On Thu, Aug 29, 2024 at 11:12:41PM +0200, Oleg Nesterov wrote: > Ah. we certainly misunderstand each other. > > On 08/29, Jiri Olsa wrote: > > > > On Thu, Aug 29, 2024 at 05:20:33PM +0200, Oleg Nesterov wrote: > > > > SNIP > > SNIP > > > right.. if the event is not added by perf_trace_add on this cpu > > it won't go pass this point, so no problem for perf > > Yes, and this is what I tried to verify. In your previous email you said > > and I think the same will happen for perf record in this case where > instead of > running the program we will execute perf_tp_event > > and I tried verify this can't happen. So no problem for perf ;)
yea, I was wrong, you should be used to it by now ;-) > > > but the issue is with bpf program triggered earlier by return uprobe > > Well, the issue with bpf program (with the bpf_prog_array_valid(call) code > in __uprobe_perf_func) was clear from the very beginning, no questions. > > > and [1] patch seems to fix that > > I'd say this patch fixes the symptoms, and it doesn't fix all the problems. > But I can't suggest anything better for bpf code, so I won't really argue. > However the changelog and even the subject is wrong. > > > I sent out the bpf selftest that triggers the issue [2] > > Thanks, I'll try take a look tomorrow. thanks, jirka
