From: Jan Kara <jack@suse.com>
To: xfs@oss.sgi.com
Cc: Jan Kara <jack@suse.com>
Subject: [PATCH] xfsprogs: Fix attr leaf block definition
Date: Wed, 12 Aug 2015 15:53:14 +0200 [thread overview]
Message-ID: <1439387594-8747-1-git-send-email-jack@suse.com> (raw)
struct xfs_attr_leafblock contains 'entries' array which is declared
with size 1 altough it can in fact contain much more entries. Since this
array is followed by further struct members, gcc (at least in version
4.8.3) thinks that the delared size of the array is the real one and
thus optimizes away all accesses beyond the end of array resulting in
non-working code.
Signed-off-by: Jan Kara <jack@suse.com>
---
include/xfs_da_format.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/xfs_da_format.h b/include/xfs_da_format.h
index 11f142078e12..39bfeb042844 100644
--- a/include/xfs_da_format.h
+++ b/include/xfs_da_format.h
@@ -1180,8 +1180,14 @@ typedef struct xfs_attr_leaf_name_remote {
typedef struct xfs_attr_leafblock {
xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */
xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */
+ /*
+ * Definitions below are commented out so that gcc doesn't optimize
+ * away accesses into 'entries' for indexes larger than 1
+ */
+#if 0
xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */
xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */
+#endif
} xfs_attr_leafblock_t;
/*
--
2.1.4
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next reply other threads:[~2015-08-12 13:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-12 13:53 Jan Kara [this message]
2015-08-13 1:29 ` [PATCH] xfsprogs: Fix attr leaf block definition Dave Chinner
2015-08-13 7:06 ` Christoph Hellwig
2015-08-13 8:46 ` Jan Kara
-- strict thread matches above, loose matches on Subject: below --
2015-08-13 9:11 Jan Kara
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=1439387594-8747-1-git-send-email-jack@suse.com \
--to=jack@suse.com \
--cc=xfs@oss.sgi.com \
/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