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    Subject[PATCH 5.7 349/376] RISC-V: Dont mark init section as non-executable
    Date
    From: Anup Patel <anup.patel@wdc.com>

    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>

    ---
    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)
    {

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