From patchwork Thu Sep 26 11:36:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean Pihet X-Patchwork-Id: 2948101 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 00F85BFF05 for ; Thu, 26 Sep 2013 11:40:04 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B26422032D for ; Thu, 26 Sep 2013 11:40:02 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5CBAF20204 for ; Thu, 26 Sep 2013 11:40:01 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VP9tv-0003TF-M5; Thu, 26 Sep 2013 11:38:32 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VP9tX-0004JS-Ee; Thu, 26 Sep 2013 11:38:07 +0000 Received: from mail-ee0-f46.google.com ([74.125.83.46]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VP9sp-0004C3-Va for linux-arm-kernel@lists.infradead.org; Thu, 26 Sep 2013 11:37:26 +0000 Received: by mail-ee0-f46.google.com with SMTP id c13so472656eek.5 for ; Thu, 26 Sep 2013 04:37:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=z3Qdl/uVQ9tTpYEEPlfaKPMHZ61pKDufEZH/K3rdDrA=; b=bAefDmBNrAB40B7sD+leUB3sJJb/cXKwE1Mcif/UKkhZRJS2srvbXMjHpIBdjoeIO/ P6LyxOdvNgSWOdw8LXwdC1VeJc0YsF4nNHTO49jv4V1JQiA/LhqxS5jwQ43TBk+DW0D5 qzzZyJLe4+2Tbnrn4rfN6jO86YR6APe2f1fOihO83764m69N+5xYxSMaMekKSZNIWhEi AGLwxcHV3ABJgryHO/CdL/b6Thb7jFdF57ErALIrc3dWMjHRO2t7G1/KuUECUon9OCRd yWKFEXg+0B2JPjRAYY02MJMMSimTRws7EBp1xIM3tcfJ1YNa0Y0hTU09fQM1H/2lEhul ap1A== X-Gm-Message-State: ALoCoQmU3rignjXEC9tZ/yDamukFpXzs2Vplrb73V3gFHllztGeYX/v+3AIIQoYIlfLkP0wqkP+I X-Received: by 10.14.179.9 with SMTP id g9mr12655eem.93.1380195421904; Thu, 26 Sep 2013 04:37:01 -0700 (PDT) Received: from localhost.localdomain (221.61-241-81.adsl-dyn.isp.belgacom.be. [81.241.61.221]) by mx.google.com with ESMTPSA id f49sm2945588eec.7.1969.12.31.16.00.00 (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 26 Sep 2013 04:37:01 -0700 (PDT) From: Jean Pihet To: Will Deacon , Jiri Olsa , linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, Ingo Molnar , linux-arm-kernel@lists.infradead.org Subject: [PATCH 4/4] perf: parse the .debug_frame section in case .eh_frame is not present Date: Thu, 26 Sep 2013 13:36:38 +0200 Message-Id: <1380195398-4402-5-git-send-email-jean.pihet@linaro.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1380195398-4402-1-git-send-email-jean.pihet@linaro.org> References: <1380195398-4402-1-git-send-email-jean.pihet@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130926_073724_191160_A65C4794 X-CRM114-Status: GOOD ( 15.55 ) X-Spam-Score: -2.6 (--) Cc: Jean Pihet , patches@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in dwarf format. Use libunwind to load and parse the debug info. Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame. Note: --enable-debug-frame is automatically selected on ARM. Signed-off-by: Jean Pihet Acked-by: Jiri Olsa --- tools/perf/util/unwind.c | 75 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 59 insertions(+), 16 deletions(-) diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c index 2f891f7..5390d0b 100644 --- a/tools/perf/util/unwind.c +++ b/tools/perf/util/unwind.c @@ -39,6 +39,15 @@ UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) +extern int +UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, + unw_word_t ip, + unw_word_t segbase, + const char *obj_name, unw_word_t start, + unw_word_t end); + +#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) + #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ @@ -245,8 +254,9 @@ static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, return 0; } -static int read_unwind_spec(struct dso *dso, struct machine *machine, - u64 *table_data, u64 *segbase, u64 *fde_count) +static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, + u64 *table_data, u64 *segbase, + u64 *fde_count) { int ret = -EINVAL, fd; u64 offset; @@ -255,6 +265,7 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, if (fd < 0) return -EINVAL; + /* Check the .eh_frame section for unwinding info */ offset = elf_section_offset(fd, ".eh_frame_hdr"); close(fd); @@ -263,10 +274,29 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, table_data, segbase, fde_count); - /* TODO .debug_frame check if eh_frame_hdr fails */ return ret; } +#ifndef NO_LIBUNWIND_DEBUG_FRAME +static int read_unwind_spec_debug_frame(struct dso *dso, + struct machine *machine, u64 *offset) +{ + int fd = dso__data_fd(dso, machine); + + if (fd < 0) + return -EINVAL; + + /* Check the .debug_frame section for unwinding info */ + *offset = elf_section_offset(fd, ".debug_frame"); + close(fd); + + if (*offset) + return 0; + + return -EINVAL; +} +#endif + static struct map *find_map(unw_word_t ip, struct unwind_info *ui) { struct addr_location al; @@ -291,20 +321,33 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, pr_debug("unwind: find_proc_info dso %s\n", map->dso->name); - if (read_unwind_spec(map->dso, ui->machine, - &table_data, &segbase, &fde_count)) - return -EINVAL; + /* Check the .eh_frame section for unwinding info */ + if (!read_unwind_spec_eh_frame(map->dso, ui->machine, + &table_data, &segbase, &fde_count)) { + memset(&di, 0, sizeof(di)); + di.format = UNW_INFO_FORMAT_REMOTE_TABLE; + di.start_ip = map->start; + di.end_ip = map->end; + di.u.rti.segbase = map->start + segbase; + di.u.rti.table_data = map->start + table_data; + di.u.rti.table_len = fde_count * sizeof(struct table_entry) + / sizeof(unw_word_t); + return dwarf_search_unwind_table(as, ip, &di, pi, + need_unwind_info, arg); + } + +#ifndef NO_LIBUNWIND_DEBUG_FRAME + /* Check the .debug_frame section for unwinding info */ + if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { + memset(&di, 0, sizeof(di)); + dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name, + map->start, map->end); + return dwarf_search_unwind_table(as, ip, &di, pi, + need_unwind_info, arg); + } +#endif - memset(&di, 0, sizeof(di)); - di.format = UNW_INFO_FORMAT_REMOTE_TABLE; - di.start_ip = map->start; - di.end_ip = map->end; - di.u.rti.segbase = map->start + segbase; - di.u.rti.table_data = map->start + table_data; - di.u.rti.table_len = fde_count * sizeof(struct table_entry) - / sizeof(unw_word_t); - return dwarf_search_unwind_table(as, ip, &di, pi, - need_unwind_info, arg); + return -EINVAL; } static int access_fpreg(unw_addr_space_t __maybe_unused as,