From: Dave Jiang <dave.jiang@intel.com>
Date: Mon, 11 Apr 2022 22:08:55 +0000 (-0700)
Subject: dmaengine: idxd: add RO check for wq max_batch_size write
X-Git-Tag: v5.10.113~58
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9a3c026dc3a59fa23c63d90752f07538a3c75646;p=thirdparty%2Fkernel%2Fstable.git

dmaengine: idxd: add RO check for wq max_batch_size write

[ Upstream commit 66903461ffed0b66fc3e0200082d4e09365aacdc ]

Block wq_max_batch_size_store() when the device is configured as read-only
and not configurable.

Fixes: e7184b159dd3 ("dmaengine: idxd: add support for configurable max wq batch size")
Reported-by: Bernice Zhang <bernice.zhang@intel.com>
Tested-by: Bernice Zhang <bernice.zhang@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/164971493551.2201159.1942042593642155209.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 7b41cdff1a2ce..5bf4b4be64e45 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1132,6 +1132,9 @@ static ssize_t wq_max_batch_size_store(struct device *dev, struct device_attribu
 	u64 batch_size;
 	int rc;
 
+	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
+		return -EPERM;
+
 	if (wq->state != IDXD_WQ_DISABLED)
 		return -EPERM;