From: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
To: Matthew Wilcox <mawilcox@microsoft.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Subject: [PATCH 1/1] dax: initialize variable pfn before using it
Date: Sun, 3 Sep 2017 10:30:00 +0200 [thread overview]
Message-ID: <20170903083000.587-1-nicolas.iooss_linux@m4x.org> (raw)
Function dax_pmd_insert_mapping() contains the following code:
pfn_t pfn;
if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
goto fallback;
/* ... */
fallback:
trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
When the condition in the if statement fails, the function calls
trace_dax_pmd_insert_mapping_fallback() with an uninitialized pfn value.
This issue has been found while building the kernel with clang. The
compiler reported:
fs/dax.c:1280:6: error: variable 'pfn' is used uninitialized
whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/dax.c:1310:60: note: uninitialized use occurs here
trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
^~~
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
---
fs/dax.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index ab925dc6647a..20e6d76d6fff 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1283,7 +1283,7 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
void *ret = NULL, *kaddr;
long length = 0;
pgoff_t pgoff;
- pfn_t pfn;
+ pfn_t pfn = {};
int id;
if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
--
2.14.1
next reply other threads:[~2017-09-03 8:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-03 8:30 Nicolas Iooss [this message]
2017-09-05 18:37 ` [PATCH 1/1] dax: initialize variable pfn before using it Ross Zwisler
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=20170903083000.587-1-nicolas.iooss_linux@m4x.org \
--to=nicolas.iooss_linux@m4x.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mawilcox@microsoft.com \
--cc=ross.zwisler@linux.intel.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;
as well as URLs for NNTP newsgroup(s).