[PATCH AUTOSEL 4.9 17/22] samples/bpf: Fix broken tracex1 due to kprobe argument change
From: Sasha Levin <sashal@kernel.org>
Date: 2021-05-05 17:16:14
Also in:
bpf, lkml, netdev
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Yaqi Chen <redacted> [ Upstream commit 137733d08f4ab14a354dacaa9a8fc35217747605 ]
From commit c0bbbdc32feb ("__netif_receive_skb_core: pass skb byreference"), the first argument passed into __netif_receive_skb_core has changed to reference of a skb pointer. This commit fixes by using bpf_probe_read_kernel. Signed-off-by: Yaqi Chen <redacted> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <redacted> Link: https://lore.kernel.org/bpf/20210416154803.37157-1-chendotjs@gmail.com (local) Signed-off-by: Sasha Levin <sashal@kernel.org> --- samples/bpf/tracex1_kern.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/samples/bpf/tracex1_kern.c b/samples/bpf/tracex1_kern.c
index 107da148820f..9c74b45c5720 100644
--- a/samples/bpf/tracex1_kern.c
+++ b/samples/bpf/tracex1_kern.c@@ -20,7 +20,7 @@ SEC("kprobe/__netif_receive_skb_core") int bpf_prog1(struct pt_regs *ctx) { - /* attaches to kprobe netif_receive_skb, + /* attaches to kprobe __netif_receive_skb_core, * looks for packets on loobpack device and prints them */ char devname[IFNAMSIZ];
@@ -29,7 +29,7 @@ int bpf_prog1(struct pt_regs *ctx) int len; /* non-portable! works for the given kernel only */ - skb = (struct sk_buff *) PT_REGS_PARM1(ctx); + bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx)); dev = _(skb->dev); len = _(skb->len);
--
2.30.2