From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr()
Date: Fri, 05 Sep 2014 19:51:27 +0200 [thread overview]
Message-ID: <89457154.qOQEu4X27r@wuerfel> (raw)
In-Reply-To: <20140905174122.GD8080@google.com>
On Friday 05 September 2014 11:41:22 Bjorn Helgaas wrote:
> On Fri, Aug 08, 2014 at 05:34:05PM +0200, Geert Uytterhoeven wrote:
> > 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) {
> > ^
> >
> > If there's ever gonna be a configuration space or 64-bit memory space
> > entry in DT, rtype will be uninitialized, and the wrong entry may be
> > returned.
> >
> > Initialize rtype to 0 (which is an unused IORESOURCE_* type) to fix this.
> >
> > Introduced in commit 11be65472a427dcf7a11ab6e3e3628f1c6768b5b ("PCI:
> > mvebu: Adapt to the new device tree layout").
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > Alternatively, should the "else if (DT_FLAGS_TO_TYPE(flags) ==
> > DT_TYPE_MEM32)" just be changed to "else", assuming there can never be
> > other entries than for I/O or 32-bit memory space?
> > ---
> > drivers/pci/host/pci-mvebu.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> > index ce23e0f076b6..9515f0d13fd4 100644
> > --- a/drivers/pci/host/pci-mvebu.c
> > +++ b/drivers/pci/host/pci-mvebu.c
> > @@ -877,7 +877,7 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
> > u32 flags = of_read_number(range, 1);
> > u32 slot = of_read_number(range + 1, 1);
> > u64 cpuaddr = of_read_number(range + na, pna);
> > - unsigned long rtype;
> > + unsigned long rtype = 0;
> >
> > if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
> > rtype = IORESOURCE_IO;
>
> This fix looks right to me. I added a stable tag as follows. Thomas
> and/or Jason, and you ack this?
I had a local fix for this, which I haven't gotten around to
send a proper changelog for, but it seems like a more appropriate
fix, avoiding the spurious initialization.
The other fix looks technically correct as well though.
Arnd
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index a8c6f1a92e0f..678849836649 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -883,6 +883,8 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
rtype = IORESOURCE_IO;
else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
rtype = IORESOURCE_MEM;
+ else
+ rtype = -1;
if (slot == PCI_SLOT(devfn) && type == rtype) {
*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
next prev parent reply other threads:[~2014-09-05 17:51 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-08 15:34 [PATCH] PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr() Geert Uytterhoeven
2014-09-05 17:41 ` Bjorn Helgaas
2014-09-05 17:51 ` Arnd Bergmann [this message]
2014-09-05 18:20 ` Thomas Petazzoni
2014-09-05 18:34 ` Arnd Bergmann
2014-09-05 19:00 ` Bjorn Helgaas
2014-09-16 23:17 ` Bjorn Helgaas
2014-09-17 15:58 Thomas Petazzoni
2014-09-22 20:43 ` Bjorn Helgaas
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