[PATCH] iio: buffer: use sysfs_attr_init() on allocated attrs

From: Alexandru Ardelean <aardelean@deviqon.com>
To: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org
Cc: jic23@kernel.org, Alexandru Ardelean <aardelean@deviqon.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: [PATCH] iio: buffer: use sysfs_attr_init() on allocated attrs
Date: Fri,  2 Apr 2021 20:42:26 +0300	[thread overview]
Message-ID: <20210402174226.630346-1-aardelean@deviqon.com> (raw)

When dynamically allocating sysfs attributes, it's a good idea to call
sysfs_attr_init() on them to initialize lock_class_keys.
This change does that.

The lock_class_keys are set when the CONFIG_DEBUG_LOCK_ALLOC symbol is
enabled. Which is [likely] one reason why I did not see this during
development.

I also am not able to see this even with CONFIG_DEBUG_LOCK_ALLOC enabled,
so this may [likely] be reproduce-able on some system configurations.

This was reported via:
  https://lore.kernel.org/linux-iio/CA+U=DsrsvGgXEF30-vXuXS_k=-mjSjiBwEEzwKb1hJVn1P98OA@mail.gmail.com/T/#u

Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> 
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---

@Marek: could you maybe test this on your setup?

I haven't been able to reproduce this on mine.

Thanks
Alex

 drivers/iio/industrialio-buffer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index ee5aab9d4a23..06b2ea087408 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1309,6 +1309,7 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer,
 	iio_attr->buffer = buffer;
 	memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr));
 	iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL);
+	sysfs_attr_init(&iio_attr->dev_attr.attr);
 
 	list_add(&iio_attr->l, &buffer->buffer_attr_list);
 
-- 
2.30.2

