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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 <arch/barrier.h>
  49. #include <panic.h>
  50. #include <adt/avl.h>
  51. #include <adt/btree.h>
  52. #include <adt/list.h>
  53. #include <ipc/ipc.h>
  54. #include <security/cap.h>
  55. #include <memstr.h>
  56. #include <print.h>
  57. #include <lib/elf.h>
  58. #include <errno.h>
  59. #include <func.h>
  60. #include <syscall/copy.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 %" PRIu64 "\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.     ipc_answerbox_init(&ta->answerbox, ta);
  176.     for (i = 0; i < IPC_MAX_PHONES; i++)
  177.         ipc_phone_init(&ta->phones[i]);
  178.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  179.         ta->context)))
  180.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  181.     atomic_set(&ta->active_calls, 0);
  182.  
  183.     mutex_initialize(&ta->futexes_lock);
  184.     btree_create(&ta->futexes);
  185.    
  186.     ipl = interrupts_disable();
  187.  
  188.     /*
  189.      * Increment address space reference count.
  190.      */
  191.     atomic_inc(&as->refcount);
  192.  
  193.     spinlock_lock(&tasks_lock);
  194.     ta->taskid = ++task_counter;
  195.     avltree_node_initialize(&ta->tasks_tree_node);
  196.     ta->tasks_tree_node.key = ta->taskid;
  197.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  198.     spinlock_unlock(&tasks_lock);
  199.     interrupts_restore(ipl);
  200.  
  201.     return ta;
  202. }
  203.  
  204. /** Destroy task.
  205.  *
  206.  * @param t Task to be destroyed.
  207.  */
  208. void task_destroy(task_t *t)
  209. {
  210.     /*
  211.      * Remove the task from the task B+tree.
  212.      */
  213.     spinlock_lock(&tasks_lock);
  214.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  215.     spinlock_unlock(&tasks_lock);
  216.  
  217.     /*
  218.      * Perform architecture specific task destruction.
  219.      */
  220.     task_destroy_arch(t);
  221.  
  222.     /*
  223.      * Free up dynamically allocated state.
  224.      */
  225.     btree_destroy(&t->futexes);
  226.  
  227.     /*
  228.      * Drop our reference to the address space.
  229.      */
  230.     if (atomic_predec(&t->as->refcount) == 0)
  231.         as_destroy(t->as);
  232.    
  233.     free(t);
  234.     TASK = NULL;
  235. }
  236.  
  237. /** Syscall for reading task ID from userspace.
  238.  *
  239.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  240.  * current task ID.
  241.  *
  242.  * @return 0 on success or an error code from @ref errno.h.
  243.  */
  244. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  245. {
  246.     /*
  247.      * No need to acquire lock on TASK because taskid
  248.      * remains constant for the lifespan of the task.
  249.      */
  250.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  251.         sizeof(TASK->taskid));
  252. }
  253.  
  254. unative_t sys_task_spawn(void *image, size_t size)
  255. {
  256.     void *kimage = malloc(size, 0);
  257.     if (kimage == NULL)
  258.         return ENOMEM;
  259.    
  260.     int rc = copy_from_uspace(kimage, image, size);
  261.     if (rc != EOK)
  262.         return rc;
  263.  
  264.     /*
  265.      * Not very efficient and it would be better to call it on code only,
  266.      * but this whole function is a temporary hack anyway and one day it
  267.      * will go in favor of the userspace dynamic loader.
  268.      */
  269.     smc_coherence_block(kimage, size);
  270.    
  271.     uspace_arg_t *kernel_uarg;
  272.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  273.     if (kernel_uarg == NULL) {
  274.         free(kimage);
  275.         return ENOMEM;
  276.     }
  277.    
  278.     kernel_uarg->uspace_entry =
  279.         (void *) ((elf_header_t *) kimage)->e_entry;
  280.     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
  281.     kernel_uarg->uspace_thread_function = NULL;
  282.     kernel_uarg->uspace_thread_arg = NULL;
  283.     kernel_uarg->uspace_uarg = NULL;
  284.    
  285.     as_t *as = as_create(0);
  286.     if (as == NULL) {
  287.         free(kernel_uarg);
  288.         free(kimage);
  289.         return ENOMEM;
  290.     }
  291.    
  292.     unsigned int erc = elf_load((elf_header_t *) kimage, as);
  293.     if (erc != EE_OK) {
  294.         as_destroy(as);
  295.         free(kernel_uarg);
  296.         free(kimage);
  297.         return ENOENT;
  298.     }
  299.    
  300.     as_area_t *area = as_area_create(as,
  301.         AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
  302.         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
  303.         AS_AREA_ATTR_NONE, &anon_backend, NULL);
  304.     if (area == NULL) {
  305.         as_destroy(as);
  306.         free(kernel_uarg);
  307.         free(kimage);
  308.         return ENOMEM;
  309.     }
  310.    
  311.     task_t *task = task_create(as, "app");
  312.     if (task == NULL) {
  313.         as_destroy(as);
  314.         free(kernel_uarg);
  315.         free(kimage);
  316.         return ENOENT;
  317.     }
  318.    
  319.     // FIXME: control the capabilities
  320.     cap_set(task, cap_get(TASK));
  321.    
  322.     thread_t *thread = thread_create(uinit, kernel_uarg, task,
  323.         THREAD_FLAG_USPACE, "user", false);
  324.     if (thread == NULL) {
  325.         task_destroy(task);
  326.         as_destroy(as);
  327.         free(kernel_uarg);
  328.         free(kimage);
  329.         return ENOENT;
  330.     }
  331.    
  332.     thread_ready(thread);
  333.    
  334.     return EOK;
  335. }
  336.  
  337. /** Find task structure corresponding to task ID.
  338.  *
  339.  * The tasks_lock must be already held by the caller of this function
  340.  * and interrupts must be disabled.
  341.  *
  342.  * @param id Task ID.
  343.  *
  344.  * @return Task structure address or NULL if there is no such task ID.
  345.  */
  346. task_t *task_find_by_id(task_id_t id)
  347. {
  348.     avltree_node_t *node;
  349.    
  350.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  351.  
  352.     if (node)
  353.         return avltree_get_instance(node, task_t, tasks_tree_node);
  354.     return NULL;
  355. }
  356.  
  357. /** Get accounting data of given task.
  358.  *
  359.  * Note that task lock of 't' must be already held and
  360.  * interrupts must be already disabled.
  361.  *
  362.  * @param t Pointer to thread.
  363.  *
  364.  */
  365. uint64_t task_get_accounting(task_t *t)
  366. {
  367.     /* Accumulated value of task */
  368.     uint64_t ret = t->cycles;
  369.    
  370.     /* Current values of threads */
  371.     link_t *cur;
  372.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  373.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  374.        
  375.         spinlock_lock(&thr->lock);
  376.         /* Process only counted threads */
  377.         if (!thr->uncounted) {
  378.             if (thr == THREAD) {
  379.                 /* Update accounting of current thread */
  380.                 thread_update_accounting();
  381.             }
  382.             ret += thr->cycles;
  383.         }
  384.         spinlock_unlock(&thr->lock);
  385.     }
  386.    
  387.     return ret;
  388. }
  389.  
  390. /** Kill task.
  391.  *
  392.  * This function is idempotent.
  393.  * It signals all the task's threads to bail it out.
  394.  *
  395.  * @param id ID of the task to be killed.
  396.  *
  397.  * @return 0 on success or an error code from errno.h
  398.  */
  399. int task_kill(task_id_t id)
  400. {
  401.     ipl_t ipl;
  402.     task_t *ta;
  403.     link_t *cur;
  404.  
  405.     if (id == 1)
  406.         return EPERM;
  407.    
  408.     ipl = interrupts_disable();
  409.     spinlock_lock(&tasks_lock);
  410.     if (!(ta = task_find_by_id(id))) {
  411.         spinlock_unlock(&tasks_lock);
  412.         interrupts_restore(ipl);
  413.         return ENOENT;
  414.     }
  415.     spinlock_unlock(&tasks_lock);
  416.    
  417.     /*
  418.      * Interrupt all threads except ktaskclnp.
  419.      */
  420.     spinlock_lock(&ta->lock);
  421.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  422.         thread_t *thr;
  423.         bool sleeping = false;
  424.        
  425.         thr = list_get_instance(cur, thread_t, th_link);
  426.            
  427.         spinlock_lock(&thr->lock);
  428.         thr->interrupted = true;
  429.         if (thr->state == Sleeping)
  430.             sleeping = true;
  431.         spinlock_unlock(&thr->lock);
  432.        
  433.         if (sleeping)
  434.             waitq_interrupt_sleep(thr);
  435.     }
  436.     spinlock_unlock(&ta->lock);
  437.     interrupts_restore(ipl);
  438.    
  439.     return 0;
  440. }
  441.  
  442. static bool task_print_walker(avltree_node_t *node, void *arg)
  443. {
  444.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  445.     int j;
  446.        
  447.     spinlock_lock(&t->lock);
  448.            
  449.     uint64_t cycles;
  450.     char suffix;
  451.     order(task_get_accounting(t), &cycles, &suffix);
  452.  
  453. #ifdef __32_BITS__ 
  454.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %10p %10p %9" PRIu64
  455.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  456.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  457. #endif
  458.  
  459. #ifdef __64_BITS__
  460.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %18p %18p %9" PRIu64
  461.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  462.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  463. #endif
  464.  
  465.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  466.         if (t->phones[j].callee)
  467.             printf(" %d:%p", j, t->phones[j].callee);
  468.     }
  469.     printf("\n");
  470.            
  471.     spinlock_unlock(&t->lock);
  472.     return true;
  473. }
  474.  
  475. /** Print task list */
  476. void task_print_list(void)
  477. {
  478.     ipl_t ipl;
  479.    
  480.     /* Messing with task structures, avoid deadlock */
  481.     ipl = interrupts_disable();
  482.     spinlock_lock(&tasks_lock);
  483.  
  484. #ifdef __32_BITS__ 
  485.     printf("taskid name       ctx address    as         "
  486.         "cycles     threads calls  callee\n");
  487.     printf("------ ---------- --- ---------- ---------- "
  488.         "---------- ------- ------ ------>\n");
  489. #endif
  490.  
  491. #ifdef __64_BITS__
  492.     printf("taskid name       ctx address            as                 "
  493.         "cycles     threads calls  callee\n");
  494.     printf("------ ---------- --- ------------------ ------------------ "
  495.         "---------- ------- ------ ------>\n");
  496. #endif
  497.  
  498.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  499.  
  500.     spinlock_unlock(&tasks_lock);
  501.     interrupts_restore(ipl);
  502. }
  503.  
  504. /** @}
  505.  */
  506.