From: Yaqi Chen chendotjs@gmail.com
[ Upstream commit 137733d08f4ab14a354dacaa9a8fc35217747605 ]
From commit c0bbbdc32feb ("__netif_receive_skb_core: pass skb by
reference"), 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 chendotjs@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Yonghong Song yhs@fb.com Link: https://lore.kernel.org/bpf/20210416154803.37157-1-chendotjs@gmail.com 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);