nvme: don't allow unprivileged passthrough on partitions

[linux-2.6-microblaze.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 89b8b6c..7a08025 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -756,8 +756,13 @@ static void check_mm(struct mm_struct *mm)
                         "Please make sure 'struct resident_page_types[]' is updated as well");
 
        for (i = 0; i < NR_MM_COUNTERS; i++) {
-               long x = atomic_long_read(&mm->rss_stat.count[i]);
+               long x = percpu_counter_sum(&mm->rss_stat[i]);
 
+               if (likely(!x))
+                       continue;
+
+               /* Making sure this is not due to race with CPU offlining. */
+               x = percpu_counter_sum_all(&mm->rss_stat[i]);
                if (unlikely(x))
                        pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld\n",
                                 mm, resident_page_types[i], x);
@@ -782,6 +787,8 @@ static void check_mm(struct mm_struct *mm)
  */
 void __mmdrop(struct mm_struct *mm)
 {
+       int i;
+
        BUG_ON(mm == &init_mm);
        WARN_ON_ONCE(mm == current->mm);
        WARN_ON_ONCE(mm == current->active_mm);
@@ -791,6 +798,9 @@ void __mmdrop(struct mm_struct *mm)
        check_mm(mm);
        put_user_ns(mm->user_ns);
        mm_pasid_drop(mm);
+
+       for (i = 0; i < NR_MM_COUNTERS; i++)
+               percpu_counter_destroy(&mm->rss_stat[i]);
        free_mm(mm);
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
@@ -1110,6 +1120,8 @@ static void mm_init_uprobes_state(struct mm_struct *mm)
 static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
        struct user_namespace *user_ns)
 {
+       int i;
+
        mt_init_flags(&mm->mm_mt, MM_MT_FLAGS);
        mt_set_external_lock(&mm->mm_mt, &mm->mmap_lock);
        atomic_set(&mm->mm_users, 1);
@@ -1151,10 +1163,17 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
        if (init_new_context(p, mm))
                goto fail_nocontext;
 
+       for (i = 0; i < NR_MM_COUNTERS; i++)
+               if (percpu_counter_init(&mm->rss_stat[i], 0, GFP_KERNEL_ACCOUNT))
+                       goto fail_pcpu;
+
        mm->user_ns = get_user_ns(user_ns);
        lru_gen_init_mm(mm);
        return mm;
 
+fail_pcpu:
+       while (i > 0)
+               percpu_counter_destroy(&mm->rss_stat[--i]);
 fail_nocontext:
        mm_free_pgd(mm);
 fail_nopgd: