From patchwork Tue Jan 31 13:16:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 50849 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp2747556wrn; Tue, 31 Jan 2023 05:23:36 -0800 (PST) X-Google-Smtp-Source: AK7set90DYS627Zr6TCJxIPFpeXITfKCGNfkRJAwGsYs+qejVpyYQFD4X7TJv0bpVr4OCUIVLOdN X-Received: by 2002:a17:902:e48d:b0:196:768a:a9ae with SMTP id i13-20020a170902e48d00b00196768aa9aemr8364251ple.47.1675171415773; Tue, 31 Jan 2023 05:23:35 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1675171415; cv=none; d=google.com; s=arc-20160816; b=M02zjJJ14lqcHq8ZjmrSqhK9zE2No/s7KNIT0MfZzWE5+/0VfOwVYmlW5Ny6Ex0+C4 dMlLxLqxZWg8Xm0uBceA5N2L4N1oZ8j829Xhn57xxd7ial8BW2MRQoLosj8kR6zUpSz6 Y16LqzLK7LhnBuwFfUUVph045tHyqXrHOtsfhAQw5DxUWRqWrdU/4C02iLgrHKaN69BI ZTA5hBb9D7Xm7gQN2rWsLb0pXBRUVw6AX1Sg3dC34QKgzbq4YeUPWGCjQA0SKFj4kaO1 RakmNVOR+BCwU0ZxNWjGUq0lhVQCQ4BtOr1nYg+y11TZEG2VORlq0qItioA6RzlqxFER YykA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:organization :mime-version:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=fR0vNSISLs2z0PmTwF1jfwk32UyM0IMlV9ht7ldmjTE=; b=i/FD302sl7U17T0KPA3t1fHN7yh+kQ0XTE3ZUvVq+rKYzX8yc9fuTKhhpvcTgweMPW A9Ho/WnRd91cqK4BJM5oVYIdxyVAdcXtubXLIWjRXCvTf0nE7Nru00/hL8v4lKrvYmls raZO1I4qYlxP/B+aMy+C1Ugzvuv9y6BNCThppd7G4mAWIYxFJMFRxz++ahIj075M65VH hCIDBF7scD88hote8/FnIYrbwP4Tf1pTjDa83yxYk8HVjnNzQ520mUA4CKQqbA6hkix6 La55a4iIOZsTh8b1qVcw016TwLjdKORpQCIWIeQ6cP6jWwiMU338sal+3LLEueIEB7JC SB9Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=l8q9ApxI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id z6-20020a170903018600b0019680715ea0si8297929plg.392.2023.01.31.05.23.23; Tue, 31 Jan 2023 05:23:35 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=l8q9ApxI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231868AbjAaNRS (ORCPT + 99 others); Tue, 31 Jan 2023 08:17:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231992AbjAaNRC (ORCPT ); Tue, 31 Jan 2023 08:17:02 -0500 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C81D342DE5; Tue, 31 Jan 2023 05:16:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675171018; x=1706707018; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gSCQ96tg4l0FNHIgMJQtf3tGIwORYZgZx/efj/0fnbo=; b=l8q9ApxIiu+CUwlfKvp5I1t3eh3tu5L6J+4L5WKYemboLFPanBxdbueI hVuSvd2ey0T7TkboWRLzXUBlcs0Jalsd/VxfvDppuMwlG45cbmlab4iVa uzDJ1VampeZ+XfYOpBtqx97mrXu/krkmDIgQVssmKUOZ35ffDtl5ks7/V ASRTKcIqVNelcEBCeF3iLgG450DlJP9332lhWJWIvf1X6xE5Z/1GJPnlW VusWHSce+cuEumI6StcgMFfK/b7xq+JIztjMw8kmNteFzI7aCgbssx9Qb 7ZuhLgjh5CZWxyxS9YmhqRuDIx4r8FUfRAB9yz1Mi5fWQejycVCXaR+ly g==; X-IronPort-AV: E=McAfee;i="6500,9779,10606"; a="325534214" X-IronPort-AV: E=Sophos;i="5.97,261,1669104000"; d="scan'208";a="325534214" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2023 05:16:58 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10606"; a="657864857" X-IronPort-AV: E=Sophos;i="5.97,261,1669104000"; d="scan'208";a="657864857" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.252.47.218]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2023 05:16:55 -0800 From: Adrian Hunter To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Namhyung Kim , Ian Rogers , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH V2 8/9] perf symbols: Start adding support for .plt.got for x86 Date: Tue, 31 Jan 2023 15:16:24 +0200 Message-Id: <20230131131625.6964-9-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230131131625.6964-1-adrian.hunter@intel.com> References: <20230131131625.6964-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE,URI_NOVOWEL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756544542706857158?= X-GMAIL-MSGID: =?utf-8?q?1756544542706857158?= For x86, .plt.got is used, for example, when the address is taken of a dynamically linked function. Start adding support by synthesizing a symbol for each entry. A subsequent patch will attempt to get a better name for the symbol. Example: Before: $ cat tstpltlib.c void fn1(void) {} void fn2(void) {} void fn3(void) {} void fn4(void) {} $ cat tstpltgot.c void fn1(void); void fn2(void); void fn3(void); void fn4(void); void callfn(void (*fn)(void)) { fn(); } int main() { fn4(); fn1(); callfn(fn3); fn2(); fn3(); return 0; } $ gcc --version gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0 Copyright (C) 2021 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c $ gcc -Wall -Wextra -o tstpltgot tstpltgot.c -L . -ltstpltlib -Wl,-rpath="$(pwd)" $ readelf -SW tstpltgot | grep 'Name\|plt\|dyn' [Nr] Name Type Address Off Size ES Flg Lk Inf Al [ 6] .dynsym DYNSYM 00000000000003d8 0003d8 0000f0 18 A 7 1 8 [ 7] .dynstr STRTAB 00000000000004c8 0004c8 0000c6 00 A 0 0 1 [10] .rela.dyn RELA 00000000000005d8 0005d8 0000d8 18 A 6 0 8 [11] .rela.plt RELA 00000000000006b0 0006b0 000048 18 AI 6 24 8 [13] .plt PROGBITS 0000000000001020 001020 000040 10 AX 0 0 16 [14] .plt.got PROGBITS 0000000000001060 001060 000020 10 AX 0 0 16 [15] .plt.sec PROGBITS 0000000000001080 001080 000030 10 AX 0 0 16 [23] .dynamic DYNAMIC 0000000000003d90 002d90 000210 10 WA 7 0 8 $ perf record -e intel_pt//u --filter 'filter main @ ./tstpltgot , filter callfn @ ./tstpltgot' ./tstpltgot [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.011 MB perf.data ] $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso 28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0 28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0 28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd 28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0 28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12 28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0 28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0 28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16 28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21 28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0 28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26 28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 [unknown] <- call to fn3 via .plt.got 28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b 28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80 After: $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso 28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0 28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0 28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd 28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0 28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12 28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0 28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0 28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16 28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21 28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0 28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26 28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 offset_0x1060@plt+0x0 28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b 28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80 Signed-off-by: Adrian Hunter --- tools/perf/util/symbol-elf.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 9e265a726418..254116d40e59 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -466,6 +466,30 @@ static bool machine_is_x86(GElf_Half e_machine) return e_machine == EM_386 || e_machine == EM_X86_64; } +static int dso__synthesize_plt_got_symbols(struct dso *dso, Elf *elf, + GElf_Ehdr *ehdr, + char *buf, size_t buf_sz) +{ + struct symbol *sym; + GElf_Shdr shdr; + Elf_Scn *scn; + size_t i; + + scn = elf_section_by_name(elf, ehdr, &shdr, ".plt.got", NULL); + if (!scn || !shdr.sh_entsize) + return 0; + + for (i = 0; i < shdr.sh_size; i += shdr.sh_entsize) { + snprintf(buf, buf_sz, "offset_%#zx@plt", shdr.sh_offset + i); + sym = symbol__new(shdr.sh_offset + i, shdr.sh_entsize, STB_GLOBAL, STT_FUNC, buf); + if (!sym) + return -1; + symbols__insert(&dso->symbols, sym); + } + + return 0; +} + /* * We need to check if we have a .dynsym, so that we can handle the * .plt, synthesizing its symbols, that aren't on the symtabs (be it @@ -514,6 +538,11 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) goto out_elf_end; symbols__insert(&dso->symbols, plt_sym); + /* Only x86 has .plt.got */ + if (machine_is_x86(ehdr.e_machine) && + dso__synthesize_plt_got_symbols(dso, elf, &ehdr, sympltname, sizeof(sympltname))) + goto out_elf_end; + /* Only x86 has .plt.sec */ if (machine_is_x86(ehdr.e_machine) && elf_section_by_name(elf, &ehdr, &plt_sec_shdr, ".plt.sec", NULL)) {