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

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@vger.kernel.org
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 736de6c8739fcf3ab005864f5ed5701c0b0f6fd1..fdc772f57edc3e46106f43f2b82a3a34fb402eb4 100644 (file)
--- 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)
 {