[PATCH v2] malloc_stats(): Fix `unsigned int` overflow

["Niklas Hambüchen" <mail@nh2.me>]

Fixes malloc_stats() returning vastly wrong information for programs
that use more than 2 GiB memory.

`man mallinfo` documents that it uses `int` and wraps around, but
`man malloc_stats` does not, and should not.

Fixes https://sourceware.org/bugzilla/show_bug.cgi?id=21556

Signed-off-by: Niklas Hambüchen <mail@nh2.me>
---
 malloc/malloc.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/malloc/malloc.c b/malloc/malloc.c
index 78a531bc7a..dfb266a226 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -5374,7 +5374,7 @@ __malloc_stats (void)
 {
   int i;
   mstate ar_ptr;
-  unsigned int in_use_b = mp_.mmapped_mem, system_b = in_use_b;
+  size_t in_use_b = mp_.mmapped_mem, system_b = in_use_b;
 
   if (!__malloc_initialized)
     ptmalloc_init ();
@@ -5389,8 +5389,8 @@ __malloc_stats (void)
       __libc_lock_lock (ar_ptr->mutex);
       int_mallinfo (ar_ptr, &mi);
       fprintf (stderr, "Arena %d:\n", i);
-      fprintf (stderr, "system bytes     = %10u\n", (unsigned int) mi.arena);
-      fprintf (stderr, "in use bytes     = %10u\n", (unsigned int) mi.uordblks);
+      fprintf (stderr, "system bytes     = %10zu\n", mi.arena);
+      fprintf (stderr, "in use bytes     = %10zu\n", mi.uordblks);
 #if MALLOC_DEBUG > 1
       if (i > 0)
         dump_heap (heap_for_ptr (top (ar_ptr)));
@@ -5403,11 +5403,10 @@ __malloc_stats (void)
         break;
     }
   fprintf (stderr, "Total (incl. mmap):\n");
-  fprintf (stderr, "system bytes     = %10u\n", system_b);
-  fprintf (stderr, "in use bytes     = %10u\n", in_use_b);
-  fprintf (stderr, "max mmap regions = %10u\n", (unsigned int) mp_.max_n_mmaps);
-  fprintf (stderr, "max mmap bytes   = %10lu\n",
-           (unsigned long) mp_.max_mmapped_mem);
+  fprintf (stderr, "system bytes     = %10zu\n", system_b);
+  fprintf (stderr, "in use bytes     = %10zu\n", in_use_b);
+  fprintf (stderr, "max mmap regions = %10d\n", mp_.max_n_mmaps);
+  fprintf (stderr, "max mmap bytes   = %10zu\n", mp_.max_mmapped_mem);
   stderr->_flags2 = old_flags2;
   _IO_funlockfile (stderr);
 }
-- 
2.40.1