Re: [PATCH 1/3] RISC-V: Fix .init section permission update

From: Palmer Dabbelt
Date: Tue Feb 02 2021 - 21:36:05 EST


On Fri, 29 Jan 2021 11:00:36 PST (-0800), Atish Patra wrote:
.init section permission should only updated to non-execute if
STRICT_KERNEL_RWX is enabled. Otherwise, this will lead to a kernel hang.

Fixes: 19a00869028f ("RISC-V: Protect all kernel sections including init early")

Suggested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
---
arch/riscv/kernel/setup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 3fa3f26dde85..c7c0655dd45b 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -293,6 +293,8 @@ void free_initmem(void)
unsigned long init_begin = (unsigned long)__init_begin;
unsigned long init_end = (unsigned long)__init_end;

- set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
+ if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
+ set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
+
free_initmem_default(POISON_FREE_INITMEM);
}

Thanks, this is on fixes.