glibc: malloc: Add missing arena lock in malloc_info

There are the multiple process crashes seen while using malloc_info.
Obtain the size information while the arena lock is acquired, and only
print it later.

Backport patch from https://sourceware.org/git/gitweb.cgi?p=glibc.git;
h=7a9368a1174cb15b9f1d6342e0e10dd90dae238d

(From OE-Core rev: 7ecbb31fbaf1d056c9301166700e2967bd623489)

Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 173 insertions, 0 deletions

diff --git a/meta/recipes-core/glibc/glibc/0029-malloc-add-missing-arena-lock-in-malloc-info.patch b/meta/recipes-core/glibc/glibc/0029-malloc-add-missing-arena-lock-in-malloc-info.patch
new file mode 100644
index 0000000000..626e0e9039
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0029-malloc-add-missing-arena-lock-in-malloc-info.patch
@@ -0,0 +1,172 @@
+From: Florian Weimer <fweimer@redhat.com>
+Date: Wed, 15 Nov 2017 11:39:01 +0100
+Subject: [PATCH] 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.
+
+Upstream-Status: Backport
+
+Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com>
+
+Index: git/malloc/Makefile
+===================================================================
+--- git.orig/malloc/Makefile    2017-09-04 17:34:06.758018978 +0800
++++ git/malloc/Makefile 2017-11-20 14:57:43.440337572 +0800
+@@ -35,6 +35,7 @@
+         tst-interpose-thread \
+         tst-alloc_buffer \
+         tst-malloc-tcache-leak \
++        tst-malloc_info \
+ 
+ tests-static := \
+         tst-interpose-static-nothread \
+@@ -245,3 +246,5 @@
+        $(evaluate-test)
+ 
+ $(objpfx)tst-malloc-tcache-leak: $(shared-thread-library)
++
++$(objpfx)tst-malloc_info: $(shared-thread-library)
+Index: git/malloc/malloc.c
+===================================================================
+--- git.orig/malloc/malloc.c    2017-09-04 17:34:06.758018978 +0800
++++ git/malloc/malloc.c 2017-11-20 15:01:02.412338959 +0800
+@@ -5547,6 +5547,15 @@
+          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;
+@@ -5580,13 +5589,12 @@
+ 
+       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
+        {
+Index: git/malloc/tst-malloc_info.c
+===================================================================
+--- /dev/null   1970-01-01 00:00:00.000000000 +0000
++++ git/malloc/tst-malloc_info.c        2017-11-20 15:02:03.208339383 +0800
+@@ -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>
diff --git a/meta/recipes-core/glibc/glibc_2.26.bb b/meta/recipes-core/glibc/glibc_2.26.bb
index 5213a6a942..04d97734b3 100644
--- a/meta/recipes-core/glibc/glibc_2.26.bb
+++ b/meta/recipes-core/glibc/glibc_2.26.bb
@@ -42,6 +42,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
            file://0025-locale-fix-hard-coded-reference-to-gcc-E.patch \
            file://0027-glibc-reset-dl-load-write-lock-after-forking.patch \
            file://0028-Bug-4578-add-ld.so-lock-while-fork.patch \
+           file://0029-malloc-add-missing-arena-lock-in-malloc-info.patch \
 "
 
 NATIVESDKFIXES ?= ""