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Prefaulting of utcb pages seem to work.

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Next: fs0 should shmat() on others' utcbs.
This commit is contained in:
Bahadir Balban
2008-03-22 15:57:20 +00:00
parent 0dfbde6bc0
commit 82a7228d89
9 changed files with 211 additions and 78 deletions
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67
tasks/mm0/src/task.c
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@@ -359,55 +359,6 @@ void init_pm(struct initdata *initdata)
start_boot_tasks(initdata);
}
/*
* Makes the virtual to page translation for a given user task.
* If page is not mapped (either not faulted or swapped), returns 0.
*/
struct page *task_virt_to_page(struct tcb *t, unsigned long virtual)
{
unsigned long vma_offset;
unsigned long file_offset;
struct vm_obj_link *vmo_link;
struct vm_area *vma;
struct page *page;
/* First find the vma that maps that virtual address */
if (!(vma = find_vma(virtual, &t->vm_area_list))) {
printf("%s: No VMA found for 0x%x on task: %d\n",
__FUNCTION__, virtual, t->tid);
return PTR_ERR(-EINVAL);
}
/* Find the pfn offset of virtual address in this vma */
BUG_ON(__pfn(virtual) < vma->pfn_start ||
__pfn(virtual) > vma->pfn_end);
vma_offset = __pfn(virtual) - vma->pfn_start;
/* Find the file offset of virtual address in this file */
file_offset = vma->file_offset + vma_offset;
/* Get the initial link */
BUG_ON(!(vmo_link = vma_next_link(&vma->vm_obj_list,
&vma->vm_obj_list)));
/* Is page there in the cache ??? */
while(!(page = find_page(vmo_link->obj, file_offset))) {
/* No, check the next link */
if (!(vmo_link = vma_next_link(&vma->vm_obj_list,
&vma->vm_obj_list)));
/* Exhausted the objects. The page is not there. */
return 0;
}
/* Found it */
printf("%s: %s: Found page @ 0x%x, file_offset: 0x%x, "
"with vma @ 0x%x, vm object @ 0x%x\n", __TASKNAME__,
__FUNCTION__, (unsigned long)page, page->offset,
vma, vmo_link->obj);
return page;
}
struct task_data {
unsigned long tid;
unsigned long utcb_address;
@@ -423,7 +374,7 @@ struct task_data_head {
* are running, and their tids, which includes itself. This function
* provides that information.
*/
void send_task_data(l4id_t requester)
int send_task_data(l4id_t requester)
{
int li, err;
struct tcb *t, *vfs;
@@ -433,15 +384,21 @@ void send_task_data(l4id_t requester)
printf("%s: Task data requested by %d, which is not "
"FS0 id %d, ignoring.\n", __TASKNAME__, requester,
VFS_TID);
return;
return 0;
}
BUG_ON(!(vfs = find_task(requester)));
BUG_ON(!vfs->utcb_address);
/* Map in vfs's utcb. FIXME: Whatif it is already mapped? */
l4_map((void *)page_to_phys(task_virt_to_page(vfs, vfs->utcb_address)),
(void *)vfs->utcb_address, 1, MAP_USR_RW_FLAGS, self_tid());
/*
* When task does shmat() for its utcb, mm0 prefaults and maps it
* to itself, and sets this flag. Check that this has occured
* to ensure we have access to it. Otherwise return error.
*/
if (!vfs->utcb_mapped) {
l4_ipc_return(-ENOENT);
return 0;
}
/* Write all requested task information to utcb's user buffer area */
tdata_head = (struct task_data_head *)vfs->utcb_address;
@@ -462,5 +419,7 @@ void send_task_data(l4id_t requester)
printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
BUG();
}
return 0;
}