[dpdk-dev] bugs and glitches in rte_cryptodev_devices_get
Stephen Hemminger
stephen at networkplumber.org
Wed Feb 1 17:53:50 CET 2017
The function rte_cryptodev_devices_get has several issues. I was just going to
fix it, but think it need to be explained.
One potentially serious one (reported by coverity) is:
*** CID 141067: (BAD_COMPARE)
/lib/librte_cryptodev/rte_cryptodev.c: 503 in rte_cryptodev_devices_get()
497 && (*devs + i)->attached ==
498 RTE_CRYPTODEV_ATTACHED) {
499
500 dev = (*devs + i)->device;
501
502 if (dev)
>>> CID 141067: (BAD_COMPARE)
>>> Truncating the result of "strncmp" to "unsigned char" may cause it to be misinterpreted as 0. Note that "strncmp" may return an integer besides -1, 0, or 1.
503 cmp = strncmp(dev->driver->name,
504 dev_name,
505 strlen(dev_name));
506 else
507 cmp = strncmp((*devs + i)->data->name,
508 dev_name,
/lib/librte_cryptodev/rte_cryptodev.c: 507 in rte_cryptodev_devices_get()
501
502 if (dev)
503 cmp = strncmp(dev->driver->name,
504 dev_name,
505 strlen(dev_name));
506 else
>>> CID 141067: (BAD_COMPARE)
>>> Truncating the result of "strncmp" to "unsigned char" may cause it to be misinterpreted as 0. Note that "strncmp" may return an integer besides -1, 0, or 1.
507 cmp = strncmp((*devs + i)->data->name,
508 dev_name,
509 strlen(dev_name));
510
511 if (cmp == 0)
512 devices[count++] = (*devs + i)->data->dev_id;
But also:
1. Incorrect function signature:
* function returns int but never a negative value. should be unsigned.
* devices argument is not modified should be const.
2. Original ABI seems short sighted with limit of 256 cryptodevs
* this seems like 8 bit mindset, should really use unsigned int instead
of uint8_t for number of devices.
3. Wacky indention of the if statement.
4. Make variables local to the block they are used (cmp, dev)
5. Use array instead of pointer:
ie. instead of *devs + i use devs[i]
The overall code in question is:
int
rte_cryptodev_devices_get(const char *dev_name, uint8_t *devices,
uint8_t nb_devices)
{
uint8_t i, cmp, count = 0;
struct rte_cryptodev **devs = &rte_cryptodev_globals->devs;
struct rte_device *dev;
for (i = 0; i < rte_cryptodev_globals->max_devs && count < nb_devices;
i++) {
if ((*devs + i)
&& (*devs + i)->attached ==
RTE_CRYPTODEV_ATTACHED) {
dev = (*devs + i)->device;
if (dev)
cmp = strncmp(dev->driver->name,
dev_name,
strlen(dev_name));
else
cmp = strncmp((*devs + i)->data->name,
dev_name,
strlen(dev_name));
if (cmp == 0)
devices[count++] = (*devs + i)->data->dev_id;
}
}
return count;
}
Please fix it.
More information about the dev
mailing list