[PATCH] tools/mm/thpmaps: handle carriage returns and non-UTF-8 filenames

[Weilin Tong <tongweilin@linux.alibaba.com>]

VMAList opens smaps with universal newline handling and strict decoding.
A carriage return in a mapped filename can split a header into multiple
records, while non-UTF-8 bytes cause UnicodeDecodeError.

Read LF-terminated records and use surrogateescape to preserve filename
bytes.

Fixes: 2444172cfde4 ("tools/mm: add thpmaps script to dump THP usage info")
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/linux-mm/20261101211644.c63a2028bbede0f763f41f80@linux-foundation.org/
Signed-off-by: Weilin Tong <tongweilin@linux.alibaba.com>
---
This is a follow-up to "tools/mm/thpmaps: fix missing mapping names":
https://lore.kernel.org/linux-mm/20261027074904.3328878-4-tongweilin@linux.alibaba.com/

 tools/mm/thpmaps | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/mm/thpmaps b/tools/mm/thpmaps
index a1a9bc30514f..f89568bd499e 100644
--- a/tools/mm/thpmaps
+++ b/tools/mm/thpmaps
@@ -196,7 +196,8 @@ class VMAList:
     # instance to receive VMAs.
     def __init__(self, pid='self', stats=[]):
         self.vmas = []
-        with open(f'/proc/{pid}/smaps', 'r') as file:
+        with open(f'/proc/{pid}/smaps', 'r', newline='\n',
+                  errors='surrogateescape') as file:
             for line in file:
                 elements = line.rstrip('\n').split(maxsplit=5)
                 if '-' in elements[0]:
-- 
2.43.7