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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. #include <tdebug/tdebug.h>
  61.  
  62. #ifndef LOADED_PROG_STACK_PAGES_NO
  63. #define LOADED_PROG_STACK_PAGES_NO 1
  64. #endif
  65.  
  66. /** Spinlock protecting the tasks_tree AVL tree. */
  67. SPINLOCK_INITIALIZE(tasks_lock);
  68.  
  69. /** AVL tree of active tasks.
  70.  *
  71.  * The task is guaranteed to exist after it was found in the tasks_tree as
  72.  * long as:
  73.  * @li the tasks_lock is held,
  74.  * @li the task's lock is held when task's lock is acquired before releasing
  75.  *     tasks_lock or
  76.  * @li the task's refcount is greater than 0
  77.  *
  78.  */
  79. avltree_t tasks_tree;
  80.  
  81. static task_id_t task_counter = 0;
  82.  
  83. /** Initialize tasks
  84.  *
  85.  * Initialize kernel tasks support.
  86.  *
  87.  */
  88. void task_init(void)
  89. {
  90.     TASK = NULL;
  91.     avltree_create(&tasks_tree);
  92. }
  93.  
  94. /*
  95.  * The idea behind this walker is to remember a single task different from TASK.
  96.  */
  97. static bool task_done_walker(avltree_node_t *node, void *arg)
  98. {
  99.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  100.     task_t **tp = (task_t **) arg;
  101.  
  102.     if (t != TASK) {
  103.         *tp = t;
  104.         return false;   /* stop walking */
  105.     }
  106.  
  107.     return true;    /* continue the walk */
  108. }
  109.  
  110. /** Kill all tasks except the current task.
  111.  *
  112.  */
  113. void task_done(void)
  114. {
  115.     task_t *t;
  116.     do { /* Repeat until there are any tasks except TASK */
  117.        
  118.         /* Messing with task structures, avoid deadlock */
  119.         ipl_t ipl = interrupts_disable();
  120.         spinlock_lock(&tasks_lock);
  121.        
  122.         t = NULL;
  123.         avltree_walk(&tasks_tree, task_done_walker, &t);
  124.        
  125.         if (t != NULL) {
  126.             task_id_t id = t->taskid;
  127.            
  128.             spinlock_unlock(&tasks_lock);
  129.             interrupts_restore(ipl);
  130.            
  131. #ifdef CONFIG_DEBUG
  132.             printf("Killing task %llu\n", id);
  133. #endif         
  134.             task_kill(id);
  135.             thread_usleep(10000);
  136.         } else {
  137.             spinlock_unlock(&tasks_lock);
  138.             interrupts_restore(ipl);
  139.         }
  140.        
  141.     } while (t != NULL);
  142. }
  143.  
  144. /** Create new task
  145.  *
  146.  * Create new task with no threads.
  147.  *
  148.  * @param as Task's address space.
  149.  * @param name Symbolic name.
  150.  *
  151.  * @return New task's structure
  152.  *
  153.  */
  154. task_t *task_create(as_t *as, char *name)
  155. {
  156.     ipl_t ipl;
  157.     task_t *ta;
  158.     int i;
  159.    
  160.     ta = (task_t *) malloc(sizeof(task_t), 0);
  161.  
  162.     task_create_arch(ta);
  163.  
  164.     spinlock_initialize(&ta->lock, "task_ta_lock");
  165.     list_initialize(&ta->th_head);
  166.     ta->as = as;
  167.     ta->name = name;
  168.     atomic_set(&ta->refcount, 0);
  169.     atomic_set(&ta->lifecount, 0);
  170.     ta->context = CONTEXT;
  171.  
  172.     ta->capabilities = 0;
  173.     ta->cycles = 0;
  174.  
  175.     /* init tdebug related stuff */
  176.     tdebug_task_init(ta);
  177.  
  178.     ipc_answerbox_init(&ta->answerbox);
  179.     for (i = 0; i < IPC_MAX_PHONES; i++)
  180.         ipc_phone_init(&ta->phones[i]);
  181.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  182.         ta->context)))
  183.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  184.     atomic_set(&ta->active_calls, 0);
  185.  
  186.     mutex_initialize(&ta->futexes_lock);
  187.     btree_create(&ta->futexes);
  188.    
  189.     ipl = interrupts_disable();
  190.  
  191.     /*
  192.      * Increment address space reference count.
  193.      */
  194.     atomic_inc(&as->refcount);
  195.  
  196.     spinlock_lock(&tasks_lock);
  197.     ta->taskid = ++task_counter;
  198.     avltree_node_initialize(&ta->tasks_tree_node);
  199.     ta->tasks_tree_node.key = ta->taskid;
  200.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  201.     spinlock_unlock(&tasks_lock);
  202.     interrupts_restore(ipl);
  203.  
  204.     return ta;
  205. }
  206.  
  207. /** Destroy task.
  208.  *
  209.  * @param t Task to be destroyed.
  210.  */
  211. void task_destroy(task_t *t)
  212. {
  213.     /*
  214.      * Remove the task from the task B+tree.
  215.      */
  216.     spinlock_lock(&tasks_lock);
  217.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  218.     spinlock_unlock(&tasks_lock);
  219.  
  220.     /*
  221.      * Perform architecture specific task destruction.
  222.      */
  223.     task_destroy_arch(t);
  224.  
  225.     /*
  226.      * Free up dynamically allocated state.
  227.      */
  228.     btree_destroy(&t->futexes);
  229.  
  230.     /*
  231.      * Drop our reference to the address space.
  232.      */
  233.     if (atomic_predec(&t->as->refcount) == 0)
  234.         as_destroy(t->as);
  235.    
  236.     free(t);
  237.     TASK = NULL;
  238. }
  239.  
  240. /** Create new task with 1 thread and run it
  241.  *
  242.  * @param program_addr Address of program executable image.
  243.  * @param name Program name.
  244.  *
  245.  * @return Task of the running program or NULL on error.
  246.  */
  247. task_t *task_run_program(void *program_addr, char *name)
  248. {
  249.     as_t *as;
  250.     as_area_t *a;
  251.     unsigned int rc;
  252.     thread_t *t;
  253.     task_t *task;
  254.     uspace_arg_t *kernel_uarg;
  255.  
  256.     as = as_create(0);
  257.     ASSERT(as);
  258.  
  259.     rc = elf_load((elf_header_t *) program_addr, as);
  260.     if (rc != EE_OK) {
  261.         as_destroy(as);
  262.         return NULL;
  263.     }
  264.    
  265.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  266.     kernel_uarg->uspace_entry =
  267.         (void *) ((elf_header_t *) program_addr)->e_entry;
  268.     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
  269.     kernel_uarg->uspace_thread_function = NULL;
  270.     kernel_uarg->uspace_thread_arg = NULL;
  271.     kernel_uarg->uspace_uarg = NULL;
  272.    
  273.     task = task_create(as, name);
  274.     ASSERT(task);
  275.  
  276.     /*
  277.      * Create the data as_area.
  278.      */
  279.     a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
  280.         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
  281.         AS_AREA_ATTR_NONE, &anon_backend, NULL);
  282.  
  283.     /*
  284.      * Create the main thread.
  285.      */
  286.     t = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
  287.         "uinit", false);
  288.     ASSERT(t);
  289.    
  290.     thread_ready(t);
  291.  
  292.     return task;
  293. }
  294.  
  295. /** Syscall for reading task ID from userspace.
  296.  *
  297.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  298.  * current task ID.
  299.  *
  300.  * @return 0 on success or an error code from @ref errno.h.
  301.  */
  302. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  303. {
  304.     /*
  305.      * No need to acquire lock on TASK because taskid
  306.      * remains constant for the lifespan of the task.
  307.      */
  308.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  309.         sizeof(TASK->taskid));
  310. }
  311.  
  312. /** Find task structure corresponding to task ID.
  313.  *
  314.  * The tasks_lock must be already held by the caller of this function
  315.  * and interrupts must be disabled.
  316.  *
  317.  * @param id Task ID.
  318.  *
  319.  * @return Task structure address or NULL if there is no such task ID.
  320.  */
  321. task_t *task_find_by_id(task_id_t id)
  322. {
  323.     avltree_node_t *node;
  324.    
  325.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  326.  
  327.     if (node)
  328.         return avltree_get_instance(node, task_t, tasks_tree_node);
  329.     return NULL;
  330. }
  331.  
  332. /** Get accounting data of given task.
  333.  *
  334.  * Note that task lock of 't' must be already held and
  335.  * interrupts must be already disabled.
  336.  *
  337.  * @param t Pointer to thread.
  338.  *
  339.  */
  340. uint64_t task_get_accounting(task_t *t)
  341. {
  342.     /* Accumulated value of task */
  343.     uint64_t ret = t->cycles;
  344.    
  345.     /* Current values of threads */
  346.     link_t *cur;
  347.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  348.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  349.        
  350.         spinlock_lock(&thr->lock);
  351.         /* Process only counted threads */
  352.         if (!thr->uncounted) {
  353.             if (thr == THREAD) {
  354.                 /* Update accounting of current thread */
  355.                 thread_update_accounting();
  356.             }
  357.             ret += thr->cycles;
  358.         }
  359.         spinlock_unlock(&thr->lock);
  360.     }
  361.    
  362.     return ret;
  363. }
  364.  
  365. /** Kill task.
  366.  *
  367.  * This function is idempotent.
  368.  * It signals all the task's threads to bail it out.
  369.  *
  370.  * @param id ID of the task to be killed.
  371.  *
  372.  * @return 0 on success or an error code from errno.h
  373.  */
  374. int task_kill(task_id_t id)
  375. {
  376.     ipl_t ipl;
  377.     task_t *ta;
  378.     link_t *cur;
  379.  
  380.     if (id == 1)
  381.         return EPERM;
  382.    
  383.     ipl = interrupts_disable();
  384.     spinlock_lock(&tasks_lock);
  385.     if (!(ta = task_find_by_id(id))) {
  386.         spinlock_unlock(&tasks_lock);
  387.         interrupts_restore(ipl);
  388.         return ENOENT;
  389.     }
  390.     spinlock_unlock(&tasks_lock);
  391.    
  392.     /*
  393.      * Interrupt all threads except ktaskclnp.
  394.      */
  395.     spinlock_lock(&ta->lock);
  396.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  397.         thread_t *thr;
  398.         bool sleeping = false;
  399.        
  400.         thr = list_get_instance(cur, thread_t, th_link);
  401.            
  402.         spinlock_lock(&thr->lock);
  403.         thr->interrupted = true;
  404.         if (thr->state == Sleeping)
  405.             sleeping = true;
  406.         spinlock_unlock(&thr->lock);
  407.        
  408.         if (sleeping)
  409.             waitq_interrupt_sleep(thr);
  410.     }
  411.     spinlock_unlock(&ta->lock);
  412.     interrupts_restore(ipl);
  413.    
  414.     return 0;
  415. }
  416.  
  417. static bool task_print_walker(avltree_node_t *node, void *arg)
  418. {
  419.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  420.     int j;
  421.        
  422.     spinlock_lock(&t->lock);
  423.            
  424.     uint64_t cycles;
  425.     char suffix;
  426.     order(task_get_accounting(t), &cycles, &suffix);
  427.    
  428.     if (sizeof(void *) == 4)
  429.         printf("%-6llu %-10s %-3ld %#10zx %#10zx %9llu%c %7zd %6zd",
  430.             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
  431.             t->refcount, atomic_get(&t->active_calls));
  432.     else
  433.         printf("%-6llu %-10s %-3ld %#18zx %#18zx %9llu%c %7zd %6zd",
  434.             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
  435.             t->refcount, atomic_get(&t->active_calls));
  436.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  437.         if (t->phones[j].callee)
  438.             printf(" %zd:%#zx", j, t->phones[j].callee);
  439.     }
  440.     printf("\n");
  441.            
  442.     spinlock_unlock(&t->lock);
  443.     return true;
  444. }
  445.  
  446. /** Print task list */
  447. void task_print_list(void)
  448. {
  449.     ipl_t ipl;
  450.    
  451.     /* Messing with task structures, avoid deadlock */
  452.     ipl = interrupts_disable();
  453.     spinlock_lock(&tasks_lock);
  454.    
  455.     if (sizeof(void *) == 4) {
  456.         printf("taskid name       ctx address    as         "
  457.             "cycles     threads calls  callee\n");
  458.         printf("------ ---------- --- ---------- ---------- "
  459.             "---------- ------- ------ ------>\n");
  460.     } else {
  461.         printf("taskid name       ctx address            as                 "
  462.             "cycles     threads calls  callee\n");
  463.         printf("------ ---------- --- ------------------ ------------------ "
  464.             "---------- ------- ------ ------>\n");
  465.     }
  466.  
  467.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  468.  
  469.     spinlock_unlock(&tasks_lock);
  470.     interrupts_restore(ipl);
  471. }
  472.  
  473. /** @}
  474.  */
  475.