Unverified Commit 4e0f9e3a authored Jun 01, 2020 by Anup Patel Committed by Palmer Dabbelt Jun 09, 2020

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



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: d27c3c90 ("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>

parent e71ee06e

arch/riscv/mm/init.c

+0 −11

Original line number	Diff line number	Diff line
		@@ -481,17 +481,6 @@ 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)
		{

Admin message