Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

[firefly-linux-kernel-4.4.55.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3e97da37b67c1d18522de52a616c0c76c1efc25e..200e3b29aa22d535a37b17e1d51f194a68e21c1e 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -298,23 +298,29 @@ static int do_maps_open(struct inode *inode, struct file *file,
                                sizeof(struct proc_maps_private));
 }
 
-static pid_t pid_of_stack(struct proc_maps_private *priv,
-                               struct vm_area_struct *vma, bool is_pid)
+/*
+ * 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 proc_maps_private *priv,
+                   struct vm_area_struct *vma, int is_pid)
 {
-       struct inode *inode = priv->inode;
-       struct task_struct *task;
-       pid_t ret = 0;
+       int stack = 0;
+
+       if (is_pid) {
+               stack = vma->vm_start <= vma->vm_mm->start_stack &&
+                       vma->vm_end >= vma->vm_mm->start_stack;
+       } else {
+               struct inode *inode = priv->inode;
+               struct task_struct *task;
 
-       rcu_read_lock();
-       task = pid_task(proc_pid(inode), PIDTYPE_PID);
-       if (task) {
-               task = task_of_stack(task, vma, is_pid);
+               rcu_read_lock();
+               task = pid_task(proc_pid(inode), PIDTYPE_PID);
                if (task)
-                       ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
+                       stack = vma_is_stack_for_task(vma, task);
+               rcu_read_unlock();
        }
-       rcu_read_unlock();
-
-       return ret;
+       return stack;
 }
 
 static void
@@ -374,8 +380,6 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 
        name = arch_vma_name(vma);
        if (!name) {
-               pid_t tid;
-
                if (!mm) {
                        name = "[vdso]";
                        goto done;
@@ -387,23 +391,10 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
                        goto done;
                }
 
-               tid = pid_of_stack(priv, vma, is_pid);
-               if (tid != 0) {
-                       /*
-                        * Thread stack in /proc/PID/task/TID/maps or
-                        * the main process stack.
-                        */
-                       if (!is_pid || (vma->vm_start <= mm->start_stack &&
-                           vma->vm_end >= mm->start_stack)) {
-                               name = "[stack]";
-                       } else {
-                               /* Thread stack in /proc/PID/maps */
-                               seq_pad(m, ' ');
-                               seq_printf(m, "[stack:%d]", tid);
-                       }
+               if (is_stack(priv, vma, is_pid)) {
+                       name = "[stack]";
                        goto done;
                }
-
                if (vma_get_anon_name(vma)) {
                        seq_pad(m, ' ');
                        seq_print_vma_name(m, vma);
@@ -1628,19 +1619,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
                seq_file_path(m, file, "\n\t= ");
        } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
                seq_puts(m, " heap");
-       } else {
-               pid_t tid = pid_of_stack(proc_priv, vma, is_pid);
-               if (tid != 0) {
-                       /*
-                        * Thread stack in /proc/PID/task/TID/maps or
-                        * the main process stack.
-                        */
-                       if (!is_pid || (vma->vm_start <= mm->start_stack &&
-                           vma->vm_end >= mm->start_stack))
-                               seq_puts(m, " stack");
-                       else
-                               seq_printf(m, " stack:%d", tid);
-               }
+       } else if (is_stack(proc_priv, vma, is_pid)) {
+               seq_puts(m, " stack");
        }
 
        if (is_vm_hugetlb_page(vma))