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vma_intersect() was erroneous, replaced by a nice and simple set_intersection() routine.

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Still testing sys_munmap(). It now correctly spots and unmaps the overlapping vma.
The issue now is that if a split occurs, we forgot to add same objects to new vma.
This commit is contained in:
Bahadir Balban
2008-11-07 20:13:28 +02:00
parent 93ca3f88a8
commit 61751a896b
4 changed files with 24 additions and 20 deletions
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2
tasks/mm0/include/vm_area.h
View File

@@ -183,8 +183,6 @@ struct vm_area {
unsigned long file_offset; /* File offset in pfns */
};
int vma_intersect(unsigned long pfn_start, unsigned long pfn_end,
struct vm_area *vma);
/*
* Finds the vma that has the given address.
* TODO: In the future a lot of use cases may need to traverse each vma

23
tasks/mm0/src/mmap.c
View File

@@ -3,6 +3,7 @@
*
* Copyright (C) 2007, 2008 Bahadir Balban
*/
#include <l4/lib/math.h>
#include <vm_area.h>
#include <kmalloc/kmalloc.h>
#include INC_API(errno.h)
@@ -37,20 +38,6 @@ struct vm_area *vma_new(unsigned long pfn_start, unsigned long npages,
return vma;
}
int vma_intersect(unsigned long pfn_start, unsigned long pfn_end,
struct vm_area *vma)
{
if ((pfn_start <= vma->pfn_start) && (pfn_end > vma->pfn_start)) {
printf("%s: VMAs overlap.\n", __FUNCTION__);
return 1;
}
if ((pfn_end >= vma->pfn_end) && (pfn_start < vma->pfn_end)) {
printf("%s: VMAs overlap.\n", __FUNCTION__);
return 1;
}
return 0;
}
/* Search an empty space in the task's mmapable address region. */
unsigned long find_unmapped_area(unsigned long npages, struct tcb *task)
{
@@ -72,7 +59,8 @@ unsigned long find_unmapped_area(unsigned long npages, struct tcb *task)
while (pfn_end <= __pfn(task->end)) {
/* If intersection, skip the vma and fast-forward to next */
if (vma_intersect(pfn_start, pfn_end, vma)) {
if (set_intersection(pfn_start, pfn_end,
vma->pfn_start, vma->pfn_end)) {
/* Update interval to next available space */
pfn_start = vma->pfn_end;
@@ -204,8 +192,9 @@ void *do_mmap(struct vm_file *mapfile, unsigned long file_offset,
* splitting, shrink/grow etc.
*/
list_for_each_entry(mapped, &task->vm_area_head->list, list)
BUG_ON(vma_intersect(map_pfn, map_pfn + npages,
mapped));
BUG_ON(set_intersection(map_pfn, map_pfn + npages,
mapped->pfn_start,
mapped->pfn_end));
}
/* For valid regions that aren't allocated by us, create the vma. */

4
tasks/mm0/src/munmap.c
View File

@@ -6,6 +6,7 @@
#include <mmap.h>
#include <file.h>
#include <l4/api/errno.h>
#include <l4/lib/math.h>
#include <l4lib/arch/syslib.h>
@@ -134,7 +135,8 @@ int do_munmap(struct tcb *task, void *vaddr, unsigned long npages)
list_for_each_entry_safe(vma, n, &task->vm_area_head->list, list) {
/* Check for intersection */
if (vma_intersect(munmap_start, munmap_end, vma)) {
if (set_intersection(munmap_start, munmap_end,
vma->pfn_start, vma->pfn_end)) {
/*
* Flush pages if vma is writable,
* dirty and file-backed.