Hi Martin, Boris,
On Fri, 22 Jun 2018 16:50:25 +0200, Martin Kaiser <mar...@kaiser.cx>
wrote:
> mxcnd_probe_dt is called from mxcnd_probe, which is not marked as __init.
>
I think this line is just a side note and should be at the end of the
commit log.
> Using the sysfs unbind, bind nodes, mxcnd_probe and mxcnd_probe_dt can
> potentially be called at any time. After the __init functions are cleaned,
> mxcnd_probe_dt is no longer available. Calling it anyway causes a crash.
The above paragraph explains the problem and the solution, you can just
add something like "mcvnd_probe is untouched because it is already not
marked as __init" instead of the first line.
>
> Signed-off-by: Martin Kaiser <mar...@kaiser.cx>
Boris, do you think this patch is a good candidate for stable?
If yes, Martin, could you please add a couple of stable/fixes tags above
your SoB?
Thanks,
Miquèl
> ---
> I hope that my understanding is correct.
>
> In practice, I could not get the kernel to crash, my compiler would
> inline mxcnd_probe_dt into mxcnd_probe and ignore the __init.
>
> If I marked mxcnd_probe_dt as noinline, I could trigger a crash as
> follows
>
> [root@host ]# echo bb000000.nand > /sys/bus/platform/drivers/mxc_nand/unbind
> [root@host ]# echo bb000000.nand > /sys/bus/platform/drivers/mxc_nand/bind
> Internal error: Oops - undefined instruction: 0 [#1] ARM
> ...
>
> drivers/mtd/nand/raw/mxc_nand.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/mxc_nand.c b/drivers/mtd/nand/raw/mxc_nand.c
> index 26cef21..90cfb5e 100644
> --- a/drivers/mtd/nand/raw/mxc_nand.c
> +++ b/drivers/mtd/nand/raw/mxc_nand.c
> @@ -1686,7 +1686,7 @@ static const struct of_device_id mxcnd_dt_ids[] = {
> };
> MODULE_DEVICE_TABLE(of, mxcnd_dt_ids);
>
> -static int __init mxcnd_probe_dt(struct mxc_nand_host *host)
> +static int mxcnd_probe_dt(struct mxc_nand_host *host)
> {
> struct device_node *np = host->dev->of_node;
> const struct of_device_id *of_id =
> @@ -1700,7 +1700,7 @@ static int __init mxcnd_probe_dt(struct mxc_nand_host
> *host)
> return 0;
> }
> #else
> -static int __init mxcnd_probe_dt(struct mxc_nand_host *host)
> +static int mxcnd_probe_dt(struct mxc_nand_host *host)
> {
> return 1;
> }
