diff options
Diffstat (limited to 'kernel/time/namespace.c')
| -rw-r--r-- | kernel/time/namespace.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index 6ca625f5e554..0775b9ec952a 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -88,13 +88,13 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns, goto fail; err = -ENOMEM; - ns = kmalloc(sizeof(*ns), GFP_KERNEL); + ns = kmalloc(sizeof(*ns), GFP_KERNEL_ACCOUNT); if (!ns) goto fail_dec; refcount_set(&ns->ns.count, 1); - ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO); + ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!ns->vvar_page) goto fail_free; @@ -192,6 +192,24 @@ static void timens_setup_vdso_data(struct vdso_data *vdata, offset[CLOCK_BOOTTIME_ALARM] = boottime; } +struct page *find_timens_vvar_page(struct vm_area_struct *vma) +{ + if (likely(vma->vm_mm == current->mm)) + return current->nsproxy->time_ns->vvar_page; + + /* + * VM_PFNMAP | VM_IO protect .fault() handler from being called + * through interfaces like /proc/$pid/mem or + * process_vm_{readv,writev}() as long as there's no .access() + * in special_mapping_vmops(). + * For more details check_vma_flags() and __access_remote_vm() + */ + + WARN(1, "vvar_page accessed remotely"); + + return NULL; +} + /* * Protects possibly multiple offsets writers racing each other * and tasks entering the namespace. @@ -465,9 +483,3 @@ struct time_namespace init_time_ns = { .ns.ops = &timens_operations, .frozen_offsets = true, }; - -static int __init time_ns_init(void) -{ - return 0; -} -subsys_initcall(time_ns_init); |