[PATCH 09/10] perf sort: Separate out branch stack specific sort keys

[Namhyung Kim <namhyung@kernel.org>]

From: Namhyung Kim <namhyung.kim@lge.com>

Current perf report gets segmentation fault when a branch stack
specific sort key is provided by --sort option to a perf.data file
which contains no branch infomation.  It's because those sort keys
reference branch info of a hist entry unconditionally.  Maybe we can
change it checks whether such branch info is valid or not.  But if the
branch stacks are not recorded, it'd be nop.  Thus it'd be better to
make those keys are unselectable.

This patch separates those keys to a different dimension array, so
that if user passes such a key to a file which has no branch stack
will get following message rather than a segfault.

  Error: Invalid --sort key: `symbol_from'

Reported-by: Stefan Beller <stefanbeller@googlemail.com>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/sort.c | 64 ++++++++++++++++++++++++++++++++++++++++----------
 tools/perf/util/sort.h |  8 +++++--
 2 files changed, 58 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index a5e732a03bda..012a077fbce9 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -469,30 +469,40 @@ struct sort_dimension {
 
 #define DIM(d, n, func) [d] = { .name = n, .entry = &(func) }
 
-static struct sort_dimension sort_dimensions[] = {
+static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_PID, "pid", sort_thread),
 	DIM(SORT_COMM, "comm", sort_comm),
 	DIM(SORT_DSO, "dso", sort_dso),
-	DIM(SORT_DSO_FROM, "dso_from", sort_dso_from),
-	DIM(SORT_DSO_TO, "dso_to", sort_dso_to),
 	DIM(SORT_SYM, "symbol", sort_sym),
-	DIM(SORT_SYM_TO, "symbol_from", sort_sym_from),
-	DIM(SORT_SYM_FROM, "symbol_to", sort_sym_to),
 	DIM(SORT_PARENT, "parent", sort_parent),
 	DIM(SORT_CPU, "cpu", sort_cpu),
-	DIM(SORT_MISPREDICT, "mispredict", sort_mispredict),
 	DIM(SORT_SRCLINE, "srcline", sort_srcline),
 };
 
+#undef DIM
+
+#define DIM(d, n, func) [d - __SORT_BRANCH_STACK] = { .name = n, .entry = &(func) }
+
+static struct sort_dimension bstack_sort_dimensions[] = {
+	DIM(SORT_DSO_FROM, "dso_from", sort_dso_from),
+	DIM(SORT_DSO_TO, "dso_to", sort_dso_to),
+	DIM(SORT_SYM_FROM, "symbol_from", sort_sym_from),
+	DIM(SORT_SYM_TO, "symbol_to", sort_sym_to),
+	DIM(SORT_MISPREDICT, "mispredict", sort_mispredict),
+};
+
+#undef DIM
+
 int sort_dimension__add(const char *tok)
 {
 	unsigned int i;
 
-	for (i = 0; i < ARRAY_SIZE(sort_dimensions); i++) {
-		struct sort_dimension *sd = &sort_dimensions[i];
+	for (i = 0; i < ARRAY_SIZE(common_sort_dimensions); i++) {
+		struct sort_dimension *sd = &common_sort_dimensions[i];
 
 		if (strncasecmp(tok, sd->name, strlen(tok)))
 			continue;
+
 		if (sd->entry == &sort_parent) {
 			int ret = regcomp(&parent_regex, parent_pattern, REG_EXTENDED);
 			if (ret) {
@@ -503,9 +513,7 @@ int sort_dimension__add(const char *tok)
 				return -EINVAL;
 			}
 			sort__has_parent = 1;
-		} else if (sd->entry == &sort_sym ||
-			   sd->entry == &sort_sym_from ||
-			   sd->entry == &sort_sym_to) {
+		} else if (sd->entry == &sort_sym) {
 			sort__has_sym = 1;
 		}
 
@@ -523,6 +531,34 @@ int sort_dimension__add(const char *tok)
 
 		return 0;
 	}
+
+	for (i = 0; i < ARRAY_SIZE(bstack_sort_dimensions); i++) {
+		struct sort_dimension *sd = &bstack_sort_dimensions[i];
+
+		if (strncasecmp(tok, sd->name, strlen(tok)))
+			continue;
+
+		if (sort__branch_mode != 1)
+			return -EINVAL;
+
+		if (sd->entry == &sort_sym_from || sd->entry == &sort_sym_to)
+			sort__has_sym = 1;
+
+		if (sd->taken)
+			return 0;
+
+		if (sd->entry->se_collapse)
+			sort__need_collapse = 1;
+
+		if (list_empty(&hist_entry__sort_list))
+			sort__first_dimension = i + __SORT_BRANCH_STACK;
+
+		list_add_tail(&sd->entry->list, &hist_entry__sort_list);
+		sd->taken = 1;
+
+		return 0;
+	}
+
 	return -ESRCH;
 }
 
@@ -537,7 +573,11 @@ void setup_sorting(const char * const usagestr[], const struct option *opts)
 
 	for (tok = strtok_r(str, ", ", &tmp);
 			tok; tok = strtok_r(NULL, ", ", &tmp)) {
-		if (sort_dimension__add(tok) < 0) {
+		int ret = sort_dimension__add(tok);
+		if (ret == -EINVAL) {
+			error("Invalid --sort key: `%s'", tok);
+			usage_with_options(usagestr, opts);
+		} else if (ret == -ESRCH) {
 			error("Unknown --sort key: `%s'", tok);
 			usage_with_options(usagestr, opts);
 		}
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index a1c0d56b6885..e994ad3e9897 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -122,18 +122,22 @@ static inline void hist_entry__add_pair(struct hist_entry *he,
 }
 
 enum sort_type {
+	/* common sort keys */
 	SORT_PID,
 	SORT_COMM,
 	SORT_DSO,
 	SORT_SYM,
 	SORT_PARENT,
 	SORT_CPU,
-	SORT_DSO_FROM,
+	SORT_SRCLINE,
+
+	/* branch stack specific sort keys */
+	__SORT_BRANCH_STACK,
+	SORT_DSO_FROM = __SORT_BRANCH_STACK,
 	SORT_DSO_TO,
 	SORT_SYM_FROM,
 	SORT_SYM_TO,
 	SORT_MISPREDICT,
-	SORT_SRCLINE,
 };
 
 /*
-- 
1.7.11.7