2020-09-18 08:58:04

by 刘邵华BTD

Subject: [V2] riscv: fix pfn_to_virt err in do_page_fault().

The argument to pfn_to_virt() should be pfn not the value of CSR_SATP.

Signed-off-by: liush <[email protected]>
---
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 716d64e..3e560ec13 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -198,6 +198,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
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))
@@ -212,7 +213,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* 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))
--
2.7.4

2020-09-27 00:38:04

by Palmer Dabbelt

Subject: Re: [V2] riscv: fix pfn_to_virt err in do_page_fault().

On Fri, 18 Sep 2020 01:55:58 PDT (-0700), [email protected] wrote:
> The argument to pfn_to_virt() should be pfn not the value of CSR_SATP.

Reviewed-by: Palmer Dabbelt <[email protected]>

> Signed-off-by: liush <[email protected]>

IIUC you're supposed to use an actual name.

> ---
> 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 716d64e..3e560ec13 100644
> --- a/arch/riscv/mm/fault.c
> +++ b/arch/riscv/mm/fault.c
> @@ -198,6 +198,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
> 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))
> @@ -212,7 +213,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
> * 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))