From patchwork Mon Sep 9 10:00:15 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean Pihet X-Patchwork-Id: 2860121 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 954C0BF43F for ; Mon, 9 Sep 2013 10:03:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 37FF820430 for ; Mon, 9 Sep 2013 10:03:14 +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 D9B2C20250 for ; Mon, 9 Sep 2013 10:03:12 +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 1VIyII-0005sL-Jp; Mon, 09 Sep 2013 10:02:07 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VIyHz-00019j-Pg; Mon, 09 Sep 2013 10:01:47 +0000 Received: from mail-we0-f178.google.com ([74.125.82.178]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VIyHM-00012h-J8 for linux-arm-kernel@lists.infradead.org; Mon, 09 Sep 2013 10:01:10 +0000 Received: by mail-we0-f178.google.com with SMTP id u57so3929004wes.23 for ; Mon, 09 Sep 2013 03:00:47 -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=gNwW6SZ5KGjBXb0ugRV5MzlWRC4TZzfsRoHKpJABdXM=; b=WSke7hr//8JMrp3+oQrHmmFkyjsVne932815glOk/xghwCo1LAHU8D8sfy69j0lr4l DH+e3pFINGQN1qjIcWDaRIg4caalO8np3iRi9TIJ93kouDVa91Qou+fkrmHfq/qmqKwb qelGOBaQfpfB8bpnEUAkshRfwAz1nP/uhQ0Y9/AxB5zfJGgFNzDtoQz7/GXbkSI1VvOX Ei2sajiog7qXgd6jOTE5B2bJXRta9UNng5YdzzNGQdI8BP49shSCmio5BAn1WvkBI81Q Z6bK0y4uuEIXv9a/tVm1bPni3Q/yYHaqiusu2AqLh28SD5ElBmmbEu+gdTEUn8m+SUx+ f42w== X-Gm-Message-State: ALoCoQnYYB4/aNux6P/s5PlK4V2irzgeGi7qG7Ml7pL6g/PvJG3L8kTmFnb0mxpo07J/PzvwScd4 X-Received: by 10.194.178.166 with SMTP id cz6mr612273wjc.53.1378720846937; Mon, 09 Sep 2013 03:00:46 -0700 (PDT) Received: from localhost.localdomain (189.116-241-81.adsl-dyn.isp.belgacom.be. [81.241.116.189]) by mx.google.com with ESMTPSA id iz19sm13411847wic.9.1969.12.31.16.00.00 (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 09 Sep 2013 03:00:46 -0700 (PDT) From: Jean Pihet To: Will Deacon , Jiri Olsa , linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] perf: parse the .debug_frame section in case .eh_frame is not present Date: Mon, 9 Sep 2013 12:00:15 +0200 Message-Id: <1378720815-23964-4-git-send-email-jean.pihet@linaro.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1378720815-23964-1-git-send-email-jean.pihet@linaro.org> References: <1378720815-23964-1-git-send-email-jean.pihet@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130909_060108_860231_287EF3CC X-CRM114-Status: GOOD ( 16.32 ) 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=-5.1 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 the 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 to prevent a linkage error. Note: --enable-debug-frame is automatically selected on ARM). Signed-off-by: Jean Pihet --- tools/perf/config/Makefile | 2 +- tools/perf/util/unwind.c | 71 +++++++++++++++++++++++++++++++++++----------- 2 files changed, 56 insertions(+), 17 deletions(-) diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 7014373..54532b8 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -222,7 +222,7 @@ endif FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(CFLAGS) $(LIBUNWIND_LDFLAGS) $(LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS) ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y) - msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 0.99); + msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1); NO_LIBUNWIND := 1 endif # Libunwind support endif # NO_LIBUNWIND diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c index 958723b..028c18a 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 +274,27 @@ 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; } +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; +} + static struct map *find_map(unw_word_t ip, struct unwind_info *ui) { struct addr_location al; @@ -291,20 +319,31 @@ 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); + } + + /* 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); + } - 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,