Ensure WP bit to be set to prevent boot code from writing to non-writable memory pages. Tested-by: Mario Limonciello <mario.limonciello@xxxxxxx> 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 03c4328a88cb..01fa42d31648 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -660,9 +660,8 @@ SYM_CODE_START(trampoline_32bit_src) pushl $__KERNEL_CS pushl %eax - /* Enable paging again. */ - movl %cr0, %eax - btsl $X86_CR0_PG_BIT, %eax + /* Enable paging and set CR0 to known state (this also sets WP flag) */ + movl $CR0_STATE, %eax movl %eax, %cr0 lret -- 2.39.2
