From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH bpf-next] bpf: remove tracepoints from bpf core Date: Sun, 29 Apr 2018 00:37:39 -0400 (EDT) Message-ID: <20180429.003739.873200779196020197.davem@davemloft.net> References: <20180429025637.2510982-1-ast@kernel.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: daniel@iogearbox.net, ebiggers3@gmail.com, netdev@vger.kernel.org, kernel-team@fb.com To: ast@kernel.org Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:44404 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750801AbeD2Ehn (ORCPT ); Sun, 29 Apr 2018 00:37:43 -0400 In-Reply-To: <20180429025637.2510982-1-ast@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Alexei Starovoitov Date: Sat, 28 Apr 2018 19:56:37 -0700 > tracepoints to bpf core were added as a way to provide introspection > to bpf programs and maps, but after some time it became clear that > this approach is inadequate, so prog_id, map_id and corresponding > get_next_id, get_fd_by_id, get_info_by_fd, prog_query APIs were > introduced and fully adopted by bpftool and other applications. > The tracepoints in bpf core started to rot and causing syzbot warnings: > WARNING: CPU: 0 PID: 3008 at kernel/trace/trace_event_perf.c:274 > Kernel panic - not syncing: panic_on_warn set ... > perf_trace_bpf_map_keyval+0x260/0xbd0 include/trace/events/bpf.h:228 > trace_bpf_map_update_elem include/trace/events/bpf.h:274 [inline] > map_update_elem kernel/bpf/syscall.c:597 [inline] > SYSC_bpf kernel/bpf/syscall.c:1478 [inline] > Hence this patch deletes tracepoints in bpf core. > > Reported-by: Eric Biggers > Reported-by: syzbot > Signed-off-by: Alexei Starovoitov Acked-by: David S. Miller