On Mon, 2019-06-03 at 13:00:51 UTC, Christophe Leroy wrote: > When booting through OF, setup_disp_bat() does nothing because > disp_BAT are not set. By change, it used to work because BOOTX > buffer is mapped 1:1 at address 0x81000000 by the bootloader, and > btext_setup_display() sets virt addr same as phys addr. > > But since commit 215b823707ce ("powerpc/32s: set up an early static > hash table for KASAN."), a temporary page table overrides the > bootloader mapping. > > This 0x81000000 is also problematic with the newly implemented > Kernel Userspace Access Protection (KUAP) because it is within user > address space. > > This patch fixes those issues by properly setting disp_BAT through > a call to btext_prepare_BAT(), allowing setup_disp_bat() to > properly setup BAT3 for early bootx screen buffer access. > > Reported-by: Mathieu Malaterre <ma...@debian.org> > Fixes: 215b823707ce ("powerpc/32s: set up an early static hash table for > KASAN.") > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > Tested-by: Mathieu Malaterre <ma...@debian.org>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/c21f5a9ed85ca3e914ca11f421677ae9 cheers