Date:   Wed, 05 Jan 2022 20:00:28 -0800 (PST)
Subject:     Re: [PATCH] riscv: Make vmalloc/vmemmap end equal to the start of the next region
In-Reply-To: <20211118134539.137212-1-alexandre.ghiti@canonical.com>
CC:     Paul Walmsley <paul.walmsley@sifive.com>, aou@eecs.berkeley.edu,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        alexandre.ghiti@canonical.com
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     alexandre.ghiti@canonical.com
Message-ID: <mhng-2006bfc7-264b-4d1b-96a3-6b4a012f8be9@palmer-ri-x1c9>
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On Thu, 18 Nov 2021 05:45:39 PST (-0800), alexandre.ghiti@canonical.com wrote:
> We used to define VMALLOC_END equal to the start of the next region
> *minus one* which is inconsistent with the use of this define in the
> core code (for example, see the definitions of VMALLOC_TOTAL and
> is_vmalloc_addr).
>
> And then make the definition of VMEMMAP_END consistent with VMALLOC_END
> and all other regions actually.
>
> Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
> ---
>  arch/riscv/include/asm/pgtable.h | 4 ++--
>  arch/riscv/mm/fault.c            | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index d34f3a7a9701..5155048274c2 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -25,7 +25,7 @@
>  #endif
>
>  #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
> -#define VMALLOC_END      (PAGE_OFFSET - 1)
> +#define VMALLOC_END      PAGE_OFFSET
>  #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
>
>  #define BPF_JIT_REGION_SIZE	(SZ_128M)
> @@ -53,7 +53,7 @@
>  #define VMEMMAP_SHIFT \
>  	(CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>  #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
> -#define VMEMMAP_END	(VMALLOC_START - 1)
> +#define VMEMMAP_END	VMALLOC_START
>  #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
>
>  /*
> diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
> index aa08dd2f8fae..41ae0aa8f2b8 100644
> --- a/arch/riscv/mm/fault.c
> +++ b/arch/riscv/mm/fault.c
> @@ -235,7 +235,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
>  	 * only copy the information from the master page table,
>  	 * nothing more.
>  	 */
> -	if (unlikely((addr >= VMALLOC_START) && (addr <= VMALLOC_END))) {
> +	if (unlikely((addr >= VMALLOC_START) && (addr < VMALLOC_END))) {
>  		vmalloc_fault(regs, code, addr);
>  		return;
>  	}

Thanks, this is on for-next.