Re: [PATCH 1/5] mm: introduce vma_is_stack() and vma_is_heap()

[Christian Göttsche]

On Wed, 12 Jul 2023 at 16:25, Kefeng Wang  wrote:
>
> Introduce the two helpers for general use.
>
> Signed-off-by: Kefeng Wang 
> ---
>  include/linux/mm.h | 12 
>  1 file changed, 12 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 1462cf15badf..0bbeb31ac750 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -926,6 +926,18 @@ static inline bool vma_is_anonymous(struct 
> vm_area_struct *vma)
> return !vma->vm_ops;
>  }
>
> +static inline bool vma_is_heap(struct vm_area_struct *vma)

What about declaring the parameters const to document in code these
functions do not modify any state, and allow callers to pass pointers
to const?

> +{
> +   return vma->vm_start <= vma->vm_mm->brk &&
> +   vma->vm_end >= vma->vm_mm->start_brk;
> +}
> +
> +static inline bool vma_is_stack(struct vm_area_struct *vma)
> +{
> +   return vma->vm_start <= vma->vm_mm->start_stack &&
> +  vma->vm_end >= vma->vm_mm->start_stack;
> +}
> +
>  static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
>  {
> int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
> --
> 2.41.0
>

Re: [PATCH 1/5] mm: introduce vma_is_stack() and vma_is_heap()

[David Hildenbrand]

On 12.07.23 16:38, Kefeng Wang wrote:

Introduce the two helpers for general use.

Signed-off-by: Kefeng Wang 
---
  include/linux/mm.h | 12 
  1 file changed, 12 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1462cf15badf..0bbeb31ac750 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -926,6 +926,18 @@ static inline bool vma_is_anonymous(struct vm_area_struct 
*vma)
return !vma->vm_ops;
  }
  
+static inline bool vma_is_heap(struct vm_area_struct *vma)

+{
+   return vma->vm_start <= vma->vm_mm->brk &&
+   vma->vm_end >= vma->vm_mm->start_brk;
+}
+
+static inline bool vma_is_stack(struct vm_area_struct *vma)
+{
+   return vma->vm_start <= vma->vm_mm->start_stack &&
+  vma->vm_end >= vma->vm_mm->start_stack;
+}
+
  static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
  {
int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);


Looking at the comments in patch #3, should these functions be called

vma_is_initial_heap / vma_is_initial_stack ?

--
Cheers,

David / dhildenb

[PATCH 1/5] mm: introduce vma_is_stack() and vma_is_heap()

[Kefeng Wang]

Introduce the two helpers for general use.

Signed-off-by: Kefeng Wang 
---
 include/linux/mm.h | 12 
 1 file changed, 12 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1462cf15badf..0bbeb31ac750 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -926,6 +926,18 @@ static inline bool vma_is_anonymous(struct vm_area_struct 
*vma)
return !vma->vm_ops;
 }
 
+static inline bool vma_is_heap(struct vm_area_struct *vma)
+{
+   return vma->vm_start <= vma->vm_mm->brk &&
+   vma->vm_end >= vma->vm_mm->start_brk;
+}
+
+static inline bool vma_is_stack(struct vm_area_struct *vma)
+{
+   return vma->vm_start <= vma->vm_mm->start_stack &&
+  vma->vm_end >= vma->vm_mm->start_stack;
+}
+
 static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
 {
int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
-- 
2.41.0