Memory overrides doesn't work correctly

[Serhiy Ivanov]

Have next memory overrides:

#include <stdio.h>
#include <stdlib.h>
#include <execinfo.h>
#include <openssl/ssl.h>
#include <openssl/bio.h>
#include <openssl/err.h>


static FILE * FBacktrLog, *FAll, *FDeall;
static size_t all_allocated;

/* sample addresswise statistics:*/
static void ReportAlloc(FILE *f, const void *p)
{
  fprintf(f, "%p\n", p);
}

static void LogBackTrace(size_t n, void *p)
{
  static void *bt[256];
  int bt_c;
  //
  fprintf(FBacktrLog, "%ld (in %p) allocated under context:\n", n, p);
  fflush(FBacktrLog);
  bt_c=backtrace(bt, 100); // up to 100 bt
  backtrace_symbols_fd(bt, bt_c, fileno(FBacktrLog));
}

static void * my_alloc(size_t n)
{
  void *new_obj;
  //
  all_allocated+=n;
  new_obj=malloc(n);
  if (!new_obj)
    return NULL;
  LogBackTrace(n, new_obj);
  ReportAlloc(FAll, new_obj);
  return new_obj;
}

static void my_free(void *p)
{
  if (!p)
    return;
  ReportAlloc(FDeall, p);
  free(p);
}

static void *my_realloc(void *ptr, size_t size)
{
  void *new_obj;
  //
  if (ptr==NULL)
    return my_alloc(size);
  else if (size==0)
  {
    my_free(ptr);
    return NULL;
  }
  ReportAlloc(FDeall, ptr);
  new_obj=realloc(ptr, size);
  if (!new_obj)
    return NULL;
  ReportAlloc(FAll, new_obj);
  return new_obj;
}

int main(int argc, const char **argv)
{
  FBacktrLog=fopen("./mem_log", "w");
  if (!FBacktrLog)
    goto l_err;
  FAll=fopen("./alloc", "w");
  if (!FAll)
    goto l_err;
  FDeall=fopen("./dealloc", "w");
  if (!FDeall)
    goto l_err;
  CRYPTO_set_mem_functions(&my_alloc, &my_realloc, &my_free);
  ERR_load_BIO_strings();
l_err:
  if (FAll)
    fclose(FAll);
  if (FDeall)
    fclose(FDeall);
  if (FBacktrLog)
    fclose(FBacktrLog);
  system("sleep 1; sort alloc > alloc_s; sort dealloc > dealloc_s; rm alloc
dealloc");
  return 0;
}

After runnig just compare alloc_s and dealloc_s.
They should be identical. But they aren't. Also in backtrace there is a
stack reported. For example i see that memory allocated in context
of lh_new is freed.
While  memory under lh_insert isn't. Valgrind+memcheck shows only "still
reachable" so i think free is called but not under overriden stuff.


-- 
kind regards,

Serhiy Ivanov|