From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-by2nam03on0120.outbound.protection.outlook.com ([104.47.42.120]:61603 "EHLO NAM03-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754405AbeDIA3M (ORCPT ); Sun, 8 Apr 2018 20:29:12 -0400 From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Wang Nan , Alexei Starovoitov , Hendrik Brueckner , Zefan Li , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH AUTOSEL for 4.9 095/293] perf test llvm: Avoid error when PROFILE_ALL_BRANCHES is set Date: Mon, 9 Apr 2018 00:24:08 +0000 Message-ID: <20180409002239.163177-95-alexander.levin@microsoft.com> References: <20180409002239.163177-1-alexander.levin@microsoft.com> In-Reply-To: <20180409002239.163177-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Wang Nan [ Upstream commit 9b57fb7e35957c6838f89f4ed7e3f8433a4bbfc5 ] 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=3Dnull_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 entrie= s: Offset Info Type Sym. Value Sym. Name 000000000000 000200000001 unrecognized: 1 0000000000000000 .L__fun= c__.bpf_func__n 000000000008 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000028 000200000001 unrecognized: 1 0000000000000000 .L__fun= c__.bpf_func__n 000000000030 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000050 000200000001 unrecognized: 1 0000000000000000 .L__fun= c__.bpf_func__n 000000000058 000100000001 unrecognized: 1 0000000000000015 .L.str 000000000078 000200000001 unrecognized: 1 0000000000000000 .L__fun= c__.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 Signed-off-by: Sasha Levin --- 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 @@ =20 #include =20 +/* + * 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 =20 --=20 2.15.1