commit 7a9368a1174cb15b9f1d6342e0e10dd90dae238d

Author: Florian Weimer <fweimer@redhat.com>

Date:   Wed Nov 15 11:39:01 2017 +0100

    malloc: Add missing arena lock in malloc_info [BZ #22408]

    Obtain the size information while the arena lock is acquired, and only

    print it later.

Conflicts:

	malloc/Makefile

	  (Differences in available tests.)

diff --git a/malloc/Makefile b/malloc/Makefile

index 992cec6b03115a76..6f216f423293dc6c 100644

--- a/malloc/Makefile

+++ b/malloc/Makefile

@@ -31,6 +31,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \

 	 tst-malloc-thread-fail tst-malloc-fork-deadlock \

 	 tst-interpose-nothread \

 	 tst-interpose-thread \

+	 tst-malloc_info \

 	 tst-interpose-static-nothread \

 	 tst-interpose-static-thread \

 	 tst-scratch_buffer \

@@ -214,3 +215,5 @@ $(objpfx)tst-dynarray-mem: $(objpfx)tst-dynarray.out

 tst-dynarray-fail-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray-fail.mtrace

 $(objpfx)tst-dynarray-fail-mem: $(objpfx)tst-dynarray-fail.out

 	$(common-objpfx)malloc/mtrace $(objpfx)tst-dynarray-fail.mtrace > $@

+

+$(objpfx)tst-malloc_info: $(shared-thread-library)

diff --git a/malloc/malloc.c b/malloc/malloc.c

index d2a5e251da4f1191..035f2167be7019d8 100644

--- a/malloc/malloc.c

+++ b/malloc/malloc.c

@@ -5108,6 +5108,15 @@ __malloc_info (int options, FILE *fp)

 	  avail += sizes[NFASTBINS - 1 + i].total;

 	}

+      size_t heap_size = 0;

+      size_t heap_mprotect_size = 0;

+      if (ar_ptr != &main_arena)

+	{

+	  heap_info *heap = heap_for_ptr (top (ar_ptr));

+	  heap_size = heap->size;

+	  heap_mprotect_size = heap->mprotect_size;

+	}

+

       __libc_lock_unlock (ar_ptr->mutex);

       total_nfastblocks += nfastblocks;

@@ -5141,13 +5150,12 @@ __malloc_info (int options, FILE *fp)

       if (ar_ptr != &main_arena)

 	{

-	  heap_info *heap = heap_for_ptr (top (ar_ptr));

 	  fprintf (fp,

 		   "<aspace type=\"total\" size=\"%zu\"/>\n"

 		   "<aspace type=\"mprotect\" size=\"%zu\"/>\n",

-		   heap->size, heap->mprotect_size);

-	  total_aspace += heap->size;

-	  total_aspace_mprotect += heap->mprotect_size;

+		   heap_size, heap_mprotect_size);

+	  total_aspace += heap_size;

+	  total_aspace_mprotect += heap_mprotect_size;

 	}

       else

 	{

diff --git a/malloc/tst-malloc_info.c b/malloc/tst-malloc_info.c

new file mode 100644

index 0000000000000000..a25b8cbeae78e710

--- /dev/null

+++ b/malloc/tst-malloc_info.c

@@ -0,0 +1,101 @@

+/* Smoke test for malloc_info.

+   Copyright (C) 2017 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <http://www.gnu.org/licenses/>.  */

+

+/* The purpose of this test is to provide a quick way to run

+   malloc_info in a multi-threaded process.  */

+

+#include <array_length.h>

+#include <malloc.h>

+#include <stdlib.h>

+#include <support/support.h>

+#include <support/xthread.h>

+

+/* This barrier is used to have the main thread wait until the helper

+   threads have performed their allocations.  */

+static pthread_barrier_t barrier;

+

+enum

+  {

+    /* Number of threads performing allocations.  */

+    thread_count  = 4,

+

+    /* Amount of memory allocation per thread.  This should be large

+       enough to cause the allocation of multiple heaps per arena.  */

+    per_thread_allocations

+      = sizeof (void *) == 4 ? 16 * 1024 * 1024 : 128 * 1024 * 1024,

+  };

+

+static void *

+allocation_thread_function (void *closure)

+{

+  struct list

+  {

+    struct list *next;

+    long dummy[4];

+  };

+

+  struct list *head = NULL;

+  size_t allocated = 0;

+  while (allocated < per_thread_allocations)

+    {

+      struct list *new_head = xmalloc (sizeof (*new_head));

+      allocated += sizeof (*new_head);

+      new_head->next = head;

+      head = new_head;

+    }

+

+  xpthread_barrier_wait (&barrier);

+

+  /* Main thread prints first statistics here.  */

+

+  xpthread_barrier_wait (&barrier);

+

+  while (head != NULL)

+    {

+      struct list *next_head = head->next;

+      free (head);

+      head = next_head;

+    }

+

+  return NULL;

+}

+

+static int

+do_test (void)

+{

+  xpthread_barrier_init (&barrier, NULL, thread_count + 1);

+

+  pthread_t threads[thread_count];

+  for (size_t i = 0; i < array_length (threads); ++i)

+    threads[i] = xpthread_create (NULL, allocation_thread_function, NULL);

+

+  xpthread_barrier_wait (&barrier);

+  puts ("info: After allocation:");

+  malloc_info (0, stdout);

+

+  xpthread_barrier_wait (&barrier);

+  for (size_t i = 0; i < array_length (threads); ++i)

+    xpthread_join (threads[i]);

+

+  puts ("\ninfo: After deallocation:");

+  malloc_info (0, stdout);

+

+  return 0;

+}

+

+#include <support/test-driver.c>