[PATCH] malloc: fix perturb_byte handling for tcache

[Joern Engel <joern at purestorage dot com>]

Also removes stale comment for tcache_free.

JIRA: PURE-27597
---
 tpc/malloc2.13/malloc.c | 5 +----
 tpc/malloc2.13/tcache.h | 9 ++++++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tpc/malloc2.13/malloc.c b/tpc/malloc2.13/malloc.c
index 190c1d24b082..74b35f6aa366 100644
--- a/tpc/malloc2.13/malloc.c
+++ b/tpc/malloc2.13/malloc.c
@@ -3290,7 +3290,7 @@ Void_t *public_mALLOc(size_t bytes)
 
 	victim = tcache_malloc(bytes);
 	if (victim)
-		goto out;
+		return victim;
 
 	ar_ptr = arena_get(bytes);
 	if (!ar_ptr)
@@ -3302,9 +3302,6 @@ Void_t *public_mALLOc(size_t bytes)
 	}
 	arena_unlock(ar_ptr);
 	assert(!victim || chunk_is_mmapped(mem2chunk(victim)) || ar_ptr == arena_for_chunk(mem2chunk(victim)));
-out:
-	if (perturb_byte)
-		alloc_perturb(victim, bytes);
 	return victim;
 }
 
diff --git a/tpc/malloc2.13/tcache.h b/tpc/malloc2.13/tcache.h
index edfe7acbc75e..00fe24249d49 100644
--- a/tpc/malloc2.13/tcache.h
+++ b/tpc/malloc2.13/tcache.h
@@ -287,6 +287,8 @@ static void *tcache_malloc(size_t size)
 		void *p = chunk2mem(victim);
 		cache->tc_size -= chunksize(victim);
 		cache->tc_count--;
+		if (perturb_byte)
+			alloc_perturb(p, size);
 		return p;
 	}
 
@@ -333,12 +335,11 @@ static void *tcache_malloc(size_t size)
 	}
 	arena_unlock(arena);
 	assert(!victim || arena == arena_for_chunk(mem2chunk(victim)));
+	if (perturb_byte)
+		alloc_perturb(victim, size);
 	return victim;
 }
 
-/*
- * returns 1 if object was freed
- */
 static void tcache_free(mchunkptr p)
 {
 	struct thread_cache *cache;
@@ -367,6 +368,8 @@ static void tcache_free(mchunkptr p)
 		malloc_printerr(check_action, "invalid tcache entry", chunk2mem(p));
 		return;
 	}
+	if (perturb_byte)
+		free_perturb(p, size - 2 * SIZE_SZ);
 	add_to_bin(bin, p);
 	if (cache->tc_size > CACHE_SIZE)
 		tcache_gc(cache);
-- 
2.7.0.rc3