From 52c5d2bc32133966974edb8d8c49bf7763101622 Mon Sep 17 00:00:00 2001 From: Jim Cromie Date: Thu, 16 Nov 2023 15:43:18 -0700 Subject: [PATCH] kmemleak: add checksum to backtrace report Change /sys/kernel/debug/kmemleak report format slightly, adding "(extra info)" to the backtrace header: from: " backtrace:" to: " backtrace (crc ):" The allows a user to see recurring backtraces without detailed/careful reading of multiline stacks. So after cycling kmemleak-test a few times, I know some leaks are repeating. bash-5.2# grep backtrace /sys/kernel/debug/kmemleak | wc 62 186 1792 bash-5.2# grep backtrace /sys/kernel/debug/kmemleak | sort -u | wc 37 111 1067 syzkaller parses kmemleak for "unreferenced object" only, so is unaffected by this change. Other github repos are moribund. Link: https://lkml.kernel.org/r/20231116224318.124209-3-jim.cromie@gmail.com Signed-off-by: Jim Cromie Reviewed-by: Catalin Marinas Signed-off-by: Andrew Morton --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index a87b3dd8f3b7..0fb4dcc3b06a 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -362,7 +362,7 @@ static void print_unreferenced(struct seq_file *seq, warn_or_seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu\n", object->comm, object->pid, object->jiffies); hex_dump_object(seq, object); - warn_or_seq_printf(seq, " backtrace:\n"); + warn_or_seq_printf(seq, " backtrace (crc %x):\n", object->checksum); for (i = 0; i < nr_entries; i++) { void *ptr = (void *)entries[i];