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Fixed an msync() issue.

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msync used find_vma_byrange() instead of traversing each vma. Fixed now.
This commit is contained in:
Bahadir Balban
2008-11-07 15:10:19 +02:00
parent 3cb36b632a
commit f0348cc356
2 changed files with 17 additions and 3 deletions
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6
tasks/mm0/include/vm_area.h
View File

@@ -183,6 +183,7 @@ struct vm_area {
unsigned long file_offset; /* File offset in pfns */ unsigned long file_offset; /* File offset in pfns */
}; };
/* Finds 'a' vma that is in this range. Only useful for munmap() */
static inline struct vm_area * static inline struct vm_area *
find_vma_byrange(unsigned long pfn_start, find_vma_byrange(unsigned long pfn_start,
unsigned long pfn_end, struct list_head *vm_area_list) unsigned long pfn_end, struct list_head *vm_area_list)
@@ -199,6 +200,11 @@ find_vma_byrange(unsigned long pfn_start,
} }
/*
* Finds the vma that has the given address.
* TODO: In the future a lot of use cases may need to traverse each vma
* rather than searching the address. E.g. munmap/msync
*/
static inline struct vm_area *find_vma(unsigned long addr, static inline struct vm_area *find_vma(unsigned long addr,
struct list_head *vm_area_list) struct list_head *vm_area_list)
{ {

14
tasks/mm0/src/munmap.c
View File

@@ -169,23 +169,31 @@ int do_msync(struct tcb *task, void *vaddr, unsigned long npages, int flags)
const unsigned long msync_start = __pfn(vaddr); const unsigned long msync_start = __pfn(vaddr);
const unsigned long msync_end = msync_start + npages; const unsigned long msync_end = msync_start + npages;
struct vm_area *vma; struct vm_area *vma;
unsigned long addr = (unsigned long)vaddr;
int err; int err;
/* Find a vma that overlaps with this address range */ /* Find a vma that overlaps with this address range */
while ((vma = find_vma_byrange(msync_start, msync_end, while ((vma = find_vma(addr, &task->vm_area_head->list))) {
&task->vm_area_head->list))) {
/* Flush pages if vma is writable, dirty and file-backed. */ /* Flush pages if vma is writable, dirty and file-backed. */
if ((err = vma_flush_pages(vma)) < 0) if ((err = vma_flush_pages(vma)) < 0)
return err; return err;
/* Update address to next vma */
addr = __pfn_to_addr(vma->pfn_end);
/* Are we still good to go? */
if (addr >= msync_end)
break;
} }
return 0; return 0;
} }
int sys_msync(struct tcb *task, void *start, unsigned long length, int flags) int sys_msync(struct tcb *task, void *start, unsigned long length, int flags)
{ {
/* Must be aligned on a page boundary */ /* Must be aligned on a page boundary */
if ((unsigned long)start & PAGE_MASK) if (!is_page_aligned(start))
return -EINVAL; return -EINVAL;
/* /*