On Tue, 17 Dec 2024 at 10:19, Linus Torvalds torvalds@linux-foundation.org wrote:
What *woiuld* have been an acceptable model is to actually modify the boot-time buffers in place, using actual real heuristics that look at whether a pointer was IN THE CODE SECTION OR THE STATIC DATA section of the previous boot.
But you never did that. All this delta code has always been complete and utter garbage, and complete hacks.
Actually, I think the proper model isn't even that "modify boot time buffers in place" thing.
The proper model was probably always to just do the "give the raw data, and analyze the previous boot data in user mode". Don't do "delta between old and new kernel", print out the actual KASLR base of the old kernel, and let user mode figure it out. Because user mode may actually have the old and different vmlinux image too - something that kernel mode *never* has.
Linus