From 0290c9e328e04052e317171953feb18177a34aed Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 16 Nov 2020 08:06:41 +0100 Subject: s390/mm: use invalid asce instead of kernel asce Create a region 3 page table which contains only invalid entries, and use that via "s390_invalid_asce" instead of the kernel ASCE whenever there is either - no user address space available, e.g. during early startup - as an intermediate ASCE when address spaces are switched This makes sure that user space accesses in such situations are guaranteed to fail. Reviewed-by: Sven Schnelle Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens --- arch/s390/kernel/vmlinux.lds.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/s390/kernel/vmlinux.lds.S') diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 177ccfbda40a..4c0e19145cc6 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -10,7 +10,8 @@ * Put .bss..swapper_pg_dir as the first thing in .bss. This will * make sure it has 16k alignment. */ -#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir) +#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir) \ + *(.bss..invalid_pg_dir) /* Handle ro_after_init data on our own. */ #define RO_AFTER_INIT_DATA -- cgit