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Added detailed mapping of bss.

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.data and .text now needs to be 4K apart.
removed an early copy of test0 called test1
This commit is contained in:
Bahadir Balban
2008-11-23 21:27:11 +02:00
parent 311d6917c4
commit d0e878b32c
12 changed files with 119 additions and 386 deletions
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84
tasks/mm0/src/task.c
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@@ -16,6 +16,7 @@
#include <l4lib/arch/utcb.h>
#include <l4lib/ipcdefs.h>
#include <l4lib/exregs.h>
#include <l4/lib/math.h>
#include <lib/addr.h>
#include <lib/malloc.h>
#include <init.h>
@@ -342,12 +343,79 @@ struct tcb *task_create(struct tcb *parent, struct task_ids *ids,
return task;
}
/*
* If bss comes consecutively after the data section, prefault the
* last page of the data section and zero out the bit that contains
* the beginning of bss. If bss spans into more pages, then map those
* pages as anonymous pages which are mapped by the devzero file.
*/
int task_map_bss(struct vm_file *f, struct exec_file_desc *efd, struct tcb *task)
{
unsigned long bss_mmap_start;
void *mapped;
/*
* Test if bss starts right from the end of data,
* and not on a new page boundary.
*/
if ((task->data_end == task->bss_start) &&
!is_page_aligned(task->bss_start)) {
unsigned long bss_size = task->bss_end - task->bss_start;
struct page *last_data_page;
void *pagebuf, *bss;
/* Prefault the last data page */
BUG_ON(prefault_page(task, task->data_end,
VM_READ | VM_WRITE) < 0);
/* Get the page */
last_data_page = task_virt_to_page(task, task->data_end);
/* Map the page */
pagebuf = l4_map_helper((void *)page_to_phys(last_data_page), 1);
/* Find the bss offset */
bss = (void *)((unsigned long)pagebuf |
(PAGE_MASK & task->bss_start));
/*
* Zero out the part that is bss. This is minimum of either
* end of bss or until the end of page, whichever is met first.
*/
memset((void *)bss, 0, min(TILL_PAGE_ENDS(task->data_end),
(int)bss_size));
/* Unmap the page */
l4_unmap_helper(pagebuf, 1);
/* Push bss mmap start to next page */
bss_mmap_start = page_align_up(task->bss_start);
} else /* Otherwise bss mmap start is same as bss_start */
bss_mmap_start = task->bss_start;
/*
* Now if there are more pages covering bss,
* map those as anonymous zero pages
*/
if (task->bss_end > bss_mmap_start) {
if (IS_ERR(mapped = do_mmap(0, 0, task, task->bss_start,
VM_READ | VM_WRITE |
VMA_PRIVATE | VMA_ANONYMOUS,
__pfn(page_align_up(task->bss_end) -
page_align(task->bss_start))))) {
printf("do_mmap: Mapping environment failed with %d.\n",
(int)mapped);
return (int)mapped;
}
}
return 0;
}
int task_mmap_segments(struct tcb *task, struct vm_file *file, struct exec_file_desc *efd)
{
void *mapped;
struct vm_file *shm;
/* Set up heap as one page after bss */
int err;
/* mmap task's text to task's address space. */
if (IS_ERR(mapped = do_mmap(file, efd->text_offset, task, task->text_start,
@@ -368,14 +436,12 @@ int task_mmap_segments(struct tcb *task, struct vm_file *file, struct exec_file_
}
/* mmap task's bss as anonymous memory. */
if (IS_ERR(mapped = do_mmap(0, 0, task, task->bss_start,
VM_READ | VM_WRITE |
VMA_PRIVATE | VMA_ANONYMOUS,
__pfn(task->bss_end - task->bss_start)))) {
printf("do_mmap: Mapping environment failed with %d.\n",
(int)mapped);
return (int)mapped;
if ((err = task_map_bss(file, efd, task)) < 0) {
printf("%s: Mapping bss has failed.\n",
__FUNCTION__);
return err;
}
/* mmap task's environment as anonymous memory. */
if (IS_ERR(mapped = do_mmap(0, 0, task, task->env_start,
VM_READ | VM_WRITE |