mm: simplify and improve print_vma_addr() output

Use '%pD' to print out the filename, and print out the actual offset
within the file too, rather than just what the virtual address of the
mapping is (which doesn't tell you anything about any mapping offsets).

Also, use the exact vma_lookup() instead of find_vma() - the latter
looks up any vma _after_ the address, which is of questionable value
(yes, maybe you fell off the beginning, but you'd be more likely to fall
off the end).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 13 deletions

diff --git a/mm/memory.c b/mm/memory.c
index b5453b86ec4b..0f47a533014e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6210,21 +6210,14 @@ void print_vma_addr(char *prefix, unsigned long ip)
 	if (!mmap_read_trylock(mm))
 		return;
 
-	vma = find_vma(mm, ip);
+	vma = vma_lookup(mm, ip);
 	if (vma && vma->vm_file) {
 		struct file *f = vma->vm_file;
-		char *buf = (char *)__get_free_page(GFP_NOWAIT);
-		if (buf) {
-			char *p;
-
-			p = file_path(f, buf, PAGE_SIZE);
-			if (IS_ERR(p))
-				p = "?";
-			printk("%s%s[%lx+%lx]", prefix, kbasename(p),
-					vma->vm_start,
-					vma->vm_end - vma->vm_start);
-			free_page((unsigned long)buf);
-		}
+		ip -= vma->vm_start;
+		ip += vma->vm_pgoff << PAGE_SHIFT;
+		printk("%s%pD[%lx,%lx+%lx]", prefix, f, ip,
+				vma->vm_start,
+				vma->vm_end - vma->vm_start);
 	}
 	mmap_read_unlock(mm);
 }