linux-kernel - [PATCH] dmaengine: idxd: Remove a useless mutex

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 linux-cve-announce PHC
Open Source and information security mailing list archives

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

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

Message-ID: <e08df764e7046178ada4ec066852c0ce65410373.1730547933.git.christophe.jaillet@wanadoo.fr>
Date: Sat,  2 Nov 2024 12:46:04 +0100
From: Christophe JAILLET <christophe.jaillet@...adoo.fr>
To: Fenghua Yu <fenghua.yu@...el.com>,
	Dave Jiang <dave.jiang@...el.com>,
	Vinod Koul <vkoul@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org,
	Christophe JAILLET <christophe.jaillet@...adoo.fr>,
	dmaengine@...r.kernel.org
Subject: [PATCH] dmaengine: idxd: Remove a useless mutex

ida_alloc()/ida_free() don't need any mutex, so remove this one.

It was introduced by commit e6fd6d7e5f0f ("dmaengine: idxd: add a device to
represent the file opened").

Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
---
See:
https://elixir.bootlin.com/linux/v6.11.2/source/lib/idr.c#L375
https://elixir.bootlin.com/linux/v6.11.2/source/lib/idr.c#L484
---
 drivers/dma/idxd/cdev.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 57f1bf2ab20b..ff94ee892339 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -28,7 +28,6 @@ struct idxd_cdev_context {
  * global to avoid conflict file names.
  */
 static DEFINE_IDA(file_ida);
-static DEFINE_MUTEX(ida_lock);
 
 /*
  * ictx is an array based off of accelerator types. enum idxd_type
@@ -123,9 +122,7 @@ static void idxd_file_dev_release(struct device *dev)
 	struct idxd_device *idxd = wq->idxd;
 	int rc;
 
-	mutex_lock(&ida_lock);
 	ida_free(&file_ida, ctx->id);
-	mutex_unlock(&ida_lock);
 
 	/* Wait for in-flight operations to complete. */
 	if (wq_shared(wq)) {
@@ -284,9 +281,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 	}
 
 	idxd_cdev = wq->idxd_cdev;
-	mutex_lock(&ida_lock);
 	ctx->id = ida_alloc(&file_ida, GFP_KERNEL);
-	mutex_unlock(&ida_lock);
 	if (ctx->id < 0) {
 		dev_warn(dev, "ida alloc failure\n");
 		goto failed_ida;
-- 
2.47.0