On Mon, Jun 29, 2020 at 5:35 PM Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> From: Alexei Starovoitov <ast@xxxxxxxxxx>
>
> Sleepable BPF programs can now use copy_from_user() to access user memory.
>
> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> ---
> include/linux/bpf.h | 1 +
> include/uapi/linux/bpf.h | 11 ++++++++++-
> kernel/bpf/helpers.c | 22 ++++++++++++++++++++++
> kernel/trace/bpf_trace.c | 2 ++
> tools/include/uapi/linux/bpf.h | 11 ++++++++++-
> 5 files changed, 45 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index e2b1581b2195..c9f27d5fdb7c 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1657,6 +1657,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto;
> extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto;
> extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto;
> extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto;
> +extern const struct bpf_func_proto bpf_copy_from_user_proto;
>
> const struct bpf_func_proto *bpf_tracing_func_proto(
> enum bpf_func_id func_id, const struct bpf_prog *prog);
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 73f9e3f84b77..6b347454dedc 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -3293,6 +3293,13 @@ union bpf_attr {
> * Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
> * Return
> * *sk* if casting is valid, or NULL otherwise.
> + *
> + * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr)
> + * Description
> + * Read *size* bytes from user space address *user_ptr* and store
> + * the data in *dst*. This is a wrapper of copy_from_user().
> + * Return
> + * 0 on success, or a negative error in case of failure.
> */
> #define __BPF_FUNC_MAPPER(FN) \
> FN(unspec), \
> @@ -3435,7 +3442,9 @@ union bpf_attr {
> FN(skc_to_tcp_sock), \
> FN(skc_to_tcp_timewait_sock), \
> FN(skc_to_tcp_request_sock), \
> - FN(skc_to_udp6_sock),
> + FN(skc_to_udp6_sock), \
> + FN(copy_from_user), \
> + /* */
Thank you for this! Those trivial merge conflicts due to '\' were
really annoying.
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
[...]
