mm: factor out VMA stack and heap checks

Patch series "mm: convert to vma_is_initial_heap/stack()", v3.

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

This patch (of 4):

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

Link: https://lkml.kernel.org/r/20230728050043.59880-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20230728050043.59880-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 507cd4e59d074d2b65cac1adeaad4257fb5e39bc..bf25178ae66a93d05bb66f80aba6c83362247258 100644 (file)
--- 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;
                }
@@ -1971,9 +1955,9 @@ 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 2c8b622659814485a1f5a74b95870f3747096904..a8ac0dd8041ebca2178ab245c6337a3b9db2cbe6 100644 (file)
--- 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 b2520dd555f9116e2f8fae0c1ba81b1594fc76e0..f64d1de3af09d7f1cd4e77e6c7314027e68720bb 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -833,6 +833,31 @@ 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);