[PATCH 4.4 19/53] atm: eni: fix uninitialized variable warning

From: Greg Kroah-Hartman
Date: Mon Feb 03 2020 - 11:23:11 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

[ Upstream commit 30780d086a83332adcd9362281201cee7c3d9d19 ]

With -O3, gcc has found an actual unintialized variable stored
into an mmio register in two instances:

drivers/atm/eni.c: In function 'discard':
drivers/atm/eni.c:465:13: error: 'dma[1]' is used uninitialized in this function [-Werror=uninitialized]
writel(dma[i*2+1],eni_dev->rx_dma+dma_wr*8+4);
^
drivers/atm/eni.c:465:13: error: 'dma[3]' is used uninitialized in this function [-Werror=uninitialized]

Change the code to always write zeroes instead.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/atm/eni.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c
index 6339efd326972..ad591a2f7c822 100644
--- a/drivers/atm/eni.c
+++ b/drivers/atm/eni.c
@@ -372,7 +372,7 @@ static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb,
here = (eni_vcc->descr+skip) & (eni_vcc->words-1);
dma[j++] = (here << MID_DMA_COUNT_SHIFT) | (vcc->vci
<< MID_DMA_VCI_SHIFT) | MID_DT_JK;
- j++;
+ dma[j++] = 0;
}
here = (eni_vcc->descr+size+skip) & (eni_vcc->words-1);
if (!eff) size += skip;
@@ -445,7 +445,7 @@ static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb,
if (size != eff) {
dma[j++] = (here << MID_DMA_COUNT_SHIFT) |
(vcc->vci << MID_DMA_VCI_SHIFT) | MID_DT_JK;
- j++;
+ dma[j++] = 0;
}
if (!j || j > 2*RX_DMA_BUF) {
printk(KERN_CRIT DEV_LABEL "!j or j too big!!!\n");
--
2.20.1