1c87f73578
I forgot to account for the fact that the device core holds a
reference to a device added with device_initialize() that need
to be released with a corresponding put_device() to reach a 0
refcount at the end of the lifecycle.
This led to a NULL pointer reference when freeing the device
when e.g. unbidning the host device in sysfs.
Fix this and use the device .release() callback to free the
IDA and free:ing the memory used by the RPMB device.
Before this patch:
/sys/bus/amba/drivers/mmci-pl18x$ echo 80114000.sdi4_per2 > unbind
[ 29.797332] mmc3: card 0001 removed
[ 29.810791] Unable to handle kernel NULL pointer dereference at
virtual address 00000050
[ 29.818878] pgd = de70c000
[ 29.821624] [00000050] *pgd=1e70a831, *pte=00000000, *ppte=00000000
[ 29.827911] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 29.833282] Modules linked in:
[ 29.836334] CPU: 1 PID: 154 Comm: sh Not tainted
4.14.0-rc3-00039-g83318e309566-dirty #736
[ 29.844604] Hardware name: ST-Ericsson Ux5x0 platform (Device Tree Support)
[ 29.851562] task: de572700 task.stack: de742000
[ 29.856079] PC is at kernfs_find_ns+0x8/0x100
[ 29.860443] LR is at kernfs_find_and_get_ns+0x30/0x48
After this patch:
/sys/bus/amba/drivers/mmci-pl18x$ echo 80005000.sdi4_per2 > unbind
[ 20.623382] mmc3: card 0001 removed
Fixes: 97548575bef3 ("mmc: block: Convert RPMB to a character device")
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.