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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 <ipc/ipcrsc.h>
  55. #include <security/cap.h>
  56. #include <memstr.h>
  57. #include <print.h>
  58. #include <lib/elf.h>
  59. #include <errno.h>
  60. #include <func.h>
  61. #include <syscall/copy.h>
  62.  
  63. #ifndef LOADED_PROG_STACK_PAGES_NO
  64. #define LOADED_PROG_STACK_PAGES_NO 1
  65. #endif
  66.  
  67. /** Spinlock protecting the tasks_tree AVL tree. */
  68. SPINLOCK_INITIALIZE(tasks_lock);
  69.  
  70. /** AVL tree of active tasks.
  71.  *
  72.  * The task is guaranteed to exist after it was found in the tasks_tree as
  73.  * long as:
  74.  * @li the tasks_lock is held,
  75.  * @li the task's lock is held when task's lock is acquired before releasing
  76.  *     tasks_lock or
  77.  * @li the task's refcount is greater than 0
  78.  *
  79.  */
  80. avltree_t tasks_tree;
  81.  
  82. static task_id_t task_counter = 0;
  83.  
  84. /**
  85.  * Points to the binary image used as the program loader. All non-initial
  86.  * tasks are created from this executable image.
  87.  */
  88. void *program_loader = NULL;
  89.  
  90.  
  91. /** Initialize tasks
  92.  *
  93.  * Initialize kernel tasks support.
  94.  *
  95.  */
  96. void task_init(void)
  97. {
  98.     TASK = NULL;
  99.     avltree_create(&tasks_tree);
  100. }
  101.  
  102. /*
  103.  * The idea behind this walker is to remember a single task different from TASK.
  104.  */
  105. static bool task_done_walker(avltree_node_t *node, void *arg)
  106. {
  107.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  108.     task_t **tp = (task_t **) arg;
  109.  
  110.     if (t != TASK) {
  111.         *tp = t;
  112.         return false;   /* stop walking */
  113.     }
  114.  
  115.     return true;    /* continue the walk */
  116. }
  117.  
  118. /** Kill all tasks except the current task.
  119.  *
  120.  */
  121. void task_done(void)
  122. {
  123.     task_t *t;
  124.     do { /* Repeat until there are any tasks except TASK */
  125.        
  126.         /* Messing with task structures, avoid deadlock */
  127.         ipl_t ipl = interrupts_disable();
  128.         spinlock_lock(&tasks_lock);
  129.        
  130.         t = NULL;
  131.         avltree_walk(&tasks_tree, task_done_walker, &t);
  132.        
  133.         if (t != NULL) {
  134.             task_id_t id = t->taskid;
  135.            
  136.             spinlock_unlock(&tasks_lock);
  137.             interrupts_restore(ipl);
  138.            
  139. #ifdef CONFIG_DEBUG
  140.             printf("Killing task %" PRIu64 "\n", id);
  141. #endif         
  142.             task_kill(id);
  143.             thread_usleep(10000);
  144.         } else {
  145.             spinlock_unlock(&tasks_lock);
  146.             interrupts_restore(ipl);
  147.         }
  148.        
  149.     } while (t != NULL);
  150. }
  151.  
  152. /** Create new task
  153.  *
  154.  * Create new task with no threads.
  155.  *
  156.  * @param as Task's address space.
  157.  * @param name Symbolic name.
  158.  *
  159.  * @return New task's structure
  160.  *
  161.  */
  162. task_t *task_create(as_t *as, char *name)
  163. {
  164.     ipl_t ipl;
  165.     task_t *ta;
  166.     int i;
  167.    
  168.     ta = (task_t *) malloc(sizeof(task_t), 0);
  169.  
  170.     task_create_arch(ta);
  171.  
  172.     spinlock_initialize(&ta->lock, "task_ta_lock");
  173.     list_initialize(&ta->th_head);
  174.     ta->as = as;
  175.     ta->name = name;
  176.     atomic_set(&ta->refcount, 0);
  177.     atomic_set(&ta->lifecount, 0);
  178.     ta->context = CONTEXT;
  179.  
  180.     ta->capabilities = 0;
  181.     ta->cycles = 0;
  182.    
  183.     ipc_answerbox_init(&ta->answerbox, ta);
  184.     for (i = 0; i < IPC_MAX_PHONES; i++)
  185.         ipc_phone_init(&ta->phones[i]);
  186.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  187.         ta->context)))
  188.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  189.     atomic_set(&ta->active_calls, 0);
  190.  
  191.     mutex_initialize(&ta->futexes_lock, MUTEX_PASSIVE);
  192.     btree_create(&ta->futexes);
  193.    
  194.     ipl = interrupts_disable();
  195.  
  196.     /*
  197.      * Increment address space reference count.
  198.      */
  199.     atomic_inc(&as->refcount);
  200.  
  201.     spinlock_lock(&tasks_lock);
  202.     ta->taskid = ++task_counter;
  203.     avltree_node_initialize(&ta->tasks_tree_node);
  204.     ta->tasks_tree_node.key = ta->taskid;
  205.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  206.     spinlock_unlock(&tasks_lock);
  207.     interrupts_restore(ipl);
  208.  
  209.     return ta;
  210. }
  211.  
  212. /** Destroy task.
  213.  *
  214.  * @param t Task to be destroyed.
  215.  */
  216. void task_destroy(task_t *t)
  217. {
  218.     /*
  219.      * Remove the task from the task B+tree.
  220.      */
  221.     spinlock_lock(&tasks_lock);
  222.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  223.     spinlock_unlock(&tasks_lock);
  224.  
  225.     /*
  226.      * Perform architecture specific task destruction.
  227.      */
  228.     task_destroy_arch(t);
  229.  
  230.     /*
  231.      * Free up dynamically allocated state.
  232.      */
  233.     btree_destroy(&t->futexes);
  234.  
  235.     /*
  236.      * Drop our reference to the address space.
  237.      */
  238.     if (atomic_predec(&t->as->refcount) == 0)
  239.         as_destroy(t->as);
  240.    
  241.     free(t);
  242.     TASK = NULL;
  243. }
  244.  
  245. /** Create new task with 1 thread and run it
  246.  *
  247.  * @param as Address space containing a binary program image.
  248.  * @param entry_addr Program entry-point address in program address space.
  249.  * @param name Program name.
  250.  *
  251.  * @return Task of the running program or NULL on error.
  252.  */
  253. task_t *task_create_from_as(as_t *as, uintptr_t entry_addr, char *name,
  254.     thread_t **thr)
  255. {
  256.     as_area_t *a;
  257.     thread_t *t;
  258.     task_t *task;
  259.     uspace_arg_t *kernel_uarg;
  260.  
  261.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  262.     kernel_uarg->uspace_entry = (void *) entry_addr;
  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.     *thr = t;
  286.    
  287.     return task;
  288. }
  289.  
  290. /** Parse an executable image in the physical memory.
  291.  *
  292.  * If the image belongs to a program loader, it is registered as such,
  293.  * (and *task is set to NULL). Otherwise a task is created from the
  294.  * executable image. The task is returned in *task.
  295.  *
  296.  * @param program_addr Address of program executable image.
  297.  * @param name Program name.
  298.  * @param task Where to store the pointer to the newly created task.
  299.  *
  300.  * @return EOK on success or negative error code.
  301.  */
  302. int task_parse_initial(void *program_addr, char *name, thread_t **t)
  303. {
  304.     as_t *as;
  305.     unsigned int rc;
  306.     task_t *task;
  307.  
  308.     as = as_create(0);
  309.     ASSERT(as);
  310.  
  311.     rc = elf_load((elf_header_t *) program_addr, as, 0);
  312.     if (rc != EE_OK) {
  313.         as_destroy(as);
  314.         *t = NULL;
  315.         if (rc != EE_LOADER)
  316.             return ENOTSUP;
  317.        
  318.         /* Register image as the program loader */
  319.         ASSERT(program_loader == NULL);
  320.         program_loader = program_addr;
  321.         return EOK;
  322.     }
  323.  
  324.     task = task_create_from_as(as, ((elf_header_t *) program_addr)->e_entry,
  325.         name, t);
  326.  
  327.     return EOK;
  328. }
  329.  
  330. /** Create a task from the program loader image.
  331.  *
  332.  * @param name Program name.
  333.  * @param t Buffer for storing pointer to the newly created task.
  334.  *
  335.  * @return Task of the running program or NULL on error.
  336.  */
  337. int task_create_from_loader(char *name, task_t **t)
  338. {
  339.     as_t *as;
  340.     unsigned int rc;
  341.     void *loader;
  342.     thread_t *thr;
  343.  
  344.     as = as_create(0);
  345.     ASSERT(as);
  346.  
  347.     loader = program_loader;
  348.     if (!loader) return ENOENT;
  349.  
  350.     rc = elf_load((elf_header_t *) program_loader, as, ELD_F_LOADER);
  351.     if (rc != EE_OK) {
  352.         as_destroy(as);
  353.         return ENOENT;
  354.     }
  355.  
  356.     *t = task_create_from_as(
  357.         as, ((elf_header_t *) program_loader)->e_entry, name, &thr);
  358.  
  359.     return EOK;
  360. }
  361.  
  362. /** Make task ready.
  363.  *
  364.  * Switch task's thread to the ready state.
  365.  *
  366.  * @param ta Task to make ready.
  367.  */
  368. void task_ready(task_t *t)
  369. {
  370.     thread_t *th;
  371.  
  372.     th = list_get_instance(t->th_head.next, thread_t, th_link);
  373.     thread_ready(th);
  374. }
  375.  
  376. /** Syscall for reading task ID from userspace.
  377.  *
  378.  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  379.  * current task ID.
  380.  *
  381.  * @return 0 on success or an error code from @ref errno.h.
  382.  */
  383. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  384. {
  385.     /*
  386.      * No need to acquire lock on TASK because taskid
  387.      * remains constant for the lifespan of the task.
  388.      */
  389.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  390.         sizeof(TASK->taskid));
  391. }
  392.  
  393. /** Syscall for creating a new task from userspace.
  394.  *
  395.  * Creates a new task from the program loader image, connects a phone
  396.  * to it and stores the phone id into the provided buffer.
  397.  *
  398.  * @param uspace_phone_id Userspace address where to store the phone id.
  399.  *
  400.  * @return 0 on success or an error code from @ref errno.h.
  401.  */
  402. unative_t sys_task_spawn_loader(int *uspace_phone_id)
  403. {
  404.     task_t *t;
  405.     int fake_id;
  406.     int rc;
  407.     int phone_id;
  408.  
  409.     fake_id = 0;
  410.  
  411.     /* Before we even try creating the task, see if we can write the id */
  412.     rc = (unative_t) copy_to_uspace(uspace_phone_id, &fake_id,
  413.         sizeof(fake_id));
  414.     if (rc != 0)
  415.         return rc;
  416.  
  417.     phone_id = phone_alloc();
  418.     if (phone_id < 0)
  419.         return ELIMIT;
  420.  
  421.     rc = task_create_from_loader("loader", &t);
  422.     if (rc != 0)
  423.         return rc;
  424.  
  425.     phone_connect(phone_id, &t->answerbox);
  426.  
  427.     /* No need to aquire lock before task_ready() */
  428.     rc = (unative_t) copy_to_uspace(uspace_phone_id, &phone_id,
  429.         sizeof(phone_id));
  430.     if (rc != 0) {
  431.         /* Ooops */
  432.         ipc_phone_hangup(&TASK->phones[phone_id]);
  433.         task_kill(t->taskid);
  434.         return rc;
  435.     }
  436.  
  437.     // FIXME: control the capabilities
  438.     cap_set(t, cap_get(TASK));
  439.  
  440.     task_ready(t);
  441.  
  442.     return EOK;
  443. }
  444.  
  445. /** Find task structure corresponding to task ID.
  446.  *
  447.  * The tasks_lock must be already held by the caller of this function
  448.  * and interrupts must be disabled.
  449.  *
  450.  * @param id Task ID.
  451.  *
  452.  * @return Task structure address or NULL if there is no such task ID.
  453.  */
  454. task_t *task_find_by_id(task_id_t id)
  455. {
  456.     avltree_node_t *node;
  457.    
  458.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  459.  
  460.     if (node)
  461.         return avltree_get_instance(node, task_t, tasks_tree_node);
  462.     return NULL;
  463. }
  464.  
  465. /** Get accounting data of given task.
  466.  *
  467.  * Note that task lock of 't' must be already held and
  468.  * interrupts must be already disabled.
  469.  *
  470.  * @param t Pointer to thread.
  471.  *
  472.  */
  473. uint64_t task_get_accounting(task_t *t)
  474. {
  475.     /* Accumulated value of task */
  476.     uint64_t ret = t->cycles;
  477.    
  478.     /* Current values of threads */
  479.     link_t *cur;
  480.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  481.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  482.        
  483.         spinlock_lock(&thr->lock);
  484.         /* Process only counted threads */
  485.         if (!thr->uncounted) {
  486.             if (thr == THREAD) {
  487.                 /* Update accounting of current thread */
  488.                 thread_update_accounting();
  489.             }
  490.             ret += thr->cycles;
  491.         }
  492.         spinlock_unlock(&thr->lock);
  493.     }
  494.    
  495.     return ret;
  496. }
  497.  
  498. /** Kill task.
  499.  *
  500.  * This function is idempotent.
  501.  * It signals all the task's threads to bail it out.
  502.  *
  503.  * @param id ID of the task to be killed.
  504.  *
  505.  * @return 0 on success or an error code from errno.h
  506.  */
  507. int task_kill(task_id_t id)
  508. {
  509.     ipl_t ipl;
  510.     task_t *ta;
  511.     link_t *cur;
  512.  
  513.     if (id == 1)
  514.         return EPERM;
  515.    
  516.     ipl = interrupts_disable();
  517.     spinlock_lock(&tasks_lock);
  518.     if (!(ta = task_find_by_id(id))) {
  519.         spinlock_unlock(&tasks_lock);
  520.         interrupts_restore(ipl);
  521.         return ENOENT;
  522.     }
  523.     spinlock_unlock(&tasks_lock);
  524.    
  525.     /*
  526.      * Interrupt all threads except ktaskclnp.
  527.      */
  528.     spinlock_lock(&ta->lock);
  529.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  530.         thread_t *thr;
  531.         bool sleeping = false;
  532.        
  533.         thr = list_get_instance(cur, thread_t, th_link);
  534.            
  535.         spinlock_lock(&thr->lock);
  536.         thr->interrupted = true;
  537.         if (thr->state == Sleeping)
  538.             sleeping = true;
  539.         spinlock_unlock(&thr->lock);
  540.        
  541.         if (sleeping)
  542.             waitq_interrupt_sleep(thr);
  543.     }
  544.     spinlock_unlock(&ta->lock);
  545.     interrupts_restore(ipl);
  546.    
  547.     return 0;
  548. }
  549.  
  550. static bool task_print_walker(avltree_node_t *node, void *arg)
  551. {
  552.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  553.     int j;
  554.        
  555.     spinlock_lock(&t->lock);
  556.            
  557.     uint64_t cycles;
  558.     char suffix;
  559.     order(task_get_accounting(t), &cycles, &suffix);
  560.  
  561. #ifdef __32_BITS__ 
  562.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %10p %10p %9" PRIu64
  563.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  564.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  565. #endif
  566.  
  567. #ifdef __64_BITS__
  568.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %18p %18p %9" PRIu64
  569.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  570.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  571. #endif
  572.  
  573.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  574.         if (t->phones[j].callee)
  575.             printf(" %d:%p", j, t->phones[j].callee);
  576.     }
  577.     printf("\n");
  578.            
  579.     spinlock_unlock(&t->lock);
  580.     return true;
  581. }
  582.  
  583. /** Print task list */
  584. void task_print_list(void)
  585. {
  586.     ipl_t ipl;
  587.    
  588.     /* Messing with task structures, avoid deadlock */
  589.     ipl = interrupts_disable();
  590.     spinlock_lock(&tasks_lock);
  591.  
  592. #ifdef __32_BITS__ 
  593.     printf("taskid name       ctx address    as         "
  594.         "cycles     threads calls  callee\n");
  595.     printf("------ ---------- --- ---------- ---------- "
  596.         "---------- ------- ------ ------>\n");
  597. #endif
  598.  
  599. #ifdef __64_BITS__
  600.     printf("taskid name       ctx address            as                 "
  601.         "cycles     threads calls  callee\n");
  602.     printf("------ ---------- --- ------------------ ------------------ "
  603.         "---------- ------- ------ ------>\n");
  604. #endif
  605.  
  606.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  607.  
  608.     spinlock_unlock(&tasks_lock);
  609.     interrupts_restore(ipl);
  610. }
  611.  
  612. /** @}
  613.  */
  614.