Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[deliverable/linux.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index 1e0d6b237f4418c2f8b8ca50e88d85a787adc0a7..21631ab8c08b8d0b22fc7c48e38249a66bf18ce2 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -987,25 +987,18 @@ out:
 /*
  * Determine the nodes of an array of pages and store it in an array of status.
  */
-static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
-                        const void __user * __user *pages,
-                        int __user *status)
+static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
+                               const void __user **pages, int *status)
 {
        unsigned long i;
-       int err;
 
        down_read(&mm->mmap_sem);
 
        for (i = 0; i < nr_pages; i++) {
-               const void __user *p;
-               unsigned long addr;
+               unsigned long addr = (unsigned long)(*pages);
                struct vm_area_struct *vma;
                struct page *page;
-
-               err = -EFAULT;
-               if (get_user(p, pages+i))
-                       goto out;
-               addr = (unsigned long) p;
+               int err = -EFAULT;
 
                vma = find_vma(mm, addr);
                if (!vma)
@@ -1024,12 +1017,52 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
 
                err = page_to_nid(page);
 set_status:
-               put_user(err, status+i);
+               *status = err;
+
+               pages++;
+               status++;
+       }
+
+       up_read(&mm->mmap_sem);
+}
+
+/*
+ * Determine the nodes of a user array of pages and store it in
+ * a user array of status.
+ */
+static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
+                        const void __user * __user *pages,
+                        int __user *status)
+{
+#define DO_PAGES_STAT_CHUNK_NR 16
+       const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR];
+       int chunk_status[DO_PAGES_STAT_CHUNK_NR];
+       unsigned long i, chunk_nr = DO_PAGES_STAT_CHUNK_NR;
+       int err;
+
+       for (i = 0; i < nr_pages; i += chunk_nr) {
+               if (chunk_nr + i > nr_pages)
+                       chunk_nr = nr_pages - i;
+
+               err = copy_from_user(chunk_pages, &pages[i],
+                                    chunk_nr * sizeof(*chunk_pages));
+               if (err) {
+                       err = -EFAULT;
+                       goto out;
+               }
+
+               do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
+
+               err = copy_to_user(&status[i], chunk_status,
+                                  chunk_nr * sizeof(*chunk_status));
+               if (err) {
+                       err = -EFAULT;
+                       goto out;
+               }
        }
        err = 0;
 
 out:
-       up_read(&mm->mmap_sem);
        return err;
 }
 
@@ -1042,6 +1075,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
                        const int __user *nodes,
                        int __user *status, int flags)
 {
+       const struct cred *cred = current_cred(), *tcred;
        struct task_struct *task;
        struct mm_struct *mm;
        int err;
@@ -1072,12 +1106,16 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
         * capabilities, superuser privileges or the same
         * userid as the target process.
         */
-       if ((current->euid != task->suid) && (current->euid != task->uid) &&
-           (current->uid != task->suid) && (current->uid != task->uid) &&
+       rcu_read_lock();
+       tcred = __task_cred(task);
+       if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
+           cred->uid  != tcred->suid && cred->uid  != tcred->uid &&
            !capable(CAP_SYS_NICE)) {
+               rcu_read_unlock();
                err = -EPERM;
                goto out;
        }
+       rcu_read_unlock();
 
        err = security_task_movememory(task);
        if (err)