Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 585 insertions, 0 deletions

diff --git a/REORG.TODO/malloc/hooks.c b/REORG.TODO/malloc/hooks.c
new file mode 100644
index 0000000000..1d80be20d2
--- /dev/null
+++ b/REORG.TODO/malloc/hooks.c
@@ -0,0 +1,585 @@
+/* Malloc implementation for multiple threads without lock contention.
+   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
+
+   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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/* What to do if the standard debugging hooks are in place and a
+   corrupt pointer is detected: do nothing (0), print an error message
+   (1), or call abort() (2). */
+
+/* Hooks for debugging versions.  The initial hooks just call the
+   initialization routine, then do the normal work. */
+
+static void *
+malloc_hook_ini (size_t sz, const void *caller)
+{
+  __malloc_hook = NULL;
+  ptmalloc_init ();
+  return __libc_malloc (sz);
+}
+
+static void *
+realloc_hook_ini (void *ptr, size_t sz, const void *caller)
+{
+  __malloc_hook = NULL;
+  __realloc_hook = NULL;
+  ptmalloc_init ();
+  return __libc_realloc (ptr, sz);
+}
+
+static void *
+memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
+{
+  __memalign_hook = NULL;
+  ptmalloc_init ();
+  return __libc_memalign (alignment, sz);
+}
+
+/* Whether we are using malloc checking.  */
+static int using_malloc_checking;
+
+/* A flag that is set by malloc_set_state, to signal that malloc checking
+   must not be enabled on the request from the user (via the MALLOC_CHECK_
+   environment variable).  It is reset by __malloc_check_init to tell
+   malloc_set_state that the user has requested malloc checking.
+
+   The purpose of this flag is to make sure that malloc checking is not
+   enabled when the heap to be restored was constructed without malloc
+   checking, and thus does not contain the required magic bytes.
+   Otherwise the heap would be corrupted by calls to free and realloc.  If
+   it turns out that the heap was created with malloc checking and the
+   user has requested it malloc_set_state just calls __malloc_check_init
+   again to enable it.  On the other hand, reusing such a heap without
+   further malloc checking is safe.  */
+static int disallow_malloc_check;
+
+/* Activate a standard set of debugging hooks. */
+void
+__malloc_check_init (void)
+{
+  if (disallow_malloc_check)
+    {
+      disallow_malloc_check = 0;
+      return;
+    }
+  using_malloc_checking = 1;
+  __malloc_hook = malloc_check;
+  __free_hook = free_check;
+  __realloc_hook = realloc_check;
+  __memalign_hook = memalign_check;
+}
+
+/* A simple, standard set of debugging hooks.  Overhead is `only' one
+   byte per chunk; still this will catch most cases of double frees or
+   overruns.  The goal here is to avoid obscure crashes due to invalid
+   usage, unlike in the MALLOC_DEBUG code. */
+
+static unsigned char
+magicbyte (const void *p)
+{
+  unsigned char magic;
+
+  magic = (((uintptr_t) p >> 3) ^ ((uintptr_t) p >> 11)) & 0xFF;
+  /* Do not return 1.  See the comment in mem2mem_check().  */
+  if (magic == 1)
+    ++magic;
+  return magic;
+}
+
+
+/* Visualize the chunk as being partitioned into blocks of 255 bytes from the
+   highest address of the chunk, downwards.  The end of each block tells
+   us the size of that block, up to the actual size of the requested
+   memory.  Our magic byte is right at the end of the requested size, so we
+   must reach it with this iteration, otherwise we have witnessed a memory
+   corruption.  */
+static size_t
+malloc_check_get_size (mchunkptr p)
+{
+  size_t size;
+  unsigned char c;
+  unsigned char magic = magicbyte (p);
+
+  assert (using_malloc_checking == 1);
+
+  for (size = chunksize (p) - 1 + (chunk_is_mmapped (p) ? 0 : SIZE_SZ);
+       (c = ((unsigned char *) p)[size]) != magic;
+       size -= c)
+    {
+      if (c <= 0 || size < (c + 2 * SIZE_SZ))
+        {
+          malloc_printerr (check_action, "malloc_check_get_size: memory corruption",
+                           chunk2mem (p),
+			   chunk_is_mmapped (p) ? NULL : arena_for_chunk (p));
+          return 0;
+        }
+    }
+
+  /* chunk2mem size.  */
+  return size - 2 * SIZE_SZ;
+}
+
+/* Instrument a chunk with overrun detector byte(s) and convert it
+   into a user pointer with requested size req_sz. */
+
+static void *
+internal_function
+mem2mem_check (void *ptr, size_t req_sz)
+{
+  mchunkptr p;
+  unsigned char *m_ptr = ptr;
+  size_t max_sz, block_sz, i;
+  unsigned char magic;
+
+  if (!ptr)
+    return ptr;
+
+  p = mem2chunk (ptr);
+  magic = magicbyte (p);
+  max_sz = chunksize (p) - 2 * SIZE_SZ;
+  if (!chunk_is_mmapped (p))
+    max_sz += SIZE_SZ;
+  for (i = max_sz - 1; i > req_sz; i -= block_sz)
+    {
+      block_sz = MIN (i - req_sz, 0xff);
+      /* Don't allow the magic byte to appear in the chain of length bytes.
+         For the following to work, magicbyte cannot return 0x01.  */
+      if (block_sz == magic)
+        --block_sz;
+
+      m_ptr[i] = block_sz;
+    }
+  m_ptr[req_sz] = magic;
+  return (void *) m_ptr;
+}
+
+/* Convert a pointer to be free()d or realloc()ed to a valid chunk
+   pointer.  If the provided pointer is not valid, return NULL. */
+
+static mchunkptr
+internal_function
+mem2chunk_check (void *mem, unsigned char **magic_p)
+{
+  mchunkptr p;
+  INTERNAL_SIZE_T sz, c;
+  unsigned char magic;
+
+  if (!aligned_OK (mem))
+    return NULL;
+
+  p = mem2chunk (mem);
+  sz = chunksize (p);
+  magic = magicbyte (p);
+  if (!chunk_is_mmapped (p))
+    {
+      /* Must be a chunk in conventional heap memory. */
+      int contig = contiguous (&main_arena);
+      if ((contig &&
+           ((char *) p < mp_.sbrk_base ||
+            ((char *) p + sz) >= (mp_.sbrk_base + main_arena.system_mem))) ||
+          sz < MINSIZE || sz & MALLOC_ALIGN_MASK || !inuse (p) ||
+          (!prev_inuse (p) && ((prev_size (p) & MALLOC_ALIGN_MASK) != 0 ||
+                               (contig && (char *) prev_chunk (p) < mp_.sbrk_base) ||
+                               next_chunk (prev_chunk (p)) != p)))
+        return NULL;
+
+      for (sz += SIZE_SZ - 1; (c = ((unsigned char *) p)[sz]) != magic; sz -= c)
+        {
+          if (c == 0 || sz < (c + 2 * SIZE_SZ))
+            return NULL;
+        }
+    }
+  else
+    {
+      unsigned long offset, page_mask = GLRO (dl_pagesize) - 1;
+
+      /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two
+         alignment relative to the beginning of a page.  Check this
+         first. */
+      offset = (unsigned long) mem & page_mask;
+      if ((offset != MALLOC_ALIGNMENT && offset != 0 && offset != 0x10 &&
+           offset != 0x20 && offset != 0x40 && offset != 0x80 && offset != 0x100 &&
+           offset != 0x200 && offset != 0x400 && offset != 0x800 && offset != 0x1000 &&
+           offset < 0x2000) ||
+          !chunk_is_mmapped (p) || prev_inuse (p) ||
+          ((((unsigned long) p - prev_size (p)) & page_mask) != 0) ||
+          ((prev_size (p) + sz) & page_mask) != 0)
+        return NULL;
+
+      for (sz -= 1; (c = ((unsigned char *) p)[sz]) != magic; sz -= c)
+        {
+          if (c == 0 || sz < (c + 2 * SIZE_SZ))
+            return NULL;
+        }
+    }
+  ((unsigned char *) p)[sz] ^= 0xFF;
+  if (magic_p)
+    *magic_p = (unsigned char *) p + sz;
+  return p;
+}
+
+/* Check for corruption of the top chunk, and try to recover if
+   necessary. */
+
+static int
+internal_function
+top_check (void)
+{
+  mchunkptr t = top (&main_arena);
+  char *brk, *new_brk;
+  INTERNAL_SIZE_T front_misalign, sbrk_size;
+  unsigned long pagesz = GLRO (dl_pagesize);
+
+  if (t == initial_top (&main_arena) ||
+      (!chunk_is_mmapped (t) &&
+       chunksize (t) >= MINSIZE &&
+       prev_inuse (t) &&
+       (!contiguous (&main_arena) ||
+        (char *) t + chunksize (t) == mp_.sbrk_base + main_arena.system_mem)))
+    return 0;
+
+  malloc_printerr (check_action, "malloc: top chunk is corrupt", t,
+		   &main_arena);
+
+  /* Try to set up a new top chunk. */
+  brk = MORECORE (0);
+  front_misalign = (unsigned long) chunk2mem (brk) & MALLOC_ALIGN_MASK;
+  if (front_misalign > 0)
+    front_misalign = MALLOC_ALIGNMENT - front_misalign;
+  sbrk_size = front_misalign + mp_.top_pad + MINSIZE;
+  sbrk_size += pagesz - ((unsigned long) (brk + sbrk_size) & (pagesz - 1));
+  new_brk = (char *) (MORECORE (sbrk_size));
+  if (new_brk == (char *) (MORECORE_FAILURE))
+    {
+      __set_errno (ENOMEM);
+      return -1;
+    }
+  /* Call the `morecore' hook if necessary.  */
+  void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
+  if (hook)
+    (*hook)();
+  main_arena.system_mem = (new_brk - mp_.sbrk_base) + sbrk_size;
+
+  top (&main_arena) = (mchunkptr) (brk + front_misalign);
+  set_head (top (&main_arena), (sbrk_size - front_misalign) | PREV_INUSE);
+
+  return 0;
+}
+
+static void *
+malloc_check (size_t sz, const void *caller)
+{
+  void *victim;
+
+  if (sz + 1 == 0)
+    {
+      __set_errno (ENOMEM);
+      return NULL;
+    }
+
+  __libc_lock_lock (main_arena.mutex);
+  victim = (top_check () >= 0) ? _int_malloc (&main_arena, sz + 1) : NULL;
+  __libc_lock_unlock (main_arena.mutex);
+  return mem2mem_check (victim, sz);
+}
+
+static void
+free_check (void *mem, const void *caller)
+{
+  mchunkptr p;
+
+  if (!mem)
+    return;
+
+  __libc_lock_lock (main_arena.mutex);
+  p = mem2chunk_check (mem, NULL);
+  if (!p)
+    {
+      __libc_lock_unlock (main_arena.mutex);
+
+      malloc_printerr (check_action, "free(): invalid pointer", mem,
+		       &main_arena);
+      return;
+    }
+  if (chunk_is_mmapped (p))
+    {
+      __libc_lock_unlock (main_arena.mutex);
+      munmap_chunk (p);
+      return;
+    }
+  _int_free (&main_arena, p, 1);
+  __libc_lock_unlock (main_arena.mutex);
+}
+
+static void *
+realloc_check (void *oldmem, size_t bytes, const void *caller)
+{
+  INTERNAL_SIZE_T nb;
+  void *newmem = 0;
+  unsigned char *magic_p;
+
+  if (bytes + 1 == 0)
+    {
+      __set_errno (ENOMEM);
+      return NULL;
+    }
+  if (oldmem == 0)
+    return malloc_check (bytes, NULL);
+
+  if (bytes == 0)
+    {
+      free_check (oldmem, NULL);
+      return NULL;
+    }
+  __libc_lock_lock (main_arena.mutex);
+  const mchunkptr oldp = mem2chunk_check (oldmem, &magic_p);
+  __libc_lock_unlock (main_arena.mutex);
+  if (!oldp)
+    {
+      malloc_printerr (check_action, "realloc(): invalid pointer", oldmem,
+		       &main_arena);
+      return malloc_check (bytes, NULL);
+    }
+  const INTERNAL_SIZE_T oldsize = chunksize (oldp);
+
+  checked_request2size (bytes + 1, nb);
+  __libc_lock_lock (main_arena.mutex);
+
+  if (chunk_is_mmapped (oldp))
+    {
+#if HAVE_MREMAP
+      mchunkptr newp = mremap_chunk (oldp, nb);
+      if (newp)
+        newmem = chunk2mem (newp);
+      else
+#endif
+      {
+        /* Note the extra SIZE_SZ overhead. */
+        if (oldsize - SIZE_SZ >= nb)
+          newmem = oldmem; /* do nothing */
+        else
+          {
+            /* Must alloc, copy, free. */
+            if (top_check () >= 0)
+              newmem = _int_malloc (&main_arena, bytes + 1);
+            if (newmem)
+              {
+                memcpy (newmem, oldmem, oldsize - 2 * SIZE_SZ);
+                munmap_chunk (oldp);
+              }
+          }
+      }
+    }
+  else
+    {
+      if (top_check () >= 0)
+        {
+          INTERNAL_SIZE_T nb;
+          checked_request2size (bytes + 1, nb);
+          newmem = _int_realloc (&main_arena, oldp, oldsize, nb);
+        }
+    }
+
+  /* mem2chunk_check changed the magic byte in the old chunk.
+     If newmem is NULL, then the old chunk will still be used though,
+     so we need to invert that change here.  */
+  if (newmem == NULL)
+    *magic_p ^= 0xFF;
+
+  __libc_lock_unlock (main_arena.mutex);
+
+  return mem2mem_check (newmem, bytes);
+}
+
+static void *
+memalign_check (size_t alignment, size_t bytes, const void *caller)
+{
+  void *mem;
+
+  if (alignment <= MALLOC_ALIGNMENT)
+    return malloc_check (bytes, NULL);
+
+  if (alignment < MINSIZE)
+    alignment = MINSIZE;
+
+  /* If the alignment is greater than SIZE_MAX / 2 + 1 it cannot be a
+     power of 2 and will cause overflow in the check below.  */
+  if (alignment > SIZE_MAX / 2 + 1)
+    {
+      __set_errno (EINVAL);
+      return 0;
+    }
+
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - alignment - MINSIZE)
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+
+  /* Make sure alignment is power of 2.  */
+  if (!powerof2 (alignment))
+    {
+      size_t a = MALLOC_ALIGNMENT * 2;
+      while (a < alignment)
+        a <<= 1;
+      alignment = a;
+    }
+
+  __libc_lock_lock (main_arena.mutex);
+  mem = (top_check () >= 0) ? _int_memalign (&main_arena, alignment, bytes + 1) :
+        NULL;
+  __libc_lock_unlock (main_arena.mutex);
+  return mem2mem_check (mem, bytes);
+}
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25)
+
+/* Get/set state: malloc_get_state() records the current state of all
+   malloc variables (_except_ for the actual heap contents and `hook'
+   function pointers) in a system dependent, opaque data structure.
+   This data structure is dynamically allocated and can be free()d
+   after use.  malloc_set_state() restores the state of all malloc
+   variables to the previously obtained state.  This is especially
+   useful when using this malloc as part of a shared library, and when
+   the heap contents are saved/restored via some other method.  The
+   primary example for this is GNU Emacs with its `dumping' procedure.
+   `Hook' function pointers are never saved or restored by these
+   functions, with two exceptions: If malloc checking was in use when
+   malloc_get_state() was called, then malloc_set_state() calls
+   __malloc_check_init() if possible; if malloc checking was not in
+   use in the recorded state but the user requested malloc checking,
+   then the hooks are reset to 0.  */
+
+#define MALLOC_STATE_MAGIC   0x444c4541l
+#define MALLOC_STATE_VERSION (0 * 0x100l + 5l) /* major*0x100 + minor */
+
+struct malloc_save_state
+{
+  long magic;
+  long version;
+  mbinptr av[NBINS * 2 + 2];
+  char *sbrk_base;
+  int sbrked_mem_bytes;
+  unsigned long trim_threshold;
+  unsigned long top_pad;
+  unsigned int n_mmaps_max;
+  unsigned long mmap_threshold;
+  int check_action;
+  unsigned long max_sbrked_mem;
+  unsigned long max_total_mem;	/* Always 0, for backwards compatibility.  */
+  unsigned int n_mmaps;
+  unsigned int max_n_mmaps;
+  unsigned long mmapped_mem;
+  unsigned long max_mmapped_mem;
+  int using_malloc_checking;
+  unsigned long max_fast;
+  unsigned long arena_test;
+  unsigned long arena_max;
+  unsigned long narenas;
+};
+
+/* Dummy implementation which always fails.  We need to provide this
+   symbol so that existing Emacs binaries continue to work with
+   BIND_NOW.  */
+void *
+attribute_compat_text_section
+malloc_get_state (void)
+{
+  __set_errno (ENOSYS);
+  return NULL;
+}
+compat_symbol (libc, malloc_get_state, malloc_get_state, GLIBC_2_0);
+
+int
+attribute_compat_text_section
+malloc_set_state (void *msptr)
+{
+  struct malloc_save_state *ms = (struct malloc_save_state *) msptr;
+
+  if (ms->magic != MALLOC_STATE_MAGIC)
+    return -1;
+
+  /* Must fail if the major version is too high. */
+  if ((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl))
+    return -2;
+
+  /* We do not need to perform locking here because __malloc_set_state
+     must be called before the first call into the malloc subsytem
+     (usually via __malloc_initialize_hook).  pthread_create always
+     calls calloc and thus must be called only afterwards, so there
+     cannot be more than one thread when we reach this point.  */
+
+  /* Disable the malloc hooks (and malloc checking).  */
+  __malloc_hook = NULL;
+  __realloc_hook = NULL;
+  __free_hook = NULL;
+  __memalign_hook = NULL;
+  using_malloc_checking = 0;
+
+  /* Patch the dumped heap.  We no longer try to integrate into the
+     existing heap.  Instead, we mark the existing chunks as mmapped.
+     Together with the update to dumped_main_arena_start and
+     dumped_main_arena_end, realloc and free will recognize these
+     chunks as dumped fake mmapped chunks and never free them.  */
+
+  /* Find the chunk with the lowest address with the heap.  */
+  mchunkptr chunk = NULL;
+  {
+    size_t *candidate = (size_t *) ms->sbrk_base;
+    size_t *end = (size_t *) (ms->sbrk_base + ms->sbrked_mem_bytes);
+    while (candidate < end)
+      if (*candidate != 0)
+	{
+	  chunk = mem2chunk ((void *) (candidate + 1));
+	  break;
+	}
+      else
+	++candidate;
+  }
+  if (chunk == NULL)
+    return 0;
+
+  /* Iterate over the dumped heap and patch the chunks so that they
+     are treated as fake mmapped chunks.  */
+  mchunkptr top = ms->av[2];
+  while (chunk < top)
+    {
+      if (inuse (chunk))
+	{
+	  /* Mark chunk as mmapped, to trigger the fallback path.  */
+	  size_t size = chunksize (chunk);
+	  set_head (chunk, size | IS_MMAPPED);
+	}
+      chunk = next_chunk (chunk);
+    }
+
+  /* The dumped fake mmapped chunks all lie in this address range.  */
+  dumped_main_arena_start = (mchunkptr) ms->sbrk_base;
+  dumped_main_arena_end = top;
+
+  return 0;
+}
+compat_symbol (libc, malloc_set_state, malloc_set_state, GLIBC_2_0);
+
+#endif	/* SHLIB_COMPAT */
+
+/*
+ * Local variables:
+ * c-basic-offset: 2
+ * End:
+ */