From: "Pulavarty, Badari" <badari.pulavarty@intel.com>
To: "damon@lists.linux.dev" <damon@lists.linux.dev>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: [PATCH] DAMON dbgfs_mk_context() error handling
Date: Fri, 12 Aug 2022 18:01:25 +0000 [thread overview]
Message-ID: <DM6PR11MB3978994F75A4104D714437379C679@DM6PR11MB3978.namprd11.prod.outlook.com> (raw)
damon dbgfs_mk_context() does not handle error from debugfs_create_dir() correctly.
For example, if one tries to create a context with existing name, debugfs_create_dir() fails
with -EEXIST, but dbgfs_mk_context() assumes the call is successful and adds another entry - which
will cause failures when try to enable the monitor.
Test case:
echo "off" > /sys/kernel/debug/damon/monitor_on
echo "abc" > /sys/kernel/debug/damon/mk_context
echo "abc" > /sys/kernel/debug/damon/mk_context
echo <pid> > /sys/kernel/debug/damon/target_ids
echo "on" > /sys/kernel/debug/damon/monitor_on <<< fails to enable monitor
Signed-off-by: Badari Pulavarty badari.pulavarty@intel.com
---
--- orig/mm/damon/dbgfs.c 2022-08-05 13:35:54.416831666 -0400
+++ new/mm/damon/dbgfs.c 2022-08-05 13:44:25.121849930 -0400
@@ -721,6 +721,9 @@ static int dbgfs_mk_context(char *name)
return -ENOENT;
new_dir = debugfs_create_dir(name, root);
+ if (IS_ERR(new_dir)) {
+ return PTR_ERR(new_dir);
+ }
dbgfs_dirs[dbgfs_nr_ctxs] = new_dir;
new_ctx = dbgfs_new_ctx();
next reply other threads:[~2022-08-12 18:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-12 18:01 Pulavarty, Badari [this message]
2022-08-12 18:07 ` [PATCH] DAMON dbgfs_mk_context() error handling Pulavarty, Badari
2022-08-14 16:32 ` SeongJae Park
2022-08-15 21:51 ` Pulavarty, Badari
2022-08-15 23:42 ` SeongJae Park
2022-08-15 23:54 ` Pulavarty, Badari
2022-08-16 0:12 ` SeongJae Park
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