> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxx] > Sent: Wednesday, October 05, 2011 12:37 AM > To: KY Srinivasan > Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > virtualization@xxxxxxxxxxxxxx; Long Li; Haiyang Zhang > Subject: Re: [PATCH 1/1] Staging: hv: util: Fix a bug in kvp implementation > > On Tue, Oct 04, 2011 at 02:00:02PM -0700, K. Y. Srinivasan wrote: > > The host gurantees that there can be only one kvp transaction active > > against the guest. So, the transaction active state is needed only to > > protect against spurious user level calls. The current code had a race > > condition where the guest could prematurely return because the previous > > transaction state was not cleared - this state was being cleared after > > sending the response to the host and there was a window where the host > > could notify the guest of a new transaction before the transaction active > > state was properly set. > > Also deal with the case when the user mode component > > does not respond in a timely fashion correctly. > > I would like to thank Long Li <longli@xxxxxxxxxxxxx> > > for identifying the problem. > > So that would be a "Reported-by:" tag, we don't have a "Diagnosed-by" do > we? Reported-by tag would do. > > And should this go to the older (i.e. stable) kernels as well? > While the bug can be triggered by doing something that is not the way this (KVP) feature is to be used, I don't think this bug can be triggered under normal usage. The test case that exposed this bug was one where KVP values were being queried from the host in a tight loop - hardly a typical usage scenario. So, I was not sure if this would qualify for back porting to other stable kernels. What do you think? Regards, K. Y _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
