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Commit 418c85ea authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman
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gpu: ipu-v3: prg: avoid possible array underflow 



[ Upstream commit 746d024c3211813946b319411aeb2b47767f8fb0 ]

gcc-8 reports that we access an array with a negative index
in an error case:

drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable':
drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds]

This moves the range check in front of the first time that
variable gets used.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 05c40118

drivers/gpu/ipu-v3/ipu-prg.c

+9 −3
Original line number Diff line number Diff line
@@ -252,10 +252,14 @@ void ipu_prg_channel_disable(struct ipuv3_channel *ipu_chan) 
{

	int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num);

	struct ipu_prg *prg = ipu_chan->ipu->prg_priv;

	struct ipu_prg_channel *chan = &prg->chan[prg_chan];

	struct ipu_prg_channel *chan;

	u32 val;



	if (!chan->enabled || prg_chan < 0)

	if (prg_chan < 0)

		return;



	chan = &prg->chan[prg_chan];

	if (!chan->enabled)

		return;



	clk_prepare_enable(prg->clk_ipg);
@@ -282,13 +286,15 @@ int ipu_prg_channel_configure(struct ipuv3_channel *ipu_chan, 
{

	int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num);

	struct ipu_prg *prg = ipu_chan->ipu->prg_priv;

	struct ipu_prg_channel *chan = &prg->chan[prg_chan];

	struct ipu_prg_channel *chan;

	u32 val;

	int ret;



	if (prg_chan < 0)

		return prg_chan;



	chan = &prg->chan[prg_chan];



	if (chan->enabled) {

		ipu_pre_update(prg->pres[chan->used_pre], *eba);

		return 0;