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Date:   Thu, 05 Nov 2020 21:15:23 -0800 (PST)
Subject:     Re: [PATCH v3] riscv: fix pfn_to_virt err in do_page_fault().
In-Reply-To: <1603715214-29082-1-git-send-email-liush@allwinnertech.com>
CC:     Paul Walmsley <paul.walmsley@sifive.com>, aou@eecs.berkeley.edu,
        penberg@kernel.org, akpm@linux-foundation.org, peterx@redhat.com,
        vbabka@suse.cz, walken@google.com, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, liush@allwinnertech.com
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     liush@allwinnertech.com
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On Mon, 26 Oct 2020 05:26:54 PDT (-0700), liush@allwinnertech.com wrote:
> From: Liu Shaohua <liush@allwinnertech.com>
>
> The argument to pfn_to_virt() should be pfn not the value of CSR_SATP.
>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Signed-off-by: liush <liush@allwinnertech.com>
> ---
>  arch/riscv/mm/fault.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
> index 1359e21..3c8b9e4 100644
> --- a/arch/riscv/mm/fault.c
> +++ b/arch/riscv/mm/fault.c
> @@ -86,6 +86,7 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
>  	pmd_t *pmd, *pmd_k;
>  	pte_t *pte_k;
>  	int index;
> +	unsigned long pfn;
>
>  	/* User mode accesses just cause a SIGSEGV */
>  	if (user_mode(regs))
> @@ -100,7 +101,8 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
>  	 * of a task switch.
>  	 */
>  	index = pgd_index(addr);
> -	pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
> +	pfn = csr_read(CSR_SATP) & SATP_PPN;
> +	pgd = (pgd_t *)pfn_to_virt(pfn) + index;
>  	pgd_k = init_mm.pgd + index;
>
>  	if (!pgd_present(*pgd_k)) {

This is on fixes, thanks!