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

Jastrzebski, MichalX K michalx.k.jastrzebski at intel.com
Fri Jul 22 18:23:04 CEST 2016


> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> Sent: Friday, July 22, 2016 5:25 PM
> To: Jastrzebski, MichalX K <michalx.k.jastrzebski at intel.com>
> Cc: Richardson, Bruce <bruce.richardson at intel.com>; dev at dpdk.org;
> Kobylinski, MichalX <michalx.kobylinski at intel.com>; Gonzalez Monroy,
> Sergio <sergio.gonzalez.monroy at intel.com>; david.marchand at 6wind.com
> Subject: Re: [PATCH v2] eal: fix check number of bytes from read function
> 
> 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.

Thanks Thomas. Please apply.


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