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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/avl.h>
  50. #include <adt/btree.h>
  51. #include <adt/list.h>
  52. #include <ipc/ipc.h>
  53. #include <security/cap.h>
  54. #include <memstr.h>
  55. #include <print.h>
  56. #include <lib/elf.h>
  57. #include <errno.h>
  58. #include <func.h>
  59. #include <syscall/copy.h>
  60.  
  61. #ifndef LOADED_PROG_STACK_PAGES_NO
  62. #define LOADED_PROG_STACK_PAGES_NO 1
  63. #endif
  64.  
  65. /** Spinlock protecting the tasks_tree AVL tree. */
  66. SPINLOCK_INITIALIZE(tasks_lock);
  67.  
  68. /** AVL tree of active tasks.
  69.  *
  70.  * The task is guaranteed to exist after it was found in the tasks_tree as
  71.  * long as:
  72.  * @li the tasks_lock is held,
  73.  * @li the task's lock is held when task's lock is acquired before releasing
  74.  *     tasks_lock or
  75.  * @li the task's refcount is greater than 0
  76.  *
  77.  */
  78. avltree_t tasks_tree;
  79.  
  80. static task_id_t task_counter = 0;
  81.  
  82. /** Initialize tasks
  83.  *
  84.  * Initialize kernel tasks support.
  85.  *
  86.  */
  87. void task_init(void)
  88. {
  89.     TASK = NULL;
  90.     avltree_create(&tasks_tree);
  91. }
  92.  
  93. /*
  94.  * The idea behind this walker is to remember a single task different from TASK.
  95.  */
  96. static bool task_done_walker(avltree_node_t *node, void *arg)
  97. {
  98.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  99.     task_t **tp = (task_t **) arg;
  100.  
  101.     if (t != TASK) {
  102.         *tp = t;
  103.         return false;   /* stop walking */
  104.     }
  105.  
  106.     return true;    /* continue the walk */
  107. }
  108.  
  109. /** Kill all tasks except the current task.
  110.  *
  111.  */
  112. void task_done(void)
  113. {
  114.     task_t *t;
  115.     do { /* Repeat until there are any tasks except TASK */
  116.        
  117.         /* Messing with task structures, avoid deadlock */
  118.         ipl_t ipl = interrupts_disable();
  119.         spinlock_lock(&tasks_lock);
  120.        
  121.         t = NULL;
  122.         avltree_walk(&tasks_tree, task_done_walker, &t);
  123.        
  124.         if (t != NULL) {
  125.             task_id_t id = t->taskid;
  126.            
  127.             spinlock_unlock(&tasks_lock);
  128.             interrupts_restore(ipl);
  129.            
  130. #ifdef CONFIG_DEBUG
  131.             printf("Killing task %llu\n", id);
  132. #endif         
  133.             task_kill(id);
  134.         } else {
  135.             spinlock_unlock(&tasks_lock);
  136.             interrupts_restore(ipl);
  137.         }
  138.        
  139.     } while (t != NULL);
  140. }
  141.  
  142. /** Create new task
  143.  *
  144.  * Create new task with no threads.
  145.  *
  146.  * @param as Task's address space.
  147.  * @param name Symbolic name.
  148.  *
  149.  * @return New task's structure
  150.  *
  151.  */
  152. task_t *task_create(as_t *as, char *name)
  153. {
  154.     ipl_t ipl;
  155.     task_t *ta;
  156.     int i;
  157.    
  158.     ta = (task_t *) malloc(sizeof(task_t), 0);
  159.  
  160.     task_create_arch(ta);
  161.  
  162.     spinlock_initialize(&ta->lock, "task_ta_lock");
  163.     list_initialize(&ta->th_head);
  164.     ta->as = as;
  165.     ta->name = name;
  166.     atomic_set(&ta->refcount, 0);
  167.     atomic_set(&ta->lifecount, 0);
  168.     ta->context = CONTEXT;
  169.  
  170.     ta->capabilities = 0;
  171.     ta->cycles = 0;
  172.    
  173.     ipc_answerbox_init(&ta->answerbox);
  174.     for (i = 0; i < IPC_MAX_PHONES; i++)
  175.         ipc_phone_init(&ta->phones[i]);
  176.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  177.         ta->context)))
  178.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  179.     atomic_set(&ta->active_calls, 0);
  180.  
  181.     mutex_initialize(&ta->futexes_lock);
  182.     btree_create(&ta->futexes);
  183.    
  184.     ipl = interrupts_disable();
  185.  
  186.     /*
  187.      * Increment address space reference count.
  188.      */
  189.     atomic_inc(&as->refcount);
  190.  
  191.     spinlock_lock(&tasks_lock);
  192.     ta->taskid = ++task_counter;
  193.     avltree_node_initialize(&ta->tasks_tree_node);
  194.     ta->tasks_tree_node.key = ta->taskid;
  195.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  196.     spinlock_unlock(&tasks_lock);
  197.     interrupts_restore(ipl);
  198.  
  199.     return ta;
  200. }
  201.  
  202. /** Destroy task.
  203.  *
  204.  * @param t Task to be destroyed.
  205.  */
  206. void task_destroy(task_t *t)
  207. {
  208.     /*
  209.      * Remove the task from the task B+tree.
  210.      */
  211.     spinlock_lock(&tasks_lock);
  212.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  213.     spinlock_unlock(&tasks_lock);
  214.  
  215.     /*
  216.      * Perform architecture specific task destruction.
  217.      */
  218.     task_destroy_arch(t);
  219.  
  220.     /*
  221.      * Free up dynamically allocated state.
  222.      */
  223.     btree_destroy(&t->futexes);
  224.  
  225.     /*
  226.      * Drop our reference to the address space.
  227.      */
  228.     if (atomic_predec(&t->as->refcount) == 0)
  229.         as_destroy(t->as);
  230.    
  231.     free(t);
  232.     TASK = NULL;
  233. }
  234.  
  235. /** Create new task with 1 thread and run it
  236.  *
  237.  * @param program_addr Address of program executable image.
  238.  * @param name Program name.
  239.  *
  240.  * @return Task of the running program or NULL on error.
  241.  */
  242. task_t *task_run_program(void *program_addr, char *name)
  243. {
  244.     as_t *as;
  245.     as_area_t *a;
  246.     int rc;
  247.     thread_t *t;
  248.     task_t *task;
  249.     uspace_arg_t *kernel_uarg;
  250.  
  251.     as = as_create(0);
  252.     ASSERT(as);
  253.  
  254.     rc = elf_load((elf_header_t *) program_addr, as);
  255.     if (rc != EE_OK) {
  256.         as_destroy(as);
  257.         return NULL;
  258.     }
  259.    
  260.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  261.     kernel_uarg->uspace_entry =
  262.         (void *) ((elf_header_t *) program_addr)->e_entry;
  263.     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
  264.     kernel_uarg->uspace_thread_function = NULL;
  265.     kernel_uarg->uspace_thread_arg = NULL;
  266.     kernel_uarg->uspace_uarg = NULL;
  267.    
  268.     task = task_create(as, name);
  269.     ASSERT(task);
  270.  
  271.     /*
  272.      * Create the data as_area.
  273.      */
  274.     a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
  275.         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
  276.         AS_AREA_ATTR_NONE, &anon_backend, NULL);
  277.  
  278.     /*
  279.      * Create the main thread.
  280.      */
  281.     t = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
  282.         "uinit", false);
  283.     ASSERT(t);
  284.    
  285.     thread_ready(t);
  286.  
  287.     return task;
  288. }
  289.  
  290. /** Syscall for reading task ID from userspace.
  291.  *
  292.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  293.  * current task ID.
  294.  *
  295.  * @return 0 on success or an error code from @ref errno.h.
  296.  */
  297. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  298. {
  299.     /*
  300.      * No need to acquire lock on TASK because taskid
  301.      * remains constant for the lifespan of the task.
  302.      */
  303.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  304.         sizeof(TASK->taskid));
  305. }
  306.  
  307. /** Find task structure corresponding to task ID.
  308.  *
  309.  * The tasks_lock must be already held by the caller of this function
  310.  * and interrupts must be disabled.
  311.  *
  312.  * @param id Task ID.
  313.  *
  314.  * @return Task structure address or NULL if there is no such task ID.
  315.  */
  316. task_t *task_find_by_id(task_id_t id)
  317. {
  318.     avltree_node_t *node;
  319.    
  320.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  321.  
  322.     if (node)
  323.         return avltree_get_instance(node, task_t, tasks_tree_node);
  324.     return NULL;
  325. }
  326.  
  327. /** Get accounting data of given task.
  328.  *
  329.  * Note that task lock of 't' must be already held and
  330.  * interrupts must be already disabled.
  331.  *
  332.  * @param t Pointer to thread.
  333.  *
  334.  */
  335. uint64_t task_get_accounting(task_t *t)
  336. {
  337.     /* Accumulated value of task */
  338.     uint64_t ret = t->cycles;
  339.    
  340.     /* Current values of threads */
  341.     link_t *cur;
  342.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  343.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  344.        
  345.         spinlock_lock(&thr->lock);
  346.         /* Process only counted threads */
  347.         if (!thr->uncounted) {
  348.             if (thr == THREAD) {
  349.                 /* Update accounting of current thread */
  350.                 thread_update_accounting();
  351.             }
  352.             ret += thr->cycles;
  353.         }
  354.         spinlock_unlock(&thr->lock);
  355.     }
  356.    
  357.     return ret;
  358. }
  359.  
  360. /** Kill task.
  361.  *
  362.  * This function is idempotent.
  363.  * It signals all the task's threads to bail it out.
  364.  *
  365.  * @param id ID of the task to be killed.
  366.  *
  367.  * @return 0 on success or an error code from errno.h
  368.  */
  369. int task_kill(task_id_t id)
  370. {
  371.     ipl_t ipl;
  372.     task_t *ta;
  373.     link_t *cur;
  374.  
  375.     if (id == 1)
  376.         return EPERM;
  377.    
  378.     ipl = interrupts_disable();
  379.     spinlock_lock(&tasks_lock);
  380.     if (!(ta = task_find_by_id(id))) {
  381.         spinlock_unlock(&tasks_lock);
  382.         interrupts_restore(ipl);
  383.         return ENOENT;
  384.     }
  385.     spinlock_unlock(&tasks_lock);
  386.    
  387.     /*
  388.      * Interrupt all threads except ktaskclnp.
  389.      */
  390.     spinlock_lock(&ta->lock);
  391.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  392.         thread_t *thr;
  393.         bool sleeping = false;
  394.        
  395.         thr = list_get_instance(cur, thread_t, th_link);
  396.            
  397.         spinlock_lock(&thr->lock);
  398.         thr->interrupted = true;
  399.         if (thr->state == Sleeping)
  400.             sleeping = true;
  401.         spinlock_unlock(&thr->lock);
  402.        
  403.         if (sleeping)
  404.             waitq_interrupt_sleep(thr);
  405.     }
  406.     spinlock_unlock(&ta->lock);
  407.     interrupts_restore(ipl);
  408.    
  409.     return 0;
  410. }
  411.  
  412. static bool task_print_walker(avltree_node_t *node, void *arg)
  413. {
  414.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  415.     int j;
  416.        
  417.     spinlock_lock(&t->lock);
  418.            
  419.     uint64_t cycles;
  420.     char suffix;
  421.     order(task_get_accounting(t), &cycles, &suffix);
  422.            
  423.     printf("%-6llu %-10s %-3ld %#10zx %#10zx %9llu%c %7zd %6zd",
  424.         t->taskid, t->name, t->context, t, t->as, cycles, suffix,
  425.         t->refcount, atomic_get(&t->active_calls));
  426.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  427.         if (t->phones[j].callee)
  428.             printf(" %zd:%#zx", j, t->phones[j].callee);
  429.     }
  430.     printf("\n");
  431.            
  432.     spinlock_unlock(&t->lock);
  433.     return true;
  434. }
  435.  
  436. /** Print task list */
  437. void task_print_list(void)
  438. {
  439.     ipl_t ipl;
  440.    
  441.     /* Messing with task structures, avoid deadlock */
  442.     ipl = interrupts_disable();
  443.     spinlock_lock(&tasks_lock);
  444.    
  445.     printf("taskid name       ctx address    as         cycles     threads "
  446.         "calls  callee\n");
  447.     printf("------ ---------- --- ---------- ---------- ---------- ------- "
  448.         "------ ------>\n");
  449.  
  450.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  451.  
  452.     spinlock_unlock(&tasks_lock);
  453.     interrupts_restore(ipl);
  454. }
  455.  
  456. /** @}
  457.  */
  458.