[2/5] mm: use vma_is_stack() and vma_is_heap()

Commit Message

Kefeng Wang July 12, 2023, 2:38 p.m. UTC

Use the helpers to simplify code.

Signed-off-by: Kefeng Wang <[e-mail]>
---
 fs/proc/task_mmu.c   | 24 ++++--------------------
 fs/proc/task_nommu.c | 15 +--------------
 2 files changed, 5 insertions(+), 34 deletions(-)

Comments

David Hildenbrand July 17, 2023, 10:25 a.m. UTC | #1

On 12.07.23 16:38, Kefeng Wang wrote:
> Use the helpers to simplify code.
> 
> Signed-off-by: Kefeng Wang <[e-mail]>
> ---
>   fs/proc/task_mmu.c   | 24 ++++--------------------
>   fs/proc/task_nommu.c | 15 +--------------
>   2 files changed, 5 insertions(+), 34 deletions(-)
> 

Please squash patch #1 and this patch and call it something like

"mm: factor out VMA stack and heap checks"

And then, maybe also keep the comments in these functions, they sound 
reasonable to have.

Kefeng Wang July 18, 2023, 12:50 a.m. UTC | #2

On 2023/7/17 18:25, David Hildenbrand wrote:
> On 12.07.23 16:38, Kefeng Wang wrote:
>> Use the helpers to simplify code.
>>
>> Signed-off-by: Kefeng Wang <[e-mail]>
>> ---
>>   fs/proc/task_mmu.c   | 24 ++++--------------------
>>   fs/proc/task_nommu.c | 15 +--------------
>>   2 files changed, 5 insertions(+), 34 deletions(-)
>>
> 
> Please squash patch #1 and this patch and call it something like
> 
> "mm: factor out VMA stack and heap checks"
> 
> And then, maybe also keep the comments in these functions, they sound 
> reasonable to have.

Thanks, will re-post them.
>

Patch

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index cfab855fe7e9..05e9893552ce 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_heap(vma)) {
 			name = "[heap]";
 			goto done;
 		}
 
-		if (is_stack(vma)) {
+		if (vma_is_stack(vma)) {
 			name = "[stack]";
 			goto done;
 		}
@@ -1974,9 +1958,9 @@  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_heap(vma)) {
 		seq_puts(m, " heap");
-	} else if (is_stack(vma)) {
+	} else if (vma_is_stack(vma)) {
 		seq_puts(m, " stack");
 	}
 
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 2c8b62265981..f42c84172b9e 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_stack(vma)) {
 		seq_pad(m, ' ');
 		seq_puts(m, "[stack]");
 	}