On Thu, May 02, 2013 at 02:34:38PM +0200, Pavel Machek wrote: > Hi! > > > The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 > > ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path > > is not needed.") assumes that for the hibernate path the booting > > kernel and the resuming kernel MUST be the same. That is certainly > > the case for a 32-bit kernel (see check_image_kernel and > > CONFIG_ARCH_HIBERNATION_HEADER config option). > > > > However for 64-bit kernels it is OK to have a different kernel > > version (and size of the image) of the booting and resuming kernels. > > Hence the above mentioned git commit introduces an regression. > > Ok. > > > This patch fixes it by introducing a 'struct desc_ptr gdt_desc' > > back in the 'struct saved_context'. However instead of having in the > > 'save_processor_state' and 'restore_processor_state' the > > store/load_gdt calls, we are only saving the GDT in the > > save_processor_state. > > > > For the restore path the lgdt operation is done in > > hibernate_asm_[32|64].S in the 'restore_registers' path. > > So the on-disk format changed and we need to bump the version number > somewhere?
Fortunatly not. The patch (7a5cd063c7b4c58417f674821d63f5eb6747e37) that just just landed in Linus a couple of days ago did change it a bit (as the 'saved_context' struct shrunk), but this patch brings it back to what it was before. But I don't know if the 'saved_context' structure is actually somewhere specifically mentioned as 'on-disk' or in the kernel. Looking at the code, I think the on-disk structure you are referring to is the 'struct restore_data_record' (please correct me if I am incorrect) which has not been affected by any of these patches. > > I guess we should add big fat warning to the affected structures. We certainly can. I can prep a patch to that affect on Friday or Monday. > > Pavel > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/