From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 7 Apr 2024 20:18:39 +0000 (-0700)
Subject: mm: simplify and improve print_vma_addr() output
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=de7e71ef8bed222dd144d8878091ecb6d5dfd208;p=linux.git

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>
---

diff --git a/mm/memory.c b/mm/memory.c
index b5453b86ec4b7..0f47a533014e4 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);
 }