[dpdk-dev] [PATCH v2] eal: fix check number of bytes from read function

[Sergio Gonzalez Monroy]

On 22/07/2016 16:24, Thomas Monjalon wrote:
> 2016-07-22 16:33, Michal Jastrzebski:
>> v2:
>> -moved close(fd) just after read.
>> -when read() from fd we expect 8 bytes, so PFN_MASK_SIZE macro
>> was introduced instead sizeof(uint64_t).
>> -removed errno print when read returns less than 8 bytes
> Looks better.
> Note: this changelog should be below --- to avoid appearing in
> the commit.
>
>> In rte_mem_virt2phy: Value returned from a function and indicating the
>> number of bytes was ignored. This could cause a wrong pfn (page frame
>> number) mask read from pagemap file.
>> When read returns less than the number of sizeof(uint64_t) bytes,
>> function rte_mem_virt2phy returns error.
> Better title to explain the issue:
> mem: fix check of physical address retrieval
>
>> +#define PFN_MASK_SIZE	8
>> +
>>   #ifdef RTE_LIBRTE_XEN_DOM0
>>   int rte_xen_dom0_supported(void)
>>   {
>> @@ -158,7 +160,7 @@ rte_mem_lock_page(const void *virt)
>>   phys_addr_t
>>   rte_mem_virt2phy(const void *virtaddr)
>>   {
>> -	int fd;
>> +	int fd, retval;
>>   	uint64_t page, physaddr;
>>   	unsigned long virt_pfn;
>>   	int page_size;
>> @@ -209,10 +211,19 @@ rte_mem_virt2phy(const void *virtaddr)
>>   		close(fd);
>>   		return RTE_BAD_PHYS_ADDR;
>>   	}
>> -	if (read(fd, &page, sizeof(uint64_t)) < 0) {
>> +
>> +	retval = read(fd, &page, sizeof(uint64_t));
> We could use PFN_MASK_SIZE here
>
>> +	close(fd);
>> +	if (retval < 0) {
>>   		RTE_LOG(ERR, EAL, "%s(): cannot read /proc/self/pagemap: %s\n",
>>   				__func__, strerror(errno));
>> -		close(fd);
>> +
> useless whitespace
>
>> +		return RTE_BAD_PHYS_ADDR;
>> +	} else if (retval != PFN_MASK_SIZE) {
>> +		RTE_LOG(ERR, EAL, "%s(): read %d bytes from /proc/self/pagemap "
>> +				"but expected %d:\n",
>> +				__func__, retval, PFN_MASK_SIZE);
>> +
> useless whitespace
>
>>   		return RTE_BAD_PHYS_ADDR;
>>   	}
>>   
>> @@ -222,7 +233,7 @@ rte_mem_virt2phy(const void *virtaddr)
>>   	 */
>>   	physaddr = ((page & 0x7fffffffffffffULL) * page_size)
>>   		+ ((unsigned long)virtaddr % page_size);
>> -	close(fd);
>> +
>>   	return physaddr;
>>   }
> If you and Sergio agree, I can make the minor changes before applying.

Go for it!

Sergio