[PATCH 1/4]: PowerPC: EEH: balance pcidev_get/put calls

From: Linas Vepstas
Date: Fri Sep 15 2006 - 19:55:55 EST




This patch corrects a pci_dev get/put imbalance that can occur
only in highly unlikely situations (kmalloc failures, pci devices
with overlapping resource addresses). No actual failures seen,
this was spotted during code review.

Signed-off-by: Linas Vepstas <linas@xxxxxxxxxxxxxx>

----
arch/powerpc/platforms/pseries/eeh_cache.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)

Index: linux-2.6.18-rc7-git1/arch/powerpc/platforms/pseries/eeh_cache.c
===================================================================
--- linux-2.6.18-rc7-git1.orig/arch/powerpc/platforms/pseries/eeh_cache.c 2006-09-14 13:13:57.000000000 -0500
+++ linux-2.6.18-rc7-git1/arch/powerpc/platforms/pseries/eeh_cache.c 2006-09-14 13:52:34.000000000 -0500
@@ -157,6 +157,7 @@ pci_addr_cache_insert(struct pci_dev *de
if (!piar)
return NULL;

+ pci_dev_get(dev);
piar->addr_lo = alo;
piar->addr_hi = ahi;
piar->pcidev = dev;
@@ -178,7 +179,6 @@ static void __pci_addr_cache_insert_devi
struct device_node *dn;
struct pci_dn *pdn;
int i;
- int inserted = 0;

dn = pci_device_to_OF_node(dev);
if (!dn) {
@@ -197,9 +197,6 @@ static void __pci_addr_cache_insert_devi
return;
}

- /* The cache holds a reference to the device... */
- pci_dev_get(dev);
-
/* Walk resources on this device, poke them into the tree */
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
unsigned long start = pci_resource_start(dev,i);
@@ -212,12 +209,7 @@ static void __pci_addr_cache_insert_devi
if (start == 0 || ~start == 0 || end == 0 || ~end == 0)
continue;
pci_addr_cache_insert(dev, start, end, flags);
- inserted = 1;
}
-
- /* If there was nothing to add, the cache has no reference... */
- if (!inserted)
- pci_dev_put(dev);
}

/**
@@ -240,7 +232,6 @@ void pci_addr_cache_insert_device(struct
static inline void __pci_addr_cache_remove_device(struct pci_dev *dev)
{
struct rb_node *n;
- int removed = 0;

restart:
n = rb_first(&pci_io_addr_cache_root.rb_root);
@@ -250,16 +241,12 @@ restart:

if (piar->pcidev == dev) {
rb_erase(n, &pci_io_addr_cache_root.rb_root);
- removed = 1;
+ pci_dev_put(piar->pcidev);
kfree(piar);
goto restart;
}
n = rb_next(n);
}
-
- /* The cache no longer holds its reference to this device... */
- if (removed)
- pci_dev_put(dev);
}

/**
-
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