drd/drd_malloc_wrappers.c

/*
  This file is part of drd, a thread error detector.

  Copyright (C) 2006-2009 Bart Van Assche <bart.vanassche@gmail.com>.

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of the
  License, or (at your option) any later version.

  This program 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
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  02111-1307, USA.

  The GNU General Public License is contained in the file COPYING.
*/


#include "drd_malloc_wrappers.h"
#include "drd_thread.h"
#include "pub_tool_basics.h"
#include "pub_tool_execontext.h"
#include "pub_tool_hashtable.h"
#include "pub_tool_libcassert.h"
#include "pub_tool_libcbase.h"
#include "pub_tool_libcprint.h"
#include "pub_tool_mallocfree.h"
#include "pub_tool_options.h"
#include "pub_tool_replacemalloc.h"
#include "pub_tool_threadstate.h"
#include "pub_tool_tooliface.h"


/* Local type definitions. */

typedef struct _DRD_Chunk {
  struct _DRD_Chunk* next;
  Addr          data;            // ptr to actual block
  SizeT         size : (sizeof(UWord)*8)-2; //size requested; 30 or 62 bits
  ExeContext*   where;           // where it was allocated
} DRD_Chunk;


/* Local variables. */

static StartUsingMem DRD_(s_start_using_mem_callback);
static StopUsingMem  DRD_(s_stop_using_mem_callback);
/* Stats ... */
static SizeT DRD_(s_cmalloc_n_mallocs)  = 0;
static SizeT DRD_(s_cmalloc_n_frees)    = 0;
static SizeT DRD_(s_cmalloc_bs_mallocd) = 0;
/* Record malloc'd blocks. */
static VgHashTable DRD_(s_malloc_list) = NULL;


/*------------------------------------------------------------*/
/*--- Tracking malloc'd and free'd blocks                  ---*/
/*------------------------------------------------------------*/

/** Allocate its shadow chunk, put it on the appropriate list. */
static DRD_Chunk* DRD_(create_chunk)(ThreadId tid, Addr p, SizeT size)
{
  DRD_Chunk* mc = VG_(malloc)("drd.malloc_wrappers.cDC.1",
                              sizeof(DRD_Chunk));
  mc->data      = p;
  mc->size      = size;
  mc->where     = VG_(record_ExeContext)(tid, 0);

  return mc;
}

/*------------------------------------------------------------*/
/*--- client_malloc(), etc                                 ---*/
/*------------------------------------------------------------*/

/* Allocate memory and note change in memory available */
static
__inline__
void* DRD_(new_block)(ThreadId tid,
                      SizeT size, SizeT align,
                      Bool is_zeroed)
{
  Addr p;

  DRD_(s_cmalloc_n_mallocs) ++;

  // Allocate and zero
  p = (Addr)VG_(cli_malloc)(align, size);
  if (!p) {
    return NULL;
  }
  if (is_zeroed) VG_(memset)((void*)p, 0, size);
  DRD_(s_start_using_mem_callback)(p, p + size, 0/*ec_uniq*/);

  // Only update this stat if allocation succeeded.
  DRD_(s_cmalloc_bs_mallocd) += size;

  VG_(HT_add_node)(DRD_(s_malloc_list), DRD_(create_chunk)(tid, p, size));

  return (void*)p;
}

static void* DRD_(malloc)(ThreadId tid, SizeT n)
{
  return DRD_(new_block)(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
}

static void* DRD_(memalign)(ThreadId tid, SizeT align, SizeT n)
{
  return DRD_(new_block)(tid, n, align, /*is_zeroed*/False);
}

static void* DRD_(calloc)(ThreadId tid, SizeT nmemb, SizeT size1)
{
  return DRD_(new_block)(tid, nmemb*size1, VG_(clo_alignment),
                         /*is_zeroed*/True);
}

static __inline__ void DRD_(handle_free)(ThreadId tid, Addr p)
{
  DRD_Chunk* mc;

  DRD_(s_cmalloc_n_frees)++;

  mc = VG_(HT_remove)(DRD_(s_malloc_list), (UWord)p);
  if (mc == NULL)
  {
    tl_assert(0);
  }
  else
  {
    tl_assert(p == mc->data);
    if (mc->size > 0)
      DRD_(s_stop_using_mem_callback)(mc->data, mc->size);
    VG_(cli_free)((void*)p);
    VG_(free)(mc);
  }
}

static void DRD_(free)(ThreadId tid, void* p)
{
  DRD_(handle_free)(tid, (Addr)p);
}

static void* DRD_(realloc)(ThreadId tid, void* p_old, SizeT new_size)
{
  DRD_Chunk* mc;
  void*     p_new;
  SizeT     old_size;

  DRD_(s_cmalloc_n_frees) ++;
  DRD_(s_cmalloc_n_mallocs) ++;
  DRD_(s_cmalloc_bs_mallocd) += new_size;

  /* Remove the old block */
  mc = VG_(HT_remove)(DRD_(s_malloc_list), (UWord)p_old);
  if (mc == NULL) {
    tl_assert(0);
    return NULL;
  }

  old_size = mc->size;

  if (old_size == new_size)
  {
    /* size unchanged */
    mc->where = VG_(record_ExeContext)(tid, 0);
    p_new = p_old;
      
  }
  else if (old_size > new_size)
  {
    /* new size is smaller */
    DRD_(s_stop_using_mem_callback)(mc->data + new_size, old_size);
    mc->size = new_size;
    mc->where = VG_(record_ExeContext)(tid, 0);
    p_new = p_old;

  }
  else
  {
    /* new size is bigger */
    /* Get new memory */
    const Addr a_new = (Addr)VG_(cli_malloc)(VG_(clo_alignment), new_size);

    if (a_new)
    {
      /* Copy from old to new */
      VG_(memcpy)((void*)a_new, p_old, mc->size);

      /* Free old memory */
      DRD_(s_stop_using_mem_callback)(mc->data, mc->size);
      VG_(free)(mc);

      // Allocate a new chunk.
      mc = DRD_(create_chunk)(tid, a_new, new_size);
      DRD_(s_start_using_mem_callback)(a_new, a_new + new_size, 0/*ec_uniq*/);
    }
    else
    {
      /* Allocation failed -- leave original block untouched. */
    }

    p_new = (void*)a_new;
  }  

  // Now insert the new mc (with a possibly new 'data' field) into
  // malloc_list.  If this realloc() did not increase the memory size, we
  // will have removed and then re-added mc unnecessarily.  But that's ok
  // because shrinking a block with realloc() is (presumably) much rarer
  // than growing it, and this way simplifies the growing case.
  VG_(HT_add_node)(DRD_(s_malloc_list), mc);

  return p_new;
}

static void* DRD_(__builtin_new)(ThreadId tid, SizeT n)
{
  void* const result = DRD_(new_block)(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
  //VG_(message)(Vg_DebugMsg, "__builtin_new(%d, %d) = %p", tid, n, result);
  return result;
}

static void DRD_(__builtin_delete)(ThreadId tid, void* p)
{
  //VG_(message)(Vg_DebugMsg, "__builtin_delete(%d, %p)", tid, p);
  DRD_(handle_free)(tid, (Addr)p);
}

static void* DRD_(__builtin_vec_new)(ThreadId tid, SizeT n)
{
  return DRD_(new_block)(tid, n, VG_(clo_alignment), /*is_zeroed*/False);
}

static void DRD_(__builtin_vec_delete)(ThreadId tid, void* p)
{
  DRD_(handle_free)(tid, (Addr)p);
}

static SizeT DRD_(malloc_usable_size) ( ThreadId tid, void* p )
{
   DRD_Chunk *mc = VG_(HT_lookup)( DRD_(s_malloc_list), (UWord)p );

   // There may be slop, but pretend there isn't because only the asked-for
   // area will have been shadowed properly.
   return ( mc ? mc->size : 0 );
}

void DRD_(register_malloc_wrappers)(const StartUsingMem start_callback,
                                    const StopUsingMem stop_callback)
{
  tl_assert(DRD_(s_malloc_list) == 0);
  DRD_(s_malloc_list) = VG_(HT_construct)("drd_malloc_list");   // a big prime
  tl_assert(DRD_(s_malloc_list) != 0);
  tl_assert(start_callback);
  tl_assert(stop_callback);

  DRD_(s_start_using_mem_callback) = start_callback;
  DRD_(s_stop_using_mem_callback)  = stop_callback;

  VG_(needs_malloc_replacement)(DRD_(malloc),
                                DRD_(__builtin_new),
                                DRD_(__builtin_vec_new),
                                DRD_(memalign),
                                DRD_(calloc),
                                DRD_(free),
                                DRD_(__builtin_delete),
                                DRD_(__builtin_vec_delete),
                                DRD_(realloc),
                                DRD_(malloc_usable_size),
                                0);
}

Bool DRD_(heap_addrinfo)(Addr const a,
                         Addr* const data,
                         SizeT* const size,
                         ExeContext** const where)
{
  DRD_Chunk* mc;

  tl_assert(data);
  tl_assert(size);
  tl_assert(where);

  VG_(HT_ResetIter)(DRD_(s_malloc_list));
  while ((mc = VG_(HT_Next)(DRD_(s_malloc_list))))
  {
    if (mc->data <= a && a < mc->data + mc->size)
    {
      *data  = mc->data;
      *size  = mc->size;
      *where = mc->where;
      return True;
    }
  }
  return False;
}

/*------------------------------------------------------------*/
/*--- Statistics printing                                  ---*/
/*------------------------------------------------------------*/

void DRD_(print_malloc_stats)(void)
{
  DRD_Chunk* mc;
  SizeT     nblocks = 0;
  SizeT     nbytes  = 0;
   
  if (VG_(clo_verbosity) == 0)
    return;
  if (VG_(clo_xml))
    return;

  /* Count memory still in use. */
  VG_(HT_ResetIter)(DRD_(s_malloc_list));
  while ((mc = VG_(HT_Next)(DRD_(s_malloc_list))))
  {
    nblocks++;
    nbytes += mc->size;
  }

  VG_(message)(Vg_DebugMsg, 
               "malloc/free: in use at exit: %lu bytes in %lu blocks.",
               nbytes, nblocks);
  VG_(message)(Vg_DebugMsg, 
               "malloc/free: %lu allocs, %lu frees, %lu bytes allocated.",
               DRD_(s_cmalloc_n_mallocs),
               DRD_(s_cmalloc_n_frees), DRD_(s_cmalloc_bs_mallocd));
  if (VG_(clo_verbosity) > 1)
    VG_(message)(Vg_DebugMsg, " ");
}

/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/