linux-kernel - [PATCH] nvmem: core: Check read_only flag for force_ro in bin_attr_nvmem

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Message-ID: <20240713154001.107439-1-marex@denx.de>
Date: Sat, 13 Jul 2024 17:39:35 +0200
From: Marek Vasut <marex@...x.de>
To: linux-i2c@...r.kernel.org
Cc: Marek Vasut <marex@...x.de>,
	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] nvmem: core: Check read_only flag for force_ro in bin_attr_nvmem_write()

The bin_attr_nvmem_write() must check the read_only flag and block
writes on read-only devices, now that a nvmem device can be switched
between read-write and read-only mode at runtime using the force_ro
attribute. Add the missing check.

Fixes: 9d7eb234ac7a ("nvmem: core: Implement force_ro sysfs attribute")
Signed-off-by: Marek Vasut <marex@...x.de>
---
Cc: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Cc: linux-kernel@...r.kernel.org
---
 drivers/nvmem/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 516dfd861b9f9..9cfe7d4bcda39 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -267,7 +267,7 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
 
 	count = round_down(count, nvmem->word_size);
 
-	if (!nvmem->reg_write)
+	if (!nvmem->reg_write || nvmem->read_only)
 		return -EPERM;
 
 	rc = nvmem_reg_write(nvmem, pos, buf, count);
-- 
2.43.0