qemu/scripts/coverity-model.c

387 lines
8.5 KiB
C

/* 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.
*/
/*
* 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
* http://scan.coverity.com/projects/378
*/
#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_read(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs,
uint8_t *buf, int len)
{
MemTxResult result;
// TODO: investigate impact of treating reads as producing
// tainted data, with __coverity_tainted_data_argument__(buf).
__bufwrite(buf, len);
return result;
}
MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs,
const uint8_t *buf, int len)
{
MemTxResult result;
__bufread(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;
}
}
/* Replay data is considered trusted. */
uint8_t replay_get_byte(void)
{
uint8_t byte;
return byte;
}
/*
* 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__();
}