[PATCH] mm: dup_mmap use oldmm more

Use the parent's oldmm throughout dup_mmap, instead of perversely going back
to current->mm.  (Can you hear the sigh of relief from those mpnts?  Usually I
squash them, but not today.)

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index 2048ed7b5872262f963c6bbb633769b7baaff4cb..0e7fe4a8a8df149a54c534932f61011b5184afc2 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -182,16 +182,16 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 }
 
 #ifdef CONFIG_MMU
-static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
+static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 {
-       struct vm_area_struct * mpnt, *tmp, **pprev;
+       struct vm_area_struct *mpnt, *tmp, **pprev;
        struct rb_node **rb_link, *rb_parent;
        int retval;
        unsigned long charge;
        struct mempolicy *pol;
 
        down_write(&oldmm->mmap_sem);
-       flush_cache_mm(current->mm);
+       flush_cache_mm(oldmm);
        mm->locked_vm = 0;
        mm->mmap = NULL;
        mm->mmap_cache = NULL;
@@ -204,7 +204,7 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
        rb_parent = NULL;
        pprev = &mm->mmap;
 
-       for (mpnt = current->mm->mmap ; mpnt ; mpnt = mpnt->vm_next) {
+       for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
                struct file *file;
 
                if (mpnt->vm_flags & VM_DONTCOPY) {
@@ -265,7 +265,7 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
                rb_parent = &tmp->vm_rb;
 
                mm->map_count++;
-               retval = copy_page_range(mm, current->mm, tmp);
+               retval = copy_page_range(mm, oldmm, tmp);
                spin_unlock(&mm->page_table_lock);
 
                if (tmp->vm_ops && tmp->vm_ops->open)
@@ -277,7 +277,7 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
        retval = 0;
 
 out:
-       flush_tlb_mm(current->mm);
+       flush_tlb_mm(oldmm);
        up_write(&oldmm->mmap_sem);
        return retval;
 fail_nomem_policy: