| Message ID | 20200531095748.753388-1-anup.patel@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | RISC-V: Don't mark init section as non-executable | expand |
On Sun, May 31, 2020 at 3:28 PM Anup Patel <anup.patel@wdc.com> wrote: > > 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> > --- > arch/riscv/mm/init.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 736de6c8739f..e0f8ccab8a41 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -482,11 +482,6 @@ static void __init setup_vm_final(void) > > 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); > } I just realized that updated free_initmem() over here is exactly same as generic free_initmem() defined in init/main.c so it's better to remove free_initmem() from here. I will send v2. Regards, Anup
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 736de6c8739f..e0f8ccab8a41 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -482,11 +482,6 @@ static void __init setup_vm_final(void) 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); }
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> --- arch/riscv/mm/init.c | 5 ----- 1 file changed, 5 deletions(-)