From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371AbcGSLcP (ORCPT ); Tue, 19 Jul 2016 07:32:15 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:15110 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753353AbcGSLcL (ORCPT ); Tue, 19 Jul 2016 07:32:11 -0400 X-IBM-Helo: d01dlp03.pok.ibm.com X-IBM-MailFrom: gongss@linux.vnet.ibm.com From: Song Shan Gong To: acme@kernel.org, jolsa@kernel.org Cc: borntraeger@de.ibm.com, dsahern@gmail.com, linux-kernel@vger.kernel.org, Song Shan Gong Subject: [PATCH] s390/perf: fix 'start' address of module's map Date: Tue, 19 Jul 2016 19:31:58 +0800 X-Mailer: git-send-email 2.4.3 In-Reply-To: <1468927918-19879-1-git-send-email-gongss@linux.vnet.ibm.com> References: <1468927918-19879-1-git-send-email-gongss@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16071911-0040-0000-0000-000000D77D96 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16071911-0041-0000-0000-000004B1BAC2 Message-Id: <1468927918-19879-2-git-send-email-gongss@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-07-19_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607190123 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At preset, when creating module's map, perf gets 'start' address by parsing '/proc/modules', but it's module base address, isn't the start address of '.text' section. In most archs, it's OK. But for s390, it places 'GOT' and 'PLT' relocations before '.text' section. So there exists an offset between module base address and '.text' section, which will incur wrong symbol resolution for modules. Fix this bug by getting 'start' address of module's map from parsing '/sys/module/[module name]/sections/.text', not from '/proc/modules'. Signed-off-by: Song Shan Gong --- tools/perf/arch/s390/util/Build | 2 ++ tools/perf/arch/s390/util/sym-handling.c | 19 +++++++++++++++++++ tools/perf/util/machine.c | 8 ++++++++ tools/perf/util/machine.h | 1 + 4 files changed, 30 insertions(+) create mode 100644 tools/perf/arch/s390/util/sym-handling.c diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build index 8a61372..5e322ed 100644 --- a/tools/perf/arch/s390/util/Build +++ b/tools/perf/arch/s390/util/Build @@ -2,3 +2,5 @@ libperf-y += header.o libperf-y += kvm-stat.o libperf-$(CONFIG_DWARF) += dwarf-regs.o + +libperf-y += sym-handling.o diff --git a/tools/perf/arch/s390/util/sym-handling.c b/tools/perf/arch/s390/util/sym-handling.c new file mode 100644 index 0000000..ebfc55d --- /dev/null +++ b/tools/perf/arch/s390/util/sym-handling.c @@ -0,0 +1,19 @@ +#include +#include +#include +#include "util.h" +#include "machine.h" +#include "api/fs/fs.h" + +int arch__fix_module_text_start(u64 *start, const char *name) +{ + char path[PATH_MAX]; + + snprintf(path, PATH_MAX, "module/%.*s/sections/.text", + (int)strlen(name) - 2, name + 1); + + if (sysfs__read_ull(path, (unsigned long long *)start) < 0) + return -1; + + return 0; +} diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index b177218..97cc9f0 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1091,12 +1091,20 @@ static int machine__set_modules_path(struct machine *machine) return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0); } +int __weak arch__fix_module_text_start(u64 *start __maybe_unused, + const char *name __maybe_unused) +{ + return 0; +} static int machine__create_module(void *arg, const char *name, u64 start) { struct machine *machine = arg; struct map *map; + if (arch__fix_module_text_start(&start, name) < 0) + return -1; + map = machine__findnew_module_map(machine, start, name); if (map == NULL) return -1; diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index 41ac9cf..20739f7 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -216,6 +216,7 @@ struct symbol *machine__find_kernel_function_by_name(struct machine *machine, struct map *machine__findnew_module_map(struct machine *machine, u64 start, const char *filename); +int arch__fix_module_text_start(u64 *start, const char *name); int __machine__load_kallsyms(struct machine *machine, const char *filename, enum map_type type, bool no_kcore, symbol_filter_t filter); -- 2.3.0