps() below would deadlock. * Even if a blocked upimutex_lock is made interruptible, * curthread's upimutexes need to be unlocked: do it here. */ if (curthread->t_upimutex != NULL) upimutex_cleanup(); /* * Grab p_lock in order to check and set SEXITLWPS to declare a winner. * We must also block any further /proc access from this point forward. */ mutex_enter(&p->p_lock); prbarrier(p); if (p->p_flag & SEXITLWPS) { mutex_exit(&p->p_lock); aston(curthread); /* force a trip through post_syscall */ return (set_errno(EINTR)); } p->p_flag |= SEXITLWPS; if (coredump) /* tell other lwps to stop, not exit */ p->p_flag |= SCOREDUMP; /* * Give precedence to exitlwps() if a holdlwps() is * in progress. The lwp doing the holdlwps() operation * is aborted when it is awakened. */ while (p->p_flag & (SHOLDFORK | SHOLDFORK1 | SHOLDWATCH)) { cv_broadcast(&p->p_holdlwps); cv_wait(&p->p_holdlwps, &p->p_lock); prbarrier(p); } p->p_flag |= SHOLDFORK; pokelwps(p); /* * Wait for process to become quiescent. */ --p->p_lwprcnt; while (p->p_lwprcnt > 0) { cv_wait(&p->p_holdlwps, &p->p_lock); prbarrier(p); } p->p_lwprcnt++; ASSERT(p->p_lwprcnt == 1); /* * The SCOREDUMP flag puts the process into a quiescent * state. The process's lwps remain attached to this * process until exitlwps() is called again without the * 'coredump' flag set, then the lwps are terminated * and the process can exit. */ if (coredump) { p->p_flag &= ~(SCOREDUMP | SHOLDFORK | SEXITLWPS); goto out; } /* * Determine if there are any lwps left dangling in * the stopped state. This happens when exitlwps() * aborts a holdlwps() operation. */ p->p_flag &= ~SHOLDFORK; if ((heldcnt = p->p_lwpcnt) > 1) { kthread_t *t; for (t = curthread->t_forw; --heldcnt > 0; t = t->t_forw) { t->t_proc_flag &= ~TP_TWAIT; lwp_continue(t); } } /* * Wait for all other lwps to exit. */ --p->p_lwprcnt; while (p->p_lwpcnt > 1) { cv_wait(&p->p_holdlwps, &p->p_lock); prbarrier(p); } ++p->p_lwprcnt; ASSERT(p->p_lwpcnt == 1 && p->p_lwprcnt == 1); p->p_flag &= ~SEXITLWPS; curthread->t_proc_flag &= ~TP_TWAIT; out: if (!coredump && p->p_zombcnt) { /* cleanup the zombie lwps */ lwpdir_t *ldp; lwpent_t *lep; int i; for (ldp = p->p_lwpdir, i = 0; i < p->p_lwpdir_sz; i++, ldp++) { lep = ldp->ld_entry; if (lep != NULL && lep->le_thread != curthread) { ASSERT(lep->le_thread == NULL); p->p_zombcnt--; lwp_hash_out(p, lep->le_lwpid); } } ASSERT(p->p_zombcnt == 0); } /* * If some other LWP in the process wanted us to suspend ourself, * then we will not do it. The other LWP is now terminated and * no one will ever continue us again if we suspend ourself. */ curthread->t_proc_flag &= ~TP_HOLDLWP; p->p_flag &= ~(SHOLDFORK | SHOLDFORK1 | SHOLDWATCH | SLWPWRAP); mutex_exit(&p->p_lock); return (0); } /* * duplicate a lwp. */ klwp_t * forklwp(klwp_t *lwp, proc_t *cp, id_t lwpid) { klwp_t *clwp; void *tregs, *tfpu; kthread_t *t = lwptot(lwp); kthread_t *ct; proc_t *p = lwptoproc(lwp); int cid; void *bufp; void *brand_data; int val; ASSERT(p == curproc); ASSERT(t == curthread || (SUSPENDED(t) && lwp->lwp_asleep == 0)); #if defined(__sparc) if (t == curthread) (void) flush_user_windows_to_stack(NULL); #endif if (t == curthread) /* copy args out of registers first */ (void) save_syscall_args(); clwp = lwp_create(cp->p_lwpcnt == 0 ? lwp_rtt_initial : lwp_rtt, NULL, 0, cp, TS_STOPPED, t->t_pri, &t->t_hold, NOCLASS, lwpid); if (clwp == NULL) return (NULL); /* * most of the parent's lwp can be copied to its duplicate, * except for the fields that are unique to each lwp, like * lwp_thread, lwp_procp, lwp_regs, and lwp_ap. */ ct = clwp->lwp_thread; tregs = clwp->lwp_regs; tfpu = clwp->lwp_fpu; brand_data = clwp->lwp_brand; /* * Copy parent lwp to child lwp. Hold child's p_lock to prevent * mstate_aggr_state() from reading stale mstate entries copied * from lwp to clwp. */ mutex_enter(&cp->p_lock); *clwp = *lwp; /* clear microstate and resource usage data in new lwp */ init_mstate(ct, LMS_STOPPED); bzero(&clwp->lwp_ru, sizeof (clwp->lwp_ru)); mutex_exit(&cp->p_lock); /* fix up child's lwp */ clwp->lwp_pcb.pcb_flags = 0; #if defined(__sparc) clwp->lwp_pcb.pcb_step = STEP_NONE; #endif clwp->lwp_cursig = 0; clwp->lwp_extsig = 0; clwp->lwp_curinfo = (struct sigqueue *)0; clwp->lwp_thread = ct; ct->t_sysnum = t->t_sysnum; clwp->lwp_regs = tregs; clwp->lwp_fpu = tfpu; clwp->lwp_brand = brand_data; clwp->lwp_ap = clwp->lwp_arg; clwp->lwp_procp = cp; bzero(clwp->lwp_timer, sizeof (clwp->lwp_timer)); clwp->lwp_lastfault = 0; clwp->lwp_lastfaddr = 0; /* copy parent's struct regs to child. */ lwp_forkregs(lwp, clwp); /* * Fork thread context ops, if any. */ if (t->t_ctx) forkctx(t, ct); /* fix door state in the child */ if (t->t_door) door_fork(t, ct); /* copy current contract templates, clear latest contracts */ lwp_ctmpl_copy(clwp, lwp); mutex_enter(&cp->p_lock); /* lwp_create() set the TP_HOLDLWP flag */ if (!(t->t_proc_flag & TP_HOLDLWP)) ct->t_proc_flag &= ~TP_HOLDLWP; if (cp->p_flag & SMSACCT) ct->t_proc_flag |= TP_MSACCT; mutex_exit(&cp->p_lock); /* Allow brand to propagate brand-specific state */ if (PROC_IS_BRANDED(p)) BROP(p)->b_forklwp(lwp, clwp); retry: cid = t->t_cid; val = CL_ALLOC(&bufp, cid, KM_SLEEP); ASSERT(val == 0); mutex_enter(&p->p_lock); if (cid != t->t_cid) { /* * Someone just changed this thread's scheduling class, * so try pre-allocating the buffer again. Hopefully we * don't hit this often. */ mutex_exit(&p->p_lock); CL_FREE(cid, bufp); goto retry; } ct->t_unpark = t->t_unpark; ct->t_clfuncs = t->t_clfuncs; CL_FORK(t, ct, bufp); ct->t_cid = t->t_cid; /* after data allocated so prgetpsinfo works */ mutex_exit(&p->p_lock); return (clwp); } /* * Add a new lwp entry to the lwp directory and to the lwpid hash table. */ void lwp_hash_in(proc_t *p, lwpent_t *lep, tidhash_t *tidhash, uint_t tidhash_sz, int do_lock) { tidhash_t *thp = &tidhash[TIDHASH(lep->le_lwpid, tidhash_sz)]; lwpdir_t **ldpp; lwpdir_t *ldp; kthread_t *t; /* * Allocate a directory element from the free list. * Code elsewhere guarantees a free slot. */ ldp = p->p_lwpfree; p->p_lwpfree = ldp->ld_next; ASSERT(ldp->ld_entry == NULL); ldp->ld_entry = lep; if (do_lock) mutex_enter(&thp->th_lock); /* * Insert it into the lwpid hash table. */ ldpp = &thp->th_list; ldp->ld_next = *ldpp; *ldpp = ldp; /* * Set the active thread's directory slot entry. */ if ((t = lep->le_thread) != NULL) { ASSERT(lep->le_lwpid == t->t_tid); t->t_dslot = (int)(ldp - p->p_lwpdir); } if (do_lock) mutex_exit(&thp->th_lock); } /* * Remove an lwp from the lwpid hash table and free its directory entry. * This is done when a detached lwp exits in lwp_exit() or * when a non-detached lwp is waited for in lwp_wait() or * when a zombie lwp is detached in lwp_detach(). */ void lwp_hash_out(proc_t *p, id_t lwpid) { tidhash_t *thp = &p->p_tidhash[TIDHASH(lwpid, p->p_tidhash_sz)]; lwpdir_t **ldpp; lwpdir_t *ldp; lwpent_t *lep; mutex_enter(&thp->th_lock); for (ldpp = &thp->th_list; (ldp = *ldpp) != NULL; ldpp = &ldp->ld_next) { lep = ldp->ld_entry; if (lep->le_lwpid == lwpid) { prlwpfree(p, lep); /* /proc deals with le_trace */ *ldpp = ldp->ld_next; ldp->ld_entry = NULL; ldp->ld_next = p->p_lwpfree; p->p_lwpfree = ldp; kmem_free(lep, sizeof (*lep)); break; } } mutex_exit(&thp->th_lock); } /* * Lookup an lwp in the lwpid hash table by lwpid. */ lwpdir_t * lwp_hash_lookup(proc_t *p, id_t lwpid) { tidhash_t *thp; lwpdir_t *ldp; /* * The process may be exiting, after p_tidhash has been set to NULL in * proc_exit() but before prfee() has been called. Return failure in * this case. */ if (p->p_tidhash == NULL) return (NULL); thp = &p->p_tidhash[TIDHASH(lwpid, p->p_tidhash_sz)]; for (ldp = thp->th_list; ldp != NULL; ldp = ldp->ld_next) { if (ldp->ld_entry->le_lwpid == lwpid) return (ldp); } return (NULL); } /* * Same as lwp_hash_lookup(), but acquire and return * the tid hash table entry lock on success. */ lwpdir_t * lwp_hash_lookup_and_lock(proc_t *p, id_t lwpid, kmutex_t **mpp) { tidhash_t *tidhash; uint_t tidhash_sz; tidhash_t *thp; lwpdir_t *ldp; top: tidhash_sz = p->p_tidhash_sz; membar_consumer(); if ((tidhash = p->p_tidhash) == NULL) return (NULL); thp = &tidhash[TIDHASH(lwpid, tidhash_sz)]; mutex_enter(&thp->th_lock); /* * Since we are not holding p->p_lock, the tid hash table * may have changed. If so, start over. If not, then * it cannot change until after we drop &thp->th_lock; */ if (tidhash != p->p_tidhash || tidhash_sz != p->p_tidhash_sz) { mutex_exit(&thp->th_lock); goto top; } for (ldp = thp->th_list; ldp != NULL; ldp = ldp->ld_next) { if (ldp->ld_entry->le_lwpid == lwpid) { *mpp = &thp->th_lock; return (ldp); } } mutex_exit(&thp->th_lock); return (NULL); } /* * Update the indicated LWP usage statistic for the current LWP. */ void lwp_stat_update(lwp_stat_id_t lwp_stat_id, long inc) { klwp_t *lwp = ttolwp(curthread); if (lwp == NULL) return; switch (lwp_stat_id) { case LWP_STAT_INBLK: lwp->lwp_ru.inblock += inc; break; case LWP_STAT_OUBLK: lwp->lwp_ru.oublock += inc; break; case LWP_STAT_MSGRCV: lwp->lwp_ru.msgrcv += inc; break; case LWP_STAT_MSGSND: lwp->lwp_ru.msgsnd += inc; break; default: panic("lwp_stat_update: invalid lwp_stat_id 0x%x", lwp_stat_id); } }