1328653Shselasky/*- 2328653Shselasky * Copyright (c) 2017 Hans Petter Selasky 3328653Shselasky * All rights reserved. 4328653Shselasky * 5328653Shselasky * Redistribution and use in source and binary forms, with or without 6328653Shselasky * modification, are permitted provided that the following conditions 7328653Shselasky * are met: 8328653Shselasky * 1. Redistributions of source code must retain the above copyright 9328653Shselasky * notice unmodified, this list of conditions, and the following 10328653Shselasky * disclaimer. 11328653Shselasky * 2. Redistributions in binary form must reproduce the above copyright 12328653Shselasky * notice, this list of conditions and the following disclaimer in the 13328653Shselasky * documentation and/or other materials provided with the distribution. 14328653Shselasky * 15328653Shselasky * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16328653Shselasky * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17328653Shselasky * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18328653Shselasky * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19328653Shselasky * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20328653Shselasky * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21328653Shselasky * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22328653Shselasky * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23328653Shselasky * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24328653Shselasky * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25328653Shselasky */ 26328653Shselasky 27328653Shselasky#include <sys/cdefs.h> 28328653Shselasky__FBSDID("$FreeBSD: stable/11/sys/compat/linuxkpi/common/src/linux_current.c 363153 2020-07-13 15:37:59Z hselasky $"); 29328653Shselasky 30328653Shselasky#include <linux/compat.h> 31328653Shselasky#include <linux/completion.h> 32328653Shselasky#include <linux/mm.h> 33328653Shselasky#include <linux/kthread.h> 34328653Shselasky 35328653Shselasky#include <sys/kernel.h> 36328653Shselasky#include <sys/eventhandler.h> 37328653Shselasky#include <sys/malloc.h> 38328653Shselasky 39328653Shselaskystatic eventhandler_tag linuxkpi_thread_dtor_tag; 40328653Shselasky 41328653Shselaskystatic MALLOC_DEFINE(M_LINUX_CURRENT, "linuxcurrent", "LinuxKPI task structure"); 42328653Shselasky 43328653Shselaskyint 44328653Shselaskylinux_alloc_current(struct thread *td, int flags) 45328653Shselasky{ 46328653Shselasky struct proc *proc; 47328653Shselasky struct thread *td_other; 48328653Shselasky struct task_struct *ts; 49328653Shselasky struct task_struct *ts_other; 50328653Shselasky struct mm_struct *mm; 51328653Shselasky struct mm_struct *mm_other; 52328653Shselasky 53328653Shselasky MPASS(td->td_lkpi_task == NULL); 54328653Shselasky 55328653Shselasky ts = malloc(sizeof(*ts), M_LINUX_CURRENT, flags | M_ZERO); 56328653Shselasky if (ts == NULL) 57328653Shselasky return (ENOMEM); 58328653Shselasky 59328653Shselasky mm = malloc(sizeof(*mm), M_LINUX_CURRENT, flags | M_ZERO); 60328653Shselasky if (mm == NULL) { 61328653Shselasky free(ts, M_LINUX_CURRENT); 62328653Shselasky return (ENOMEM); 63328653Shselasky } 64328653Shselasky 65328653Shselasky /* setup new task structure */ 66328653Shselasky atomic_set(&ts->kthread_flags, 0); 67328653Shselasky ts->task_thread = td; 68328653Shselasky ts->comm = td->td_name; 69328653Shselasky ts->pid = td->td_tid; 70328653Shselasky atomic_set(&ts->usage, 1); 71328653Shselasky atomic_set(&ts->state, TASK_RUNNING); 72328653Shselasky init_completion(&ts->parked); 73328653Shselasky init_completion(&ts->exited); 74328653Shselasky 75328653Shselasky proc = td->td_proc; 76328653Shselasky 77328653Shselasky /* check if another thread already has a mm_struct */ 78328653Shselasky PROC_LOCK(proc); 79328653Shselasky FOREACH_THREAD_IN_PROC(proc, td_other) { 80328653Shselasky ts_other = td_other->td_lkpi_task; 81328653Shselasky if (ts_other == NULL) 82328653Shselasky continue; 83328653Shselasky 84328653Shselasky mm_other = ts_other->mm; 85328653Shselasky if (mm_other == NULL) 86328653Shselasky continue; 87328653Shselasky 88328653Shselasky /* try to share other mm_struct */ 89328653Shselasky if (atomic_inc_not_zero(&mm_other->mm_users)) { 90328653Shselasky /* set mm_struct pointer */ 91328653Shselasky ts->mm = mm_other; 92328653Shselasky break; 93328653Shselasky } 94328653Shselasky } 95328653Shselasky 96328653Shselasky /* use allocated mm_struct as a fallback */ 97328653Shselasky if (ts->mm == NULL) { 98328653Shselasky /* setup new mm_struct */ 99328653Shselasky init_rwsem(&mm->mmap_sem); 100328653Shselasky atomic_set(&mm->mm_count, 1); 101328653Shselasky atomic_set(&mm->mm_users, 1); 102328653Shselasky /* set mm_struct pointer */ 103328653Shselasky ts->mm = mm; 104328653Shselasky /* clear pointer to not free memory */ 105328653Shselasky mm = NULL; 106328653Shselasky } 107328653Shselasky 108328653Shselasky /* store pointer to task struct */ 109328653Shselasky td->td_lkpi_task = ts; 110328653Shselasky PROC_UNLOCK(proc); 111328653Shselasky 112328653Shselasky /* free mm_struct pointer, if any */ 113328653Shselasky free(mm, M_LINUX_CURRENT); 114328653Shselasky 115328653Shselasky return (0); 116328653Shselasky} 117328653Shselasky 118328653Shselaskystruct mm_struct * 119328653Shselaskylinux_get_task_mm(struct task_struct *task) 120328653Shselasky{ 121328653Shselasky struct mm_struct *mm; 122328653Shselasky 123328653Shselasky mm = task->mm; 124328653Shselasky if (mm != NULL) { 125328653Shselasky atomic_inc(&mm->mm_users); 126328653Shselasky return (mm); 127328653Shselasky } 128328653Shselasky return (NULL); 129328653Shselasky} 130328653Shselasky 131328653Shselaskyvoid 132328653Shselaskylinux_mm_dtor(struct mm_struct *mm) 133328653Shselasky{ 134328653Shselasky free(mm, M_LINUX_CURRENT); 135328653Shselasky} 136328653Shselasky 137328653Shselaskyvoid 138328653Shselaskylinux_free_current(struct task_struct *ts) 139328653Shselasky{ 140328653Shselasky mmput(ts->mm); 141328653Shselasky free(ts, M_LINUX_CURRENT); 142328653Shselasky} 143328653Shselasky 144328653Shselaskystatic void 145328653Shselaskylinuxkpi_thread_dtor(void *arg __unused, struct thread *td) 146328653Shselasky{ 147328653Shselasky struct task_struct *ts; 148328653Shselasky 149328653Shselasky ts = td->td_lkpi_task; 150328653Shselasky if (ts == NULL) 151328653Shselasky return; 152328653Shselasky 153328653Shselasky td->td_lkpi_task = NULL; 154328653Shselasky put_task_struct(ts); 155328653Shselasky} 156328653Shselasky 157328653Shselaskystruct task_struct * 158328653Shselaskylinux_pid_task(pid_t pid) 159328653Shselasky{ 160328653Shselasky struct thread *td; 161328653Shselasky struct proc *p; 162328653Shselasky 163328653Shselasky /* try to find corresponding thread */ 164328653Shselasky td = tdfind(pid, -1); 165328653Shselasky if (td != NULL) { 166328653Shselasky struct task_struct *ts = td->td_lkpi_task; 167328653Shselasky PROC_UNLOCK(td->td_proc); 168328653Shselasky return (ts); 169328653Shselasky } 170328653Shselasky 171328653Shselasky /* try to find corresponding procedure */ 172328653Shselasky p = pfind(pid); 173328653Shselasky if (p != NULL) { 174328653Shselasky FOREACH_THREAD_IN_PROC(p, td) { 175328653Shselasky struct task_struct *ts = td->td_lkpi_task; 176328653Shselasky if (ts != NULL) { 177328653Shselasky PROC_UNLOCK(p); 178328653Shselasky return (ts); 179328653Shselasky } 180328653Shselasky } 181328653Shselasky PROC_UNLOCK(p); 182328653Shselasky } 183328653Shselasky return (NULL); 184328653Shselasky} 185328653Shselasky 186328653Shselaskystruct task_struct * 187328653Shselaskylinux_get_pid_task(pid_t pid) 188328653Shselasky{ 189328653Shselasky struct thread *td; 190328653Shselasky struct proc *p; 191328653Shselasky 192328653Shselasky /* try to find corresponding thread */ 193328653Shselasky td = tdfind(pid, -1); 194328653Shselasky if (td != NULL) { 195328653Shselasky struct task_struct *ts = td->td_lkpi_task; 196328653Shselasky if (ts != NULL) 197328653Shselasky get_task_struct(ts); 198328653Shselasky PROC_UNLOCK(td->td_proc); 199328653Shselasky return (ts); 200328653Shselasky } 201328653Shselasky 202328653Shselasky /* try to find corresponding procedure */ 203328653Shselasky p = pfind(pid); 204328653Shselasky if (p != NULL) { 205328653Shselasky FOREACH_THREAD_IN_PROC(p, td) { 206328653Shselasky struct task_struct *ts = td->td_lkpi_task; 207328653Shselasky if (ts != NULL) { 208328653Shselasky get_task_struct(ts); 209328653Shselasky PROC_UNLOCK(p); 210328653Shselasky return (ts); 211328653Shselasky } 212328653Shselasky } 213328653Shselasky PROC_UNLOCK(p); 214328653Shselasky } 215328653Shselasky return (NULL); 216328653Shselasky} 217328653Shselasky 218345924Shselaskybool 219345924Shselaskylinux_task_exiting(struct task_struct *task) 220345924Shselasky{ 221363153Shselasky struct thread *td; 222345924Shselasky struct proc *p; 223345924Shselasky bool ret; 224345924Shselasky 225345924Shselasky ret = false; 226363153Shselasky 227363153Shselasky /* try to find corresponding thread */ 228363153Shselasky td = tdfind(task->pid, -1); 229363153Shselasky if (td != NULL) { 230363153Shselasky p = td->td_proc; 231363153Shselasky } else { 232363153Shselasky /* try to find corresponding procedure */ 233363153Shselasky p = pfind(task->pid); 234363153Shselasky } 235363153Shselasky 236345924Shselasky if (p != NULL) { 237345924Shselasky if ((p->p_flag & P_WEXIT) != 0) 238345924Shselasky ret = true; 239345924Shselasky PROC_UNLOCK(p); 240345924Shselasky } 241345924Shselasky return (ret); 242345924Shselasky} 243345924Shselasky 244328653Shselaskystatic void 245328653Shselaskylinux_current_init(void *arg __unused) 246328653Shselasky{ 247328653Shselasky linuxkpi_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor, 248328653Shselasky linuxkpi_thread_dtor, NULL, EVENTHANDLER_PRI_ANY); 249328653Shselasky} 250328653ShselaskySYSINIT(linux_current, SI_SUB_EVENTHANDLER, SI_ORDER_SECOND, linux_current_init, NULL); 251328653Shselasky 252328653Shselaskystatic void 253328653Shselaskylinux_current_uninit(void *arg __unused) 254328653Shselasky{ 255328653Shselasky struct proc *p; 256328653Shselasky struct task_struct *ts; 257328653Shselasky struct thread *td; 258328653Shselasky 259328653Shselasky sx_slock(&allproc_lock); 260328653Shselasky FOREACH_PROC_IN_SYSTEM(p) { 261328653Shselasky PROC_LOCK(p); 262328653Shselasky FOREACH_THREAD_IN_PROC(p, td) { 263328653Shselasky if ((ts = td->td_lkpi_task) != NULL) { 264328653Shselasky td->td_lkpi_task = NULL; 265328653Shselasky put_task_struct(ts); 266328653Shselasky } 267328653Shselasky } 268328653Shselasky PROC_UNLOCK(p); 269328653Shselasky } 270328653Shselasky sx_sunlock(&allproc_lock); 271328653Shselasky 272328653Shselasky EVENTHANDLER_DEREGISTER(thread_dtor, linuxkpi_thread_dtor_tag); 273328653Shselasky} 274328653ShselaskySYSUNINIT(linux_current, SI_SUB_EVENTHANDLER, SI_ORDER_SECOND, linux_current_uninit, NULL); 275