Re: [PATCH v3 linux-trace 4/8] samples: bpf: simple tracing example in C

[Steven Rostedt]

On Mon,  9 Feb 2015 19:45:57 -0800
Alexei Starovoitov <ast@xxxxxxxxxxxx> wrote:

> +static void print_netif_receive_skb(void *data, int size)
> +{
> +	struct ftrace_raw_netif_receive_skb {
> +		struct trace_entry t;
> +		void *skb;
> +		__u32 len;
> +		__u32 name;
> +	} *e = data;

Same here, there's no guarantee that this structure will always match.

cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/format 
name: netif_receive_skb
ID: 975
format:
	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
	field:int common_pid;	offset:4;	size:4;	signed:1;

	field:void * skbaddr;	offset:8;	size:8;	signed:0;
	field:unsigned int len;	offset:16;	size:4;	signed:0;
	field:__data_loc char[] name;	offset:20;	size:4;	signed:1;

print fmt: "dev=%s skbaddr=%p len=%u", __get_str(name), REC->skbaddr, REC->len

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/