From: Will Deacon <will.deacon@arm.com>
To: linux-kernel@vger.kernel.org
Cc: rkuo@codeaurora.org, arnd@arndb.de, paulus@samba.org,
Will Deacon <will.deacon@arm.com>
Subject: [PATCH 1/2] asm-generic: rwsem: ensure sem->cnt is only accessed via atomic_long_*
Date: Fri, 21 Feb 2014 17:22:26 +0000 [thread overview]
Message-ID: <1393003347-24958-1-git-send-email-will.deacon@arm.com> (raw)
The asm-generic rwsem implementation directly acceses sem->cnt when
performing a __down_read_trylock operation. Whilst this is probably safe
on all architectures, we should stick to the atomic_long_* API and use
atomic_long_read instead.
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
include/asm-generic/rwsem.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index bb1e2cdeb9bf..75af612f54f8 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -41,7 +41,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
{
long tmp;
- while ((tmp = sem->count) >= 0) {
+ while ((tmp = atomic_long_read((atomic_long_t *)&sem->count)) >= 0) {
if (tmp == cmpxchg(&sem->count, tmp,
tmp + RWSEM_ACTIVE_READ_BIAS)) {
return 1;
--
1.8.2.2
next reply other threads:[~2014-02-21 17:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-21 17:22 Will Deacon [this message]
2014-02-21 17:22 ` [PATCH 2/2] asm-generic: rwsem: de-PPCify rwsem.h Will Deacon
2014-02-26 18:05 ` rkuo
2014-02-27 5:28 ` [PATCH 1/2] asm-generic: rwsem: ensure sem->cnt is only accessed via atomic_long_* Davidlohr Bueso
2014-02-27 18:53 ` Will Deacon
2014-02-28 12:13 ` Will Deacon
2014-02-28 12:50 ` Peter Hurley
2014-02-28 15:41 ` Will Deacon
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=1393003347-24958-1-git-send-email-will.deacon@arm.com \
--to=will.deacon@arm.com \
--cc=arnd@arndb.de \
--cc=linux-kernel@vger.kernel.org \
--cc=paulus@samba.org \
--cc=rkuo@codeaurora.org \
/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
Powered by JetHome