contrib/coverity-modeling.c - main - githubmirror/libmodulemd

contrib/coverity-modeling.c
428 строк8 KB
Stephen Gallagher
Run coverity modeling file through clang-format
20 ноя 2020, 22:54
20 ноя 2020, 22:54fd69ff1
/* Coverity Scan model
 *
 * Copyright (C) 2014 Red Hat, Inc.
 *
 * Authors:
 *  Markus Armbruster <armbru@redhat.com>
 *  Paolo Bonzini <pbonzini@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or, at your
 * option, any later version.  See the COPYING file in the top-level directory.
 *
 * It originated within the QEMU project.
 */


/*
 * This is the source code for our Coverity user model file.  The
 * purpose of user models is to increase scanning accuracy by explaining
 * code Coverity can't see (out of tree libraries) or doesn't
 * sufficiently understand.  Better accuracy means both fewer false
 * positives and more true defects.  Memory leaks in particular.
 *
 * - A model file can't import any header files.  Some built-in primitives are
 *   available but not wchar_t, NULL etc.
 * - Modeling doesn't need full structs and typedefs. Rudimentary structs
 *   and similar types are sufficient.
 * - An uninitialized local variable signifies that the variable could be
 *   any value.
 *
 * The model file must be uploaded by an admin in the analysis settings of
 * https://scan.coverity.com/projects/sgallagher-libmodulemd
 */

#define NULL ((void *)0)

typedef unsigned char uint8_t;
typedef char int8_t;
typedef unsigned int uint32_t;
typedef int int32_t;
typedef long ssize_t;
typedef unsigned long long uint64_t;
typedef long long int64_t;
typedef _Bool bool;

typedef struct va_list_str *va_list;

/* exec.c */

typedef struct AddressSpace AddressSpace;
typedef uint64_t hwaddr;
typedef uint32_t MemTxResult;
typedef uint64_t MemTxAttrs;

static void
__bufwrite (uint8_t *buf, ssize_t len)
{
  int first, last;
  __coverity_negative_sink__ (len);
  if (len == 0)
    return;
  buf[0] = first;
  buf[len - 1] = last;
  __coverity_writeall__ (buf);
}

static void
__bufread (uint8_t *buf, ssize_t len)
{
  __coverity_negative_sink__ (len);
  if (len == 0)
    return;
  int first = buf[0];
  int last = buf[len - 1];
}

MemTxResult
address_space_rw (AddressSpace *as,
                  hwaddr addr,
                  MemTxAttrs attrs,
                  uint8_t *buf,
                  int len,
                  bool is_write)
{
  MemTxResult result;

  // TODO: investigate impact of treating reads as producing
  // tainted data, with __coverity_tainted_data_argument__(buf).
  if (is_write)
    __bufread (buf, len);
  else
    __bufwrite (buf, len);

  return result;
}

/* Tainting */

typedef struct
{
} name2keysym_t;
static int
get_keysym (const name2keysym_t *table, const char *name)
{
  int result;
  if (result > 0)
    {
      __coverity_tainted_string_sanitize_content__ (name);
      return result;
    }
  else
    {
      return 0;
    }
}

/*
 * GLib memory allocation functions.
 *
 * Note that we ignore the fact that g_malloc of 0 bytes returns NULL,
 * and g_realloc of 0 bytes frees the pointer.
 *
 * Modeling this would result in Coverity flagging a lot of memory
 * allocations as potentially returning NULL, and asking us to check
 * whether the result of the allocation is NULL or not.  However, the
 * resulting pointer should never be dereferenced anyway, and in fact
 * it is not in the vast majority of cases.
 *
 * If a dereference did happen, this would suppress a defect report
 * for an actual null pointer dereference.  But it's too unlikely to
 * be worth wading through the false positives, and with some luck
 * we'll get a buffer overflow reported anyway.
 */

/*
 * Allocation primitives, cannot return NULL
 * See also Coverity's library/generic/libc/all/all.c
 */

void *
g_malloc_n (size_t nmemb, size_t size)
{
  size_t sz;
  void *ptr;

  __coverity_negative_sink__ (nmemb);
  __coverity_negative_sink__ (size);
  sz = nmemb * size;
  ptr = __coverity_alloc__ (sz);
  __coverity_mark_as_uninitialized_buffer__ (ptr);
  __coverity_mark_as_afm_allocated__ (ptr, "g_free");
  return ptr;
}

void *
g_malloc0_n (size_t nmemb, size_t size)
{
  size_t sz;
  void *ptr;

  __coverity_negative_sink__ (nmemb);
  __coverity_negative_sink__ (size);
  sz = nmemb * size;
  ptr = __coverity_alloc__ (sz);
  __coverity_writeall0__ (ptr);
  __coverity_mark_as_afm_allocated__ (ptr, "g_free");
  return ptr;
}

void *
g_realloc_n (void *ptr, size_t nmemb, size_t size)
{
  size_t sz;

  __coverity_negative_sink__ (nmemb);
  __coverity_negative_sink__ (size);
  sz = nmemb * size;
  __coverity_escape__ (ptr);
  ptr = __coverity_alloc__ (sz);
  /*
     * Memory beyond the old size isn't actually initialized.  Can't
     * model that.  See Coverity's realloc() model
     */
  __coverity_writeall__ (ptr);
  __coverity_mark_as_afm_allocated__ (ptr, "g_free");
  return ptr;
}

void
g_free (void *ptr)
{
  __coverity_free__ (ptr);
  __coverity_mark_as_afm_freed__ (ptr, "g_free");
}

/*
 * Derive the g_try_FOO_n() from the g_FOO_n() by adding indeterminate
 * out of memory conditions
 */

void *
g_try_malloc_n (size_t nmemb, size_t size)
{
  int nomem;

  if (nomem)
    {
      return NULL;
    }
  return g_malloc_n (nmemb, size);
}

void *
g_try_malloc0_n (size_t nmemb, size_t size)
{
  int nomem;

  if (nomem)
    {
      return NULL;
    }
  return g_malloc0_n (nmemb, size);
}

void *
g_try_realloc_n (void *ptr, size_t nmemb, size_t size)
{
  int nomem;

  if (nomem)
    {
      return NULL;
    }
  return g_realloc_n (ptr, nmemb, size);
}

/* Trivially derive the g_FOO() from the g_FOO_n() */

void *
g_malloc (size_t size)
{
  return g_malloc_n (1, size);
}

void *
g_malloc0 (size_t size)
{
  return g_malloc0_n (1, size);
}

void *
g_realloc (void *ptr, size_t size)
{
  return g_realloc_n (ptr, 1, size);
}

void *
g_try_malloc (size_t size)
{
  return g_try_malloc_n (1, size);
}

void *
g_try_malloc0 (size_t size)
{
  return g_try_malloc0_n (1, size);
}

void *
g_try_realloc (void *ptr, size_t size)
{
  return g_try_realloc_n (ptr, 1, size);
}

/* Other memory allocation functions */

void *
g_memdup (const void *ptr, unsigned size)
{
  unsigned char *dup;
  unsigned i;

  if (!ptr)
    {
      return NULL;
    }

  dup = g_malloc (size);
  for (i = 0; i < size; i++)
    dup[i] = ((unsigned char *)ptr)[i];
  return dup;
}

/*
 * GLib string allocation functions
 */

char *
g_strdup (const char *s)
{
  char *dup;
  size_t i;

  if (!s)
    {
      return NULL;
    }

  __coverity_string_null_sink__ (s);
  __coverity_string_size_sink__ (s);
  dup = __coverity_alloc_nosize__ ();
  __coverity_mark_as_afm_allocated__ (dup, "g_free");
  for (i = 0; (dup[i] = s[i]); i++)
    ;
  return dup;
}

char *
g_strndup (const char *s, size_t n)
{
  char *dup;
  size_t i;

  __coverity_negative_sink__ (n);

  if (!s)
    {
      return NULL;
    }

  dup = g_malloc (n + 1);
  for (i = 0; i < n && (dup[i] = s[i]); i++)
    ;
  dup[i] = 0;
  return dup;
}

char *
g_strdup_printf (const char *format, ...)
{
  char ch, *s;
  size_t len;

  __coverity_string_null_sink__ (format);
  __coverity_string_size_sink__ (format);

  ch = *format;

  s = __coverity_alloc_nosize__ ();
  __coverity_writeall__ (s);
  __coverity_mark_as_afm_allocated__ (s, "g_free");
  return s;
}

char *
g_strdup_vprintf (const char *format, va_list ap)
{
  char ch, *s;
  size_t len;

  __coverity_string_null_sink__ (format);
  __coverity_string_size_sink__ (format);

  ch = *format;
  ch = *(char *)ap;

  s = __coverity_alloc_nosize__ ();
  __coverity_writeall__ (s);
  __coverity_mark_as_afm_allocated__ (s, "g_free");

  return len;
}

char *
g_strconcat (const char *s, ...)
{
  char *s;

  /*
     * Can't model: last argument must be null, the others
     * null-terminated strings
     */

  s = __coverity_alloc_nosize__ ();
  __coverity_writeall__ (s);
  __coverity_mark_as_afm_allocated__ (s, "g_free");
  return s;
}

/* Other glib functions */

typedef struct pollfd GPollFD;

int
poll ();

int
g_poll (GPollFD *fds, unsigned nfds, int timeout)
{
  return poll (fds, nfds, timeout);
}

typedef struct _GIOChannel GIOChannel;
GIOChannel *
g_io_channel_unix_new (int fd)
{
  GIOChannel *c = g_malloc0 (sizeof (GIOChannel));
  __coverity_escape__ (fd);
  return c;
}

void
g_assertion_message_expr (const char *domain,
                          const char *file,
                          int line,
                          const char *func,
                          const char *expr)
{
  __coverity_panic__ ();
}
void
g_assertion_message (const char *domain,
                     const char *file,
                     int line,
                     const char *func,
                     const char *message)
{
  __coverity_panic__ ();
}