On Fri, Sep 09, 2016 at 02:33:18PM +0100, Ross Lagerwall wrote: > On 08/24/2016 03:22 AM, Konrad Rzeszutek Wilk wrote: > > So that when we apply the patch again the .bss is cleared. > > Otherwise we may find some variables containing old values. > > > > The payloads may contain various .bss - especially if -fdata-sections > > is used which can create .bss.<name> sections. > > > > After having thought about this again, I'm not sure it makes much sense. Any > data sections in the payload are not reset to their initial values, so > resetting the bss only may result in an unexpected combination of new & old > data/bss.
Regardless of that I think clearing the .bss upon applying the livepatch is still the right thing to do. Regarding of the .data - we could have a copy of the .data the first time we load - and then during application copy over it from the original one?. > > Perhaps it just needs to be documented that a payload's bss/data is > untouched across revert/apply? It really cuts down on bugs if we clear the .bss. It is kind of ingrained in every developer that the .bss is zero-ed out at startup. > > -- > Ross Lagerwall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
