Re: [PATCH] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled

[Jisheng Zhang]

On Mon, 24 May 2021 12:05:21 +0200 Marco Elver wrote:

> 
> 
> On Mon, 24 May 2021 at 09:38, Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx> wrote:
> >
> > Fix below warning if KFENCE=y but RODATA_FULL=n:
> >  
> 
> Is this patch still relevant given you just sent "arm64: remove page
> granularity limitation from KFENCE" ?

This patch fixes a bug, so I suppose it needs to merged for linux-5.13-rcN
While the "arm64: remove page granularity limitation from KFENCE" series
is an optimization, so it need to wait for next version, I.E linux-5.14

thanks

> 
> > [    0.000000] ------------[ cut here ]------------
> > [    0.000000] WARNING: CPU: 0 PID: 0 at mm/memory.c:2462 apply_to_pmd_range+0xec/0x190
> > [    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc1+ #10
> > [    0.000000] Hardware name: linux,dummy-virt (DT)
> > [    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
> > [    0.000000] pc : apply_to_pmd_range+0xec/0x190
> > [    0.000000] lr : __apply_to_page_range+0x94/0x170
> > [    0.000000] sp : ffffffc010573e20
> > [    0.000000] x29: ffffffc010573e20 x28: ffffff801f400000 x27: ffffff801f401000
> > [    0.000000] x26: 0000000000000001 x25: ffffff801f400fff x24: ffffffc010573f28
> > [    0.000000] x23: ffffffc01002b710 x22: ffffffc0105fa450 x21: ffffffc010573ee4
> > [    0.000000] x20: ffffff801fffb7d0 x19: ffffff801f401000 x18: 00000000fffffffe
> > [    0.000000] x17: 000000000000003f x16: 000000000000000a x15: ffffffc01060b940
> > [    0.000000] x14: 0000000000000000 x13: 0098968000000000 x12: 0000000098968000
> > [    0.000000] x11: 0000000000000000 x10: 0000000098968000 x9 : 0000000000000001
> > [    0.000000] x8 : 0000000000000000 x7 : ffffffc010573ee4 x6 : 0000000000000001
> > [    0.000000] x5 : ffffffc010573f28 x4 : ffffffc01002b710 x3 : 0000000040000000
> > [    0.000000] x2 : ffffff801f5fffff x1 : 0000000000000001 x0 : 007800005f400705
> > [    0.000000] Call trace:
> > [    0.000000]  apply_to_pmd_range+0xec/0x190
> > [    0.000000]  __apply_to_page_range+0x94/0x170
> > [    0.000000]  apply_to_page_range+0x10/0x20
> > [    0.000000]  __change_memory_common+0x50/0xdc
> > [    0.000000]  set_memory_valid+0x30/0x40
> > [    0.000000]  kfence_init_pool+0x9c/0x16c
> > [    0.000000]  kfence_init+0x20/0x98
> > [    0.000000]  start_kernel+0x284/0x3f8
> >
> > Fixes: 840b23986344 ("arm64, kfence: enable KFENCE for ARM64")
> > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
> > ---
> >  arch/arm64/mm/mmu.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> > index 6dd9369e3ea0..89b66ef43a0f 100644
> > --- a/arch/arm64/mm/mmu.c
> > +++ b/arch/arm64/mm/mmu.c
> > @@ -515,7 +515,8 @@ static void __init map_mem(pgd_t *pgdp)
> >          */
> >         BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
> >
> > -       if (rodata_full || crash_mem_map || debug_pagealloc_enabled())
> > +       if (rodata_full || crash_mem_map || debug_pagealloc_enabled() ||
> > +           IS_ENABLED(CONFIG_KFENCE))
> >                 flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
> >
> >         /*
> > --
> > 2.31.0
> >