uprobes: Introduce vaddr_to_offset(vma, vaddr)
Add the new helper, vaddr_to_offset(vma, vaddr) which returns
the offset in vma->vm_file this vaddr is mapped at.
Change build_probe_list() and find_active_uprobe() to use the
new helper, the next patch adds another user.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120729182242.GA20355@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2ef1233..b03256c 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -122,6 +122,11 @@
return vaddr;
}
+static loff_t vaddr_to_offset(struct vm_area_struct *vma, unsigned long vaddr)
+{
+ return ((loff_t)vma->vm_pgoff << PAGE_SHIFT) + (vaddr - vma->vm_start);
+}
+
/**
* __replace_page - replace page in vma by new page.
* based on replace_page in mm/ksm.c
@@ -978,7 +983,7 @@
struct uprobe *u;
INIT_LIST_HEAD(head);
- min = ((loff_t)vma->vm_pgoff << PAGE_SHIFT) + start - vma->vm_start;
+ min = vaddr_to_offset(vma, start);
max = min + (end - start) - 1;
spin_lock_irqsave(&uprobes_treelock, flags);
@@ -1442,12 +1447,9 @@
vma = find_vma(mm, bp_vaddr);
if (vma && vma->vm_start <= bp_vaddr) {
if (valid_vma(vma, false)) {
- struct inode *inode;
- loff_t offset;
+ struct inode *inode = vma->vm_file->f_mapping->host;
+ loff_t offset = vaddr_to_offset(vma, bp_vaddr);
- inode = vma->vm_file->f_mapping->host;
- offset = bp_vaddr - vma->vm_start;
- offset += (loff_t)vma->vm_pgoff << PAGE_SHIFT;
uprobe = find_uprobe(inode, offset);
}