Re: [PATCH 1/4] riscv: Fix TASK_SIZE on 64-bit NOMMU

[Bo Gan]

On 3/27/24 12:04 AM, Jisheng Zhang wrote:
> On Mon, Feb 26, 2024 at 04:34:46PM -0800, Samuel Holland wrote:
> > On NOMMU, userspace memory can come from anywhere in physical RAM. The
> > current definition of TASK_SIZE is wrong if any RAM exists above 4G,
> > causing spurious failures in the userspace access routines.
> >
> > Fixes: 6bd33e1ece52 ("riscv: add nommu support")
> > Fixes: c3f896dcf1e4 ("mm: switch the test_vmalloc module to use __vmalloc_node")
> > Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
>
> Reviewed-by: Jisheng Zhang <jszhang@xxxxxxxxxx>

Reviewed-by: Bo Gan <ganboing@xxxxxxxxx>

Thanks for this patch! I'm doing something similar locally and it fixes the
linux nommu + musl libc build on my JH7110 S7 core.

Bo

> > ---
> >
> >   arch/riscv/include/asm/pgtable.h | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index 0c94260b5d0c..a564a39e5676 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -882,7 +882,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
> >   #define PAGE_SHARED		__pgprot(0)
> >   #define PAGE_KERNEL		__pgprot(0)
> >   #define swapper_pg_dir		NULL
> > -#define TASK_SIZE		0xffffffffUL
> > +#define TASK_SIZE		_AC(-1, UL)
> >   #define VMALLOC_START		_AC(0, UL)
> >   #define VMALLOC_END		TASK_SIZE
> >   
> > --
> > 2.43.0
> >
> >
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>
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