Re: [PATCH 4/6] uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly

[Srikar Dronamraju <srikar@linux.vnet.ibm.com>]

* Oleg Nesterov <oleg@redhat.com> [2013-04-01 18:08:54]:

> Change uprobe_event_define_fields(), and __set_print_fmt() to check
> is_ret_probe() and use the appropriate format/fields.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

> ---
>  kernel/trace/trace_uprobe.c |   19 +++++++++++++++----
>  1 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index db2718a..f75e52d 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -631,8 +631,14 @@ static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
>  	struct uprobe_trace_entry_head field;
>  	struct trace_uprobe *tu = event_call->data;
> 
> -	DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
> -	size = SIZEOF_TRACE_ENTRY(1);
> +	if (is_ret_probe(tu)) {
> +		DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
> +		DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
> +		size = SIZEOF_TRACE_ENTRY(2);
> +	} else {
> +		DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
> +		size = SIZEOF_TRACE_ENTRY(1);
> +	}
>  	/* Set argument names as fields */
>  	for (i = 0; i < tu->nr_args; i++) {
>  		ret = trace_define_field(event_call, tu->args[i].type->fmttype,
> @@ -655,8 +661,13 @@ static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len)
>  	int i;
>  	int pos = 0;
> 
> -	fmt = "(%lx)";
> -	arg = "REC->" FIELD_STRING_IP;
> +	if (is_ret_probe(tu)) {
> +		fmt = "(%lx <- %lx)";
> +		arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
> +	} else {
> +		fmt = "(%lx)";
> +		arg = "REC->" FIELD_STRING_IP;
> +	}
> 
>  	/* When len=0, we just calculate the needed length */
> 
> -- 
> 1.5.5.1
> 

-- 
Thanks and Regards
Srikar Dronamraju