On 8/31/05, Vincenzo Mallozzi <vinjunior@xxxxxxxx> wrote:
> Hi all,
> I've another problem with list_head. This problem is different from the
> previous one I've encountered (I've resolved it).
> I've now the following code:
>
>
> struct mtpmc_pages{
> struct list_head list;
> unsigned long addr;
> char page[PAGE_SIZE];
> };
>
> struct mtpmc_mm_struct{
> .......
> struct list_head pages_list;
> };
>
> struct mtpmc_mm_struct mtpmc_dump_memory_descriptor(struct mm_struct *mm)
> {
> struct mtpmc_mm_struct md;
this should be a pointer as your are returning it at the end of this function.
> struct list_head *temp_list;
> struct mtpmc_wrprotected_pages *wrpage;
> pte_t *pte;
> struct page *page;
> struct mtpmc_pages *temp_page;
>
> INIT_LIST_HEAD(&md.pages_list);
> for (each address "address" we need) do{
> temp_page = (struct mtpmc_pages*) vmalloc(sizeof(struct mtpmc_pages));
> INIT_LIST_HEAD(&temp_page->list);
> temp_page->addr = address;
> mtpmc_read_page(address, temp_page->page);/*this fills the "page"
> field" of temp_page */
> list_add(&temp_page->list, &md.pages_list);
> }
>
> return md;
here is the bug, you are retun the local structure, what does this
mean .... is it right, I dont think so.
-Gaurav
> }
>
> void other_function()
> {
> struct list_head *temp_list;
> struct mtpmc_pages *temp_page;
> struct mtpmc_mm_struct md =mtpmc_dump_memory_descriptor(mm);
>
> printk(KERN_DEBUG "mtpmc:listing addresses added\n");
> list_for_each(temp_list, &md.pages_list){
> temp_page = list_entry(temp_list, struct mtpmc_pages, list);
> printk(KERN_DEBUG "mtpmc: temp_page->addr = %08lx\n",
> temp_page->addr);
> }
> return;
> }
>
>
> The problem is in other_function function where I only scan the list created
> in the previous function.
> If I do this scanning within the mtpmc_dump_memory_descriptor function after
> the creation of the list, the right elements are printed but in
> other_function fuction are listed more elements that the ones I've inserted
> in. And then segfault.
> I don't know where is the problem as the list seems to be well filled.
> Thanks.
> Vincenzo Mallozzi.
>
>
>
>
>
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