On Fri, Aug 30, 2019 at 08:06:38AM -0400, Sasha Levin wrote: > On Fri, Aug 30, 2019 at 01:17:23AM +0300, Kirill A. Shutemov wrote: > > On Thu, Aug 29, 2019 at 02:12:46PM -0400, Sasha Levin wrote: > > > From: "Kirill A. Shutemov" <[email protected]> > > > > > > [ Upstream commit 0a46fff2f9108c2c44218380a43a736cf4612541 ] > > > > > > BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that > > > consists of 2 entries: > > > > > > BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable > > > BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved > > > > > > It breaks logic in find_trampoline_placement(): bios_start lands on the > > > end of the first 4k page and trampoline start gets placed below 0. > > > > > > Detect underflow and don't touch bios_start for such cases. It makes > > > kernel ignore E820 table on machines that doesn't have two usable pages > > > below BIOS_START_MAX. > > > > > > Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline > > > placement against E820") > > > Signed-off-by: Kirill A. Shutemov <[email protected]> > > > Signed-off-by: Borislav Petkov <[email protected]> > > > Cc: "H. Peter Anvin" <[email protected]> > > > Cc: Ingo Molnar <[email protected]> > > > Cc: Thomas Gleixner <[email protected]> > > > Cc: x86-ml <[email protected]> > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463 > > > Link: > > > https://lkml.kernel.org/r/[email protected] > > > Signed-off-by: Sasha Levin <[email protected]> > > > > Please postpone backporting the patch (and into other trees). There's a > > fixup for it: > > > > http://lore.kernel.org/r/20190826133326.7cxb4vbmiawffv2r@box > > Sure. Should I just queue it up for a week or two later (along with the > fixes), or do you want to let me know when?
You can queue it up later (two weeks is fine) once the fixup hit Linus' tree. -- Kirill A. Shutemov
