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-rw-r--r--kernel/bpf/arena.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index f355cf1c1a16..9c68c9b0b24a 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -341,6 +341,16 @@ static void arena_vm_open(struct vm_area_struct *vma)
refcount_inc(&vml->mmap_count);
}
+static int arena_vm_may_split(struct vm_area_struct *vma, unsigned long addr)
+{
+ return -EINVAL;
+}
+
+static int arena_vm_mremap(struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
static void arena_vm_close(struct vm_area_struct *vma)
{
struct bpf_map *map = vma->vm_file->private_data;
@@ -417,6 +427,8 @@ out_unlock_sigsegv:
static const struct vm_operations_struct arena_vm_ops = {
.open = arena_vm_open,
+ .may_split = arena_vm_may_split,
+ .mremap = arena_vm_mremap,
.close = arena_vm_close,
.fault = arena_vm_fault,
};
@@ -486,10 +498,11 @@ static int arena_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
arena->user_vm_end = vma->vm_end;
/*
* bpf_map_mmap() checks that it's being mmaped as VM_SHARED and
- * clears VM_MAYEXEC. Set VM_DONTEXPAND as well to avoid
- * potential change of user_vm_start.
+ * clears VM_MAYEXEC. Set VM_DONTEXPAND to avoid potential change
+ * of user_vm_start. Set VM_DONTCOPY to prevent arena VMA from
+ * being copied into the child process on fork.
*/
- vm_flags_set(vma, VM_DONTEXPAND);
+ vm_flags_set(vma, VM_DONTEXPAND | VM_DONTCOPY);
vma->vm_ops = &arena_vm_ops;
return 0;
}