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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.             thread_usleep(10000);
  135.         } else {
  136.             spinlock_unlock(&tasks_lock);
  137.             interrupts_restore(ipl);
  138.         }
  139.        
  140.     } while (t != NULL);
  141. }
  142.  
  143. /** Create new task
  144.  *
  145.  * Create new task with no threads.
  146.  *
  147.  * @param as Task's address space.
  148.  * @param name Symbolic name.
  149.  *
  150.  * @return New task's structure
  151.  *
  152.  */
  153. task_t *task_create(as_t *as, char *name)
  154. {
  155.     ipl_t ipl;
  156.     task_t *ta;
  157.     int i;
  158.    
  159.     ta = (task_t *) malloc(sizeof(task_t), 0);
  160.  
  161.     task_create_arch(ta);
  162.  
  163.     spinlock_initialize(&ta->lock, "task_ta_lock");
  164.     list_initialize(&ta->th_head);
  165.     ta->as = as;
  166.     ta->name = name;
  167.     atomic_set(&ta->refcount, 0);
  168.     atomic_set(&ta->lifecount, 0);
  169.     ta->context = CONTEXT;
  170.  
  171.     ta->capabilities = 0;
  172.     ta->cycles = 0;
  173.  
  174.     /* Init debugging stuff */
  175.     ta->dt_state = UDEBUG_TS_INACTIVE;
  176.     ta->debug_begin_call = NULL;
  177.     ta->not_stoppable_count = 0;
  178.     ta->debug_evmask = 0;
  179.  
  180.     /* Init kbox stuff */
  181.     ipc_answerbox_init(&ta->kernel_box, ta);
  182.     ta->kb_thread = NULL;
  183.     spinlock_initialize(&ta->kb_cleanup_lock, "task_kb_cleanup_lock");
  184.     ta->kb_finished = false;
  185.     waitq_initialize(&ta->kb_thread_shutdown_wq);
  186.  
  187.     ipc_answerbox_init(&ta->answerbox, ta);
  188.     for (i = 0; i < IPC_MAX_PHONES; i++)
  189.         ipc_phone_init(&ta->phones[i]);
  190.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  191.         ta->context)))
  192.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  193.     atomic_set(&ta->active_calls, 0);
  194.  
  195.     mutex_initialize(&ta->futexes_lock);
  196.     btree_create(&ta->futexes);
  197.    
  198.     ipl = interrupts_disable();
  199.  
  200.     /*
  201.      * Increment address space reference count.
  202.      */
  203.     atomic_inc(&as->refcount);
  204.  
  205.     spinlock_lock(&tasks_lock);
  206.     ta->taskid = ++task_counter;
  207.     avltree_node_initialize(&ta->tasks_tree_node);
  208.     ta->tasks_tree_node.key = ta->taskid;
  209.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  210.     spinlock_unlock(&tasks_lock);
  211.     interrupts_restore(ipl);
  212.  
  213.     return ta;
  214. }
  215.  
  216. /** Destroy task.
  217.  *
  218.  * @param t Task to be destroyed.
  219.  */
  220. void task_destroy(task_t *t)
  221. {
  222.     /*
  223.      * Remove the task from the task B+tree.
  224.      */
  225.     spinlock_lock(&tasks_lock);
  226.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  227.     spinlock_unlock(&tasks_lock);
  228.  
  229.     /*
  230.      * Perform architecture specific task destruction.
  231.      */
  232.     task_destroy_arch(t);
  233.  
  234.     /*
  235.      * Free up dynamically allocated state.
  236.      */
  237.     btree_destroy(&t->futexes);
  238.  
  239.     /*
  240.      * Drop our reference to the address space.
  241.      */
  242.     if (atomic_predec(&t->as->refcount) == 0)
  243.         as_destroy(t->as);
  244.    
  245.     free(t);
  246.     TASK = NULL;
  247. }
  248.  
  249. /** Create new task with 1 thread and run it
  250.  *
  251.  * @param program_addr Address of program executable image.
  252.  * @param name Program name.
  253.  *
  254.  * @return Task of the running program or NULL on error.
  255.  */
  256. task_t *task_run_program(void *program_addr, char *name)
  257. {
  258.     as_t *as;
  259.     as_area_t *a;
  260.     unsigned int rc;
  261.     thread_t *t;
  262.     task_t *task;
  263.     uspace_arg_t *kernel_uarg;
  264.  
  265.     as = as_create(0);
  266.     ASSERT(as);
  267.  
  268.     rc = elf_load((elf_header_t *) program_addr, as);
  269.     if (rc != EE_OK) {
  270.         as_destroy(as);
  271.         return NULL;
  272.     }
  273.    
  274.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  275.     kernel_uarg->uspace_entry =
  276.         (void *) ((elf_header_t *) program_addr)->e_entry;
  277.     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
  278.     kernel_uarg->uspace_thread_function = NULL;
  279.     kernel_uarg->uspace_thread_arg = NULL;
  280.     kernel_uarg->uspace_uarg = NULL;
  281.    
  282.     task = task_create(as, name);
  283.     ASSERT(task);
  284.  
  285.     /*
  286.      * Create the data as_area.
  287.      */
  288.     a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
  289.         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
  290.         AS_AREA_ATTR_NONE, &anon_backend, NULL);
  291.  
  292.     /*
  293.      * Create the main thread.
  294.      */
  295.     t = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
  296.         "uinit", false);
  297.     ASSERT(t);
  298.    
  299.     thread_ready(t);
  300.  
  301.     return task;
  302. }
  303.  
  304. /** Syscall for reading task ID from userspace.
  305.  *
  306.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  307.  * current task ID.
  308.  *
  309.  * @return 0 on success or an error code from @ref errno.h.
  310.  */
  311. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  312. {
  313.     /*
  314.      * No need to acquire lock on TASK because taskid
  315.      * remains constant for the lifespan of the task.
  316.      */
  317.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  318.         sizeof(TASK->taskid));
  319. }
  320.  
  321. /** Find task structure corresponding to task ID.
  322.  *
  323.  * The tasks_lock must be already held by the caller of this function
  324.  * and interrupts must be disabled.
  325.  *
  326.  * @param id Task ID.
  327.  *
  328.  * @return Task structure address or NULL if there is no such task ID.
  329.  */
  330. task_t *task_find_by_id(task_id_t id)
  331. {
  332.     avltree_node_t *node;
  333.    
  334.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  335.  
  336.     if (node)
  337.         return avltree_get_instance(node, task_t, tasks_tree_node);
  338.     return NULL;
  339. }
  340.  
  341. /** Get accounting data of given task.
  342.  *
  343.  * Note that task lock of 't' must be already held and
  344.  * interrupts must be already disabled.
  345.  *
  346.  * @param t Pointer to thread.
  347.  *
  348.  */
  349. uint64_t task_get_accounting(task_t *t)
  350. {
  351.     /* Accumulated value of task */
  352.     uint64_t ret = t->cycles;
  353.    
  354.     /* Current values of threads */
  355.     link_t *cur;
  356.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  357.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  358.        
  359.         spinlock_lock(&thr->lock);
  360.         /* Process only counted threads */
  361.         if (!thr->uncounted) {
  362.             if (thr == THREAD) {
  363.                 /* Update accounting of current thread */
  364.                 thread_update_accounting();
  365.             }
  366.             ret += thr->cycles;
  367.         }
  368.         spinlock_unlock(&thr->lock);
  369.     }
  370.    
  371.     return ret;
  372. }
  373.  
  374. /** Kill task.
  375.  *
  376.  * This function is idempotent.
  377.  * It signals all the task's threads to bail it out.
  378.  *
  379.  * @param id ID of the task to be killed.
  380.  *
  381.  * @return 0 on success or an error code from errno.h
  382.  */
  383. int task_kill(task_id_t id)
  384. {
  385.     ipl_t ipl;
  386.     task_t *ta;
  387.     link_t *cur;
  388.  
  389.     if (id == 1)
  390.         return EPERM;
  391.    
  392.     ipl = interrupts_disable();
  393.     spinlock_lock(&tasks_lock);
  394.     if (!(ta = task_find_by_id(id))) {
  395.         spinlock_unlock(&tasks_lock);
  396.         interrupts_restore(ipl);
  397.         return ENOENT;
  398.     }
  399.     spinlock_unlock(&tasks_lock);
  400.    
  401.     /*
  402.      * Interrupt all threads except ktaskclnp.
  403.      */
  404.     spinlock_lock(&ta->lock);
  405.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  406.         thread_t *thr;
  407.         bool sleeping = false;
  408.        
  409.         thr = list_get_instance(cur, thread_t, th_link);
  410.            
  411.         spinlock_lock(&thr->lock);
  412.         thr->interrupted = true;
  413.         if (thr->state == Sleeping)
  414.             sleeping = true;
  415.         spinlock_unlock(&thr->lock);
  416.        
  417.         if (sleeping)
  418.             waitq_interrupt_sleep(thr);
  419.     }
  420.     spinlock_unlock(&ta->lock);
  421.     interrupts_restore(ipl);
  422.    
  423.     return 0;
  424. }
  425.  
  426. static bool task_print_walker(avltree_node_t *node, void *arg)
  427. {
  428.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  429.     int j;
  430.        
  431.     spinlock_lock(&t->lock);
  432.            
  433.     uint64_t cycles;
  434.     char suffix;
  435.     order(task_get_accounting(t), &cycles, &suffix);
  436.    
  437.     if (sizeof(void *) == 4)
  438.         printf("%-6llu %-10s %-3ld %#10zx %#10zx %9llu%c %7zd %6zd",
  439.             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
  440.             t->refcount, atomic_get(&t->active_calls));
  441.     else
  442.         printf("%-6llu %-10s %-3ld %#18zx %#18zx %9llu%c %7zd %6zd",
  443.             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
  444.             t->refcount, atomic_get(&t->active_calls));
  445.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  446.         if (t->phones[j].callee)
  447.             printf(" %zd:%#zx", j, t->phones[j].callee);
  448.     }
  449.     printf("\n");
  450.            
  451.     spinlock_unlock(&t->lock);
  452.     return true;
  453. }
  454.  
  455. /** Print task list */
  456. void task_print_list(void)
  457. {
  458.     ipl_t ipl;
  459.    
  460.     /* Messing with task structures, avoid deadlock */
  461.     ipl = interrupts_disable();
  462.     spinlock_lock(&tasks_lock);
  463.    
  464.     if (sizeof(void *) == 4) {
  465.         printf("taskid name       ctx address    as         "
  466.             "cycles     threads calls  callee\n");
  467.         printf("------ ---------- --- ---------- ---------- "
  468.             "---------- ------- ------ ------>\n");
  469.     } else {
  470.         printf("taskid name       ctx address            as                 "
  471.             "cycles     threads calls  callee\n");
  472.         printf("------ ---------- --- ------------------ ------------------ "
  473.             "---------- ------- ------ ------>\n");
  474.     }
  475.  
  476.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  477.  
  478.     spinlock_unlock(&tasks_lock);
  479.     interrupts_restore(ipl);
  480. }
  481.  
  482. /** @}
  483.  */
  484.