1 files changed, 33 insertions, 9 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 2b47757c9c68..6c4020213e13 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -459,7 +459,7 @@ struct mem_size_stats {
 };
 
 static void smaps_account(struct mem_size_stats *mss, struct page *page,
-		bool compound, bool young, bool dirty)
+		bool compound, bool young, bool dirty, bool locked)
 {
 	int i, nr = compound ? 1 << compound_order(page) : 1;
 	unsigned long size = nr * PAGE_SIZE;
@@ -486,24 +486,31 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 		else
 			mss->private_clean += size;
 		mss->pss += (u64)size << PSS_SHIFT;
+		if (locked)
+			mss->pss_locked += (u64)size << PSS_SHIFT;
 		return;
 	}
 
 	for (i = 0; i < nr; i++, page++) {
 		int mapcount = page_mapcount(page);
+		unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
 
 		if (mapcount >= 2) {
 			if (dirty || PageDirty(page))
 				mss->shared_dirty += PAGE_SIZE;
 			else
 				mss->shared_clean += PAGE_SIZE;
-			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
+			mss->pss += pss / mapcount;
+			if (locked)
+				mss->pss_locked += pss / mapcount;
 		} else {
 			if (dirty || PageDirty(page))
 				mss->private_dirty += PAGE_SIZE;
 			else
 				mss->private_clean += PAGE_SIZE;
-			mss->pss += PAGE_SIZE << PSS_SHIFT;
+			mss->pss += pss;
+			if (locked)
+				mss->pss_locked += pss;
 		}
 	}
 }
@@ -526,6 +533,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
 	struct page *page = NULL;
 
 	if (pte_present(*pte)) {
@@ -568,7 +576,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 	if (!page)
 		return;
 
-	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
+	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -577,6 +585,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
 	struct page *page;
 
 	/* FOLL_DUMP will return -EFAULT on huge zero page */
@@ -591,7 +600,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 		/* pass */;
 	else
 		VM_BUG_ON_PAGE(1, page);
-	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
 }
 #else
 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -749,7 +758,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 	};
 	int ret = 0;
 	bool rollup_mode;
-	bool last_vma;
+	bool last_vma = false;
 
 	if (priv->rollup) {
 		rollup_mode = true;
@@ -792,11 +801,8 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 		}
 	}
 #endif
-
 	/* mmap_sem is held in m_start */
 	walk_page_vma(vma, &smaps_walk);
-	if (vma->vm_flags & VM_LOCKED)
-		mss->pss_locked += mss->pss;
 
 	if (!rollup_mode) {
 		show_map_vma(m, vma, is_pid);
@@ -1154,6 +1160,24 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 					count = -EINTR;
 					goto out_mm;
 				}
+				/*
+				 * Avoid to modify vma->vm_flags
+				 * without locked ops while the
+				 * coredump reads the vm_flags.
+				 */
+				if (!mmget_still_valid(mm)) {
+					/*
+					 * Silently return "count"
+					 * like if get_task_mm()
+					 * failed. FIXME: should this
+					 * function have returned
+					 * -ESRCH if get_task_mm()
+					 * failed like if
+					 * get_proc_task() fails?
+					 */
+					up_write(&mm->mmap_sem);
+					goto out_mm;
+				}
 				for (vma = mm->mmap; vma; vma = vma->vm_next) {
 					vma->vm_flags &= ~VM_SOFTDIRTY;
 					vma_set_page_prot(vma);