From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45077C433EF for ; Mon, 4 Jul 2022 02:20:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230404AbiGDCU1 (ORCPT ); Sun, 3 Jul 2022 22:20:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229461AbiGDCUU (ORCPT ); Sun, 3 Jul 2022 22:20:20 -0400 Received: from smtp.gentoo.org (woodpecker.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0C716353; Sun, 3 Jul 2022 19:20:19 -0700 (PDT) Date: Mon, 4 Jul 2022 10:20:05 +0800 From: Yixun Lan To: Conor Dooley Cc: Palmer Dabbelt , linux-riscv@lists.infradead.org, Paul Walmsley , Albert Ou , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH] RISC-V/bpf: Enable bpf_probe_read{, str}() Message-ID: References: <20220703130924.57240-1-dlan@gentoo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Conor Dooley: On 14:12 Sun 03 Jul , Conor Dooley wrote: > On 03/07/2022 14:09, Yixun Lan wrote: > > Enable this option to fix a bcc error in RISC-V platform > > > > And, the error shows as follows: > > > > ~ # runqlen > > WARNING: This target JIT is not designed for the host you are running. \ > > If bad things happen, please choose a different -march switch. > > bpf: Failed to load program: Invalid argument > > 0: R1=ctx(off=0,imm=0) R10=fp0 > > 0: (85) call bpf_get_current_task#35 ; R0_w=scalar() > > 1: (b7) r6 = 0 ; R6_w=0 > > 2: (7b) *(u64 *)(r10 -8) = r6 ; R6_w=P0 R10=fp0 fp-8_w=00000000 > > 3: (07) r0 += 312 ; R0_w=scalar() > > 4: (bf) r1 = r10 ; R1_w=fp0 R10=fp0 > > 5: (07) r1 += -8 ; R1_w=fp-8 > > 6: (b7) r2 = 8 ; R2_w=8 > > 7: (bf) r3 = r0 ; R0_w=scalar(id=1) R3_w=scalar(id=1) > > 8: (85) call bpf_probe_read#4 > > unknown func bpf_probe_read#4 > > processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 > > > > Traceback (most recent call last): > > File "/usr/lib/python-exec/python3.9/runqlen", line 187, in > > b.attach_perf_event(ev_type=PerfType.SOFTWARE, > > File "/usr/lib/python3.9/site-packages/bcc/__init__.py", line 1228, in attach_perf_event > > fn = self.load_func(fn_name, BPF.PERF_EVENT) > > File "/usr/lib/python3.9/site-packages/bcc/__init__.py", line 522, in load_func > > raise Exception("Failed to load BPF program %s: %s" % > > Exception: Failed to load BPF program b'do_perf_event': Invalid argument > > > > Signed-off-by: Yixun Lan > > Do you know what commit this fixes? > Thanks, > Conor. > I think this is effectively broken for RISC-V 64 at the commit: 0ebeea8ca8a4: bpf: Restrict bpf_probe_read{, str}() only to archs where they work However, the bcc tools haven't got BPF support for RISC-V at that time, so no one noticed it I can add a Fixes tag if you think it's a proper way > > --- > > arch/riscv/Kconfig | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 32ffef9f6e5b4..da0016f1be6ce 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -25,6 +25,7 @@ config RISCV > > select ARCH_HAS_GIGANTIC_PAGE > > select ARCH_HAS_KCOV > > select ARCH_HAS_MMIOWB > > + select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > > select ARCH_HAS_PTE_SPECIAL > > select ARCH_HAS_SET_DIRECT_MAP if MMU > > select ARCH_HAS_SET_MEMORY if MMU -- Yixun Lan (dlan) Gentoo Linux Developer GPG Key ID AABEFD55