Messages in this thread | | | Date | Thu, 2 May 2013 14:34:38 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] x86, x86-64, gdt, hibernate: Store/load GDT for hibernate path. |
| |
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?
I guess we should add big fat warning to the affected structures.
Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
| |