Thanks for your feedback! Should I commit a patch to fix this problem?

Best wishes, Tuo Li

On 2021/8/2 1:59, Sam Ravnborg wrote:

Hi Tuo Li,

On Sat, Jul 31, 2021 at 02:28:39PM +0800, Li Tuo wrote:

...

Hello,

Our static analysis tool finds a possible uninitialized-variable access in the sis driver in Linux 5.14.0-rc3:

At the beginning of the function SiS_SetCRT2FIFO_300(), the variable modeidindex is not initialized. If the following conditions are false, it remains uninitialized. 5346:    if(!SiS_Pr->CRT1UsesCustomMode) 5438:    if(!SiS_Pr->UseCustomMode)

But it is accessed at: 5466:    colorth = SiS_GetColorDepth(SiS_Pr,CRT2ModeNo,modeidindex) >> 1;

I am not quite sure whether this possible uninitialized-variable access is real and how to fix it if it is real. Any feedback would be appreciated, thanks!

First, the report looks correct. There is a path where modeindex may not be initilized. But I find it very hard to care for such an ancient driver. If this was somethign we hit is real life we had heard about it - and the risk of introducing bugs is higher than the the cance that this fixes a real life bug.

So my advice, find something more relevant to look at.

Sam