linux-kernel - [PATCH v2 1/3] virtio-rng cleanup: move some code out of mutex protection

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 16 Sep 2014 00:02:27 +0800
From:	Amos Kong <akong@...hat.com>
To:	virtualization@...ts.linux-foundation.org
Cc:	kvm@...r.kernel.org, herbert@...dor.apana.org.au, m@...s.ch,
	mb@...sch.de, mpm@...enic.com, rusty@...tcorp.com.au,
	amit.shah@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/3] virtio-rng cleanup: move some code out of mutex protection

It doesn't save too much cpu time as expected, just a cleanup.

Signed-off-by: Amos Kong <akong@...hat.com>
---
 drivers/char/hw_random/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index aa30a25..c591d7e 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -270,8 +270,8 @@ static ssize_t hwrng_attr_current_show(struct device *dev,
 		return -ERESTARTSYS;
 	if (current_rng)
 		name = current_rng->name;
-	ret = snprintf(buf, PAGE_SIZE, "%s\n", name);
 	mutex_unlock(&rng_mutex);
+	ret = snprintf(buf, PAGE_SIZE, "%s\n", name);
 
 	return ret;
 }
@@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev,
 	ssize_t ret = 0;
 	struct hwrng *rng;
 
+	buf[0] = '\0';
 	err = mutex_lock_interruptible(&rng_mutex);
 	if (err)
 		return -ERESTARTSYS;
-	buf[0] = '\0';
 	list_for_each_entry(rng, &rng_list, list) {
 		strncat(buf, rng->name, PAGE_SIZE - ret - 1);
 		ret += strlen(rng->name);
 		strncat(buf, " ", PAGE_SIZE - ret - 1);
 		ret++;
 	}
+	mutex_unlock(&rng_mutex);
 	strncat(buf, "\n", PAGE_SIZE - ret - 1);
 	ret++;
-	mutex_unlock(&rng_mutex);
 
 	return ret;
 }
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/