Messages in this thread | | | Date | Wed, 28 Apr 2021 16:14:00 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 157/190] Revert "Input: ad7879 - add check for read errors in interrupt" |
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On Tue, Apr 27, 2021 at 12:22:12PM -0700, Dmitry Torokhov wrote: > On Tue, Apr 27, 2021 at 06:55:10PM +0200, Greg Kroah-Hartman wrote: > > On Wed, Apr 21, 2021 at 10:03:33AM -0700, Dmitry Torokhov wrote: > > > Hi Greg, > > > > > > On Wed, Apr 21, 2021 at 03:00:32PM +0200, Greg Kroah-Hartman wrote: > > > > This reverts commit e85bb0beb6498c0dffe18a2f1f16d575bc175c32. > > > > > > > > Commits from @umn.edu addresses have been found to be submitted in "bad > > > > faith" to try to test the kernel community's ability to review "known > > > > malicious" changes. The result of these submissions can be found in a > > > > paper published at the 42nd IEEE Symposium on Security and Privacy > > > > entitled, "Open Source Insecurity: Stealthily Introducing > > > > Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University > > > > of Minnesota) and Kangjie Lu (University of Minnesota). > > > > > > > > Because of this, all submissions from this group must be reverted from > > > > the kernel tree and will need to be re-reviewed again to determine if > > > > they actually are a valid fix. Until that work is complete, remove this > > > > change to ensure that no problems are being introduced into the > > > > codebase. > > > > > > This one looks really OK to me and does not have to be reverted (unless > > > Aditya will come clean and show the error introduced?). > > > > I'll drop this revert, but it isn't usually good to be calling printk() > > from an irq. > > How else do you suggest we tell that something is wrong when > communicating with the device? For these types of devices the > communication is essentially unsolicited so we can't pass failure to a > caller to deal with it (i.e. unlike USB there is no URB posted that we > could fail and use as a mechanism to signal error to some other layer) > and while we could invent "something went wrong" input event so far > there was no interest in having anything like that. > > I'd suggest sending KOBJ_ERROR uevent when a device driver detects > anomaly in the device it controls, but I wonder how systemd would react > given past experiences with KOBJ_BIND/KOBJ_UNBIND. > > The message is ratelimited so it will not overfill the logs...
Sending uevents from an irq is not a good idea, as you say :)
I don't know what the best way to "fail" this is, a ratelimited printk() seems to be about all you can do. Luckily hardware doesn't fail that often in this manner.
thanks,
greg k-h
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