Subject: Re: [PATCH v3 perf,bpf 05/11] perf, bpf: save bpf_prog_info in a rbtree in perf_env

From: Jiri Olsa <[email-masked]>
Date: Tue, 19 Feb 2019 09:51:45 +0100

On Tue, Feb 19, 2019 at 05:52:20AM +0000, Song Liu wrote:
> 
> 
> > On Feb 17, 2019, at 3:05 PM, Jiri Olsa <[email-masked]> wrote:
> > 
> > On Fri, Feb 15, 2019 at 01:53:48PM -0800, Song Liu wrote:
> > 
> > SNIP
> > 
> >> 	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
> >> 	if (IS_ERR_OR_NULL(info_linear)) {
> >> @@ -151,8 +165,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
> >> 						     machine, process);
> >> 	}
> >> 
> >> -	/* Synthesize PERF_RECORD_BPF_EVENT */
> >> 	if (opts->bpf_event) {
> >> +		/* Synthesize PERF_RECORD_BPF_EVENT */
> >> 		*bpf_event = (struct bpf_event){
> >> 			.header = {
> >> 				.type = PERF_RECORD_BPF_EVENT,
> >> @@ -165,6 +179,19 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
> >> 		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
> >> 		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
> >> 		event->header.size += machine->id_hdr_size;
> >> +
> >> +		/* save bpf_prog_info to env */
> >> +		info_node = malloc(sizeof(struct bpf_prog_info_node));
> >> +		if (info_node) {
> >> +			info_node->info_linear = info_linear;
> >> +			perf_env__insert_bpf_prog_info(env, info_node);
> >> +			info_linear = NULL;
> >> +		}
> > 
> > what if the allocation fails? we don't care?
> > 
> > jirka
> 
> My original plan is to just ignore it and accept that this program
> doesn't have annotation. Any suggestion on what would be a better 
> approach?

there's an error path in the function, I'd bail out if the malloc fails

jirka