Messages in this thread | | | Subject | Re: [PATCH] PM / devfreq: Return -ENODEV from try_then_request_governor | From | Enric Balletbo i Serra <> | Date | Tue, 23 Apr 2019 11:55:52 +0200 |
| |
Hi Tomeu,
On 23/4/19 10:11, Tomeu Vizoso wrote: > Callers don't expect it to return NULL, but an error code. > > Fixes Oops such as the one below, when one tries to set a governor that > isn't available: > > Unable to handle kernel NULL pointer dereference at virtual address 00000018 > > [<c0dcf718>] (governor_store) from [<c0539558>] (kernfs_fop_write+0x100/0x1e0) > [<c0539558>] (kernfs_fop_write) from [<c04b09b4>] (__vfs_write+0x2c/0x17c) > [<c04b09b4>] (__vfs_write) from [<c04b33fc>] (vfs_write+0xa4/0x184) > [<c04b33fc>] (vfs_write) from [<c04b361c>] (ksys_write+0x4c/0xac) > [<c04b361c>] (ksys_write) from [<c0301000>] (ret_fast_syscall+0x0/0x28) > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.") > Reported-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> > Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com> > ---
There is already a fix for that. The fix was initially sent in October [2] but unfortunately it got lost. I resend and now is queued [1]. Hopefully the Fixes tag will help to pick the fix to the proper kernel releases.
Thanks, Enric
[1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b53b0128052ffd687797d5f4deeb76327e7b5711
[2] https://lkml.org/lkml/2018/10/16/744
> drivers/devfreq/devfreq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0ae3de76833b..5539e9be718d 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name) > /* Restore previous state before return */ > mutex_lock(&devfreq_list_lock); > if (err) > - return NULL; > + return ERR_PTR(-ENODEV); > > governor = find_devfreq_governor(name); > } >
| |