From 57d485376552480602ab83bf7499b451bae5a1b9 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sun, 9 Jul 2023 02:56:27 +0000 Subject: [PATCH] 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: Yafang Shao Acked-by: Jiri Olsa Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230709025630.3735-8-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a2aef90..4aa6e57 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -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 = { -- 2.7.4