Merge tag 'perf-core-for-mingo-4.11-20170213' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

New features:

 - Introduce the 'delta-abs' 'perf diff' compute method, that orders the
   histogram entries by the absolute value of the percentage delta for a
   function in two perf.data files, i.e. the functions that changed the
   most (increase or decrease in samples) comes first (Namhyung Kim)

User visible changes:

 - Improve message about tweaking the kernel.perf_event_paranoid setting,
   telling how to make the change permanent by editing /etc/sysctl.conf
   (Arnaldo Carvalho de Melo)

Infrastructure changes:

 - Introduce linux/compiler-gcc.h as a counterpart to the kernel's,
   initially containing the definition of __fallthrough, more to
   come (__maybe_unused, etc) (Arnaldo Carvalho de Melo)

 - Fixes for problems uncovered by building tools/perf with clang, such
   as always true tests of arrays against NULL and variables that sometimes
   were used without being initialized (Arnaldo Carvalho de Melo, Steven Rostedt)

 - Before loading a new ELF, clear global variables set by the
   samples/bpf loader (Mickaël Salaün)

 - Ignore already processed ELF sections in the samples/bpf
   loader (Mickaël Salaün)

 - Fix compile error in the scripting code with some perl5
   versions (Wang YanQing)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

21 files changed, 137 insertions, 29 deletions

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h
new file mode 100644
index 000000000000..48af2f10a42d
--- /dev/null
+++ b/tools/include/linux/compiler-gcc.h
@@ -0,0 +1,14 @@
+#ifndef _TOOLS_LINUX_COMPILER_H_
+#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
+#endif
+
+/*
+ * Common definitions for all gcc versions go here.
+ */
+#define GCC_VERSION (__GNUC__ * 10000           \
+                     + __GNUC_MINOR__ * 100     \
+                     + __GNUC_PATCHLEVEL__)
+
+#if GCC_VERSION >= 70000 && !defined(__CHECKER__)
+# define __fallthrough __attribute__ ((fallthrough))
+#endif
diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index d94179f94caa..6326ede9aece 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -1,6 +1,10 @@
 #ifndef _TOOLS_LINUX_COMPILER_H_
 #define _TOOLS_LINUX_COMPILER_H_
 
+#ifdef __GNUC__
+#include <linux/compiler-gcc.h>
+#endif
+
 /* Optimization barrier */
 /* The "volatile" is due to gcc bugs */
 #define barrier() __asm__ __volatile__("": : :"memory")
@@ -128,11 +132,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 
 
 #ifndef __fallthrough
-# if defined(__GNUC__) && __GNUC__ >= 7
-#  define __fallthrough __attribute__ ((fallthrough))
-# else
-#  define __fallthrough
-# endif
+# define __fallthrough
 #endif
 
 #endif /* _TOOLS_LINUX_COMPILER_H */
diff --git a/tools/lib/traceevent/kbuffer-parse.c b/tools/lib/traceevent/kbuffer-parse.c
index 65984f1c2974..c94e3641b046 100644
--- a/tools/lib/traceevent/kbuffer-parse.c
+++ b/tools/lib/traceevent/kbuffer-parse.c
@@ -315,6 +315,7 @@ static unsigned int old_update_pointers(struct kbuffer *kbuf)
                 extend += delta;
                 delta = extend;
                 ptr += 4;
+                length = 0;
                 break;
 
         case OLD_RINGBUF_TYPE_TIME_STAMP:
diff --git a/tools/lib/traceevent/plugin_function.c b/tools/lib/traceevent/plugin_function.c
index a00ec190821a..42dbf73758f3 100644
--- a/tools/lib/traceevent/plugin_function.c
+++ b/tools/lib/traceevent/plugin_function.c
@@ -130,7 +130,7 @@ static int function_handler(struct trace_seq *s, struct pevent_record *record,
         unsigned long long pfunction;
         const char *func;
         const char *parent;
-        int index;
+        int index = 0;
 
         if (pevent_get_field_val(s, event, "ip", record, &function, 1))
                 return trace_seq_putc(s, '!');
diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index 9365b75fd04f..5b4fff3adc4b 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -498,6 +498,18 @@ record.*::
                 But if this option is 'no-cache', it will not update the build-id cache.
                 'skip' skips post-processing and does not update the cache.
 
+diff.*::
+        diff.order::
+                This option sets the number of columns to sort the result.
+                The default is 0, which means sorting by baseline.
+                Setting it to 1 will sort the result by delta (or other
+                compute method selected).
+
+        diff.compute::
+                This options sets the method for computing the diff result.
+                Possible values are 'delta', 'delta-abs', 'ratio' and
+                'wdiff'.  Default is 'delta'.
+
 SEE ALSO
 --------
 linkperf:perf[1]
diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index 3e9490b9c533..66dbe3dee74b 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -86,8 +86,9 @@ OPTIONS
 
 -c::
 --compute::
-        Differential computation selection - delta,ratio,wdiff (default is delta).
-        See COMPARISON METHODS section for more info.
+        Differential computation selection - delta, ratio, wdiff, delta-abs
+        (default is delta-abs).  Default can be changed using diff.compute
+        config option.  See COMPARISON METHODS section for more info.
 
 -p::
 --period::
@@ -99,7 +100,11 @@ OPTIONS
 
 -o::
 --order::
-       Specify compute sorting column number.
+       Specify compute sorting column number.  0 means sorting by baseline
+       overhead and 1 (default) means sorting by computed value of column 1
+       (data from the first file other base baseline).  Values more than 1
+       can be used only if enough data files are provided.
+       The default value can be set using the diff.order config option.
 
 --percentage::
         Determine how to display the overhead percentage of filtered entries.
@@ -181,6 +186,10 @@ with:
     relative to how entries are filtered.  Use --percentage=absolute to
     prevent such fluctuation.
 
+delta-abs
+~~~~~~~~~
+Same as 'delta` method, but sort the result with the absolute values.
+
 ratio
 ~~~~~
 If specified the 'Ratio' column is displayed with value 'r' computed as:
diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST
index a511e5f31e36..8672f835ae4e 100644
--- a/tools/perf/MANIFEST
+++ b/tools/perf/MANIFEST
@@ -61,6 +61,7 @@ tools/include/asm-generic/bitops.h
 tools/include/linux/atomic.h
 tools/include/linux/bitops.h
 tools/include/linux/compiler.h
+tools/include/linux/compiler-gcc.h
 tools/include/linux/coresight-pmu.h
 tools/include/linux/filter.h
 tools/include/linux/hash.h
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 933aeec46f4a..70a289347591 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -17,6 +17,7 @@
 #include "util/symbol.h"
 #include "util/util.h"
 #include "util/data.h"
+#include "util/config.h"
 
 #include <stdlib.h>
 #include <math.h>
@@ -30,6 +31,7 @@ enum {
         PERF_HPP_DIFF__RATIO,
         PERF_HPP_DIFF__WEIGHTED_DIFF,
         PERF_HPP_DIFF__FORMULA,
+        PERF_HPP_DIFF__DELTA_ABS,
 
         PERF_HPP_DIFF__MAX_INDEX
 };
@@ -64,7 +66,7 @@ static bool force;
 static bool show_period;
 static bool show_formula;
 static bool show_baseline_only;
-static unsigned int sort_compute;
+static unsigned int sort_compute = 1;
 
 static s64 compute_wdiff_w1;
 static s64 compute_wdiff_w2;
@@ -73,19 +75,22 @@ enum {
         COMPUTE_DELTA,
         COMPUTE_RATIO,
         COMPUTE_WEIGHTED_DIFF,
+        COMPUTE_DELTA_ABS,
         COMPUTE_MAX,
 };
 
 const char *compute_names[COMPUTE_MAX] = {
         [COMPUTE_DELTA] = "delta",
+        [COMPUTE_DELTA_ABS] = "delta-abs",
         [COMPUTE_RATIO] = "ratio",
         [COMPUTE_WEIGHTED_DIFF] = "wdiff",
 };
 
-static int compute;
+static int compute = COMPUTE_DELTA_ABS;
 
 static int compute_2_hpp[COMPUTE_MAX] = {
         [COMPUTE_DELTA]         = PERF_HPP_DIFF__DELTA,
+        [COMPUTE_DELTA_ABS]     = PERF_HPP_DIFF__DELTA_ABS,
         [COMPUTE_RATIO]         = PERF_HPP_DIFF__RATIO,
         [COMPUTE_WEIGHTED_DIFF] = PERF_HPP_DIFF__WEIGHTED_DIFF,
 };
@@ -111,6 +116,10 @@ static struct header_column {
                 .name  = "Delta",
                 .width = 7,
         },
+        [PERF_HPP_DIFF__DELTA_ABS] = {
+                .name  = "Delta Abs",
+                .width = 7,
+        },
         [PERF_HPP_DIFF__RATIO] = {
                 .name  = "Ratio",
                 .width = 14,
@@ -298,6 +307,7 @@ static int formula_fprintf(struct hist_entry *he, struct hist_entry *pair,
 {
         switch (compute) {
         case COMPUTE_DELTA:
+        case COMPUTE_DELTA_ABS:
                 return formula_delta(he, pair, buf, size);
         case COMPUTE_RATIO:
                 return formula_ratio(he, pair, buf, size);
@@ -461,6 +471,7 @@ static void hists__precompute(struct hists *hists)
 
                         switch (compute) {
                         case COMPUTE_DELTA:
+                        case COMPUTE_DELTA_ABS:
                                 compute_delta(he, pair);
                                 break;
                         case COMPUTE_RATIO:
@@ -498,6 +509,13 @@ __hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
 
                 return cmp_doubles(l, r);
         }
+        case COMPUTE_DELTA_ABS:
+        {
+                double l = fabs(left->diff.period_ratio_delta);
+                double r = fabs(right->diff.period_ratio_delta);
+
+                return cmp_doubles(l, r);
+        }
         case COMPUTE_RATIO:
         {
                 double l = left->diff.period_ratio;
@@ -564,7 +582,7 @@ hist_entry__cmp_compute_idx(struct hist_entry *left, struct hist_entry *right,
         if (!p_left || !p_right)
                 return p_left ? -1 : 1;
 
-        if (c != COMPUTE_DELTA) {
+        if (c != COMPUTE_DELTA && c != COMPUTE_DELTA_ABS) {
                 /*
                  * The delta can be computed without the baseline, but
                  * others are not.  Put those entries which have no
@@ -607,6 +625,15 @@ hist_entry__cmp_delta(struct perf_hpp_fmt *fmt,
 }
 
 static int64_t
+hist_entry__cmp_delta_abs(struct perf_hpp_fmt *fmt,
+                      struct hist_entry *left, struct hist_entry *right)
+{
+        struct data__file *d = fmt_to_data_file(fmt);
+
+        return hist_entry__cmp_compute(right, left, COMPUTE_DELTA_ABS, d->idx);
+}
+
+static int64_t
 hist_entry__cmp_ratio(struct perf_hpp_fmt *fmt,
                       struct hist_entry *left, struct hist_entry *right)
 {
@@ -633,6 +660,14 @@ hist_entry__cmp_delta_idx(struct perf_hpp_fmt *fmt __maybe_unused,
 }
 
 static int64_t
+hist_entry__cmp_delta_abs_idx(struct perf_hpp_fmt *fmt __maybe_unused,
+                              struct hist_entry *left, struct hist_entry *right)
+{
+        return hist_entry__cmp_compute_idx(right, left, COMPUTE_DELTA_ABS,
+                                           sort_compute);
+}
+
+static int64_t
 hist_entry__cmp_ratio_idx(struct perf_hpp_fmt *fmt __maybe_unused,
                           struct hist_entry *left, struct hist_entry *right)
 {
@@ -775,7 +810,7 @@ static const struct option options[] = {
         OPT_BOOLEAN('b', "baseline-only", &show_baseline_only,
                     "Show only items with match in baseline"),
         OPT_CALLBACK('c', "compute", &compute,
-                     "delta,ratio,wdiff:w1,w2 (default delta)",
+                     "delta,delta-abs,ratio,wdiff:w1,w2 (default delta-abs)",
                      "Entries differential computation selection",
                      setup_compute),
         OPT_BOOLEAN('p', "period", &show_period,
@@ -945,6 +980,7 @@ hpp__entry_pair(struct hist_entry *he, struct hist_entry *pair,
 
         switch (idx) {
         case PERF_HPP_DIFF__DELTA:
+        case PERF_HPP_DIFF__DELTA_ABS:
                 if (pair->diff.computed)
                         diff = pair->diff.period_ratio_delta;
                 else
@@ -1118,6 +1154,10 @@ static void data__hpp_register(struct data__file *d, int idx)
                 fmt->color = hpp__color_wdiff;
                 fmt->sort  = hist_entry__cmp_wdiff;
                 break;
+        case PERF_HPP_DIFF__DELTA_ABS:
+                fmt->color = hpp__color_delta;
+                fmt->sort  = hist_entry__cmp_delta_abs;
+                break;
         default:
                 fmt->sort  = hist_entry__cmp_nop;
                 break;
@@ -1195,6 +1235,9 @@ static int ui_init(void)
         case COMPUTE_WEIGHTED_DIFF:
                 fmt->sort = hist_entry__cmp_wdiff_idx;
                 break;
+        case COMPUTE_DELTA_ABS:
+                fmt->sort = hist_entry__cmp_delta_abs_idx;
+                break;
         default:
                 BUG_ON(1);
         }
@@ -1249,6 +1292,31 @@ static int data_init(int argc, const char **argv)
         return 0;
 }
 
+static int diff__config(const char *var, const char *value,
+                        void *cb __maybe_unused)
+{
+        if (!strcmp(var, "diff.order")) {
+                sort_compute = perf_config_int(var, value);
+                return 0;
+        }
+        if (!strcmp(var, "diff.compute")) {
+                if (!strcmp(value, "delta")) {
+                        compute = COMPUTE_DELTA;
+                } else if (!strcmp(value, "delta-abs")) {
+                        compute = COMPUTE_DELTA_ABS;
+                } else if (!strcmp(value, "ratio")) {
+                        compute = COMPUTE_RATIO;
+                } else if (!strcmp(value, "wdiff")) {
+                        compute = COMPUTE_WEIGHTED_DIFF;
+                } else {
+                        pr_err("Invalid compute method: %s\n", value);
+                        return -1;
+                }
+        }
+
+        return 0;
+}
+
 int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
 {
         int ret = hists__init();
@@ -1256,6 +1324,8 @@ int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
         if (ret < 0)
                 return ret;
 
+        perf_config(diff__config, NULL);
+
         argc = parse_options(argc, argv, options, diff_usage, 0);
 
         if (symbol__init(NULL) < 0)
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 29f4751a3574..6da8d083e4e5 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -1065,7 +1065,7 @@ static void __print_page_alloc_result(struct perf_session *session, int n_lines)
 
                 data = rb_entry(next, struct page_stat, node);
                 sym = machine__find_kernel_function(machine, data->callsite, &map);
-                if (sym && sym->name)
+                if (sym)
                         caller = sym->name;
                 else
                         scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
@@ -1107,7 +1107,7 @@ static void __print_page_caller_result(struct perf_session *session, int n_lines
 
                 data = rb_entry(next, struct page_stat, node);
                 sym = machine__find_kernel_function(machine, data->callsite, &map);
-                if (sym && sym->name)
+                if (sym)
                         caller = sym->name;
                 else
                         scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ffac8ca9fb01..2ddf189968dc 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -418,7 +418,7 @@ static int record__mmap(struct record *rec)
 
 static int record__open(struct record *rec)
 {
-        char msg[512];
+        char msg[BUFSIZ];
         struct perf_evsel *pos;
         struct perf_evlist *evlist = rec->evlist;
         struct perf_session *session = rec->session;
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index daceb3202200..270eb2d8ca6b 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -2067,7 +2067,7 @@ static void save_task_callchain(struct perf_sched *sched,
                         break;
 
                 sym = node->sym;
-                if (sym && sym->name) {
+                if (sym) {
                         if (!strcmp(sym->name, "schedule") ||
                             !strcmp(sym->name, "__schedule") ||
                             !strcmp(sym->name, "preempt_schedule"))
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a02f2e965628..f28719178b51 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -533,7 +533,7 @@ static int store_counter_ids(struct perf_evsel *counter)
 static int __run_perf_stat(int argc, const char **argv)
 {
         int interval = stat_config.interval;
-        char msg[512];
+        char msg[BUFSIZ];
         unsigned long long t0, t1;
         struct perf_evsel *counter;
         struct timespec ts;
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d90927f31ff6..5a7fd7af3a6d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -859,7 +859,7 @@ static void perf_top__mmap_read(struct perf_top *top)
 
 static int perf_top__start_counters(struct perf_top *top)
 {
-        char msg[512];
+        char msg[BUFSIZ];
         struct perf_evsel *counter;
         struct perf_evlist *evlist = top->evlist;
         struct record_opts *opts = &top->record_opts;
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index 8f2e1de6d0ea..541da7a68f91 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -66,7 +66,7 @@ int test__PERF_RECORD(int subtest __maybe_unused)
         if (evlist == NULL) /* Fallback for kernels lacking PERF_COUNT_SW_DUMMY */
                 evlist = perf_evlist__new_default();
 
-        if (evlist == NULL || argv == NULL) {
+        if (evlist == NULL) {
                 pr_debug("Not enough memory to create evlist\n");
                 goto out;
         }
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 04e536ae4d88..cd2fb42e5dd4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2469,7 +2469,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
                  "  -1: Allow use of (almost) all events by all users\n"
                  ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
                  ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
-                 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
+                 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+                 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
+                 "      kernel.perf_event_paranoid = -1\n" ,
                                  target->system_wide ? "system-wide " : "",
                                  perf_event_paranoid());
         case ENOENT:
diff --git a/tools/perf/util/evsel_fprintf.c b/tools/perf/util/evsel_fprintf.c
index 6b2925542c0a..4ef5184819a0 100644
--- a/tools/perf/util/evsel_fprintf.c
+++ b/tools/perf/util/evsel_fprintf.c
@@ -168,7 +168,6 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
 
                         if (symbol_conf.bt_stop_list &&
                             node->sym &&
-                            node->sym->name &&
                             strlist__has_entry(symbol_conf.bt_stop_list,
                                                node->sym->name)) {
                                 break;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 747a034d1ff3..a1043cf9b89c 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1565,7 +1565,7 @@ int machine__process_event(struct machine *machine, union perf_event *event,
 
 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
 {
-        if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
+        if (!regexec(regex, sym->name, 0, NULL, 0))
                 return 1;
         return 0;
 }
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 4f9a71c63026..0a943e7b1ea7 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -387,10 +387,10 @@ size_t map__fprintf_dsoname(struct map *map, FILE *fp)
 {
         const char *dsoname = "[unknown]";
 
-        if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+        if (map && map->dso) {
                 if (symbol_conf.show_kernel_path && map->dso->long_name)
                         dsoname = map->dso->long_name;
-                else if (map->dso->name)
+                else
                         dsoname = map->dso->name;
         }
 
diff --git a/tools/perf/util/scripting-engines/Build b/tools/perf/util/scripting-engines/Build
index 6516e220c247..82d28c67e0f3 100644
--- a/tools/perf/util/scripting-engines/Build
+++ b/tools/perf/util/scripting-engines/Build
@@ -1,6 +1,6 @@
 libperf-$(CONFIG_LIBPERL)   += trace-event-perl.o
 libperf-$(CONFIG_LIBPYTHON) += trace-event-python.o
 
-CFLAGS_trace-event-perl.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow -Wno-undef -Wno-switch-default
+CFLAGS_trace-event-perl.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow -Wno-nested-externs -Wno-undef -Wno-switch-default
 
 CFLAGS_trace-event-python.o += $(PYTHON_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 014ecd6f67c4..c1555fd0035a 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -309,10 +309,10 @@ static SV *perl_process_callchain(struct perf_sample *sample,
                 if (node->map) {
                         struct map *map = node->map;
                         const char *dsoname = "[unknown]";
-                        if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+                        if (map && map->dso) {
                                 if (symbol_conf.show_kernel_path && map->dso->long_name)
                                         dsoname = map->dso->long_name;
-                                else if (map->dso->name)
+                                else
                                         dsoname = map->dso->name;
                         }
                         if (!hv_stores(elem, "dso", newSVpv(dsoname,0))) {
diff --git a/tools/perf/util/symbol_fprintf.c b/tools/perf/util/symbol_fprintf.c
index 7c6b33e8e2d2..63694e174e5c 100644
--- a/tools/perf/util/symbol_fprintf.c
+++ b/tools/perf/util/symbol_fprintf.c
@@ -21,7 +21,7 @@ size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
         unsigned long offset;
         size_t length;
 
-        if (sym && sym->name) {
+        if (sym) {
                 length = fprintf(fp, "%s", sym->name);
                 if (al && print_offsets) {
                         if (al->addr < sym->end)