mirror_zfs/contrib/coverity/model.c
Richard Yao d10bd7d288
Coverity model file update
Upon review, it was found that the model for malloc() was incorrect.

In addition, several general purpose memory allocation functions were
missing models:

 * kmem_vasprintf()
 * kmem_asprintf()
 * kmem_strdup()
 * kmem_strfree()
 * spl_vmem_alloc()
 * spl_vmem_zalloc()
 * spl_vmem_free()
 * calloc()

As an experiment to try to find more bugs, some less than general
purpose memory allocation functions were also given models:

 * zfsvfs_create()
 * zfsvfs_free()
 * nvlist_alloc()
 * nvlist_dup()
 * nvlist_free()
 * nvlist_pack()
 * nvlist_unpack()

Finally, the models were improved using additional coverity primitives:

 * __coverity_negative_sink__()
 * __coverity_writeall0__()
 * __coverity_mark_as_uninitialized_buffer__()
 * __coverity_mark_as_afm_allocated__()

In addition, an attempt to inform coverity that certain modelled
functions read entire buffers was used by adding the following to
certain models:

int first = buf[0];
int last = buf[buflen-1];

It was inspired by the QEMU model file.

No additional false positives were found by this, but it is believed
that the more accurate model file will help to catch false positives in
the future.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14048
2022-10-18 11:06:35 -07:00

653 lines
11 KiB
C

/*
* Coverity Scan model
* https://scan.coverity.com/models
*
* This is a modeling file for Coverity Scan.
* Modeling helps to avoid false positives.
*
* - Modeling doesn't need full structs and typedefs. Rudimentary structs
* and similar types are sufficient.
* - An uninitialized local pointer is not an error. It signifies that the
* variable could be either NULL or have some data.
*
* Coverity Scan doesn't pick up modifications automatically. The model file
* must be uploaded by an admin in the analysis settings.
*
* Some of this initially cribbed from:
*
* https://github.com/kees/coverity-linux/blob/trunk/model.c
*
* The below model was based on the original model by Brian Behlendorf for the
* original zfsonlinux/zfs repository. Some inspiration was taken from
* kees/coverity-linux, specifically involving memory copies.
*/
#include <stdarg.h>
#define UMEM_DEFAULT 0x0000 /* normal -- may fail */
#define UMEM_NOFAIL 0x0100 /* Never fails */
#define NULL (0)
typedef enum {
B_FALSE = 0,
B_TRUE = 1
} boolean_t;
typedef unsigned int uint_t;
int condition0, condition1;
int
ddi_copyin(const void *from, void *to, size_t len, int flags)
{
(void) flags;
__coverity_negative_sink__(len);
__coverity_tainted_data_argument__(from);
__coverity_tainted_data_argument__(to);
__coverity_writeall__(to);
}
void *
memset(void *dst, int c, size_t len)
{
__coverity_negative_sink__(len);
if (c == 0)
__coverity_writeall0__(dst);
else
__coverity_writeall__(dst);
return (dst);
}
void *
memmove(void *dst, void *src, size_t len)
{
int first = ((char *)src)[0];
int last = ((char *)src)[len-1];
__coverity_negative_sink__(len);
__coverity_writeall__(dst);
return (dst);
}
void *
memcpy(void *dst, void *src, size_t len)
{
int first = ((char *)src)[0];
int last = ((char *)src)[len-1];
__coverity_negative_sink__(len);
__coverity_writeall__(dst);
return (dst);
}
void *
umem_alloc_aligned(size_t size, size_t align, int kmflags)
{
__coverity_negative_sink__(size);
__coverity_negative_sink__(align);
if (((UMEM_NOFAIL & kmflags) == UMEM_NOFAIL) || condition0) {
void *buf = __coverity_alloc__(size);
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "umem_free");
return (buf);
}
return (NULL);
}
void *
umem_alloc(size_t size, int kmflags)
{
__coverity_negative_sink__(size);
if (((UMEM_NOFAIL & kmflags) == UMEM_NOFAIL) || condition0) {
void *buf = __coverity_alloc__(size);
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "umem_free");
return (buf);
}
return (NULL);
}
void *
umem_zalloc(size_t size, int kmflags)
{
__coverity_negative_sink__(size);
if (((UMEM_NOFAIL & kmflags) == UMEM_NOFAIL) || condition0) {
void *buf = __coverity_alloc__(size);
__coverity_writeall0__(buf);
__coverity_mark_as_afm_allocated__(buf, "umem_free");
return (buf);
}
return (NULL);
}
void
umem_free(void *buf, size_t size)
{
__coverity_negative_sink__(size);
__coverity_free__(buf);
}
typedef struct {} umem_cache_t;
void *
umem_cache_alloc(umem_cache_t *skc, int flags)
{
(void) skc;
if (condition1)
__coverity_sleep__();
if (((UMEM_NOFAIL & flags) == UMEM_NOFAIL) || condition0) {
void *buf = __coverity_alloc_nosize__();
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "umem_cache_free");
return (buf);
}
return (NULL);
}
void
umem_cache_free(umem_cache_t *skc, void *obj)
{
(void) skc;
__coverity_free__(obj);
}
void *
spl_kmem_alloc(size_t sz, int fl, const char *func, int line)
{
(void) func;
(void) line;
__coverity_negative_sink__(sz);
if (condition1)
__coverity_sleep__();
if ((fl == 0) || condition0) {
void *buf = __coverity_alloc__(sz);
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "spl_kmem_free");
return (buf);
}
return (NULL);
}
void *
spl_kmem_zalloc(size_t sz, int fl, const char *func, int line)
{
(void) func;
(void) line;
__coverity_negative_sink__(sz);
if (condition1)
__coverity_sleep__();
if ((fl == 0) || condition0) {
void *buf = __coverity_alloc__(sz);
__coverity_writeall0__(buf);
__coverity_mark_as_afm_allocated__(buf, "spl_kmem_free");
return (buf);
}
return (NULL);
}
void
spl_kmem_free(const void *ptr, size_t sz)
{
__coverity_negative_sink__(sz);
__coverity_free__(ptr);
}
char *
kmem_vasprintf(const char *fmt, va_list ap)
{
char *buf = __coverity_alloc_nosize__();
(void) ap;
__coverity_string_null_sink__(fmt);
__coverity_string_size_sink__(fmt);
__coverity_writeall__(buf);
__coverity_mark_as_afm_allocated__(buf, "kmem_strfree");
return (buf);
}
char *
kmem_asprintf(const char *fmt, ...)
{
char *buf = __coverity_alloc_nosize__();
__coverity_string_null_sink__(fmt);
__coverity_string_size_sink__(fmt);
__coverity_writeall__(buf);
__coverity_mark_as_afm_allocated__(buf, "kmem_strfree");
return (buf);
}
char *
kmem_strdup(const char *str)
{
char *buf = __coverity_alloc_nosize__();
__coverity_string_null_sink__(str);
__coverity_string_size_sink__(str);
__coverity_writeall__(buf);
__coverity_mark_as_afm_allocated__(buf, "kmem_strfree");
return (buf);
}
void
kmem_strfree(char *str)
{
__coverity_free__(str);
}
void *
spl_vmem_alloc(size_t sz, int fl, const char *func, int line)
{
(void) func;
(void) line;
__coverity_negative_sink__(sz);
if (condition1)
__coverity_sleep__();
if ((fl == 0) || condition0) {
void *buf = __coverity_alloc__(sz);
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "spl_vmem_free");
return (buf);
}
return (NULL);
}
void *
spl_vmem_zalloc(size_t sz, int fl, const char *func, int line)
{
(void) func;
(void) line;
if (condition1)
__coverity_sleep__();
if ((fl == 0) || condition0) {
void *buf = __coverity_alloc__(sz);
__coverity_writeall0__(buf);
__coverity_mark_as_afm_allocated__(buf, "spl_vmem_free");
return (buf);
}
return (NULL);
}
void
spl_vmem_free(const void *ptr, size_t sz)
{
__coverity_negative_sink__(sz);
__coverity_free__(ptr);
}
typedef struct {} spl_kmem_cache_t;
void *
spl_kmem_cache_alloc(spl_kmem_cache_t *skc, int flags)
{
(void) skc;
if (condition1)
__coverity_sleep__();
if ((flags == 0) || condition0) {
void *buf = __coverity_alloc_nosize__();
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "spl_kmem_cache_free");
return (buf);
}
}
void
spl_kmem_cache_free(spl_kmem_cache_t *skc, void *obj)
{
(void) skc;
__coverity_free__(obj);
}
typedef struct {} zfsvfs_t;
int
zfsvfs_create(const char *osname, boolean_t readonly, zfsvfs_t **zfvp)
{
(void) osname;
(void) readonly;
if (condition1)
__coverity_sleep__();
if (condition0) {
*zfvp = __coverity_alloc_nosize__();
__coverity_writeall__(*zfvp);
return (0);
}
return (1);
}
void
zfsvfs_free(zfsvfs_t *zfsvfs)
{
__coverity_free__(zfsvfs);
}
typedef struct {} nvlist_t;
int
nvlist_alloc(nvlist_t **nvlp, uint_t nvflag, int kmflag)
{
(void) nvflag;
if (condition1)
__coverity_sleep__();
if ((kmflag == 0) || condition0) {
*nvlp = __coverity_alloc_nosize__();
__coverity_mark_as_afm_allocated__(*nvlp, "nvlist_free");
__coverity_writeall__(*nvlp);
return (0);
}
return (-1);
}
int
nvlist_dup(const nvlist_t *nvl, nvlist_t **nvlp, int kmflag)
{
nvlist_t read = *nvl;
if (condition1)
__coverity_sleep__();
if ((kmflag == 0) || condition0) {
nvlist_t *nvl = __coverity_alloc_nosize__();
__coverity_mark_as_afm_allocated__(nvl, "nvlist_free");
__coverity_writeall__(nvl);
*nvlp = nvl;
return (0);
}
return (-1);
}
void
nvlist_free(nvlist_t *nvl)
{
__coverity_free__(nvl);
}
int
nvlist_pack(nvlist_t *nvl, char **bufp, size_t *buflen, int encoding,
int kmflag)
{
(void) nvl;
(void) encoding;
if (*bufp == NULL) {
if (condition1)
__coverity_sleep__();
if ((kmflag == 0) || condition0) {
char *buf = __coverity_alloc_nosize__();
__coverity_writeall__(buf);
/*
* We cannot use __coverity_mark_as_afm_allocated__()
* because the free function varies between the kernel
* and userspace.
*/
*bufp = buf;
return (0);
}
return (-1);
}
/*
* Unfortunately, errors from the buffer being too small are not
* possible to model, so we assume success.
*/
__coverity_negative_sink__(*buflen);
__coverity_writeall__(*bufp);
return (0);
}
int
nvlist_unpack(char *buf, size_t buflen, nvlist_t **nvlp, int kmflag)
{
__coverity_negative_sink__(buflen);
if (condition1)
__coverity_sleep__();
if ((kmflag == 0) || condition0) {
nvlist_t *nvl = __coverity_alloc_nosize__();
__coverity_mark_as_afm_allocated__(nvl, "nvlist_free");
__coverity_writeall__(nvl);
*nvlp = nvl;
int first = buf[0];
int last = buf[buflen-1];
return (0);
}
return (-1);
}
void *
malloc(size_t size)
{
void *buf = __coverity_alloc__(size);
if (condition1)
__coverity_sleep__();
__coverity_negative_sink__(size);
__coverity_mark_as_uninitialized_buffer__(buf);
__coverity_mark_as_afm_allocated__(buf, "free");
return (buf);
}
void *
calloc(size_t nmemb, size_t size)
{
void *buf = __coverity_alloc__(size * nmemb);
if (condition1)
__coverity_sleep__();
__coverity_negative_sink__(size);
__coverity_writeall0__(buf);
__coverity_mark_as_afm_allocated__(buf, "free");
return (buf);
}
void
free(void *buf)
{
__coverity_free__(buf);
}
int
sched_yield(void)
{
__coverity_sleep__();
}
typedef struct {} kmutex_t;
typedef struct {} krwlock_t;
typedef int krw_t;
/*
* Coverty reportedly does not support macros, so this only works for
* userspace.
*/
void
mutex_enter(kmutex_t *mp)
{
if (condition0)
__coverity_sleep__();
__coverity_exclusive_lock_acquire__(mp);
}
int
mutex_tryenter(kmutex_t *mp)
{
if (condition0) {
__coverity_exclusive_lock_acquire__(mp);
return (1);
}
return (0);
}
void
mutex_exit(kmutex_t *mp)
{
__coverity_exclusive_lock_release__(mp);
}
void
rw_enter(krwlock_t *rwlp, krw_t rw)
{
(void) rw;
if (condition0)
__coverity_sleep__();
__coverity_recursive_lock_acquire__(rwlp);
}
void
rw_exit(krwlock_t *rwlp)
{
__coverity_recursive_lock_release__(rwlp);
}
int
rw_tryenter(krwlock_t *rwlp, krw_t rw)
{
if (condition0) {
__coverity_recursive_lock_acquire__(rwlp);
return (1);
}
return (0);
}
/* Thus, we fallback to the Linux kernel locks */
struct {} mutex;
struct {} rw_semaphore;
void
mutex_lock(struct mutex *lock)
{
if (condition0) {
__coverity_sleep__();
}
__coverity_exclusive_lock_acquire__(lock);
}
void
mutex_unlock(struct mutex *lock)
{
__coverity_exclusive_lock_release__(lock);
}
void
down_read(struct rw_semaphore *sem)
{
if (condition0) {
__coverity_sleep__();
}
__coverity_recursive_lock_acquire__(sem);
}
void
down_write(struct rw_semaphore *sem)
{
if (condition0) {
__coverity_sleep__();
}
__coverity_recursive_lock_acquire__(sem);
}
int
down_read_trylock(struct rw_semaphore *sem)
{
if (condition0) {
__coverity_recursive_lock_acquire__(sem);
return (1);
}
return (0);
}
int
down_write_trylock(struct rw_semaphore *sem)
{
if (condition0) {
__coverity_recursive_lock_acquire__(sem);
return (1);
}
return (0);
}
void
up_read(struct rw_semaphore *sem)
{
__coverity_recursive_lock_release__(sem);
}
void
up_write(struct rw_semaphore *sem)
{
__coverity_recursive_lock_release__(sem);
}
int
__cond_resched(void)
{
if (condition0) {
__coverity_sleep__();
}
}