1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. 4 * Copyright (C) 2007 The Regents of the University of California. 5 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). 6 * Written by Brian Behlendorf <behlendorf1@llnl.gov>. 7 * UCRL-CODE-235197 8 * 9 * This file is part of the SPL, Solaris Porting Layer. 10 * 11 * The SPL is free software; you can redistribute it and/or modify it 12 * under the terms of the GNU General Public License as published by the 13 * Free Software Foundation; either version 2 of the License, or (at your 14 * option) any later version. 15 * 16 * The SPL is distributed in the hope that it will be useful, but WITHOUT 17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 19 * for more details. 20 * 21 * You should have received a copy of the GNU General Public License along 22 * with the SPL. If not, see <http://www.gnu.org/licenses/>. 23 * 24 * Solaris Porting Layer (SPL) Thread Implementation. 25 */ 26 27 #include <sys/thread.h> 28 #include <sys/kmem.h> 29 #include <sys/tsd.h> 30 #include <sys/string.h> 31 #include <sys/misc.h> 32 33 /* 34 * Thread interfaces 35 */ 36 typedef struct thread_priv_s { 37 unsigned long tp_magic; /* Magic */ 38 int tp_name_size; /* Name size */ 39 char *tp_name; /* Name (without _thread suffix) */ 40 void (*tp_func)(void *); /* Registered function */ 41 void *tp_args; /* Args to be passed to function */ 42 size_t tp_len; /* Len to be passed to function */ 43 int tp_state; /* State to start thread at */ 44 pri_t tp_pri; /* Priority to start threat at */ 45 } thread_priv_t; 46 47 static int 48 thread_generic_wrapper(void *arg) 49 { 50 thread_priv_t *tp = (thread_priv_t *)arg; 51 void (*func)(void *); 52 void *args; 53 54 ASSERT(tp->tp_magic == TP_MAGIC); 55 func = tp->tp_func; 56 args = tp->tp_args; 57 set_current_state(tp->tp_state); 58 set_user_nice((kthread_t *)current, PRIO_TO_NICE(tp->tp_pri)); 59 kmem_free(tp->tp_name, tp->tp_name_size); 60 kmem_free(tp, sizeof (thread_priv_t)); 61 62 if (func) 63 func(args); 64 65 return (0); 66 } 67 68 /* 69 * thread_create() may block forever if it cannot create a thread or 70 * allocate memory. This is preferable to returning a NULL which Solaris 71 * style callers likely never check for... since it can't fail. 72 */ 73 kthread_t * 74 __thread_create(caddr_t stk, size_t stksize, thread_func_t func, 75 const char *name, void *args, size_t len, proc_t *pp, int state, pri_t pri) 76 { 77 thread_priv_t *tp; 78 struct task_struct *tsk; 79 char *p; 80 81 /* Option pp is simply ignored */ 82 /* Variable stack size unsupported */ 83 ASSERT0P(stk); 84 85 tp = kmem_alloc(sizeof (thread_priv_t), KM_PUSHPAGE); 86 if (tp == NULL) 87 return (NULL); 88 89 tp->tp_magic = TP_MAGIC; 90 tp->tp_name_size = strlen(name) + 1; 91 92 tp->tp_name = kmem_alloc(tp->tp_name_size, KM_PUSHPAGE); 93 if (tp->tp_name == NULL) { 94 kmem_free(tp, sizeof (thread_priv_t)); 95 return (NULL); 96 } 97 98 strlcpy(tp->tp_name, name, tp->tp_name_size); 99 100 /* 101 * Strip trailing "_thread" from passed name which will be the func 102 * name since the exposed API has no parameter for passing a name. 103 */ 104 p = strstr(tp->tp_name, "_thread"); 105 if (p) 106 p[0] = '\0'; 107 108 tp->tp_func = func; 109 tp->tp_args = args; 110 tp->tp_len = len; 111 tp->tp_state = state; 112 tp->tp_pri = pri; 113 114 tsk = spl_kthread_create(thread_generic_wrapper, (void *)tp, 115 "%s", tp->tp_name); 116 if (IS_ERR(tsk)) 117 return (NULL); 118 119 wake_up_process(tsk); 120 return ((kthread_t *)tsk); 121 } 122 EXPORT_SYMBOL(__thread_create); 123 124 /* 125 * spl_kthread_create - Wrapper providing pre-3.13 semantics for 126 * kthread_create() in which it is not killable and less likely 127 * to return -ENOMEM. 128 */ 129 struct task_struct * 130 spl_kthread_create(int (*func)(void *), void *data, const char namefmt[], ...) 131 { 132 struct task_struct *tsk; 133 va_list args; 134 char name[TASK_COMM_LEN]; 135 136 va_start(args, namefmt); 137 vsnprintf(name, sizeof (name), namefmt, args); 138 va_end(args); 139 do { 140 tsk = kthread_create(func, data, "%s", name); 141 if (IS_ERR(tsk)) { 142 if (signal_pending(current)) { 143 clear_thread_flag(TIF_SIGPENDING); 144 continue; 145 } 146 if (PTR_ERR(tsk) == -ENOMEM) 147 continue; 148 return (NULL); 149 } else { 150 return (tsk); 151 } 152 } while (1); 153 } 154 EXPORT_SYMBOL(spl_kthread_create); 155 156 /* 157 * Extract the next pending signal from p_sig into p_cursig; stop the process 158 * if a stop has been requested or if a traced signal is pending. 159 */ 160 int 161 issig(void) 162 { 163 164 if (!signal_pending(current)) 165 return (0); 166 167 spl_kernel_siginfo_t __info; 168 sigset_t set; 169 siginitsetinv(&set, 1ULL << (SIGSTOP - 1) | 1ULL << (SIGTSTP - 1)); 170 sigorsets(&set, ¤t->blocked, &set); 171 172 spin_lock_irq(¤t->sighand->siglock); 173 #if defined(HAVE_DEQUEUE_SIGNAL_4ARG) 174 enum pid_type __type; 175 if (dequeue_signal(current, &set, &__info, &__type) != 0) { 176 #elif defined(HAVE_DEQUEUE_SIGNAL_3ARG_TYPE) 177 enum pid_type __type; 178 if (dequeue_signal(&set, &__info, &__type) != 0) { 179 #else 180 if (dequeue_signal(current, &set, &__info) != 0) { 181 #endif 182 spin_unlock_irq(¤t->sighand->siglock); 183 kernel_signal_stop(); 184 185 /* 186 * Dequeued SIGSTOP/SIGTSTP. 187 * Check if process has other singal pending. 188 */ 189 if (signal_pending(current)) 190 return (1); 191 192 return (0); 193 } 194 195 spin_unlock_irq(¤t->sighand->siglock); 196 197 return (1); 198 } 199 200 EXPORT_SYMBOL(issig); 201 202 /* 203 * Check if the current thread is a memory reclaim thread. 204 * Returns true if current thread is kswapd. 205 */ 206 int 207 current_is_reclaim_thread(void) 208 { 209 return (current_is_kswapd()); 210 } 211 EXPORT_SYMBOL(current_is_reclaim_thread); 212