[PATCH v6 1/4] perf util: Fix wrong block address comparison in block_info__cmp

[Jin Yao]

Commit 6041441870ab ("perf block: Cleanup and refactor block info
functions") introduces a function block_info__cmp, which compares
two blocks.

But the issues are:

1. It should return the strcmp cmp value only if it's not 0.

2. When symbol names are matched, we need to compare the addresses
   of blocks further. But it wrongly uses the symbol addresses for
   comparison.

3. If the syms are both NULL, we can't consider these two blocks are
   matched.

This patch fixes above 3 issues.

Fixes: 6041441870ab ("perf block: Cleanup and refactor block info
functions")

 v6:
 ---
 New in this patch set.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/util/block-info.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c
index c4b030bf6ec2..4ed5bce945ad 100644
--- a/tools/perf/util/block-info.c
+++ b/tools/perf/util/block-info.c
@@ -74,30 +74,21 @@ int64_t block_info__cmp(struct perf_hpp_fmt *fmt __maybe_unused,
 
 	if (!bi_l->sym || !bi_r->sym) {
 		if (!bi_l->sym && !bi_r->sym)
-			return 0;
+			return -1;
 		else if (!bi_l->sym)
 			return -1;
 		else
 			return 1;
 	}
 
-	if (bi_l->sym == bi_r->sym) {
-		if (bi_l->start == bi_r->start) {
-			if (bi_l->end == bi_r->end)
-				return 0;
-			else
-				return (int64_t)(bi_r->end - bi_l->end);
-		} else
-			return (int64_t)(bi_r->start - bi_l->start);
-	} else {
-		cmp = strcmp(bi_l->sym->name, bi_r->sym->name);
+	cmp = strcmp(bi_l->sym->name, bi_r->sym->name);
+	if (cmp)
 		return cmp;
-	}
 
-	if (bi_l->sym->start != bi_r->sym->start)
-		return (int64_t)(bi_r->sym->start - bi_l->sym->start);
+	if (bi_l->start != bi_r->start)
+		return (int64_t)(bi_r->start - bi_l->start);
 
-	return (int64_t)(bi_r->sym->end - bi_l->sym->end);
+	return (int64_t)(bi_r->end - bi_l->end);
 }
 
 static void init_block_info(struct block_info *bi, struct symbol *sym,
-- 
2.17.1