qemu/scripts/coverity-model.c

184 lines
4.7 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;
/* exec.c */
typedef struct AddressSpace AddressSpace;
typedef uint64_t hwaddr;
static void __write(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 __read(uint8_t *buf, ssize_t len)
{
__coverity_negative_sink__(len);
if (len == 0) return;
int first = buf[0];
int last = buf[len-1];
}
bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
int len, bool is_write)
{
bool result;
// TODO: investigate impact of treating reads as producing
// tainted data, with __coverity_tainted_data_argument__(buf).
if (is_write) __write(buf, len); else __read(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.
*/
void *malloc(size_t);
void *calloc(size_t, size_t);
void *realloc(void *, size_t);
void free(void *);
void *
g_malloc(size_t n_bytes)
{
void *mem;
__coverity_negative_sink__(n_bytes);
mem = malloc(n_bytes == 0 ? 1 : n_bytes);
if (!mem) __coverity_panic__();
return mem;
}
void *
g_malloc0(size_t n_bytes)
{
void *mem;
__coverity_negative_sink__(n_bytes);
mem = calloc(1, n_bytes == 0 ? 1 : n_bytes);
if (!mem) __coverity_panic__();
return mem;
}
void g_free(void *mem)
{
free(mem);
}
void *g_realloc(void * mem, size_t n_bytes)
{
__coverity_negative_sink__(n_bytes);
mem = realloc(mem, n_bytes == 0 ? 1 : n_bytes);
if (!mem) __coverity_panic__();
return mem;
}
void *g_try_malloc(size_t n_bytes)
{
__coverity_negative_sink__(n_bytes);
return malloc(n_bytes == 0 ? 1 : n_bytes);
}
void *g_try_malloc0(size_t n_bytes)
{
__coverity_negative_sink__(n_bytes);
return calloc(1, n_bytes == 0 ? 1 : n_bytes);
}
void *g_try_realloc(void *mem, size_t n_bytes)
{
__coverity_negative_sink__(n_bytes);
return realloc(mem, n_bytes == 0 ? 1 : n_bytes);
}
/* Other glib functions */
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__();
}