Re: [PATCH 4/6] drivers/pci: introduce missing kfree

[Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>]

Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Error handling code following a kmalloc should free the allocated data.
> Since the subsequent code that could provoke an error does not use the
> allocated data, the allocation is just moved below it.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> (
> if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) = NULL) S
> |
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x = NULL) S
> )
> <... when != x
>      when != if (...) { <+...x...+> }
> x->f = E
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> |
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> ---
>  drivers/pci/hotplug/pciehp_acpi.c   |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
> index 21734c3..9604801 100644
> --- a/drivers/pci/hotplug/pciehp_acpi.c
> +++ b/drivers/pci/hotplug/pciehp_acpi.c
> @@ -79,14 +79,15 @@ static int __init dummy_probe(struct pcie_device *dev)
>  	struct slot *slot, *tmp;
>  	struct pci_dev *pdev = dev->port;
>  	struct pci_bus *pbus = pdev->subordinate;
> -	if (!(slot = kzalloc(sizeof(*slot), GFP_KERNEL)))
> -		return -ENOMEM;
>  	/* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
>  	if (pciehp_get_hp_hw_control_from_firmware(pdev))
>  		return -ENODEV;
>  	if (!(pos = pci_find_capability(pdev, PCI_CAP_ID_EXP)))
>  		return -ENODEV;
>  	pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
> +	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
> +	if (!slot)
> +		return -ENOMEM;
>  	slot->number = slot_cap >> 19;
>  	list_for_each_entry(tmp, &dummy_slots, slot_list) {
>  		if (tmp->number = slot->number)

Thank you for fixing this!

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

Thanks,
Kenji Kaneshige