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* [PATCH 4/6] drivers/pci: introduce missing kfree
@ 2009-02-08 21:45 ` Julia Lawall
  0 siblings, 0 replies; 8+ messages in thread
From: Julia Lawall @ 2009-02-08 21:45 UTC (permalink / raw)
  To: jbarnes, linux-pci, linux-kernel, kernel-janitors

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)

^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2009-02-13 21:16 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-02-08 21:45 [PATCH 4/6] drivers/pci: introduce missing kfree Julia Lawall
2009-02-08 21:45 ` Julia Lawall
2009-02-09  1:21 ` Matthew Wilcox
2009-02-09  1:21   ` Matthew Wilcox
2009-02-09  4:26 ` Kenji Kaneshige
2009-02-09  4:26   ` Kenji Kaneshige
2009-02-13 21:16 ` Jesse Barnes
2009-02-13 21:16   ` Jesse Barnes

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