On Thu, Apr 28, 2022 at 4:58 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote: > > On Wed, Apr 27, 2022 at 12:26 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Wed, Apr 27, 2022 at 11:15 AM Namhyung Kim <namhyung@xxxxxxxxxx> wrote: > > > Actually I tried something similar but it was with a variable (in bss) > > > so the verifier in an old kernel rejected it due to invalid arg access. > > > > > > I guess now the const makes the verifier ignore the branch as if > > > it's dead but the compiler still generates the code, right? > > > > > > yes, exactly > > Then I'm curious how it'd work on newer kernels. > The verifier sees the false branch and detects type mismatch > for the second argument then it'd reject the program? > Verifier will know which branch is never taken, and will just ignore and remove any code in it as dead code. > Thanks, > Namhyung
