From 4bd31a104469afea3fc19b531844d9d36203ed55 Mon Sep 17 00:00:00 2001 From: Jordan Rome Date: Fri, 23 Aug 2024 12:51:00 -0700 Subject: [PATCH] bpf: Add bpf_copy_from_user_str kfunc This adds a kfunc wrapper around strncpy_from_user, which can be called from sleepable BPF programs. This matches the non-sleepable 'bpf_probe_read_user_str' helper except it includes an additional 'flags' param, which allows consumers to clear the entire destination buffer on success or failure. Signed-off-by: Jordan Rome Link: https://lore.kernel.org/r/20240823195101.3621028-1-linux@jordanrome.com Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 35bcf52..f329ee4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7512,4 +7512,13 @@ struct bpf_iter_num { __u64 __opaque[1]; } __attribute__((aligned(8))); +/* + * Flags to control BPF kfunc behaviour. + * - BPF_F_PAD_ZEROS: Pad destination buffer with zeros. (See the respective + * helper documentation for details.) + */ +enum bpf_kfunc_flags { + BPF_F_PAD_ZEROS = (1ULL << 0), +}; + #endif /* _UAPI__LINUX_BPF_H__ */