Re: [dpdk-dev] [PATCH v6] Restore support for virtio on FreeBSD

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Apr 16, 2015 at 11:02:03AM +0300, Raz Amir wrote:
> Fixes: 8a312224bcde ("eal/bsd: fix fd leak")
> 
> Closing /dev/io fd causes SIGBUS in inb/outb instructions
> as the process loses the IOPL privileges once the fd is closed:
> (gdb) bt
> 0  0x0000000000492f2c in outb (port=49170, data=0 '\000')
> at /usr/include/machine/cpufunc.h:244
> 1  0x0000000000492f7a in outb_p (data=0 '\000', port=49170)
> at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.h:211
> 2  0x000000000049328d in vtpci_set_status (hw=0x80331f380, status=0 '\000')
> at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.c:130
> 3  0x00000000004931fe in vtpci_reset (hw=0x80331f380)
> at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_pci.c:108
> 4  0x00000000004a175e in eth_virtio_dev_init (eth_dev=0x831b80 <rte_eth_devices>)
> at /dpdk/dpdk-2.0.0/lib/librte_pmd_virtio/virtio_ethdev.c:1150
> 5  0x0000000000462c09 in rte_eth_dev_init (pci_drv=0x79d1a0 <rte_virtio_pmd>,
> pci_dev=0x802417560) at /dpdk/dpdk-2.0.0/lib/librte_ether/rte_ethdev.c:326
> 6  0x000000000046f03f in rte_eal_pci_probe_one_driver (dr=0x79d1a0 <rte_virtio_pmd>,
> dev=0x802417560) at /dpdk/dpdk-2.0.0/lib/librte_eal/bsdapp/eal/eal_pci.c:487
> 7  0x0000000000475b06 in pci_probe_all_drivers (dev=0x802417560)
> at /dpdk/dpdk-2.0.0/lib/librte_eal/common/eal_common_pci.c:116
> 8  0x0000000000475bb9 in rte_eal_pci_probe ()
> at /dpdk/dpdk-2.0.0/lib/librte_eal/common/eal_common_pci.c:246
> 9  0x000000000046cd63 in rte_eal_init (argc=5, argv=0x7fffffffeaf0)
> at /dpdk/dpdk-2.0.0/lib/librte_eal/bsdapp/eal/eal.c:554
> 10 0x0000000000404544 in main ()
> 
> Signed-off-by: Raz Amir <razamir22@gmail.com>

It does look the cleanest solution, though I don't like the idea of leaking 
the file handle. Can you perhaps just change things a little so that the fd
variable is static - even locally in the function will do, as it helps indicate
that the fd is persistent.

/Bruce

> ---
>  lib/librte_eal/bsdapp/eal/eal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
> index 871d5f4..e20f915 100644
> --- a/lib/librte_eal/bsdapp/eal/eal.c
> +++ b/lib/librte_eal/bsdapp/eal/eal.c
> @@ -426,7 +426,7 @@ rte_eal_iopl_init(void)
>  	fd = open("/dev/io", O_RDWR);
>  	if (fd < 0)
>  		return -1;
> -	close(fd);
> +	/* keep fd open for iopl */
>  	return 0;
>  }
>  
> -- 
> 2.1.2
>