[PATCH] RISC-V: Don't mark init section as non-executable

From: Anup Patel
Date: Sun May 31 2020 - 05:58:28 EST

The head text section (i.e. _start, secondary_start_sbi, etc) and the
init section fall under same page table level-1 mapping.

Currently, the runtime CPU hotplug is broken because we are marking
init section as non-executable which in-turn marks head text section
as non-executable.

Further investigating other architectures, it seems marking the init
section as non-executable is redundant because the init section pages
are anyway poisoned and freed.

To fix broken runtime CPU hotplug, we simply remove the code marking
the init section as non-executable.

Fixes: d27c3c90817e ("riscv: add STRICT_KERNEL_RWX support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
arch/riscv/mm/init.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 736de6c8739f..e0f8ccab8a41 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -482,11 +482,6 @@ static void __init setup_vm_final(void)

void free_initmem(void)
- unsigned long init_begin = (unsigned long)__init_begin;
- unsigned long init_end = (unsigned long)__init_end;
- /* Make the region as non-execuatble. */
- set_memory_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);