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-rw-r--r--fs/proc/array.c85
1 files changed, 84 insertions, 1 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 725a650bbbb8..0c6bc602e6c4 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -82,6 +82,7 @@
#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
+#include <linux/swapops.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
@@ -321,6 +322,87 @@ static inline void task_context_switch_counts(struct seq_file *m,
p->nivcsw);
}
+struct stack_stats {
+ struct vm_area_struct *vma;
+ unsigned long startpage;
+ unsigned long usage;
+};
+
+static int stack_usage_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, struct mm_walk *walk)
+{
+ struct stack_stats *ss = walk->private;
+ struct vm_area_struct *vma = ss->vma;
+ pte_t *pte, ptent;
+ spinlock_t *ptl;
+ int ret = 0;
+
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; pte++, addr += PAGE_SIZE) {
+ ptent = *pte;
+
+#ifdef CONFIG_STACK_GROWSUP
+ if (pte_present(ptent) || is_swap_pte(ptent))
+ ss->usage = addr - ss->startpage + PAGE_SIZE;
+#else
+ if (pte_present(ptent) || is_swap_pte(ptent)) {
+ ss->usage = ss->startpage - addr + PAGE_SIZE;
+ pte++;
+ ret = 1;
+ break;
+ }
+#endif
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+ return ret;
+}
+
+static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
+ struct task_struct *task)
+{
+ struct stack_stats ss;
+ struct mm_walk stack_walk = {
+ .pmd_entry = stack_usage_pte_range,
+ .mm = vma->vm_mm,
+ .private = &ss,
+ };
+
+ if (!vma->vm_mm || is_vm_hugetlb_page(vma))
+ return 0;
+
+ ss.vma = vma;
+ ss.startpage = task->stack_start & PAGE_MASK;
+ ss.usage = 0;
+
+#ifdef CONFIG_STACK_GROWSUP
+ walk_page_range(KSTK_ESP(task) & PAGE_MASK, vma->vm_end,
+ &stack_walk);
+#else
+ walk_page_range(vma->vm_start, (KSTK_ESP(task) & PAGE_MASK) + PAGE_SIZE,
+ &stack_walk);
+#endif
+ return ss.usage;
+}
+
+static inline void task_show_stack_usage(struct seq_file *m,
+ struct task_struct *task)
+{
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = get_task_mm(task);
+
+ if (mm) {
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, task->stack_start);
+ if (vma)
+ seq_printf(m, "Stack usage:\t%lu kB\n",
+ get_stack_usage_in_bytes(vma, task) >> 10);
+
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ }
+}
+
int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
@@ -340,6 +422,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
task_show_regs(m, task);
#endif
task_context_switch_counts(m, task);
+ task_show_stack_usage(m, task);
return 0;
}
@@ -481,7 +564,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
rsslim,
mm ? mm->start_code : 0,
mm ? mm->end_code : 0,
- (permitted && mm) ? mm->start_stack : 0,
+ (permitted) ? task->stack_start : 0,
esp,
eip,
/* The signal information here is obsolete.
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