From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 5 Sep 2014 11:41:22 -0600 From: Bjorn Helgaas To: Geert Uytterhoeven Cc: Thomas Petazzoni , Jason Cooper , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr() Message-ID: <20140905174122.GD8080@google.com> References: <1407512045-26969-1-git-send-email-geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1407512045-26969-1-git-send-email-geert+renesas@glider.be> Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 > --- > 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; > -- > 1.9.1 > This fix looks right to me. I added a stable tag as follows. Thomas and/or Jason, and you ack this? commit f96f4040d0d01b6eeacda212cf7db105d06a55ba Author: Geert Uytterhoeven Date: Fri Aug 8 17:34:05 2014 +0200 PCI: mvebu: Fix uninitialized "rtype" in mvebu_get_tgt_attr() 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 a DT entry other than DT_TYPE_IO or DT_TYPE_MEM32, e.g., a configuration space or 64-bit memory space entry, rtype will be uninitialized, and the wrong entry may be returned. Initialize rtype to 0 (which is an unused IORESOURCE_* type) to fix this. Fixes: 11be65472a42 ("PCI: mvebu: Adapt to the new device tree layout") Signed-off-by: Geert Uytterhoeven Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.12+ diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c index a8c6f1a92e0f..081579c0971e 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;