From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: Miklos Szeredi <mszeredi@redhat.com>,
dhowells@redhat.com, torvalds@linux-foundation.org,
casey@schaufler-ca.com, sds@tycho.nsa.gov,
nicolas.dichtel@6wind.com, raven@themaw.net,
christian@brauner.io, jlayton@redhat.com, kzak@redhat.com,
mszeredi@redhat.com, linux-api@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] watch_queue: Make watch_sizeof() check record size [ver #2]
Date: Mon, 03 Aug 2020 14:06:37 +0100 [thread overview]
Message-ID: <159645999738.1779777.4882634293182825979.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <159645997768.1779777.8286723139418624756.stgit@warthog.procyon.org.uk>
Make watch_sizeof() give a build error if the size of the struct won't fit
into the size field in the header.
Reported-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
include/linux/watch_queue.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
index 5e08db2adc31..38e04c7a7951 100644
--- a/include/linux/watch_queue.h
+++ b/include/linux/watch_queue.h
@@ -120,7 +120,12 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
* watch_sizeof - Calculate the information part of the size of a watch record,
* given the structure size.
*/
-#define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)
+#define watch_sizeof(STRUCT) \
+ ({ \
+ size_t max = WATCH_INFO_LENGTH >> WATCH_INFO_LENGTH__SHIFT; \
+ BUILD_BUG_ON(sizeof(STRUCT) > max); \
+ sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT; \
+ })
#endif
next prev parent reply other threads:[~2020-08-03 13:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-03 13:06 [PATCH 0/5] Mount notifications [ver #2] David Howells
2020-08-03 13:06 ` [PATCH 1/5] watch_queue: Limit the number of watches a user can hold " David Howells
2020-08-03 13:06 ` David Howells [this message]
2020-08-03 13:06 ` [PATCH 3/5] watch_queue: Add security hooks to rule on setting mount watches " David Howells
2020-08-03 13:06 ` [PATCH 4/5] watch_queue: Implement mount topology and attribute change notifications " David Howells
2020-08-03 13:07 ` [PATCH 5/5] watch_queue: sample: Display mount tree " David Howells
2020-08-03 13:22 ` [PATCH 0/5] Mount " David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=159645999738.1779777.4882634293182825979.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=casey@schaufler-ca.com \
--cc=christian@brauner.io \
--cc=jlayton@redhat.com \
--cc=kzak@redhat.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mszeredi@redhat.com \
--cc=nicolas.dichtel@6wind.com \
--cc=raven@themaw.net \
--cc=sds@tycho.nsa.gov \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).