Jürgen Groß, le mer. 07 févr. 2024 12:43:03 +0100, a ecrit: > On 07.02.24 12:34, Samuel Thibault wrote: > > Jürgen Groß, le mer. 07 févr. 2024 12:16:44 +0100, a ecrit: > > > On 07.02.24 12:00, Samuel Thibault wrote: > > > > Jürgen Groß, le mer. 07 févr. 2024 11:42:20 +0100, a ecrit: > > > > > while implementing kexec in Mini-OS. > > > > > > > > Oh, nice :D > > > > > > > > > For that I need it for sure. > > > > > > > > It needs to be done by kexec itself then. > > > > > > That's another option, yes. > > > > > > The question is whether we want to support to be kexec-ed from other > > > systems, too. > > > > But aren't other systems' kexec supports supposed to do the memset? > > > > They really should. > > I guess there is a reason why the Linux kernel does clear its .bss section > in early boot. Maybe it is due to how the boot process works (the ELF file > is encapsulated in vmlinuz),
Yes, the unpack prevents grub etc. from doing it. > but following your reasoning they should have cleared their .bss while > unpacking the ELF contents, not while booting the contents. AIUI the decompressor itself doesn't actually know about ELF. decompress_kernel() does call handle_relocations(), but it should indeed clear bss itself and not leave it out to assembly indeed. > I'm not sure they do the .bss clearing in kexec either, AIUI they do, see kimage_load_normal_segment() which clears the page before possibly loading some file piece into it. Really, this is part of what "loading an ELF" means. Samuel
