[PATCH] ARM: orion: avoid VLA in orion_mpp_conf

Arnd Bergmann
2018-10-05T16:16:13Z

Testing randconfig builds found an instance of a VLA that was
missed when determining that we have removed them all:

arch/arm/plat-orion/mpp.c: In function 'orion_mpp_conf':
arch/arm/plat-orion/mpp.c:31:2: error: ISO C90 forbids variable length array 'mpp_ctrl' [-Werror=vla]

This one is fairly straightforward: we know what all three
callers are, and the maximum length is not very long.

Fixes: 68664695ae57 ("Makefile: Globally enable VLA warning")
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/arm/plat-orion/mpp.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/plat-orion/mpp.c b/arch/arm/plat-orion/mpp.c
index 5b4ff9373c89..8a6880d528b6 100644
--- a/arch/arm/plat-orion/mpp.c
+++ b/arch/arm/plat-orion/mpp.c
@@ -28,10 +28,15 @@ void __init orion_mpp_conf(unsigned int *mpp_list, unsigned int variant_mask,
unsigned int mpp_max, void __iomem *dev_bus)
{
unsigned int mpp_nr_regs = (1 + mpp_max/8);
- u32 mpp_ctrl[mpp_nr_regs];
+ u32 mpp_ctrl[8];
int i;

printk(KERN_DEBUG "initial MPP regs:");
+ if (mpp_nr_regs > ARRAY_SIZE(mpp_ctrl)) {
+ printk(KERN_ERR "orion_mpp_conf: invalid mpp_max\n");
+ return;
+ }
+
for (i = 0; i < mpp_nr_regs; i++) {
mpp_ctrl[i] = readl(mpp_ctrl_addr(i, dev_bus));
printk(" %08x", mpp_ctrl[i]);
--
2.18.0