From nobody Mon Sep 29 22:37:13 2025 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 6FB8BC25B08 for ; Tue, 16 Aug 2022 00:54:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244278AbiHPAyS (ORCPT ); Mon, 15 Aug 2022 20:54:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350278AbiHPAqx (ORCPT ); Mon, 15 Aug 2022 20:46:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F2B1B6012; Mon, 15 Aug 2022 13:45:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D10E461241; Mon, 15 Aug 2022 20:45:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 919DFC433D6; Mon, 15 Aug 2022 20:45:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660596333; bh=cHKoEz5AhZTMwvjljV+QjpUj/NxRWBitpdzVNprFsqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cdkY7WM6UxUPIcgFdnTYEXpI1JuayaIk3O1KIwh1y934QoSnnXpfsky0OdOhOg+lf LO/OATHYfFVZeLKBQAYWij/kyGcJLLZlE5cc/0xHVgaU0djg2s7vC+6p46+WcbH5og t7ii3WPu4M9T5R2BjIB/mayEWwVqlAmF6CEEi2GE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Leo Yan , Ian Rogers , Alexander Shishkin , Jiri Olsa , Mark Rutland , Namhyung Kim , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.19 1013/1157] perf symbol: Fail to read phdr workaround Date: Mon, 15 Aug 2022 20:06:09 +0200 Message-Id: <20220815180520.389615024@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Ian Rogers [ Upstream commit 6d518ac7be6223811ab947897273b1bbef846180 ] The perf jvmti agent doesn't create program headers, in this case fallback on section headers as happened previously. Committer notes: To test this, from a public post by Ian: 1) download a Java workload dacapo-9.12-MR1-bach.jar from https://sourceforge.net/projects/dacapobench/ 2) build perf such as "make -C tools/perf O=3D/tmp/perf NO_LIBBFD=3D1" it should detect Java and create /tmp/perf/libperf-jvmti.so 3) run perf with the jvmti agent: perf record -k 1 java -agentpath:/tmp/perf/libperf-jvmti.so -jar dacapo-9= .12-MR1-bach.jar -n 10 fop 4) run perf inject: perf inject -i perf.data -o perf-injected.data -j 5) run perf report perf report -i perf-injected.data | grep org.apache.fop With this patch reverted I see lots of symbols like: 0.00% java jitted-388040-4656.so [.] org.apache.fop.fo.F= Obj.bind(org.apache.fop.fo.PropertyList) With the patch (2d86612aacb7805f ("perf symbol: Correct address for bss symbols")) I see lots of: dso__load_sym_internal: failed to find program header for symbol: Lorg/apache/fop/fo/FObj;bind(Lorg/apache/fop/fo/PropertyList;)V st_value: 0x40 Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols") Reviewed-by: Leo Yan Signed-off-by: Ian Rogers Tested-by: Leo Yan Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20220731164923.691193-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/symbol-elf.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index b3be5b1d9dbb..75bec32d4f57 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1305,16 +1305,29 @@ dso__load_sym_internal(struct dso *dso, struct map = *map, struct symsrc *syms_ss, =20 if (elf_read_program_header(syms_ss->elf, (u64)sym.st_value, &phdr)) { - pr_warning("%s: failed to find program header for " + pr_debug4("%s: failed to find program header for " "symbol: %s st_value: %#" PRIx64 "\n", __func__, elf_name, (u64)sym.st_value); - continue; + pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " + "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", + __func__, (u64)sym.st_value, (u64)shdr.sh_addr, + (u64)shdr.sh_offset); + /* + * Fail to find program header, let's rollback + * to use shdr.sh_addr and shdr.sh_offset to + * calibrate symbol's file address, though this + * is not necessary for normal C ELF file, we + * still need to handle java JIT symbols in this + * case. + */ + sym.st_value -=3D shdr.sh_addr - shdr.sh_offset; + } else { + pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " + "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n", + __func__, (u64)sym.st_value, (u64)phdr.p_vaddr, + (u64)phdr.p_offset); + sym.st_value -=3D phdr.p_vaddr - phdr.p_offset; } - pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " - "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n", - __func__, (u64)sym.st_value, (u64)phdr.p_vaddr, - (u64)phdr.p_offset); - sym.st_value -=3D phdr.p_vaddr - phdr.p_offset; } =20 demangled =3D demangle_sym(dso, kmodule, elf_name); --=20 2.35.1