* based on replace_page in mm/ksm.c
*
* @vma: vma that holds the pte pointing to page
+ * @addr: address the old @page is mapped at
* @page: the cowed page we are replacing by kpage
* @kpage: the modified page we replace page by
*
* Returns 0 on success, -EFAULT on failure.
*/
-static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage)
+static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page, struct page *kpage)
{
struct mm_struct *mm = vma->vm_mm;
- unsigned long addr;
spinlock_t *ptl;
pte_t *ptep;
+ int err;
- addr = page_address_in_vma(page, vma);
- if (addr == -EFAULT)
- return -EFAULT;
+ /* freeze PageSwapCache() for try_to_free_swap() below */
+ lock_page(page);
+ err = -EAGAIN;
ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
- return -EAGAIN;
+ goto unlock;
get_page(kpage);
page_add_new_anon_rmap(kpage, vma, addr);
put_page(page);
pte_unmap_unlock(ptep, ptl);
- return 0;
+ err = 0;
+ unlock:
+ unlock_page(page);
+ return err;
}
/**
unsigned long vaddr, uprobe_opcode_t opcode)
{
struct page *old_page, *new_page;
- struct address_space *mapping;
void *vaddr_old, *vaddr_new;
struct vm_area_struct *vma;
- struct uprobe *uprobe;
int ret;
+
retry:
/* Read the page with vaddr into memory */
ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
if (ret <= 0)
return ret;
- ret = -EINVAL;
-
- /*
- * We are interested in text pages only. Our pages of interest
- * should be mapped for read and execute only. We desist from
- * adding probes in write mapped pages since the breakpoints
- * might end up in the file copy.
- */
- if (!valid_vma(vma, is_swbp_insn(&opcode)))
- goto put_out;
-
- uprobe = container_of(auprobe, struct uprobe, arch);
- mapping = uprobe->inode->i_mapping;
- if (mapping != vma->vm_file->f_mapping)
- goto put_out;
-
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)
- goto put_out;
+ goto put_old;
__SetPageUptodate(new_page);
- /*
- * lock page will serialize against do_wp_page()'s
- * PageAnon() handling
- */
- lock_page(old_page);
/* copy the page now that we've got it stable */
vaddr_old = kmap_atomic(old_page);
vaddr_new = kmap_atomic(new_page);
ret = anon_vma_prepare(vma);
if (ret)
- goto unlock_out;
+ goto put_new;
- lock_page(new_page);
- ret = __replace_page(vma, old_page, new_page);
- unlock_page(new_page);
+ ret = __replace_page(vma, vaddr, old_page, new_page);
-unlock_out:
- unlock_page(old_page);
+put_new:
page_cache_release(new_page);
-
-put_out:
+put_old:
put_page(old_page);
if (unlikely(ret == -EAGAIN))
int uprobe_mmap(struct vm_area_struct *vma)
{
struct list_head tmp_list;
- struct uprobe *uprobe;
+ struct uprobe *uprobe, *u;
struct inode *inode;
int ret, count;
ret = 0;
count = 0;
- list_for_each_entry(uprobe, &tmp_list, pending_list) {
+ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
if (!ret) {
loff_t vaddr = vma_address(vma, uprobe->offset);
void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
struct list_head tmp_list;
- struct uprobe *uprobe;
+ struct uprobe *uprobe, *u;
struct inode *inode;
if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
return;
+ if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
+ return;
+
if (!atomic_read(&vma->vm_mm->uprobes_state.count))
return;
mutex_lock(uprobes_mmap_hash(inode));
build_probe_list(inode, &tmp_list);
- list_for_each_entry(uprobe, &tmp_list, pending_list) {
+ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
loff_t vaddr = vma_address(vma, uprobe->offset);
if (vaddr >= start && vaddr < end) {