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From: tip-bot for He Kuang <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: sukadev@linux.vnet.ibm.com, eranian@google.com,
	hekuang@huawei.com, linux-kernel@vger.kernel.org,
	kan.liang@intel.com, mingo@kernel.org, peterz@infradead.org,
	namhyung@kernel.org, dsahern@gmail.com, mhiramat@kernel.org,
	penberg@kernel.org, wangnan0@huawei.com, tglx@linutronix.de,
	acme@redhat.com, ak@linux.intel.com, tumanova@linux.vnet.ibm.com,
	adrian.hunter@intel.com, jolsa@kernel.org,
	alexander.shishkin@linux.intel.com, hpa@zytor.com,
	jpoimboe@redhat.com
Subject: [tip:perf/core] perf unwind: Check the target platform before assigning unwind methods
Date: Wed, 8 Jun 2016 01:49:47 -0700	[thread overview]
Message-ID: <tip-d64ec10ec8b43a519f132e7c33c1815a4e86949e@git.kernel.org> (raw)
In-Reply-To: <1464924803-22214-11-git-send-email-hekuang@huawei.com>

Commit-ID:  d64ec10ec8b43a519f132e7c33c1815a4e86949e
Gitweb:     http://git.kernel.org/tip/d64ec10ec8b43a519f132e7c33c1815a4e86949e
Author:     He Kuang <hekuang@huawei.com>
AuthorDate: Fri, 3 Jun 2016 03:33:19 +0000
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 7 Jun 2016 15:09:36 -0300

perf unwind: Check the target platform before assigning unwind methods

Currently, 'perf script' uses host unwind methods to parse perf.data
callchain info without taking the target architecture into account, i.e.
assuming the perf.data file was generated on the same machine where the
analysis is being performed. So we get wrong result without any warnings
when unwinding callchains of x86(32-bit) on x86(64-bit) machine.

This patch adds an extra step that checks the target platform before
assigning unwind methods. In later patches in this series, we can use
this info to assign the right unwind methods for supported platforms.

Committer note:

After fixing it to register the local unwinder for live mode tools
('perf trace', 'perf top'), i.e. tools that don't use a perf.data file,
it works as intended and passes the 'perf test unwind' test:

  # perf trace -e nanosleep --call dwarf usleep 1
     0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0
                                       __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so)
                                       usleep+0x34 (/usr/lib64/libc-2.22.so)
                                       main+0x1eb (/usr/bin/usleep)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/bin/usleep)
  # perf test 48
  48: Test dwarf unwind         : Ok
  #

Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com
[ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/thread.c           |  2 +-
 tools/perf/util/unwind-libunwind.c | 25 ++++++++++++++++++++++++-
 tools/perf/util/unwind.h           |  8 +++++---
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 0bf55256..f30f956 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -202,7 +202,7 @@ int thread__insert_map(struct thread *thread, struct map *map)
 {
 	int ret;
 
-	ret = unwind__prepare_access(thread);
+	ret = unwind__prepare_access(thread, map);
 	if (ret)
 		return ret;
 
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index f86f903..0086726 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -1,5 +1,8 @@
 #include "unwind.h"
 #include "thread.h"
+#include "session.h"
+#include "debug.h"
+#include "arch/common.h"
 
 struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
 
@@ -9,8 +12,28 @@ static void unwind__register_ops(struct thread *thread,
 	thread->unwind_libunwind_ops = ops;
 }
 
-int unwind__prepare_access(struct thread *thread)
+int unwind__prepare_access(struct thread *thread, struct map *map)
 {
+	const char *arch;
+	enum dso_type dso_type;
+
+	if (thread->addr_space) {
+		pr_debug("unwind: thread map already set, dso=%s\n",
+			 map->dso->name);
+		return 0;
+	}
+
+	/* env->arch is NULL for live-mode (i.e. perf top) */
+	if (!thread->mg->machine->env || !thread->mg->machine->env->arch)
+		goto out_register;
+
+	dso_type = dso__type(map->dso, thread->mg->machine);
+	if (dso_type == DSO__TYPE_UNKNOWN)
+		return 0;
+
+	arch = normalize_arch(thread->mg->machine->env->arch);
+	pr_debug("unwind: target platform=%s\n", arch);
+out_register:
 	unwind__register_ops(thread, local_unwind_libunwind_ops);
 
 	return thread->unwind_libunwind_ops->prepare_access(thread);
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index bbd73d9..bf9f593 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -30,11 +30,12 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
 /* libunwind specific */
 #ifdef HAVE_LIBUNWIND_SUPPORT
 int libunwind__arch_reg_id(int regnum);
-int unwind__prepare_access(struct thread *thread);
+int unwind__prepare_access(struct thread *thread, struct map *map);
 void unwind__flush_access(struct thread *thread);
 void unwind__finish_access(struct thread *thread);
 #else
-static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+static inline int unwind__prepare_access(struct thread *thread __maybe_unused,
+					 struct map *map __maybe_unused)
 {
 	return 0;
 }
@@ -53,7 +54,8 @@ unwind__get_entries(unwind_entry_cb_t cb __maybe_unused,
 	return 0;
 }
 
-static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+static inline int unwind__prepare_access(struct thread *thread __maybe_unused,
+					 struct map *map __maybe_unused)
 {
 	return 0;
 }

  parent reply	other threads:[~2016-06-08  8:50 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-03  3:33 [PATCH v9 00/14] Add support for remote unwind He Kuang
2016-06-03  3:33 ` [PATCH v9 01/14] perf tools: Use LIBUNWIND_DIR for remote libunwind feature check He Kuang
2016-06-08  8:45   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 02/14] perf tools: Decouple thread->address_space on libunwind He Kuang
2016-06-08  8:46   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 03/14] perf tools: Introducing struct unwind_libunwind_ops for local unwind He Kuang
2016-06-08  8:46   ` [tip:perf/core] perf unwind: Introduce 'struct unwind_libunwind_ops' " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 04/14] perf tools: Move unwind__prepare_access from thread_new into thread__insert_map He Kuang
2016-06-08  8:47   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 05/14] perf tools: Don't mix LIBUNWIND_LIBS into LIBUNWIND_LDFLAGS He Kuang
2016-06-08  8:47   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 06/14] perf tools: Separate local/remote libunwind config He Kuang
2016-06-08  8:47   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 07/14] perf tools: Rename unwind-libunwind.c to unwind-libunwind-local.c He Kuang
2016-06-08  8:48   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 08/14] perf tools: Extract common API out of unwind-libunwind-local.c He Kuang
2016-06-08  8:48   ` [tip:perf/core] " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 09/14] perf tools: Export normalize_arch() function He Kuang
2016-06-08  8:49   ` [tip:perf/core] " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 10/14] perf tools: Check the target platform before assigning unwind methods He Kuang
2016-06-04  5:36   ` [PATCH v9 10/14 UPDATE] " He Kuang
2016-06-07 18:06     ` Arnaldo Carvalho de Melo
2016-06-08  8:49   ` tip-bot for He Kuang [this message]
2016-06-03  3:33 ` [PATCH v9 11/14] perf tools: Change fixed name of libunwind__arch_reg_id to macro He Kuang
2016-06-08  8:50   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 12/14] perf tools: Introduce flag to separate local/remote unwind compilation He Kuang
2016-06-08  8:50   ` [tip:perf/core] perf unwind: " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 13/14] perf callchain: Support x86 target platform He Kuang
2016-06-08  8:51   ` [tip:perf/core] " tip-bot for He Kuang
2016-06-03  3:33 ` [PATCH v9 14/14] perf callchain: Support aarch64 cross-platform He Kuang
2016-06-08  8:51   ` [tip:perf/core] " tip-bot for He Kuang
2016-06-03  7:06 ` [PATCH v9 00/14] Add support for remote unwind Jiri Olsa
2016-06-03 19:42   ` Arnaldo Carvalho de Melo
2016-06-03 21:06     ` Arnaldo Carvalho de Melo
2016-06-03 21:09       ` Arnaldo Carvalho de Melo
2016-06-04  5:39         ` Hekuang
2016-06-07 15:12           ` Arnaldo Carvalho de Melo
2016-06-07 15:14             ` Arnaldo Carvalho de Melo
2016-06-07 19:44   ` Arnaldo Carvalho de Melo
2016-06-08  7:33     ` Hekuang

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