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We can now successfully copy char *argv[] user array.

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After a lot of magic pointer arithmetic and mapping.
This commit is contained in:
Bahadir Balban
2008-11-25 11:05:41 +02:00
parent 0ddb8ea799
commit a9e6aabcae
6 changed files with 223 additions and 40 deletions
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49
tasks/mm0/src/memory.c
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@@ -15,6 +15,7 @@
#include INC_SUBARCH(mm.h)
#include <memory.h>
#include <file.h>
#include <user.h>
struct membank membank[1];
struct page *page_array;
@@ -193,3 +194,51 @@ void *pager_map_file_range(struct vm_file *f, unsigned long byte_offset,
return (void *)((unsigned long)page | (PAGE_MASK & byte_offset));
}
void *pager_validate_map_user_range2(struct tcb *user, void *userptr,
unsigned long size, unsigned int vm_flags)
{
unsigned long start = page_align(userptr);
unsigned long end = page_align_up(userptr + size);
unsigned long npages = end - start;
void *virt, *virt_start;
void *mapped = 0;
/* Validate that user task owns this address range */
if (pager_validate_user_range(user, userptr, size, vm_flags) < 0)
return 0;
/* Get the address range */
if (!(virt_start = pager_new_address(npages)))
return PTR_ERR(-ENOMEM);
virt = virt_start;
/* Map every page contiguously in the allocated virtual address range */
for (unsigned long addr = start; addr < end; addr += PAGE_SIZE) {
struct page *p = task_virt_to_page(user, addr);
if (IS_ERR(p)) {
/* Unmap pages mapped so far */
l4_unmap_helper(virt_start, __pfn(addr - start));
/* Delete virtual address range */
pager_delete_address(virt_start, npages);
return p;
}
l4_map((void *)page_to_phys(task_virt_to_page(user, addr)),
virt, 1, MAP_USR_RW_FLAGS, self_tid());
virt += PAGE_SIZE;
}
/* Set the mapped pointer to offset of user pointer given */
mapped = virt_start;
mapped = (void *)(((unsigned long)mapped) |
((unsigned long)(PAGE_MASK &
(unsigned long)userptr)));
/* Return the mapped pointer */
return mapped;
}