Messages in this thread | | | Subject | Re: [RFC PATCH 1/4] media: Add Media Device Allocator API | From | Shuah Khan <> | Date | Mon, 28 Mar 2016 07:45:45 -0600 |
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On 03/26/2016 06:50 AM, Joe Perches wrote: > On Fri, 2016-03-25 at 22:38 -0600, Shuah Khan wrote: >> Add Media Device Allocator API to manage Media Device life time problems. >> There are known problems with media device life time management. When media >> device is released while an media ioctl is in progress, ioctls fail with >> use-after-free errors and kernel hangs in some cases. > > Seems reasonable, thanks. > > trivial: > >> diff --git a/drivers/media/media-dev-allocator.c b/drivers/media/media-dev-allocator.c > [] >> +static struct media_device *__media_device_get(struct device *dev, >> + bool alloc, bool kref) >> +{ > [] >> + pr_info("%s: mdev=%p\n", __func__, &mdi->mdev); > > All of the pr_info uses here seem like debugging > and should likely be pr_debug instead.
Correct. These are for debug and I plan to either remove them completely or make them pr_debug().
>> +struct media_device *media_device_find(struct device *dev) >> +{ >> + pr_info("%s\n", __func__); > > These seem like function tracing and maybe could/should > use ftrace instead. > +/* don't allocate - increment kref if one is found */ >> +struct media_device *media_device_get_ref(struct device *dev) >> +{ >> + pr_info("%s\n", __func__); >
Same here. This is also debug. However, you gave me an idea, this could be a tracevent, if I find it useful for event tracing. It might be useful to be able to track kref holds on this.
thanks, -- Shuah
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