On Mon, 5 Dec 2022 18:22:15 GMT, Phil Race <[email protected]> wrote: >> I changed GCC toolchain from GCC6 to GCC8 on SLES12SP5 Linux s390x. >> I could see following errors: >> >> src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c: In >> function 'allocateRasterArray': >> src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c:2944:73: >> error: 'roff[3]' may be used uninitialized in this function >> [-Werror=maybe-uninitialized] >> (((*inP&rasterP->sppsm.maskArray[c]) >> roff[c]) >> ~~~~^~~ >> >> >> According to error messages, >> roff and loff may not be initialized. > >> src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c: In >> function 'allocateRasterArray': >> src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c:2944:73: >> error: 'roff[3]' may be used uninitialized in this function >> [-Werror=maybe-uninitialized] >> (((*inP&rasterP->sppsm.maskArray[c]) >> roff[c]) > > That's weird. allocateRasterArray is at lines 2360-2575 .. so why are you > seeing it at line 2944 ????
> Thanks @prrace . > > > That's weird. allocateRasterArray is at lines 2360-2575 .. so why are you > > seeing it at line 2944 ???? > > Ummm, I could not determine the reason... > > I assume AddressSanitizer detected memory errors because of following 2 codes: > > https://github.com/openjdk/jdk/blob/1e468320dc6e495343dbdf392cbcbda79672c7ad/src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c#L2937 > > > https://github.com/openjdk/jdk/blob/1e468320dc6e495343dbdf392cbcbda79672c7ad/src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c#L3118 > > So I'd like to put `memset()` on these parts. > > But I checked `if` and `else` blocks on above part. These are exactly the > same. > > https://github.com/openjdk/jdk/blob/1e468320dc6e495343dbdf392cbcbda79672c7ad/src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c#L2937-L2965 > > > https://github.com/openjdk/jdk/blob/1e468320dc6e495343dbdf392cbcbda79672c7ad/src/java.desktop/share/native/libawt/awt/medialib/awt_ImagingLib.c#L3118-L3153 > > I tried to modify from `if .. else` block to flat. AddressSanitizer did not > detect memory error. > > Could you give me any advice ? Oh you are running a tool to find these issues ? I thought it was supposed to be a build failure ? Or are you running the tool to try to understand the build failure. Tools are not always right in my experience. I think there's just as much chance as both being false positives as both being correct. I think at some point the tools arm-wave that this could be a problem but it is not provable. As Magnus pointed out "newer" compilers aren't complaining here. I don't know what kind of advice you are seeking. If you are asking me to somehow do better than the tools .. well I'd say its a whole lot easier to just memset these to zero. Zero may not be the correct offset either .. but it should be safer. ------------- PR: https://git.openjdk.org/jdk/pull/11475
