Since all processes share the kernel address space,
we only need to copy pgd in case of a vmalloc page
fault exception, the other levels of page tables are
shared, so the operation of copying pmd is unnecessary.
Signed-off-by: hanchuanhua <[email protected]>
---
arch/riscv/mm/fault.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 4e9efbe..40694f0 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -102,9 +102,9 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code
static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
{
pgd_t *pgd, *pgd_k;
- pud_t *pud, *pud_k;
- p4d_t *p4d, *p4d_k;
- pmd_t *pmd, *pmd_k;
+ pud_t *pud_k;
+ p4d_t *p4d_k;
+ pmd_t *pmd_k;
pte_t *pte_k;
int index;
unsigned long pfn;
@@ -132,14 +132,12 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
}
set_pgd(pgd, *pgd_k);
- p4d = p4d_offset(pgd, addr);
p4d_k = p4d_offset(pgd_k, addr);
if (!p4d_present(*p4d_k)) {
no_context(regs, addr);
return;
}
- pud = pud_offset(p4d, addr);
pud_k = pud_offset(p4d_k, addr);
if (!pud_present(*pud_k)) {
no_context(regs, addr);
@@ -150,13 +148,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
* Since the vmalloc area is global, it is unnecessary
* to copy individual PTEs
*/
- pmd = pmd_offset(pud, addr);
pmd_k = pmd_offset(pud_k, addr);
if (!pmd_present(*pmd_k)) {
no_context(regs, addr);
return;
}
- set_pmd(pmd, *pmd_k);
/*
* Make sure the actual PTE exists as well to
--
2.7.4
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On Thu, 27 Jan 2022 02:06:22 PST (-0800), [email protected] wrote:
> Since all processes share the kernel address space,
> we only need to copy pgd in case of a vmalloc page
> fault exception, the other levels of page tables are
> shared, so the operation of copying pmd is unnecessary.
>
> Signed-off-by: hanchuanhua <[email protected]>
> ---
> arch/riscv/mm/fault.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
> index 4e9efbe..40694f0 100644
> --- a/arch/riscv/mm/fault.c
> +++ b/arch/riscv/mm/fault.c
> @@ -102,9 +102,9 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code
> static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
> {
> pgd_t *pgd, *pgd_k;
> - pud_t *pud, *pud_k;
> - p4d_t *p4d, *p4d_k;
> - pmd_t *pmd, *pmd_k;
> + pud_t *pud_k;
> + p4d_t *p4d_k;
> + pmd_t *pmd_k;
> pte_t *pte_k;
> int index;
> unsigned long pfn;
> @@ -132,14 +132,12 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
> }
> set_pgd(pgd, *pgd_k);
>
> - p4d = p4d_offset(pgd, addr);
> p4d_k = p4d_offset(pgd_k, addr);
> if (!p4d_present(*p4d_k)) {
> no_context(regs, addr);
> return;
> }
>
> - pud = pud_offset(p4d, addr);
> pud_k = pud_offset(p4d_k, addr);
> if (!pud_present(*pud_k)) {
> no_context(regs, addr);
> @@ -150,13 +148,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
> * Since the vmalloc area is global, it is unnecessary
> * to copy individual PTEs
> */
> - pmd = pmd_offset(pud, addr);
> pmd_k = pmd_offset(pud_k, addr);
> if (!pmd_present(*pmd_k)) {
> no_context(regs, addr);
> return;
> }
> - set_pmd(pmd, *pmd_k);
>
> /*
> * Make sure the actual PTE exists as well to
This looks good, but "Signed off by" lines are supposed to have real
names associated with them and this looks like a handle to me. There
also seems to be something broken with the email, as this is causing git
to blow up, but for a small patch like this that's OK as I can resurrect
it by hand.
Reviewed-by: Palmer Dabbelt <[email protected]> # aside from the name
Please send a v2 with the proper Signed off by line, as that's not
something I'm supposed to just fix up myself.
Thanks!
On 2022/2/23 5:25, Palmer Dabbelt wrote:
> On Thu, 27 Jan 2022 02:06:22 PST (-0800), [email protected] wrote:
>> Since all processes share the kernel address space,
>> we only need to copy pgd in case of a vmalloc page
>> fault exception, the other levels of page tables are
>> shared, so the operation of copying pmd is unnecessary.
>>
>> Signed-off-by: hanchuanhua <[email protected]>
>> ---
>> arch/riscv/mm/fault.c | 10 +++-------
>> 1 file changed, 3 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
>> index 4e9efbe..40694f0 100644
>> --- a/arch/riscv/mm/fault.c
>> +++ b/arch/riscv/mm/fault.c
>> @@ -102,9 +102,9 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code
>> static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
>> {
>> pgd_t *pgd, *pgd_k;
>> - pud_t *pud, *pud_k;
>> - p4d_t *p4d, *p4d_k;
>> - pmd_t *pmd, *pmd_k;
>> + pud_t *pud_k;
>> + p4d_t *p4d_k;
>> + pmd_t *pmd_k;
>> pte_t *pte_k;
>> int index;
>> unsigned long pfn;
>> @@ -132,14 +132,12 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
>> }
>> set_pgd(pgd, *pgd_k);
>>
>> - p4d = p4d_offset(pgd, addr);
>> p4d_k = p4d_offset(pgd_k, addr);
>> if (!p4d_present(*p4d_k)) {
>> no_context(regs, addr);
>> return;
>> }
>>
>> - pud = pud_offset(p4d, addr);
>> pud_k = pud_offset(p4d_k, addr);
>> if (!pud_present(*pud_k)) {
>> no_context(regs, addr);
>> @@ -150,13 +148,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
>> * Since the vmalloc area is global, it is unnecessary
>> * to copy individual PTEs
>> */
>> - pmd = pmd_offset(pud, addr);
>> pmd_k = pmd_offset(pud_k, addr);
>> if (!pmd_present(*pmd_k)) {
>> no_context(regs, addr);
>> return;
>> }
>> - set_pmd(pmd, *pmd_k);
>>
>> /*
>> * Make sure the actual PTE exists as well to
> This looks good, but "Signed off by" lines are supposed to have real
> names associated with them and this looks like a handle to me. There
> also seems to be something broken with the email, as this is causing git
> to blow up, but for a small patch like this that's OK as I can resurrect
> it by hand.
>
> Reviewed-by: Palmer Dabbelt <[email protected]> # aside from the name
>
> Please send a v2 with the proper Signed off by line, as that's not
> something I'm supposed to just fix up myself.
>
> Thanks!
First of all, thank you for your review and reply. I don't quite
understand what's wrong with the line "Signed off by"?
Thanks!
________________________________
OPPO
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This e-mail and its attachments contain confidential information from OPPO, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!