[LTP] [PATCH] ltp_tpci.c: fix a null pointer

[Yang Xu]

Hi

Does someone notice this(I guess this is a simple fix)?

Best Regards
Yang Xu
> Since commit 3dd286bdbee ("ltp_tpci.c: Update legacy code"),
> it introduced a warning as below:
> ../ltp_tpci.c: In function ‘probe_pci_dev’:
> ../ltp_tpci.c:107:8: warning: ‘dev’ is used uninitialized in this function [-Wuninitialized]
>    struct pci_dev *dev;
>    dev = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), bus, slot)
> 
> This will lead to system crash when we run this case because it triggers a null pointer.
> Use 0 domain intead of pci_domain_nr.
> 
> ps: I want to use a dymaic domain to fix it but failed. If someone know,
> please tell me. Also, this case failed when merging this patch because
> test 13 (test_assign_resources) report no space error as below:
> [754930.757585] ltp_tpci: test-case 13
> [754930.757585] ltp_tpci: assign resources
> [754930.757585] ltp_tpci: assign resource #0
> [754930.757586] ltp_tpci: name = 0000:00:08.0, flags = 262401, start 0xc140, end 0xc17f
> [754930.757586] ltp_tpci: assign resource #1
> [754930.757587] ltp_tpci: name = 0000:00:08.0, flags = 262656, start 0xfebd7000, end 0xfebd7fff
> [754930.757587] ltp_tpci: assign resource #2
> [754930.757587] ltp_tpci: name = 0000:00:08.0, flags = 0, start 0x0, end 0x0
> [754930.757588] ltp_tpci: assign resource #3
> [754930.757588] ltp_tpci: name = 0000:00:08.0, flags = 0, start 0x0, end 0x0
> [754930.757588] ltp_tpci: assign resource #4
> [754930.757589] ltp_tpci: name = 0000:00:08.0, flags = 538190348, start 0xfe80c000, end 0xfe80ffff
> [754930.757593] virtio-pci 0000:00:08.0: BAR 4: no space for [mem size 0x00004000 64bit pref]
> [754930.757594] virtio-pci 0000:00:08.0: BAR 4: failed to assign [mem size 0x00004000 64bit pref
> 
> Fixes: 3dd286b ("ltp_tpci.c: Update legacy code")
> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> ---
>   testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c b/testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c
> index 7cbabfaa5..a57953db6 100644
> --- a/testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c
> +++ b/testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c
> @@ -104,7 +104,7 @@ static int probe_pci_dev(unsigned int bus, unsigned int slot)
>   		ltp_pci.dev = NULL;
>   	}
>   
> -	dev = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), bus, slot);
> +	dev = pci_get_domain_bus_and_slot(0, bus, slot);
>   	if (!dev || !dev->driver)
>   		return -ENODEV;
>   
>