Commit f4ce0a01 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by David S. Miller

samples/bpf: xdp_monitor first 8 bytes are not accessible by bpf

The first 8 bytes of the tracepoint context struct are not accessible
by the bpf code.  This is a choice that dates back to the original
inclusion of this code.

See explaination in:
 commit 98b5c2c6 ("perf, bpf: allow bpf programs attach to tracepoints")
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c6a15752
...@@ -17,11 +17,7 @@ struct bpf_map_def SEC("maps") redirect_err_cnt = { ...@@ -17,11 +17,7 @@ struct bpf_map_def SEC("maps") redirect_err_cnt = {
* Code in: kernel/include/trace/events/xdp.h * Code in: kernel/include/trace/events/xdp.h
*/ */
struct xdp_redirect_ctx { struct xdp_redirect_ctx {
unsigned short common_type; // offset:0; size:2; signed:0; u64 __pad; // First 8 bytes are not accessible by bpf code
unsigned char common_flags; // offset:2; size:1; signed:0;
unsigned char common_preempt_count;// offset:3; size:1; signed:0;
int common_pid; // offset:4; size:4; signed:1;
int prog_id; // offset:8; size:4; signed:1; int prog_id; // offset:8; size:4; signed:1;
u32 act; // offset:12 size:4; signed:0; u32 act; // offset:12 size:4; signed:0;
int ifindex; // offset:16 size:4; signed:1; int ifindex; // offset:16 size:4; signed:1;
......
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