[v2,0/4] mm: convert to vma_is_initial_heap/stack()

  Add vma_is_initial_stack() and vma_is_initial_heap() helper and use
them to simplify code.

v2:
- address comments per David Hildenbrand and Christian Göttsche
- fix selinux build

Kefeng Wang (4):
  mm: factor out VMA stack and heap checks
  drm/amdkfd: use vma_is_initial_stack() and vma_is_initial_heap()
  selinux: use vma_is_initial_stack() and vma_is_initial_heap()
  perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

 drivers/gpu/drm/amd/amdkfd/kfd_svm.c |  5 +----
 fs/proc/task_mmu.c                   | 24 ++++--------------------
 fs/proc/task_nommu.c                 | 15 +--------------
 include/linux/mm.h                   | 21 +++++++++++++++++++++
 kernel/events/core.c                 | 22 +++++++---------------
 security/selinux/hooks.c             |  7 ++-----
 6 files changed, 36 insertions(+), 58 deletions(-)
  

On 19.07.23 09:51, Kefeng Wang wrote:
> Use the helpers to simplify code.
> 
> Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 5ff1a5a89d96..0b7bfbd0cb66 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -2621,10 +2621,7 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
>   		return -EFAULT;
>   	}
>   
> -	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
> -			  vma->vm_end >= vma->vm_mm->start_brk) ||
> -			 (vma->vm_start <= vma->vm_mm->start_stack &&
> -			  vma->vm_end >= vma->vm_mm->start_stack);
> +	*is_heap_stack = vma_is_initial_heap(vma) || vma_is_initial_stack(vma);
>   
>   	start_limit = max(vma->vm_start >> PAGE_SHIFT,
>   		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));

Certainly a valid refactoring, although questionable if such code should 
care about that.

Reviewed-by: David Hildenbrand <david@redhat.com>
  

On 19.07.23 09:51, Kefeng Wang wrote:
> Use the helpers to simplify code.
> 
> Cc: Paul Moore <paul@paul-moore.com>
> Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
> Cc: Eric Paris <eparis@parisplace.org>
> Acked-by: Paul Moore <paul@paul-moore.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>   security/selinux/hooks.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index d06e350fedee..ee8575540a8e 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -3762,13 +3762,10 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
>   	if (default_noexec &&
>   	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
>   		int rc = 0;
> -		if (vma->vm_start >= vma->vm_mm->start_brk &&
> -		    vma->vm_end <= vma->vm_mm->brk) {
> +		if (vma_is_initial_heap(vma)) {
>   			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
>   					  PROCESS__EXECHEAP, NULL);
> -		} else if (!vma->vm_file &&
> -			   ((vma->vm_start <= vma->vm_mm->start_stack &&
> -			     vma->vm_end >= vma->vm_mm->start_stack) ||
> +		} else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
>   			    vma_is_stack_for_current(vma))) {
>   			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
>   					  PROCESS__EXECSTACK, NULL);

Reviewed-by: David Hildenbrand <david@redhat.com>
  

On Wed, 19 Jul 2023 at 09:40, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>
> Use the helpers to simplify code.
>
> Cc: Paul Moore <paul@paul-moore.com>
> Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
> Cc: Eric Paris <eparis@parisplace.org>
> Acked-by: Paul Moore <paul@paul-moore.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>  security/selinux/hooks.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index d06e350fedee..ee8575540a8e 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -3762,13 +3762,10 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
>         if (default_noexec &&
>             (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
>                 int rc = 0;
> -               if (vma->vm_start >= vma->vm_mm->start_brk &&
> -                   vma->vm_end <= vma->vm_mm->brk) {
> +               if (vma_is_initial_heap(vma)) {

This seems to change the condition from

    vma->vm_start >= vma->vm_mm->start_brk && vma->vm_end <= vma->vm_mm->brk

to

    vma->vm_start <= vma->vm_mm->brk && vma->vm_end >= vma->vm_mm->start_brk

(or AND arguments swapped)

    vma->vm_end >= vma->vm_mm->start_brk && vma->vm_start <= vma->vm_mm->brk

Is this intended?

>                         rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
>                                           PROCESS__EXECHEAP, NULL);
> -               } else if (!vma->vm_file &&
> -                          ((vma->vm_start <= vma->vm_mm->start_stack &&
> -                            vma->vm_end >= vma->vm_mm->start_stack) ||
> +               } else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
>                             vma_is_stack_for_current(vma))) {
>                         rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
>                                           PROCESS__EXECSTACK, NULL);
> --
> 2.27.0
>
  

Am 2023-07-19 um 03:51 schrieb Kefeng Wang:
> Use the helpers to simplify code.
>
> Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>


> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 5ff1a5a89d96..0b7bfbd0cb66 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -2621,10 +2621,7 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
>   		return -EFAULT;
>   	}
>   
> -	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
> -			  vma->vm_end >= vma->vm_mm->start_brk) ||
> -			 (vma->vm_start <= vma->vm_mm->start_stack &&
> -			  vma->vm_end >= vma->vm_mm->start_stack);
> +	*is_heap_stack = vma_is_initial_heap(vma) || vma_is_initial_stack(vma);
>   
>   	start_limit = max(vma->vm_start >> PAGE_SHIFT,
>   		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
  

On Wed, Jul 19, 2023 at 6:23 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> On 2023/7/19 17:02, Christian Göttsche wrote:
> > On Wed, 19 Jul 2023 at 09:40, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> >>
> >> Use the helpers to simplify code.
> >>
> >> Cc: Paul Moore <paul@paul-moore.com>
> >> Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
> >> Cc: Eric Paris <eparis@parisplace.org>
> >> Acked-by: Paul Moore <paul@paul-moore.com>
> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> >> ---
> >>   security/selinux/hooks.c | 7 ++-----
> >>   1 file changed, 2 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> >> index d06e350fedee..ee8575540a8e 100644
> >> --- a/security/selinux/hooks.c
> >> +++ b/security/selinux/hooks.c
> >> @@ -3762,13 +3762,10 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
> >>          if (default_noexec &&
> >>              (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
> >>                  int rc = 0;
> >> -               if (vma->vm_start >= vma->vm_mm->start_brk &&
> >> -                   vma->vm_end <= vma->vm_mm->brk) {
> >> +               if (vma_is_initial_heap(vma)) {
> >
> > This seems to change the condition from
> >
> >      vma->vm_start >= vma->vm_mm->start_brk && vma->vm_end <= vma->vm_mm->brk
> >
> > to
> >
> >      vma->vm_start <= vma->vm_mm->brk && vma->vm_end >= vma->vm_mm->start_brk
> >
> > (or AND arguments swapped)
> >
> >      vma->vm_end >= vma->vm_mm->start_brk && vma->vm_start <= vma->vm_mm->brk
> >
> > Is this intended?
>
> The new condition is to check whether there is intersection between
> [startbrk,brk] and [vm_start,vm_end], it contains orignal check, so
> I think it is ok, but for selinux check, I am not sure if there is
> some other problem.

This particular SELinux vma check is see if the vma falls within the
heap; can you confirm that this change preserves this?
  

On Thu, Jul 20, 2023 at 4:28 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> On 2023/7/19 23:25, Paul Moore wrote:
> > On Wed, Jul 19, 2023 at 6:23 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> >> On 2023/7/19 17:02, Christian Göttsche wrote:
> >>> On Wed, 19 Jul 2023 at 09:40, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> >>>>
> >>>> Use the helpers to simplify code.
> >>>>
> >>>> Cc: Paul Moore <paul@paul-moore.com>
> >>>> Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
> >>>> Cc: Eric Paris <eparis@parisplace.org>
> >>>> Acked-by: Paul Moore <paul@paul-moore.com>
> >>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> >>>> ---
> >>>>    security/selinux/hooks.c | 7 ++-----
> >>>>    1 file changed, 2 insertions(+), 5 deletions(-)
> >>>>
> >>>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> >>>> index d06e350fedee..ee8575540a8e 100644
> >>>> --- a/security/selinux/hooks.c
> >>>> +++ b/security/selinux/hooks.c
> >>>> @@ -3762,13 +3762,10 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
> >>>>           if (default_noexec &&
> >>>>               (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
> >>>>                   int rc = 0;
> >>>> -               if (vma->vm_start >= vma->vm_mm->start_brk &&
> >>>> -                   vma->vm_end <= vma->vm_mm->brk) {
> >>>> +               if (vma_is_initial_heap(vma)) {
> >>>
> >>> This seems to change the condition from
> >>>
> >>>       vma->vm_start >= vma->vm_mm->start_brk && vma->vm_end <= vma->vm_mm->brk
> >>>
> >>> to
> >>>
> >>>       vma->vm_start <= vma->vm_mm->brk && vma->vm_end >= vma->vm_mm->start_brk
> >>>
> >>> (or AND arguments swapped)
> >>>
> >>>       vma->vm_end >= vma->vm_mm->start_brk && vma->vm_start <= vma->vm_mm->brk
> >>>
> >>> Is this intended?
> >>
> >> The new condition is to check whether there is intersection between
> >> [startbrk,brk] and [vm_start,vm_end], it contains orignal check, so
> >> I think it is ok, but for selinux check, I am not sure if there is
> >> some other problem.
> >
> > This particular SELinux vma check is see if the vma falls within the
> > heap; can you confirm that this change preserves this?
>
> Yes, within is one case of new vma scope check.

Thanks for the confirmation.