From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752369AbdFTB6B (ORCPT ); Mon, 19 Jun 2017 21:58:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:60524 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752253AbdFTB57 (ORCPT ); Mon, 19 Jun 2017 21:57:59 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF03A239F0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Wang Nan , Alexei Starovoitov , Hendrik Brueckner , Zefan Li , Arnaldo Carvalho de Melo Subject: [PATCH 15/23] perf test llvm: Avoid error when PROFILE_ALL_BRANCHES is set Date: Mon, 19 Jun 2017 22:54:51 -0300 Message-Id: <20170620015459.29381-16-acme@kernel.org> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20170620015459.29381-1-acme@kernel.org> References: <20170620015459.29381-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wang Nan The 'if' keyword is a define that expands to complex code when CONFIG_PROFILE_ALL_BRANCHES is selected, which causes a 'perf test LLVM' failure like: $ ./perf test LLVM 35: LLVM search and compile : 35.1: Basic BPF llvm compile : Ok 35.2: kbuild searching : Ok 35.3: Compile source for BPF prologue generation: FAILED! 35.4: Compile source for BPF relocation : Skip The only affected test case is bpf-script-test-prologue.c because it uses kernel headers and has 'if' inside. This patch undefines 'if' to make it passes perf test. More detailed analysis from a message in this thread, also by Wang: The problem is caused by following relocation information: $ readelf -a ./llvmsubtest3 ... [ 5] _ftrace_branch PROGBITS 0000000000000000 00000260 00000000000000a0 0000000000000000 WA 0 0 4 ... Relocation section '.relfunc=null_lseek file->f_mode offset orig' at offset 0x490 contains 4 entries: Offset Info Type Sym. Value Sym. Name 000000000038 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch 0000000000b0 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch 000000000128 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch 0000000001c0 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch Relocation section '.rel_ftrace_branch' at offset 0x4d0 contains 8 entries: Offset Info Type Sym. Value Sym. Name 000000000000 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n 000000000008 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000028 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n 000000000030 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000050 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n 000000000058 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000078 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n 000000000080 000100000001 unrecognized: 1 0000000000000015 .L.str ... So I think the failure is because you enabled CONFIG_PROFILE_ALL_BRANCHES. I can reproduce your buggy result by selecting CONFIG_PROFILE_ALL_BRANCHES in my kbuild: $ ./perf test LLVM 35: LLVM search and compile : 35.1: Basic BPF llvm compile : Ok 35.2: kbuild searching : Ok 35.3: Compile source for BPF prologue generation: FAILED! 35.4: Compile source for BPF relocation : Skip Simply undef CONFIG_PROFILE_ALL_BRANCHES in clang opts not working because it is introduced by "#include ", which override cmdline options. So I think the best way is to undefine 'if' inside BPF script. Reported-and-Tested-by: Thomas-Mich Richter Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Hendrik Brueckner Cc: Zefan Li Link: http://lkml.kernel.org/r/20170620183203.2517-1-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/bpf-script-test-prologue.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/perf/tests/bpf-script-test-prologue.c b/tools/perf/tests/bpf-script-test-prologue.c index 7230e62c70fc..b4ebc75e25ae 100644 --- a/tools/perf/tests/bpf-script-test-prologue.c +++ b/tools/perf/tests/bpf-script-test-prologue.c @@ -10,6 +10,15 @@ #include +/* + * If CONFIG_PROFILE_ALL_BRANCHES is selected, + * 'if' is redefined after include kernel header. + * Recover 'if' for BPF object code. + */ +#ifdef if +# undef if +#endif + #define FMODE_READ 0x1 #define FMODE_WRITE 0x2 -- 2.9.4