Improve malloc initialization sequence

The current malloc initialization is quite convoluted. Instead of
sometimes calling malloc_consolidate from ptmalloc_init, call
malloc_init_state early so that the main_arena is always initialized.
The special initialization can now be removed from malloc_consolidate.
This also fixes BZ #22159.

Check all calls to malloc_consolidate and remove calls that are
redundant initialization after ptmalloc_init, like in int_mallinfo
and __libc_mallopt (but keep the latter as consolidation is required for
set_max_fast).  Update comments to improve clarity.

Remove impossible initialization check from _int_malloc, fix assert
in do_check_malloc_state to ensure arena->top != 0.  Fix the obvious bugs
in do_check_free_chunk and do_check_remalloced_chunk to enable single
threaded malloc debugging (do_check_malloc_state is not thread safe!).

	[BZ #22159]
	* malloc/arena.c (ptmalloc_init): Call malloc_init_state.
	* malloc/malloc.c (do_check_free_chunk): Fix build bug.
	(do_check_remalloced_chunk): Fix build bug.
	(do_check_malloc_state): Add assert that checks arena->top.
	(malloc_consolidate): Remove initialization.
	(int_mallinfo): Remove call to malloc_consolidate.
	(__libc_mallopt): Clarify why malloc_consolidate is needed.

1 files changed, 11 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index fca7345..6cb971d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2017-10-17  Wilco Dijkstra  <wdijkstr@arm.com>
 
+	[BZ #22159]
+	* malloc/arena.c (ptmalloc_init): Call malloc_init_state.
+	* malloc/malloc.c (do_check_free_chunk): Fix build bug.
+	(do_check_remalloced_chunk): Fix build bug.
+	(do_check_malloc_state): Add assert that checks arena->top.
+	(malloc_consolidate): Remove initialization.
+	(int_mallinfo): Remove call to malloc_consolidate.
+	 (__libc_mallopt): Clarify why malloc_consolidate is needed.
+
+2017-10-17  Wilco Dijkstra  <wdijkstr@arm.com>
+
 	* malloc/malloc.c (FASTCHUNKS_BIT): Remove.
 	(have_fastchunks): Remove.
 	(clear_fastchunks): Remove.