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From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Gregory Clement <gregory.clement@free-electrons.com>,
	linux-arm-kernel@lists.infradead.org,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Subject: [PATCH] PCI: mvebu: Fix uninitialized variable in mvebu_get_tgt_attr()
Date: Wed, 17 Sep 2014 17:58:27 +0200	[thread overview]
Message-ID: <1410969507-13692-1-git-send-email-thomas.petazzoni@free-electrons.com> (raw)

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.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This patch is a different solution than the one proposed by Geert. It
(hopefully) matches the discussion we had with Bjorn and Arnd.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/pci/host/pci-mvebu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index a8c6f1a..b1315e1 100644
--- 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 device_node *np, int devfn,
 	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 device_node *np, int devfn,
 			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;
-- 
2.0.0


             reply	other threads:[~2014-09-17 15:58 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-17 15:58 Thomas Petazzoni [this message]
2014-09-22 20:43 ` Bjorn Helgaas
  -- strict thread matches above, loose matches on Subject: below --
2014-08-08 15:34 Geert Uytterhoeven
2014-09-05 17:41 ` Bjorn Helgaas
2014-09-05 17:51   ` Arnd Bergmann
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

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