From faeadbb64094757150a8c2a3175ca418dbdd472c Mon Sep 17 00:00:00 2001
From: Suman Anna <s-anna@ti.com>
Date: Fri, 14 Sep 2018 19:37:22 -0500
Subject: [PATCH] remoteproc: Check for NULL firmwares in sysfs interface
Git-commit: faeadbb64094757150a8c2a3175ca418dbdd472c
Patch-mainline: v4.20-rc1
References: git-fixes

The remoteproc framework provides a sysfs file 'firmware'
for modifying the firmware image name from userspace. Add
an additional check to ensure NULL firmwares are errored
out right away, rather than getting a delayed error while
requesting a firmware during the start of a remoteproc
later on.

Tested-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/remoteproc/remoteproc_sysfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index 47be411400e5..3a4c3d7cafca 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -48,6 +48,11 @@ static ssize_t firmware_store(struct device *dev,
 	}
 
 	len = strcspn(buf, "\n");
+	if (!len) {
+		dev_err(dev, "can't provide a NULL firmware\n");
+		err = -EINVAL;
+		goto out;
+	}
 
 	p = kstrndup(buf, len, GFP_KERNEL);
 	if (!p) {
-- 
2.16.4