1 /* 2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. 3 * Copyright (C) 2007 The Regents of the University of California. 4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). 5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>. 6 * UCRL-CODE-235197 7 * 8 * This file is part of the SPL, Solaris Porting Layer. 9 * 10 * The SPL is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 * The SPL is distributed in the hope that it will be useful, but WITHOUT 16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18 * for more details. 19 * 20 * You should have received a copy of the GNU General Public License along 21 * with the SPL. If not, see <http://www.gnu.org/licenses/>. 22 * 23 * Solaris Porting Layer (SPL) Thread Implementation. 24 */ 25 26 #include <sys/thread.h> 27 #include <sys/kmem.h> 28 #include <sys/tsd.h> 29 30 /* 31 * Thread interfaces 32 */ 33 typedef struct thread_priv_s { 34 unsigned long tp_magic; /* Magic */ 35 int tp_name_size; /* Name size */ 36 char *tp_name; /* Name (without _thread suffix) */ 37 void (*tp_func)(void *); /* Registered function */ 38 void *tp_args; /* Args to be passed to function */ 39 size_t tp_len; /* Len to be passed to function */ 40 int tp_state; /* State to start thread at */ 41 pri_t tp_pri; /* Priority to start threat at */ 42 } thread_priv_t; 43 44 static int 45 thread_generic_wrapper(void *arg) 46 { 47 thread_priv_t *tp = (thread_priv_t *)arg; 48 void (*func)(void *); 49 void *args; 50 51 ASSERT(tp->tp_magic == TP_MAGIC); 52 func = tp->tp_func; 53 args = tp->tp_args; 54 set_current_state(tp->tp_state); 55 set_user_nice((kthread_t *)current, PRIO_TO_NICE(tp->tp_pri)); 56 kmem_free(tp->tp_name, tp->tp_name_size); 57 kmem_free(tp, sizeof (thread_priv_t)); 58 59 if (func) 60 func(args); 61 62 return (0); 63 } 64 65 void 66 __thread_exit(void) 67 { 68 tsd_exit(); 69 complete_and_exit(NULL, 0); 70 /* Unreachable */ 71 } 72 EXPORT_SYMBOL(__thread_exit); 73 74 /* 75 * thread_create() may block forever if it cannot create a thread or 76 * allocate memory. This is preferable to returning a NULL which Solaris 77 * style callers likely never check for... since it can't fail. 78 */ 79 kthread_t * 80 __thread_create(caddr_t stk, size_t stksize, thread_func_t func, 81 const char *name, void *args, size_t len, proc_t *pp, int state, pri_t pri) 82 { 83 thread_priv_t *tp; 84 struct task_struct *tsk; 85 char *p; 86 87 /* Option pp is simply ignored */ 88 /* Variable stack size unsupported */ 89 ASSERT(stk == NULL); 90 91 tp = kmem_alloc(sizeof (thread_priv_t), KM_PUSHPAGE); 92 if (tp == NULL) 93 return (NULL); 94 95 tp->tp_magic = TP_MAGIC; 96 tp->tp_name_size = strlen(name) + 1; 97 98 tp->tp_name = kmem_alloc(tp->tp_name_size, KM_PUSHPAGE); 99 if (tp->tp_name == NULL) { 100 kmem_free(tp, sizeof (thread_priv_t)); 101 return (NULL); 102 } 103 104 strncpy(tp->tp_name, name, tp->tp_name_size); 105 106 /* 107 * Strip trailing "_thread" from passed name which will be the func 108 * name since the exposed API has no parameter for passing a name. 109 */ 110 p = strstr(tp->tp_name, "_thread"); 111 if (p) 112 p[0] = '\0'; 113 114 tp->tp_func = func; 115 tp->tp_args = args; 116 tp->tp_len = len; 117 tp->tp_state = state; 118 tp->tp_pri = pri; 119 120 tsk = spl_kthread_create(thread_generic_wrapper, (void *)tp, 121 "%s", tp->tp_name); 122 if (IS_ERR(tsk)) 123 return (NULL); 124 125 wake_up_process(tsk); 126 return ((kthread_t *)tsk); 127 } 128 EXPORT_SYMBOL(__thread_create); 129 130 /* 131 * spl_kthread_create - Wrapper providing pre-3.13 semantics for 132 * kthread_create() in which it is not killable and less likely 133 * to return -ENOMEM. 134 */ 135 struct task_struct * 136 spl_kthread_create(int (*func)(void *), void *data, const char namefmt[], ...) 137 { 138 struct task_struct *tsk; 139 va_list args; 140 char name[TASK_COMM_LEN]; 141 142 va_start(args, namefmt); 143 vsnprintf(name, sizeof (name), namefmt, args); 144 va_end(args); 145 do { 146 tsk = kthread_create(func, data, "%s", name); 147 if (IS_ERR(tsk)) { 148 if (signal_pending(current)) { 149 clear_thread_flag(TIF_SIGPENDING); 150 continue; 151 } 152 if (PTR_ERR(tsk) == -ENOMEM) 153 continue; 154 return (NULL); 155 } else { 156 return (tsk); 157 } 158 } while (1); 159 } 160 EXPORT_SYMBOL(spl_kthread_create); 161 162 /* 163 * The "why" argument indicates the allowable side-effects of the call: 164 * 165 * FORREAL: Extract the next pending signal from p_sig into p_cursig; 166 * stop the process if a stop has been requested or if a traced signal 167 * is pending. 168 * 169 * JUSTLOOKING: Don't stop the process, just indicate whether or not 170 * a signal might be pending (FORREAL is needed to tell for sure). 171 */ 172 int 173 issig(int why) 174 { 175 ASSERT(why == FORREAL || why == JUSTLOOKING); 176 177 if (!signal_pending(current)) 178 return (0); 179 180 if (why != FORREAL) 181 return (1); 182 183 struct task_struct *task = current; 184 spl_kernel_siginfo_t __info; 185 sigset_t set; 186 siginitsetinv(&set, 1ULL << (SIGSTOP - 1) | 1ULL << (SIGTSTP - 1)); 187 sigorsets(&set, &task->blocked, &set); 188 189 spin_lock_irq(&task->sighand->siglock); 190 int ret; 191 if ((ret = dequeue_signal(task, &set, &__info)) != 0) { 192 #ifdef HAVE_SIGNAL_STOP 193 spin_unlock_irq(&task->sighand->siglock); 194 kernel_signal_stop(); 195 #else 196 if (current->jobctl & JOBCTL_STOP_DEQUEUED) 197 spl_set_special_state(TASK_STOPPED); 198 199 spin_unlock_irq(¤t->sighand->siglock); 200 201 schedule(); 202 #endif 203 return (0); 204 } 205 206 spin_unlock_irq(&task->sighand->siglock); 207 208 return (1); 209 } 210 211 EXPORT_SYMBOL(issig); 212