From 505a2d1032ae656b0a8c736be110255503941cde Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Mon, 11 Apr 2022 15:08:01 -0700
Subject: [PATCH] dmaengine: idxd: add RO check for wq max_transfer_size write
Git-commit: 505a2d1032ae656b0a8c736be110255503941cde
Patch-mainline: v5.18-rc4
References: git-fixes
Block wq_max_transfer_size_store() when the device is configured as
read-only and not configurable.
Fixes: d7aad5550eca ("dmaengine: idxd: add support for configurable max wq xfer 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/164971488154.2200913.10706665404118545941.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/dma/idxd/sysfs.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 6c41d429bd89..dfd549685c46 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -905,6 +905,9 @@ static ssize_t wq_max_transfer_size_store(struct device *dev, struct device_attr
u64 xfer_size;
int rc;
+ if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
+ return -EPERM;
+
if (wq->state != IDXD_WQ_DISABLED)
return -EPERM;
--
2.31.1