WebSVN – HelenOS – Diff – /branches/dynload/kernel/generic/src/proc/task.c

 /*
  * Copyright (c) 2001-2004 Jakub Jermar
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /** @addtogroup genericproc
  * @{
  */
 /**
  * @file
  * @brief   Task management.
  */
 #include <main/uinit.h>
 #include <proc/thread.h>
 #include <proc/task.h>
 #include <proc/uarg.h>
 #include <mm/as.h>
 #include <mm/slab.h>
 #include <atomic.h>
 #include <synch/spinlock.h>
 #include <synch/waitq.h>
 #include <arch.h>
 #include <panic.h>
 #include <adt/avl.h>
 #include <adt/btree.h>
 #include <adt/list.h>
 #include <ipc/ipc.h>
 #include <security/cap.h>
 #include <memstr.h>
 #include <print.h>
 #include <lib/elf.h>
 #include <errno.h>
 #include <func.h>
 #include <syscall/copy.h>
 #ifndef LOADED_PROG_STACK_PAGES_NO
 #define LOADED_PROG_STACK_PAGES_NO 1
 #endif
 /** Spinlock protecting the tasks_tree AVL tree. */
 SPINLOCK_INITIALIZE(tasks_lock);
 /** AVL tree of active tasks.
+ *
  * The task is guaranteed to exist after it was found in the tasks_tree as
  * long as:
  * @li the tasks_lock is held,
  * @li the task's lock is held when task's lock is acquired before releasing
  *     tasks_lock or
  * @li the task's refcount is greater than 0
+ *
  */
 avltree_t tasks_tree;
 static task_id_t task_counter = 0;
+/**
+ * Points to the binary image used as the program loader. All non-initial
+ * tasks are created from this executable image.
+ */
+void *program_loader = NULL;
 /** Initialize tasks
+ *
  * Initialize kernel tasks support.
+ *
  */
 void task_init(void)
+{
     TASK = NULL;
     avltree_create(&tasks_tree);
+}
 /*
  * The idea behind this walker is to remember a single task different from TASK.
  */
 static bool task_done_walker(avltree_node_t *node, void *arg)
+{
     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
     task_t **tp = (task_t **) arg;
     if (t != TASK) {
         *tp = t;
         return false;   /* stop walking */
+    }
     return true;    /* continue the walk */
+}
 /** Kill all tasks except the current task.
+ *
  */
 void task_done(void)
+{
     task_t *t;
     do { /* Repeat until there are any tasks except TASK */
         /* Messing with task structures, avoid deadlock */
         ipl_t ipl = interrupts_disable();
         spinlock_lock(&tasks_lock);
         t = NULL;
         avltree_walk(&tasks_tree, task_done_walker, &t);
         if (t != NULL) {
             task_id_t id = t->taskid;
             spinlock_unlock(&tasks_lock);
             interrupts_restore(ipl);
 #ifdef CONFIG_DEBUG
             printf("Killing task %llu\n", id);
 #endif
             task_kill(id);
             thread_usleep(10000);
         } else {
             spinlock_unlock(&tasks_lock);
             interrupts_restore(ipl);
+        }
     } while (t != NULL);
+}
 /** Create new task
+ *
  * Create new task with no threads.
+ *
  * @param as Task's address space.
  * @param name Symbolic name.
+ *
  * @return New task's structure
+ *
  */
 task_t *task_create(as_t *as, char *name)
+{
     ipl_t ipl;
     task_t *ta;
     int i;
     ta = (task_t *) malloc(sizeof(task_t), 0);
     task_create_arch(ta);
     spinlock_initialize(&ta->lock, "task_ta_lock");
     list_initialize(&ta->th_head);
     ta->as = as;
     ta->name = name;
     atomic_set(&ta->refcount, 0);
     atomic_set(&ta->lifecount, 0);
     ta->context = CONTEXT;
     ta->capabilities = 0;
     ta->cycles = 0;
     ipc_answerbox_init(&ta->answerbox, ta);
     for (i = 0; i < IPC_MAX_PHONES; i++)
         ipc_phone_init(&ta->phones[i]);
     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
         ta->context)))
         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
     atomic_set(&ta->active_calls, 0);
     mutex_initialize(&ta->futexes_lock);
     btree_create(&ta->futexes);
     ipl = interrupts_disable();
     /*
      * Increment address space reference count.
      */
     atomic_inc(&as->refcount);
     spinlock_lock(&tasks_lock);
     ta->taskid = ++task_counter;
     avltree_node_initialize(&ta->tasks_tree_node);
     ta->tasks_tree_node.key = ta->taskid;
     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
     spinlock_unlock(&tasks_lock);
     interrupts_restore(ipl);
     return ta;
+}
 /** Destroy task.
+ *
  * @param t Task to be destroyed.
  */
 void task_destroy(task_t *t)
+{
     /*
      * Remove the task from the task B+tree.
      */
     spinlock_lock(&tasks_lock);
     avltree_delete(&tasks_tree, &t->tasks_tree_node);
     spinlock_unlock(&tasks_lock);
     /*
      * Perform architecture specific task destruction.
      */
     task_destroy_arch(t);
     /*
      * Free up dynamically allocated state.
      */
     btree_destroy(&t->futexes);
     /*
      * Drop our reference to the address space.
      */
     if (atomic_predec(&t->as->refcount) == 0)
         as_destroy(t->as);
     free(t);
     TASK = NULL;
+}
 /** Create new task with 1 thread and run it
+ *
+ * @param as Address space containing a binary program image.
- * @param program_addr Address of program executable image.
+ * @param entry_addr Program entry-point address in program address space.
  * @param name Program name.
+ *
  * @return Task of the running program or NULL on error.
  */
-task_t *task_run_program(void *program_addr, char *name)
+task_t *task_create_from_as(as_t *as, uintptr_t entry_addr, char *name)
+{
-    as_t *as;
     as_area_t *a;
-    unsigned int rc;
     thread_t *t;
     task_t *task;
     uspace_arg_t *kernel_uarg;
-    as = as_create(0);
-    ASSERT(as);
-    rc = elf_load((elf_header_t *) program_addr, as);
-    if (rc != EE_OK) {
-        as_destroy(as);
-        return NULL;
-    }
     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
-    kernel_uarg->uspace_entry =
+    kernel_uarg->uspace_entry = (void *) entry_addr;
-        (void *) ((elf_header_t *) program_addr)->e_entry;
     kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
     kernel_uarg->uspace_thread_function = NULL;
     kernel_uarg->uspace_thread_arg = NULL;
     kernel_uarg->uspace_uarg = NULL;
     task = task_create(as, name);
     ASSERT(task);
     /*
      * Create the data as_area.
      */
     a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
         LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
         AS_AREA_ATTR_NONE, &anon_backend, NULL);
     /*
      * Create the main thread.
      */
     t = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
         "uinit", false);
     ASSERT(t);
-    thread_ready(t);
     return task;
+}
+/** Parse an executable image in the physical memory.
+ *
+ * If the image belongs to a program loader, it is registered as such,
+ * (and *task is set to NULL). Otherwise a task is created from the
+ * executable image. The task is returned in *task.
+ *
+ * @param program_addr Address of program executable image.
+ * @param name Program name.
+ * @param task Where to store the pointer to the newly created task.
+ *
+ * @return EOK on success or negative error code.
+ */
+int task_parse_initial(void *program_addr, char *name, task_t **task)
+{
+    as_t *as;
+    unsigned int rc;
+    as = as_create(0);
+    ASSERT(as);
+    rc = elf_load((elf_header_t *) program_addr, as, 0);
+    if (rc != EE_OK) {
+        as_destroy(as);
+        *task = NULL;
+        if (rc != EE_LOADER)
+            return ENOTSUP;
+        /* Register image as the program loader */
+        ASSERT(program_loader == NULL);
+        program_loader = program_addr;
+        return EOK;
+    }
+    *task = task_create_from_as(as, ((elf_header_t *) program_addr)->e_entry,
+        name);
+    return EOK;
+}
+/** Create a task from the program loader image.
+ *
+ * @param program_addr Address of program executable image.
+ * @param name Program name.
+ *
+ * @return Task of the running program or NULL on error.
+ */
+task_t *task_create_from_loader(char *name)
+{
+    as_t *as;
+    unsigned int rc;
+    as = as_create(0);
+    ASSERT(as);
+    rc = elf_load((elf_header_t *) program_loader, as, ELD_F_LOADER);
+    if (rc != EE_OK) {
+        as_destroy(as);
+        return NULL;
+    }
+    return task_create_from_as(
+        as, ((elf_header_t *) program_loader)->e_entry, name);
+}
+/** Make task ready.
+ *
+ * Switch task's thread to the ready state.
+ *
+ * @param ta Task to make ready.
+ */
+void task_ready(task_t *t)
+{
+    thread_t *th;
+    th = list_get_instance(t->th_head.next, thread_t, th_link);
+    thread_ready(th);
+}
 /** Syscall for reading task ID from userspace.
+ *
  * @param uspace_task_id Userspace address of 8-byte buffer where to store
  * current task ID.
+ *
  * @return 0 on success or an error code from @ref errno.h.
  */
 unative_t sys_task_get_id(task_id_t *uspace_task_id)
+{
     /*
      * No need to acquire lock on TASK because taskid
      * remains constant for the lifespan of the task.
      */
     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
         sizeof(TASK->taskid));
+}
+/** Syscall for creating a new task from userspace.
+ *
+ * Creates a new task from the program loader image and stores its
+ * task id into the provided buffer.
+ *
+ * @param uspace_task_id Userspace address of 8-byte buffer where to store
+ * current task ID.
+ *
+ * @return 0 on success or an error code from @ref errno.h.
+ */
+unative_t sys_task_spawn(task_id_t *uspace_task_id)
+{
+    task_t *t;
+    task_id_t fake_id;
+    int rc;
+    /* Before we even try creating the task, see if we can write the id */
+    rc = (unative_t) copy_to_uspace(uspace_task_id, &fake_id,
+        sizeof(fake_id));
+    if (rc != 0)
+        return rc;
+    t = task_create_from_loader("loader");
+    /* No need to aquire lock before task_ready() */
+    rc = (unative_t) copy_to_uspace(uspace_task_id, &t->taskid,
+        sizeof(t->taskid));
+    if (rc != 0) {
+        /* Ooops */
+        task_kill(t->taskid);
+        return rc;
+    }
+    task_ready(t);
+    return EOK;
+}
 /** Find task structure corresponding to task ID.
+ *
  * The tasks_lock must be already held by the caller of this function
  * and interrupts must be disabled.
+ *
  * @param id Task ID.
+ *
  * @return Task structure address or NULL if there is no such task ID.
  */
 task_t *task_find_by_id(task_id_t id)
+{
     avltree_node_t *node;
     node = avltree_search(&tasks_tree, (avltree_key_t) id);
     if (node)
         return avltree_get_instance(node, task_t, tasks_tree_node);
     return NULL;
+}
 /** Get accounting data of given task.
+ *
  * Note that task lock of 't' must be already held and
  * interrupts must be already disabled.
+ *
  * @param t Pointer to thread.
+ *
  */
 uint64_t task_get_accounting(task_t *t)
+{
     /* Accumulated value of task */
     uint64_t ret = t->cycles;
     /* Current values of threads */
     link_t *cur;
     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
         thread_t *thr = list_get_instance(cur, thread_t, th_link);
         spinlock_lock(&thr->lock);
         /* Process only counted threads */
         if (!thr->uncounted) {
             if (thr == THREAD) {
                 /* Update accounting of current thread */
                 thread_update_accounting();
+            }
             ret += thr->cycles;
+        }
         spinlock_unlock(&thr->lock);
+    }
     return ret;
+}
 /** Kill task.
+ *
  * This function is idempotent.
  * It signals all the task's threads to bail it out.
+ *
  * @param id ID of the task to be killed.
+ *
  * @return 0 on success or an error code from errno.h
  */
 int task_kill(task_id_t id)
+{
     ipl_t ipl;
     task_t *ta;
     link_t *cur;
     if (id == 1)
         return EPERM;
     ipl = interrupts_disable();
     spinlock_lock(&tasks_lock);
     if (!(ta = task_find_by_id(id))) {
         spinlock_unlock(&tasks_lock);
         interrupts_restore(ipl);
         return ENOENT;
+    }
     spinlock_unlock(&tasks_lock);
     /*
      * Interrupt all threads except ktaskclnp.
      */
     spinlock_lock(&ta->lock);
     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
         thread_t *thr;
         bool sleeping = false;
         thr = list_get_instance(cur, thread_t, th_link);
         spinlock_lock(&thr->lock);
         thr->interrupted = true;
         if (thr->state == Sleeping)
             sleeping = true;
         spinlock_unlock(&thr->lock);
         if (sleeping)
             waitq_interrupt_sleep(thr);
+    }
     spinlock_unlock(&ta->lock);
     interrupts_restore(ipl);
     return 0;
+}
 static bool task_print_walker(avltree_node_t *node, void *arg)
+{
     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
     int j;
     spinlock_lock(&t->lock);
     uint64_t cycles;
     char suffix;
     order(task_get_accounting(t), &cycles, &suffix);
     if (sizeof(void *) == 4)
         printf("%-6llu %-10s %-3ld %#10zx %#10zx %9llu%c %7zd %6zd",
             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
             t->refcount, atomic_get(&t->active_calls));
     else
         printf("%-6llu %-10s %-3ld %#18zx %#18zx %9llu%c %7zd %6zd",
             t->taskid, t->name, t->context, t, t->as, cycles, suffix,
             t->refcount, atomic_get(&t->active_calls));
     for (j = 0; j < IPC_MAX_PHONES; j++) {
         if (t->phones[j].callee)
             printf(" %zd:%#zx", j, t->phones[j].callee);
+    }
     printf("\n");
     spinlock_unlock(&t->lock);
     return true;
+}
 /** Print task list */
 void task_print_list(void)
+{
     ipl_t ipl;
     /* Messing with task structures, avoid deadlock */
     ipl = interrupts_disable();
     spinlock_lock(&tasks_lock);
     if (sizeof(void *) == 4) {
         printf("taskid name       ctx address    as         "
             "cycles     threads calls  callee\n");
         printf("------ ---------- --- ---------- ---------- "
             "---------- ------- ------ ------>\n");
     } else {
         printf("taskid name       ctx address            as                 "
             "cycles     threads calls  callee\n");
         printf("------ ---------- --- ------------------ ------------------ "
             "---------- ------- ------ ------>\n");
+    }
     avltree_walk(&tasks_tree, task_print_walker, NULL);
     spinlock_unlock(&tasks_lock);
     interrupts_restore(ipl);
+}
 /** @}
  */

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(root)/branches/dynload/kernel/generic/src/proc/task.c – Rev 2927 → 3001