On Tue, 6 Sept 2022 at 12:41, Evgeniy Baskov <baskov@xxxxxxxxx> wrote: > > Ensure WP bit to be set to prevent boot code from writing to > non-writable memory pages. > > Signed-off-by: Evgeniy Baskov <baskov@xxxxxxxxx> > --- > arch/x86/boot/compressed/head_64.S | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S > index d33f060900d2..5273367283b7 100644 > --- a/arch/x86/boot/compressed/head_64.S > +++ b/arch/x86/boot/compressed/head_64.S > @@ -619,9 +619,8 @@ SYM_CODE_START(trampoline_32bit_src) > /* Set up new stack */ > leal TRAMPOLINE_32BIT_STACK_END(%ecx), %esp > > - /* Disable paging */ > - movl %cr0, %eax > - btrl $X86_CR0_PG_BIT, %eax Why do we no longer care about CR0's prior value? > + /* Disable paging and setup CR0 */ > + movl $(CR0_STATE & ~X86_CR0_PG), %eax > movl %eax, %cr0 > > /* Check what paging mode we want to be in after the trampoline */ > -- > 2.35.1 >
