On Fri, 3 Apr 2020 at 22:07, Carl Eugen Hoyos <ceffm...@gmail.com> wrote:
> Am Fr., 3. Apr. 2020 um 22:42 Uhr schrieb FRÉDÉRIC RECOULES > <frederic.recou...@univ-grenoble-alpes.fr>: > > > we are academic researchers working in automated program analysis. > > We are currently interested in checking compliance of inline asm chunks > > as found in C programs. > > > > While benchmarking our tool and technique, we found a number of issues in > > FFMPEG. We report them to you, as well as adequate patches. > > Actually, we found 59 significant compliance issues in your code. > > We join 3 patches for some of them, together with explanations and > > we can send you other patches on demand. > > > > > > * All these bugs are related to compliance between the block of asm and > its > > surrounding "contract" (in gcc-style notation). They are akin to > undefined or > > implementation-defined behaviours in C: they currently do not manifest > > themselves in your program, but at some point in time with compiler > > optimizations becoming more and more aggressive or changes in > undocumented > > compiler choices regarding asm chunks, they can suddenly trigger a > > (hard-to-find) bug. > > So your current patch does not change compilation output (without > debug symbols) when compared with md5sum or similar? > We do not do such a comparison for C undefined behaviour changes so why should we do such a comparison for this code? Kieran _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
