/*
* This function checks all page tables of "current"
*/
void check_page_tables (void)
{
struct pgd *pg_dir;
static int err = 0;
int stack_level = (long) (&pg_dir) - current->kernel_stack_page;
if (stack_level < 1500)
printk ("** %d ** ", stack_level);
pg_dir = PAGE_DIR_OFFSET (current, 0);
if (err == 0) {
int i;
for (i = 0; i < PTRS_PER_PAGE; i++, page_dir++) {
int notok = check_one_table (page_dir);
if (notok) {
err++;
printk ("|%d:%08lx| ", i, page_dir->pgd);
}
}
if (err)
printk ("\nError MM %d\n", err);
}
}
/*
* This routine gets a long from any process space by following the page
* tables. NOTE! You should check that the long isn't on a page boundary,
* and that it is in the task area before calling this: this routine does
* no checking.
*/
static unsigned long get_long(struct vm_area_struct * vma, unsigned long addr)
{
pgd_t * pgdir;
pte_t * pgtable;
unsigned long page;
repeat:
pgdir = PAGE_DIR_OFFSET(vma->vm_mm, addr);
if (pgd_none(*pgdir)) {
do_no_page(vma, addr, 0);
goto repeat;
}
if (pgd_bad(*pgdir)) {
printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
pgd_clear(pgdir);
return 0;
}
pgtable = (pte_t *) (PAGE_PTR(addr) + pgd_page(*pgdir));
if (!pte_present(*pgtable)) {
do_no_page(vma, addr, 0);
goto repeat;
}
page = pte_page(*pgtable);
/* this is a hack for non-kernel-mapped video buffers and similar */
if (page >= high_memory)
return 0;
page += addr & ~PAGE_MASK;
return *(unsigned long *) page;
}
static unsigned long get_phys_addr(struct task_struct ** p, unsigned long ptr)
{
unsigned long page;
if (!p || !*p || ptr >= TASK_SIZE)
return 0;
page = *PAGE_DIR_OFFSET((*p)->tss.cr3,ptr);
if (!(page & 1))
return 0;
page &= PAGE_MASK;
page += PAGE_PTR(ptr);
page = *(unsigned long *) page;
if (!(page & 1))
return 0;
page &= PAGE_MASK;
page += ptr & ~PAGE_MASK;
return page;
}
/*
* This routine puts a long into any process space by following the page
* tables. NOTE! You should check that the long isn't on a page boundary,
* and that it is in the task area before calling this: this routine does
* no checking.
*
* Now keeps R/W state of page so that a text page stays readonly
* even if a debugger scribbles breakpoints into it. -M.U-
*/
static void put_long(struct vm_area_struct * vma, unsigned long addr,
unsigned long data)
{
pgd_t *pgdir;
pte_t *pgtable;
unsigned long page;
repeat:
pgdir = PAGE_DIR_OFFSET(vma->vm_task, addr);
if (!pgd_present(*pgdir)) {
do_no_page(vma, addr, 1);
goto repeat;
}
if (pgd_bad(*pgdir)) {
printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
pgd_clear(pgdir);
return;
}
pgtable = (pte_t *) (PAGE_PTR(addr) + pgd_page(*pgdir));
if (!pte_present(*pgtable)) {
do_no_page(vma, addr, 1);
goto repeat;
}
page = pte_page(*pgtable);
if (!pte_write(*pgtable)) {
do_wp_page(vma, addr, 1);
goto repeat;
}
/* this is a hack for non-kernel-mapped video buffers and similar */
if (page < high_memory) {
page += addr & ~PAGE_MASK;
*(unsigned long *) page = data;
}
/* we're bypassing pagetables, so we have to set the dirty bit ourselves */
/* this should also re-instate whatever read-only mode there was before */
*pgtable = pte_mkdirty(mk_pte(page, vma->vm_page_prot));
invalidate();
}
