[PATCH 3.16 059/127] PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr()

From: Greg Kroah-Hartman
Date: Tue Oct 28 2014 - 03:12:51 EST


3.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>

commit 56fab6e189441d714a2bfc8a64f3df9c0749dff7 upstream.

Geert Uytterhoeven reported a warning when building pci-mvebu:

drivers/pci/host/pci-mvebu.c: In function 'mvebu_get_tgt_attr':
drivers/pci/host/pci-mvebu.c:887:39: warning: 'rtype' may be used uninitialized in this function [-Wmaybe-uninitialized]
if (slot == PCI_SLOT(devfn) && type == rtype) {
^

And indeed, the code of mvebu_get_tgt_attr() may lead to the usage of rtype
when being uninitialized, even though it would only happen if we had
entries other than I/O space and 32 bits memory space.

This commit fixes that by simply skipping the current DT range being
considered, if it doesn't match the resource type we're looking for.

Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/pci/host/pci-mvebu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -873,7 +873,7 @@ static int mvebu_get_tgt_attr(struct dev
rangesz = pna + na + ns;
nranges = rlen / sizeof(__be32) / rangesz;

- for (i = 0; i < nranges; i++) {
+ for (i = 0; i < nranges; i++, range += rangesz) {
u32 flags = of_read_number(range, 1);
u32 slot = of_read_number(range + 1, 1);
u64 cpuaddr = of_read_number(range + na, pna);
@@ -883,14 +883,14 @@ static int mvebu_get_tgt_attr(struct dev
rtype = IORESOURCE_IO;
else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
rtype = IORESOURCE_MEM;
+ else
+ continue;

if (slot == PCI_SLOT(devfn) && type == rtype) {
*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
return 0;
}
-
- range += rangesz;
}

return -ENOENT;


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