[PATCH 5.7 349/376] RISC-V: Dont mark init section as non-executable

From: Greg Kroah-Hartman
Date: Fri Jun 19 2020 - 11:34:08 EST


From: Anup Patel <anup.patel@xxxxxxx>

commit 4e0f9e3a6104261f25b16fcab02fc96f5666ba11 upstream.

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>
Reviewed-by: Zong Li <zong.li@xxxxxxxxxx>
Reviewed-by: Atish Patra <atish.patra@xxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/riscv/mm/init.c | 11 -----------
1 file changed, 11 deletions(-)

--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -479,17 +479,6 @@ static void __init setup_vm_final(void)
csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
local_flush_tlb_all();
}
-
-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);
- free_initmem_default(POISON_FREE_INITMEM);
-}
-
#else
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{