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  1. /*
  2.  * Copyright (c) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericproc
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Task management.
  36.  */
  37.  
  38. #include <main/uinit.h>
  39. #include <proc/thread.h>
  40. #include <proc/task.h>
  41. #include <proc/uarg.h>
  42. #include <mm/as.h>
  43. #include <mm/slab.h>
  44. #include <atomic.h>
  45. #include <synch/spinlock.h>
  46. #include <synch/waitq.h>
  47. #include <arch.h>
  48. #include <panic.h>
  49. #include <adt/btree.h>
  50. #include <adt/list.h>
  51. #include <ipc/ipc.h>
  52. #include <security/cap.h>
  53. #include <memstr.h>
  54. #include <print.h>
  55. #include <lib/elf.h>
  56. #include <errno.h>
  57. #include <func.h>
  58. #include <syscall/copy.h>
  59.  
  60. #ifndef LOADED_PROG_STACK_PAGES_NO
  61. #define LOADED_PROG_STACK_PAGES_NO 1
  62. #endif
  63.  
  64. /** Spinlock protecting the tasks_btree B+tree. */
  65. SPINLOCK_INITIALIZE(tasks_lock);
  66.  
  67. /** B+tree of active tasks.
  68.  *
  69.  * The task is guaranteed to exist after it was found in the tasks_btree as
  70.  * long as:
  71.  * @li the tasks_lock is held,
  72.  * @li the task's lock is held when task's lock is acquired before releasing
  73.  *     tasks_lock or
  74.  * @li the task's refcount is greater than 0
  75.  *
  76.  */
  77. btree_t tasks_btree;
  78.  
  79. static task_id_t task_counter = 0;
  80.  
  81. /** Initialize tasks
  82.  *
  83.  * Initialize kernel tasks support.
  84.  *
  85.  */
  86. void task_init(void)
  87. {
  88.     TASK = NULL;
  89.     btree_create(&tasks_btree);
  90. }
  91.  
  92. /** Kill all tasks except the current task.
  93.  *
  94.  */
  95. void task_done(void)
  96. {
  97.     task_t *t;
  98.     do { /* Repeat until there are any tasks except TASK */
  99.        
  100.         /* Messing with task structures, avoid deadlock */
  101.         ipl_t ipl = interrupts_disable();
  102.         spinlock_lock(&tasks_lock);
  103.        
  104.         t = NULL;
  105.         link_t *cur;
  106.         for (cur = tasks_btree.leaf_head.next;
  107.             cur != &tasks_btree.leaf_head; cur = cur->next) {
  108.             btree_node_t *node;
  109.            
  110.             node = list_get_instance(cur, btree_node_t, leaf_link);
  111.            
  112.             unsigned int i;
  113.             for (i = 0; i < node->keys; i++) {
  114.                 if ((task_t *) node->value[i] != TASK) {
  115.                     t = (task_t *) node->value[i];
  116.                     break;
  117.                 }
  118.             }
  119.         }
  120.        
  121.         if (t != NULL) {
  122.             task_id_t id = t->taskid;
  123.            
  124.             spinlock_unlock(&tasks_lock);
  125.             interrupts_restore(ipl);
  126.            
  127. #ifdef CONFIG_DEBUG
  128.             printf("Killing task %llu\n", id);
  129. #endif         
  130.             task_kill(id);
  131.         } else {
  132.             spinlock_unlock(&tasks_lock);
  133.             interrupts_restore(ipl);
  134.         }
  135.        
  136.     } while (t != NULL);
  137. }
  138.  
  139. /** Create new task
  140.  *
  141.  * Create new task with no threads.
  142.  *
  143.  * @param as Task's address space.
  144.  * @param name Symbolic name.
  145.  *
  146.  * @return New task's structure
  147.  *
  148.  */
  149. task_t *task_create(as_t *as, char *name)
  150. {
  151.     ipl_t ipl;
  152.     task_t *ta;
  153.     int i;
  154.    
  155.     ta = (task_t *) malloc(sizeof(task_t), 0);
  156.  
  157.     task_create_arch(ta);
  158.  
  159.     spinlock_initialize(&ta->lock, "task_ta_lock");
  160.     list_initialize(&ta->th_head);
  161.     ta->as = as;
  162.     ta->name = name;
  163.     atomic_set(&ta->refcount, 0);
  164.     atomic_set(&ta->lifecount, 0);
  165.     ta->context = CONTEXT;
  166.  
  167.     ta->capabilities = 0;
  168.     ta->cycles = 0;
  169.    
  170.     ipc_answerbox_init(&ta->answerbox);
  171.     for (i = 0; i < IPC_MAX_PHONES; i++)
  172.         ipc_phone_init(&ta->phones[i]);
  173.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  174.         ta->context)))
  175.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  176.     atomic_set(&ta->active_calls, 0);
  177.  
  178.     mutex_initialize(&ta->futexes_lock);
  179.     btree_create(&ta->futexes);
  180.    
  181.     ipl = interrupts_disable();
  182.  
  183.     /*
  184.      * Increment address space reference count.
  185.      */
  186.     atomic_inc(&as->refcount);
  187.  
  188.     spinlock_lock(&tasks_lock);
  189.     ta->taskid = ++task_counter;
  190.     btree_insert(&tasks_btree, (btree_key_t) ta->taskid, (void *) ta, NULL);
  191.     spinlock_unlock(&tasks_lock);
  192.     interrupts_restore(ipl);
  193.  
  194.     return ta;
  195. }
  196.  
  197. /** Destroy task.
  198.  *
  199.  * @param t Task to be destroyed.
  200.  */
  201. void task_destroy(task_t *t)
  202. {
  203.     /*
  204.      * Remove the task from the task B+tree.
  205.      */
  206.     spinlock_lock(&tasks_lock);
  207.     btree_remove(&tasks_btree, t->taskid, NULL);
  208.     spinlock_unlock(&tasks_lock);
  209.  
  210.     /*
  211.      * Perform architecture specific task destruction.
  212.      */
  213.     task_destroy_arch(t);
  214.  
  215.     /*
  216.      * Free up dynamically allocated state.
  217.      */
  218.     btree_destroy(&t->futexes);
  219.  
  220.     /*
  221.      * Drop our reference to the address space.
  222.      */
  223.     if (atomic_predec(&t->as->refcount) == 0)
  224.         as_destroy(t->as);
  225.    
  226.     free(t);
  227.     TASK = NULL;
  228. }
  229.  
  230. /** Create new task with 1 thread and run it
  231.  *
  232.  * @param program_addr Address of program executable image.
  233.  * @param name Program name.
  234.  *
  235.  * @return Task of the running program or NULL on error.
  236.  */
  237. task_t *task_run_program(void *program_addr, char *name)
  238. {
  239.     as_t *as;
  240.     as_area_t *a;
  241.     int rc;
  242.     thread_t *t;
  243.     task_t *task;
  244.     uspace_arg_t *kernel_uarg;
  245.  
  246.     as = as_create(0);
  247.     ASSERT(as);
  248.  
  249.     rc = elf_load((elf_header_t *) program_addr, as);
  250.     if (rc != EE_OK) {
  251.         as_destroy(as);
  252.         return NULL;
  253.     }
  254.    
  255.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  256.     kernel_uarg->uspace_entry =
  257.         (void *) ((elf_header_t *) program_addr)->e_entry;
  258.     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
  259.     kernel_uarg->uspace_thread_function = NULL;
  260.     kernel_uarg->uspace_thread_arg = NULL;
  261.     kernel_uarg->uspace_uarg = NULL;
  262.    
  263.     task = task_create(as, name);
  264.     ASSERT(task);
  265.  
  266.     /*
  267.      * Create the data as_area.
  268.      */
  269.     a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
  270.         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
  271.         AS_AREA_ATTR_NONE, &anon_backend, NULL);
  272.  
  273.     /*
  274.      * Create the main thread.
  275.      */
  276.     t = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
  277.         "uinit", false);
  278.     ASSERT(t);
  279.    
  280.     thread_ready(t);
  281.  
  282.     return task;
  283. }
  284.  
  285. /** Syscall for reading task ID from userspace.
  286.  *
  287.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  288.  * current task ID.
  289.  *
  290.  * @return 0 on success or an error code from @ref errno.h.
  291.  */
  292. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  293. {
  294.     /*
  295.      * No need to acquire lock on TASK because taskid
  296.      * remains constant for the lifespan of the task.
  297.      */
  298.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  299.         sizeof(TASK->taskid));
  300. }
  301.  
  302. /** Find task structure corresponding to task ID.
  303.  *
  304.  * The tasks_lock must be already held by the caller of this function
  305.  * and interrupts must be disabled.
  306.  *
  307.  * @param id Task ID.
  308.  *
  309.  * @return Task structure address or NULL if there is no such task ID.
  310.  */
  311. task_t *task_find_by_id(task_id_t id)
  312. {
  313.     btree_node_t *leaf;
  314.    
  315.     return (task_t *) btree_search(&tasks_btree, (btree_key_t) id, &leaf);
  316. }
  317.  
  318. /** Get accounting data of given task.
  319.  *
  320.  * Note that task lock of 't' must be already held and
  321.  * interrupts must be already disabled.
  322.  *
  323.  * @param t Pointer to thread.
  324.  *
  325.  */
  326. uint64_t task_get_accounting(task_t *t)
  327. {
  328.     /* Accumulated value of task */
  329.     uint64_t ret = t->cycles;
  330.    
  331.     /* Current values of threads */
  332.     link_t *cur;
  333.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  334.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  335.        
  336.         spinlock_lock(&thr->lock);
  337.         /* Process only counted threads */
  338.         if (!thr->uncounted) {
  339.             if (thr == THREAD) {
  340.                 /* Update accounting of current thread */
  341.                 thread_update_accounting();
  342.             }
  343.             ret += thr->cycles;
  344.         }
  345.         spinlock_unlock(&thr->lock);
  346.     }
  347.    
  348.     return ret;
  349. }
  350.  
  351. /** Kill task.
  352.  *
  353.  * This function is idempotent.
  354.  * It signals all the task's threads to bail it out.
  355.  *
  356.  * @param id ID of the task to be killed.
  357.  *
  358.  * @return 0 on success or an error code from errno.h
  359.  */
  360. int task_kill(task_id_t id)
  361. {
  362.     ipl_t ipl;
  363.     task_t *ta;
  364.     link_t *cur;
  365.  
  366.     if (id == 1)
  367.         return EPERM;
  368.    
  369.     ipl = interrupts_disable();
  370.     spinlock_lock(&tasks_lock);
  371.     if (!(ta = task_find_by_id(id))) {
  372.         spinlock_unlock(&tasks_lock);
  373.         interrupts_restore(ipl);
  374.         return ENOENT;
  375.     }
  376.     spinlock_unlock(&tasks_lock);
  377.    
  378.     /*
  379.      * Interrupt all threads except ktaskclnp.
  380.      */
  381.     spinlock_lock(&ta->lock);
  382.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  383.         thread_t *thr;
  384.         bool sleeping = false;
  385.        
  386.         thr = list_get_instance(cur, thread_t, th_link);
  387.            
  388.         spinlock_lock(&thr->lock);
  389.         thr->interrupted = true;
  390.         if (thr->state == Sleeping)
  391.             sleeping = true;
  392.         spinlock_unlock(&thr->lock);
  393.        
  394.         if (sleeping)
  395.             waitq_interrupt_sleep(thr);
  396.     }
  397.     spinlock_unlock(&ta->lock);
  398.     interrupts_restore(ipl);
  399.    
  400.     return 0;
  401. }
  402.  
  403. /** Print task list */
  404. void task_print_list(void)
  405. {
  406.     link_t *cur;
  407.     ipl_t ipl;
  408.    
  409.     /* Messing with task structures, avoid deadlock */
  410.     ipl = interrupts_disable();
  411.     spinlock_lock(&tasks_lock);
  412.    
  413.     printf("taskid name       ctx address    as         cycles     threads "
  414.         "calls  callee\n");
  415.     printf("------ ---------- --- ---------- ---------- ---------- ------- "
  416.         "------ ------>\n");
  417.  
  418.     for (cur = tasks_btree.leaf_head.next; cur != &tasks_btree.leaf_head;
  419.         cur = cur->next) {
  420.         btree_node_t *node;
  421.         unsigned int i;
  422.        
  423.         node = list_get_instance(cur, btree_node_t, leaf_link);
  424.         for (i = 0; i < node->keys; i++) {
  425.             task_t *t;
  426.             int j;
  427.  
  428.             t = (task_t *) node->value[i];
  429.        
  430.             spinlock_lock(&t->lock);
  431.            
  432.             uint64_t cycles;
  433.             char suffix;
  434.             order(task_get_accounting(t), &cycles, &suffix);
  435.            
  436.             printf("%-6llu %-10s %-3ld %#10zx %#10zx %9llu%c %7zd "
  437.                 "%6zd", t->taskid, t->name, t->context, t, t->as,
  438.                 cycles, suffix, t->refcount,
  439.                 atomic_get(&t->active_calls));
  440.             for (j = 0; j < IPC_MAX_PHONES; j++) {
  441.                 if (t->phones[j].callee)
  442.                     printf(" %zd:%#zx", j,
  443.                         t->phones[j].callee);
  444.             }
  445.             printf("\n");
  446.            
  447.             spinlock_unlock(&t->lock);
  448.         }
  449.     }
  450.  
  451.     spinlock_unlock(&tasks_lock);
  452.     interrupts_restore(ipl);
  453. }
  454.  
  455. /** @}
  456.  */
  457.