Commit 57d48537 authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

bpf: Add a common helper bpf_copy_to_user() 



Add a common helper bpf_copy_to_user(), which will be used at multiple
places.
No functional change.

Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230709025630.3735-8-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent cd3910d0

kernel/bpf/syscall.c

+20 −14
Original line number Diff line number Diff line
@@ -3295,6 +3295,25 @@ static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 
		   raw_tp_link->btp->tp->name);

}



static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,

			    u32 len)

{

	if (ulen >= len + 1) {

		if (copy_to_user(ubuf, buf, len + 1))

			return -EFAULT;

	} else {

		char zero = '\0';



		if (copy_to_user(ubuf, buf, ulen - 1))

			return -EFAULT;

		if (put_user(zero, ubuf + ulen - 1))

			return -EFAULT;

		return -ENOSPC;

	}



	return 0;

}



static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,

					  struct bpf_link_info *info)

{
@@ -3313,20 +3332,7 @@ static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 
	if (!ubuf)

		return 0;



	if (ulen >= tp_len + 1) {

		if (copy_to_user(ubuf, tp_name, tp_len + 1))

			return -EFAULT;

	} else {

		char zero = '\0';



		if (copy_to_user(ubuf, tp_name, ulen - 1))

			return -EFAULT;

		if (put_user(zero, ubuf + ulen - 1))

			return -EFAULT;

		return -ENOSPC;

	}



	return 0;

	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);

}



static const struct bpf_link_ops bpf_raw_tp_link_lops = {