[PATCH v3 0/4] mm: convert to vma_is_initial_heap/stack()

[PATCH v3 0/4] mm: convert to vma_is_initial_heap/stack()

[Kefeng Wang]

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

v2:
- add comment for heap helper and remove one more goto cpy_name,
  per David Hildenbrand
- add RB
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                   | 25 +++++++++++++++++++++
 kernel/events/core.c                 | 33 ++++++++++------------------
 security/selinux/hooks.c             |  7 ++----
 6 files changed, 44 insertions(+), 65 deletions(-)

-- 
2.41.0

[PATCH v3 1/4] mm: factor out VMA stack and heap checks

[Kefeng Wang]

Factor out VMA stack and heap checks and name them
vma_is_initial_stack() and vma_is_initial_heap() for
general use.

Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 fs/proc/task_mmu.c   | 24 ++++--------------------
 fs/proc/task_nommu.c | 15 +--------------
 include/linux/mm.h   | 25 +++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 2b434b3fa2ec..3f063201b1ec 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -236,21 +236,6 @@ static int do_maps_open(struct inode *inode, struct file *file,
 				sizeof(struct proc_maps_private));
 }
 
-/*
- * Indicate if the VMA is a stack for the given task; for
- * /proc/PID/maps that is the stack of the main task.
- */
-static int is_stack(struct vm_area_struct *vma)
-{
-	/*
-	 * We make no effort to guess what a given thread considers to be
-	 * its "stack".  It's not even well-defined for programs written
-	 * languages like Go.
-	 */
-	return vma->vm_start <= vma->vm_mm->start_stack &&
-		vma->vm_end >= vma->vm_mm->start_stack;
-}
-
 static void show_vma_header_prefix(struct seq_file *m,
 				   unsigned long start, unsigned long end,
 				   vm_flags_t flags, unsigned long long pgoff,
@@ -327,13 +312,12 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 			goto done;
 		}
 
-		if (vma->vm_start <= mm->brk &&
-		    vma->vm_end >= mm->start_brk) {
+		if (vma_is_initial_heap(vma)) {
 			name = "[heap]";
 			goto done;
 		}
 
-		if (is_stack(vma)) {
+		if (vma_is_initial_stack(vma)) {
 			name = "[stack]";
 			goto done;
 		}
@@ -1975,9 +1959,9 @@ static int show_numa_map(struct seq_file *m, void *v)
 	if (file) {
 		seq_puts(m, " file=");
 		seq_file_path(m, file, "\n\t= ");
-	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
+	} else if (vma_is_initial_heap(vma)) {
 		seq_puts(m, " heap");
-	} else if (is_stack(vma)) {
+	} else if (vma_is_initial_stack(vma)) {
 		seq_puts(m, " stack");
 	}
 
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 2c8b62265981..a8ac0dd8041e 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -121,19 +121,6 @@ unsigned long task_statm(struct mm_struct *mm,
 	return size;
 }
 
-static int is_stack(struct vm_area_struct *vma)
-{
-	struct mm_struct *mm = vma->vm_mm;
-
-	/*
-	 * We make no effort to guess what a given thread considers to be
-	 * its "stack".  It's not even well-defined for programs written
-	 * languages like Go.
-	 */
-	return vma->vm_start <= mm->start_stack &&
-		vma->vm_end >= mm->start_stack;
-}
-
 /*
  * display a single VMA to a sequenced file
  */
@@ -171,7 +158,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 	if (file) {
 		seq_pad(m, ' ');
 		seq_file_path(m, file, "");
-	} else if (mm && is_stack(vma)) {
+	} else if (mm && vma_is_initial_stack(vma)) {
 		seq_pad(m, ' ');
 		seq_puts(m, "[stack]");
 	}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index acaef8d106f0..2fbc6c631764 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -866,6 +866,31 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
 	return !vma->vm_ops;
 }
 
+/*
+ * Indicate if the VMA is a heap for the given task; for
+ * /proc/PID/maps that is the heap of the main task.
+ */
+static inline bool vma_is_initial_heap(const struct vm_area_struct *vma)
+{
+       return vma->vm_start <= vma->vm_mm->brk &&
+		vma->vm_end >= vma->vm_mm->start_brk;
+}
+
+/*
+ * Indicate if the VMA is a stack for the given task; for
+ * /proc/PID/maps that is the stack of the main task.
+ */
+static inline bool vma_is_initial_stack(const struct vm_area_struct *vma)
+{
+	/*
+	 * We make no effort to guess what a given thread considers to be
+	 * its "stack".  It's not even well-defined for programs written
+	 * languages like Go.
+	 */
+       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

[PATCH v3 2/4] drm/amdkfd: use vma_is_initial_stack() and vma_is_initial_heap()

[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>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
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 01c7de2d6e19..308384dbc502 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2624,10 +2624,7 @@ 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));
-- 
2.41.0

[PATCH v3 3/4] selinux: use vma_is_initial_stack() and vma_is_initial_heap()

[Kefeng Wang]

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>
Reviewed-by: David Hildenbrand <david@redhat.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 c87b79a29fad..ac582c046c51 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3800,13 +3800,10 @@ 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);
-- 
2.41.0

[PATCH v3 4/4] perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

[Kefeng Wang]

Use the helpers to simplify code, also kill unneeded goto cpy_name.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 kernel/events/core.c | 33 +++++++++++----------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f84e2640ea2f..b36d0823ff33 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8631,7 +8631,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 	unsigned int size;
 	char tmp[16];
 	char *buf = NULL;
-	char *name;
+	char *name = NULL;
 
 	if (vma->vm_flags & VM_READ)
 		prot |= PROT_READ;
@@ -8678,29 +8678,18 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 
 		goto got_name;
 	} else {
-		if (vma->vm_ops && vma->vm_ops->name) {
+		if (vma->vm_ops && vma->vm_ops->name)
 			name = (char *) vma->vm_ops->name(vma);
-			if (name)
-				goto cpy_name;
+		if (!name)
+			name = (char *)arch_vma_name(vma);
+		if (!name) {
+			if (vma_is_initial_heap(vma))
+				name = "[heap]";
+			else if (vma_is_initial_stack(vma))
+				name = "[stack]";
+			else
+				name = "//anon";
 		}
-
-		name = (char *)arch_vma_name(vma);
-		if (name)
-			goto cpy_name;
-
-		if (vma->vm_start <= vma->vm_mm->start_brk &&
-				vma->vm_end >= vma->vm_mm->brk) {
-			name = "[heap]";
-			goto cpy_name;
-		}
-		if (vma->vm_start <= vma->vm_mm->start_stack &&
-				vma->vm_end >= vma->vm_mm->start_stack) {
-			name = "[stack]";
-			goto cpy_name;
-		}
-
-		name = "//anon";
-		goto cpy_name;
 	}
 
 cpy_name:
-- 
2.41.0

Re: [PATCH v3 0/4] mm: convert to vma_is_initial_heap/stack()

[Peter Zijlstra]

On Fri, Jul 28, 2023 at 01:00:39PM +0800, Kefeng Wang wrote:

> 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                   | 25 +++++++++++++++++++++
>  kernel/events/core.c                 | 33 ++++++++++------------------
>  security/selinux/hooks.c             |  7 ++----
>  6 files changed, 44 insertions(+), 65 deletions(-)

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>