From eae207dc0ff606d2d60aa90d33cc9b057f3d6c08 Mon Sep 17 00:00:00 2001 From: Chenbo Feng Date: Wed, 18 Oct 2017 13:00:22 -0700 Subject: BACKPORT: bpf: Add file mode configuration into bpf maps Introduce the map read/write flags to the eBPF syscalls that returns the map fd. The flags is used to set up the file mode when construct a new file descriptor for bpf maps. To not break the backward capability, the f_flags is set to O_RDWR if the flag passed by syscall is 0. Otherwise it should be O_RDONLY or O_WRONLY. When the userspace want to modify or read the map content, it will check the file mode to see if it is allowed to make the change. Signed-off-by: Chenbo Feng Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Deleted the file mode configuration code in unsupported map type and removed the file mode check in non-existing helper functions. (cherry-pick from net-next: 6e71b04a82248ccf13a94b85cbc674a9fefe53f5) Bug: 30950746 Change-Id: Icfad20f1abb77f91068d244fb0d87fa40824dd1b Signed-off-by: Chatur27 --- kernel/bpf/arraymap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel/bpf/arraymap.c') diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index f3721e150d94..a1f8b54863b2 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -16,6 +16,9 @@ #include #include +#define ARRAY_CREATE_FLAG_MASK \ + (BPF_F_RDONLY | BPF_F_WRONLY) + static void bpf_array_free_percpu(struct bpf_array *array) { int i; @@ -52,7 +55,8 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size == 0 || attr->map_flags) + attr->value_size == 0 || + attr->map_flags & ~ARRAY_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1)) -- cgit v1.2.3