Hi Arnd,

On Thu, 2018-03-15 at 17:19 +0100, Arnd Bergmann wrote:

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: Arnd Bergmann arnd@arndb.de

thank you, I've replaced v2 with this version in imx-drm/fixes.

regards Philipp

---

v1: Originally sent on Dec 4, 2017. v2: Sent again on Jan 16, after no reply, Phillipp said it was merged v3: Ran into a related problem with CONFIG_UBSAN, sent again fixing both

---

drivers/gpu/ipu-v3/ipu-prg.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/ipu-v3/ipu-prg.c b/drivers/gpu/ipu-v3/ipu-prg.c index 97b99500153d..83f9dd934a5d 100644 --- a/drivers/gpu/ipu-v3/ipu-prg.c +++ b/drivers/gpu/ipu-v3/ipu-prg.c @@ -250,10 +250,14 @@ 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;

  pm_runtime_get_sync(prg->dev);

@@ -280,13 +284,15 @@ 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;