From: Wang Qing <wangqing@vivo.com>
Date: Sat, 7 Nov 2020 07:45:44 +0000 (+0800)
Subject: bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
X-Git-Tag: v5.15~2389^2^2~15
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=abbaa433de07076fb8ef524b77ce55d94bad5fc5;p=platform%2Fkernel%2Flinux-starfive.git

bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare

There is a bug when passing zero to PTR_ERR() and return.
Fix the smatch error.

Fixes: c4d0bfb45068 ("bpf: Add bpf_snprintf_btf helper")
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1604735144-686-1-git-send-email-wangqing@vivo.com
---

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 4517c8b..5113fd4 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1198,7 +1198,7 @@ static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
 	*btf = bpf_get_btf_vmlinux();
 
 	if (IS_ERR_OR_NULL(*btf))
-		return PTR_ERR(*btf);
+		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
 
 	if (ptr->type_id > 0)
 		*btf_id = ptr->type_id;