Merge tag 'perf-urgent-for-mingo-4.12-20170616' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

- Fix probing of precise_ip level for default cycles event, that
got broken recently on x86_64 when its arch code started
considering invalid requesting precise samples when not sampling
(i.e. when attr.sample_period == 0).

This also fixes another problem in s/390 where the precision
probing with sample_period == 0 returned precise_ip > 0, that
then, when setting up the real cycles event (not probing) would
return EOPNOTSUPP for precise_ip > 0 (as determined previously
by probing) and sample_period > 0.

These problems resulted in attr_precise not being set to the
highest precision available on x86.64 when no event was specified,
i.e. the canonical:

perf record ./workload

would end up using attr.precise_ip = 0. As a workaround this would
need to be done:

perf record -e cycles:P ./workload

And on s/390 it would plain not work, requiring using:

perf record -e cycles ./workload

as a workaround. (Arnaldo Carvalho de Melo)

- Fix perf build with ARCH=x86_64, when ARCH should be transformed
into ARCH=x86, just like with the main kernel Makefile and
tools/objtool's, i.e. use SRCARCH. (Jiada Wang)

- Avoid accessing uninitialized data structures when unwinding with
elfutils's libdw, making it more closely mimic libunwind's unwinder.
(Milian Wolff)

Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

tools/perf/Makefile.config

···
 
 include $(srctree)/tools/scripts/Makefile.arch
 
-$(call detected_var,ARCH)
+$(call detected_var,SRCARCH)
 
 NO_PERF_REGS := 1
 
 # Additional ARCH settings for ppc
-ifeq ($(ARCH),powerpc)
+ifeq ($(SRCARCH),powerpc)
   NO_PERF_REGS := 0
   LIBUNWIND_LIBS := -lunwind -lunwind-ppc64
 endif
 
 # Additional ARCH settings for x86
-ifeq ($(ARCH),x86)
+ifeq ($(SRCARCH),x86)
   $(call detected,CONFIG_X86)
   ifeq (${IS_64_BIT}, 1)
     CFLAGS += -DHAVE_ARCH_X86_64_SUPPORT -DHAVE_SYSCALL_TABLE -I$(OUTPUT)arch/x86/include/generated
···
   NO_PERF_REGS := 0
 endif
 
-ifeq ($(ARCH),arm)
+ifeq ($(SRCARCH),arm)
   NO_PERF_REGS := 0
   LIBUNWIND_LIBS = -lunwind -lunwind-arm
 endif
 
-ifeq ($(ARCH),arm64)
+ifeq ($(SRCARCH),arm64)
   NO_PERF_REGS := 0
   LIBUNWIND_LIBS = -lunwind -lunwind-aarch64
 endif
···
 # Disable it on all other architectures in case libdw unwind
 # support is detected in system. Add supported architectures
 # to the check.
-ifneq ($(ARCH),$(filter $(ARCH),x86 arm))
+ifneq ($(SRCARCH),$(filter $(SRCARCH),x86 arm))
   NO_LIBDW_DWARF_UNWIND := 1
 endif
 
···
 FEATURE_CHECK_CFLAGS-libbabeltrace := $(LIBBABELTRACE_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libbabeltrace := $(LIBBABELTRACE_LDFLAGS) -lbabeltrace-ctf
 
-FEATURE_CHECK_CFLAGS-bpf = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi
+FEATURE_CHECK_CFLAGS-bpf = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(SRCARCH)/include/uapi -I$(srctree)/tools/include/uapi
 # include ARCH specific config
--include $(src-perf)/arch/$(ARCH)/Makefile
+-include $(src-perf)/arch/$(SRCARCH)/Makefile
 
 ifdef PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
   CFLAGS += -DHAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
···
 endif
 
 INC_FLAGS += -I$(src-perf)/util/include
-INC_FLAGS += -I$(src-perf)/arch/$(ARCH)/include
+INC_FLAGS += -I$(src-perf)/arch/$(SRCARCH)/include
 INC_FLAGS += -I$(srctree)/tools/include/uapi
 INC_FLAGS += -I$(srctree)/tools/include/
-INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/uapi
-INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/
-INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/
+INC_FLAGS += -I$(srctree)/tools/arch/$(SRCARCH)/include/uapi
+INC_FLAGS += -I$(srctree)/tools/arch/$(SRCARCH)/include/
+INC_FLAGS += -I$(srctree)/tools/arch/$(SRCARCH)/
 
 # $(obj-perf)      for generated common-cmds.h
 # $(obj-perf)/util for generated bison/flex headers
···
 
   ifndef NO_DWARF
     ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
-      msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
+      msg := $(warning DWARF register mappings have not been defined for architecture $(SRCARCH), DWARF support disabled);
       NO_DWARF := 1
     else
       CFLAGS += -DHAVE_DWARF_SUPPORT $(LIBDW_CFLAGS)
···
         CFLAGS += -DHAVE_BPF_PROLOGUE
         $(call detected,CONFIG_BPF_PROLOGUE)
       else
-        msg := $(warning BPF prologue is not supported by architecture $(ARCH), missing regs_query_register_offset());
+        msg := $(warning BPF prologue is not supported by architecture $(SRCARCH), missing regs_query_register_offset());
       endif
     else
       msg := $(warning DWARF support is off, BPF prologue is disabled);
···
   endif
 endif
 
-ifeq ($(ARCH),powerpc)
+ifeq ($(SRCARCH),powerpc)
   ifndef NO_DWARF
     CFLAGS += -DHAVE_SKIP_CALLCHAIN_IDX
   endif
···
 endif
 
 ifndef NO_LOCAL_LIBUNWIND
-  ifeq ($(ARCH),$(filter $(ARCH),arm arm64))
+  ifeq ($(SRCARCH),$(filter $(SRCARCH),arm arm64))
     $(call feature_check,libunwind-debug-frame)
     ifneq ($(feature-libunwind-debug-frame), 1)
       msg := $(warning No debug_frame support found in libunwind);
···
       NO_PERF_READ_VDSO32 := 1
     endif
   endif
-  ifneq ($(ARCH), x86)
+  ifneq ($(SRCARCH), x86)
     NO_PERF_READ_VDSOX32 := 1
   endif
   ifndef NO_PERF_READ_VDSOX32
···
 endif
 
 ifndef NO_AUXTRACE
-  ifeq ($(ARCH),x86)
+  ifeq ($(SRCARCH),x86)
     ifeq ($(feature-get_cpuid), 0)
       msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
       NO_AUXTRACE := 1
···
 ETC_PERFCONFIG = etc/perfconfig
 endif
 ifndef lib
-ifeq ($(ARCH)$(IS_64_BIT), x861)
+ifeq ($(SRCARCH)$(IS_64_BIT), x861)
 lib = lib64
 else
 lib = lib

tools/perf/Makefile.perf

···
 
 ifeq ($(config),0)
 include $(srctree)/tools/scripts/Makefile.arch
--include arch/$(ARCH)/Makefile
+-include arch/$(SRCARCH)/Makefile
 endif
 
 # The FEATURE_DUMP_EXPORT holds location of the actual

tools/perf/arch/Build

···
 libperf-y += common.o
-libperf-y += $(ARCH)/
+libperf-y += $(SRCARCH)/

tools/perf/pmu-events/Build

···
 
 jevents-y	+= json.o jsmn.o jevents.o
 pmu-events-y	+= pmu-events.o
-JDIR		=  pmu-events/arch/$(ARCH)
+JDIR		=  pmu-events/arch/$(SRCARCH)
 JSON		=  $(shell [ -d $(JDIR) ] &&				\
 			find $(JDIR) -name '*.json' -o -name 'mapfile.csv')
 #
···
 # directory and create tables in pmu-events.c.
 #
 $(OUTPUT)pmu-events/pmu-events.c: $(JSON) $(JEVENTS)
-	$(Q)$(call echo-cmd,gen)$(JEVENTS) $(ARCH) pmu-events/arch $(OUTPUT)pmu-events/pmu-events.c $(V)
+	$(Q)$(call echo-cmd,gen)$(JEVENTS) $(SRCARCH) pmu-events/arch $(OUTPUT)pmu-events/pmu-events.c $(V)

tools/perf/tests/Build

···
 	$(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@
 	$(Q)echo ';' >> $@
 
-ifeq ($(ARCH),$(filter $(ARCH),x86 arm arm64 powerpc))
+ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 arm arm64 powerpc))
 perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
 endif
 

tools/perf/tests/task-exit.c

···
 
 	evsel = perf_evlist__first(evlist);
 	evsel->attr.task = 1;
-	evsel->attr.sample_freq = 0;
+	evsel->attr.sample_freq = 1;
 	evsel->attr.inherit = 0;
 	evsel->attr.watermark = 0;
 	evsel->attr.wakeup_events = 1;

tools/perf/util/evsel.c

···
 	struct perf_evsel *evsel;
 
 	event_attr_init(&attr);
+	/*
+	 * Unnamed union member, not supported as struct member named
+	 * initializer in older compilers such as gcc 4.4.7
+	 *
+	 * Just for probing the precise_ip:
+	 */
+	attr.sample_period = 1;
 
 	perf_event_attr__set_max_precise_ip(&attr);
+	/*
+	 * Now let the usual logic to set up the perf_event_attr defaults
+	 * to kick in when we return and before perf_evsel__open() is called.
+	 */
+	attr.sample_period = 0;
 
 	evsel = perf_evsel__new(&attr);
 	if (evsel == NULL)

tools/perf/util/header.c

···
 
 /*
  * default get_cpuid(): nothing gets recorded
- * actual implementation must be in arch/$(ARCH)/util/header.c
+ * actual implementation must be in arch/$(SRCARCH)/util/header.c
  */
 int __weak get_cpuid(char *buffer __maybe_unused, size_t sz __maybe_unused)
 {

tools/perf/util/unwind-libdw.c

···
 	Dwarf_Addr pc;
 	bool isactivation;
 
+	if (!dwfl_frame_pc(state, &pc, NULL)) {
+		pr_err("%s", dwfl_errmsg(-1));
+		return DWARF_CB_ABORT;
+	}
+
+	// report the module before we query for isactivation
+	report_module(pc, ui);
+
 	if (!dwfl_frame_pc(state, &pc, &isactivation)) {
 		pr_err("%s", dwfl_errmsg(-1));
 		return DWARF_CB_ABORT;