find_vma_intersection() has been existing to search the intersected
vma. This uses the function where it's applicable, to simplify the
code.
Signed-off-by: Gavin Shan <[email protected]>
---
arch/arm64/kvm/mmu.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 84e70f953de6..286b603ed0d3 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
* +--------------------------------------------+
*/
do {
- struct vm_area_struct *vma = find_vma(current->mm, hva);
+ struct vm_area_struct *vma;
hva_t vm_start, vm_end;
- if (!vma || vma->vm_start >= reg_end)
+ vma = find_vma_intersection(current->mm, hva, reg_end);
+ if (!vma)
break;
/*
@@ -1330,10 +1331,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
* +--------------------------------------------+
*/
do {
- struct vm_area_struct *vma = find_vma(current->mm, hva);
+ struct vm_area_struct *vma;
hva_t vm_start, vm_end;
- if (!vma || vma->vm_start >= reg_end)
+ vma = find_vma_intersection(current->mm, hva, reg_end);
+ if (!vma)
break;
/*
--
2.23.0
Hi Gavin,
On 2021/3/15 12:18, Gavin Shan wrote:
> find_vma_intersection() has been existing to search the intersected
> vma. This uses the function where it's applicable, to simplify the
> code.
>
> Signed-off-by: Gavin Shan <[email protected]>
> ---
> arch/arm64/kvm/mmu.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 84e70f953de6..286b603ed0d3 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
> * +--------------------------------------------+
> */
> do {
> - struct vm_area_struct *vma = find_vma(current->mm, hva);
> + struct vm_area_struct *vma;
> hva_t vm_start, vm_end;
>
> - if (!vma || vma->vm_start >= reg_end)
> + vma = find_vma_intersection(current->mm, hva, reg_end);
Nit: Keep a same style may be better(Assign vma when declare it).
Other looks good to me.
Thank,
Keqian
> + if (!vma)
> break;
>
> /*
> @@ -1330,10 +1331,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
> * +--------------------------------------------+
> */
> do {
> - struct vm_area_struct *vma = find_vma(current->mm, hva);
> + struct vm_area_struct *vma;
> hva_t vm_start, vm_end;
>
> - if (!vma || vma->vm_start >= reg_end)
> + vma = find_vma_intersection(current->mm, hva, reg_end);
> + if (!vma)
> break;
>
> /*
>
On Mon, 15 Mar 2021 04:18:42 +0000,
Gavin Shan <[email protected]> wrote:
>
> find_vma_intersection() has been existing to search the intersected
> vma. This uses the function where it's applicable, to simplify the
> code.
>
> Signed-off-by: Gavin Shan <[email protected]>
> ---
> arch/arm64/kvm/mmu.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 84e70f953de6..286b603ed0d3 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
> * +--------------------------------------------+
> */
> do {
> - struct vm_area_struct *vma = find_vma(current->mm, hva);
> + struct vm_area_struct *vma;
> hva_t vm_start, vm_end;
>
> - if (!vma || vma->vm_start >= reg_end)
> + vma = find_vma_intersection(current->mm, hva, reg_end);
For context, here's the definition of find_vma_intersection():
<quote>
static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
{
struct vm_area_struct * vma = find_vma(mm,start_addr);
if (vma && end_addr <= vma->vm_start)
vma = NULL;
return vma;
}
</quote>
It seems that there is a boundary issue in either the old code or the
new one in the case where (reg_end == vma->start).
Which one is which?
M.
--
Without deviation from the norm, progress is not possible.
Hi Marc,
On 3/15/21 7:52 PM, Marc Zyngier wrote:
> On Mon, 15 Mar 2021 04:18:42 +0000,
> Gavin Shan <[email protected]> wrote:
>>
>> find_vma_intersection() has been existing to search the intersected
>> vma. This uses the function where it's applicable, to simplify the
>> code.
>>
>> Signed-off-by: Gavin Shan <[email protected]>
>> ---
>> arch/arm64/kvm/mmu.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
>> index 84e70f953de6..286b603ed0d3 100644
>> --- a/arch/arm64/kvm/mmu.c
>> +++ b/arch/arm64/kvm/mmu.c
>> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
>> * +--------------------------------------------+
>> */
>> do {
>> - struct vm_area_struct *vma = find_vma(current->mm, hva);
>> + struct vm_area_struct *vma;
>> hva_t vm_start, vm_end;
>>
>> - if (!vma || vma->vm_start >= reg_end)
>> + vma = find_vma_intersection(current->mm, hva, reg_end);
>
> For context, here's the definition of find_vma_intersection():
>
> <quote>
> static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
> {
> struct vm_area_struct * vma = find_vma(mm,start_addr);
>
> if (vma && end_addr <= vma->vm_start)
> vma = NULL;
> return vma;
> }
> </quote>
>
> It seems that there is a boundary issue in either the old code or the
> new one in the case where (reg_end == vma->start).
>
> Which one is which?
>
The old and new code is interchangeable, meaning "reg_end == vma->start"
is invalid in both cases. So if there is a boundary issue, the old and new
code should have same issue.
According to the code, "reg_end == vma->start" is invalid. So I don't see
there is a boundary issue. Hopefully, I don't miss anything :)
Thanks,
Gavin
Hi Keqian,
On 3/15/21 7:04 PM, Keqian Zhu wrote:
> On 2021/3/15 12:18, Gavin Shan wrote:
>> find_vma_intersection() has been existing to search the intersected
>> vma. This uses the function where it's applicable, to simplify the
>> code.
>>
>> Signed-off-by: Gavin Shan <[email protected]>
>> ---
>> arch/arm64/kvm/mmu.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
>> index 84e70f953de6..286b603ed0d3 100644
>> --- a/arch/arm64/kvm/mmu.c
>> +++ b/arch/arm64/kvm/mmu.c
>> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
>> * +--------------------------------------------+
>> */
>> do {
>> - struct vm_area_struct *vma = find_vma(current->mm, hva);
>> + struct vm_area_struct *vma;
>> hva_t vm_start, vm_end;
>>
>> - if (!vma || vma->vm_start >= reg_end)
>> + vma = find_vma_intersection(current->mm, hva, reg_end);
> Nit: Keep a same style may be better(Assign vma when declare it).
> Other looks good to me.
>
Yeah, I agree. I will adjust the code in v2 and included your r-b.
Thanks for your time to review.
Thanks,
Gavin
>> + if (!vma)
>> break;
>>
>> /*
>> @@ -1330,10 +1331,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
>> * +--------------------------------------------+
>> */
>> do {
>> - struct vm_area_struct *vma = find_vma(current->mm, hva);
>> + struct vm_area_struct *vma;
>> hva_t vm_start, vm_end;
>>
>> - if (!vma || vma->vm_start >= reg_end)
>> + vma = find_vma_intersection(current->mm, hva, reg_end);
>> + if (!vma)
>> break;
>>
>> /*
>>
>
Hi Keqian,
On 3/15/21 8:42 PM, Gavin Shan wrote:
> On 3/15/21 7:04 PM, Keqian Zhu wrote:
>> On 2021/3/15 12:18, Gavin Shan wrote:
>>> find_vma_intersection() has been existing to search the intersected
>>> vma. This uses the function where it's applicable, to simplify the
>>> code.
>>>
>>> Signed-off-by: Gavin Shan <[email protected]>
>>> ---
>>> ? arch/arm64/kvm/mmu.c | 10 ++++++----
>>> ? 1 file changed, 6 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
>>> index 84e70f953de6..286b603ed0d3 100644
>>> --- a/arch/arm64/kvm/mmu.c
>>> +++ b/arch/arm64/kvm/mmu.c
>>> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
>>> ?????? *???? +--------------------------------------------+
>>> ?????? */
>>> ????? do {
>>> -??????? struct vm_area_struct *vma = find_vma(current->mm, hva);
>>> +??????? struct vm_area_struct *vma;
>>> ????????? hva_t vm_start, vm_end;
>>> -??????? if (!vma || vma->vm_start >= reg_end)
>>> +??????? vma = find_vma_intersection(current->mm, hva, reg_end);
>> Nit: Keep a same style may be better(Assign vma when declare it).
>> Other looks good to me.
>>
>
> Yeah, I agree. I will adjust the code in v2 and included your r-b.
> Thanks for your time to review.
>
After rechecking the code, I think it'd better to keep current style
because there is a follow-on validation on @vma. Keeping them together
seems a good idea. I think it wouldn't a big deal to you. So I will
keep current style with your r-b in v2.
vma = find_vma_intersection(current->mm, hva, reg_end);
if (!vma)
break;
Thanks,
Gavin
>>> +??????? if (!vma)
>>> ????????????? break;
>>> ????????? /*
>>> @@ -1330,10 +1331,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
>>> ?????? *???? +--------------------------------------------+
>>> ?????? */
>>> ????? do {
>>> -??????? struct vm_area_struct *vma = find_vma(current->mm, hva);
>>> +??????? struct vm_area_struct *vma;
>>> ????????? hva_t vm_start, vm_end;
>>> -??????? if (!vma || vma->vm_start >= reg_end)
>>> +??????? vma = find_vma_intersection(current->mm, hva, reg_end);
>>> +??????? if (!vma)
>>> ????????????? break;
>>> ????????? /*
>>>
>>
>
Hi Gavin,
On 2021/3/16 11:52, Gavin Shan wrote:
> Hi Keqian,
>
> On 3/15/21 8:42 PM, Gavin Shan wrote:
>> On 3/15/21 7:04 PM, Keqian Zhu wrote:
>>> On 2021/3/15 12:18, Gavin Shan wrote:
>>>> find_vma_intersection() has been existing to search the intersected
>>>> vma. This uses the function where it's applicable, to simplify the
>>>> code.
>>>>
>>>> Signed-off-by: Gavin Shan <[email protected]>
>>>> ---
>>>> arch/arm64/kvm/mmu.c | 10 ++++++----
>>>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
>>>> index 84e70f953de6..286b603ed0d3 100644
>>>> --- a/arch/arm64/kvm/mmu.c
>>>> +++ b/arch/arm64/kvm/mmu.c
>>>> @@ -421,10 +421,11 @@ static void stage2_unmap_memslot(struct kvm *kvm,
>>>> * +--------------------------------------------+
>>>> */
>>>> do {
>>>> - struct vm_area_struct *vma = find_vma(current->mm, hva);
>>>> + struct vm_area_struct *vma;
>>>> hva_t vm_start, vm_end;
>>>> - if (!vma || vma->vm_start >= reg_end)
>>>> + vma = find_vma_intersection(current->mm, hva, reg_end);
>>> Nit: Keep a same style may be better(Assign vma when declare it).
>>> Other looks good to me.
>>>
>>
>> Yeah, I agree. I will adjust the code in v2 and included your r-b.
>> Thanks for your time to review.
>>
>
> After rechecking the code, I think it'd better to keep current style
> because there is a follow-on validation on @vma. Keeping them together
> seems a good idea. I think it wouldn't a big deal to you. So I will
> keep current style with your r-b in v2.
Sure, both is OK. ;-)
Thanks,
Keqian
>
> vma = find_vma_intersection(current->mm, hva, reg_end);
> if (!vma)
> break;
> Thanks,
> Gavin
>
>>>> + if (!vma)
>>>> break;
>>>> /*
>>>> @@ -1330,10 +1331,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
>>>> * +--------------------------------------------+
>>>> */
>>>> do {
>>>> - struct vm_area_struct *vma = find_vma(current->mm, hva);
>>>> + struct vm_area_struct *vma;
>>>> hva_t vm_start, vm_end;
>>>> - if (!vma || vma->vm_start >= reg_end)
>>>> + vma = find_vma_intersection(current->mm, hva, reg_end);
>>>> + if (!vma)
>>>> break;
>>>> /*
>>>>
>>>
>>
>
> .
>