From: "Mrozowicz, SlawomirX" <slawomirx.mrozowicz@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
"Doherty, Declan" <declan.doherty@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] bugs and glitches in rte_cryptodev_devices_get
Date: Thu, 2 Feb 2017 13:55:00 +0000 [thread overview]
Message-ID: <158888A50F43E34AAE179517F56C9745652770@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <20170201085321.7168505a@xeon-e3>
>-----Original Message-----
>From: Stephen Hemminger [mailto:stephen@networkplumber.org]
>Sent: Wednesday, February 1, 2017 5:54 PM
>To: Mrozowicz, SlawomirX <slawomirx.mrozowicz@intel.com>; Doherty,
>Declan <declan.doherty@intel.com>
>Cc: dev@dpdk.org
>Subject: bugs and glitches in rte_cryptodev_devices_get
>
>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.
[SM] Ok. To be changed.
>
>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.
[SM] Ok. To be changed to uint8_t.
>
>3. Wacky indention of the if statement.
[SM] To be changed.
>
>4. Make variables local to the block they are used (cmp, dev)
[SM] Ok. To be changed.
>
>5. Use array instead of pointer:
> ie. instead of *devs + i use devs[i]
[SM] We can't change it like this. devs[i] provide wrong address (null) for i>0
>
>
>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.
>
next prev parent reply other threads:[~2017-02-02 13:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-01 16:53 Stephen Hemminger
2017-02-02 13:55 ` Mrozowicz, SlawomirX [this message]
2017-02-03 12:26 ` Mrozowicz, SlawomirX
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