> On Aug 8, 2024, at 2:48 AM, Petr Mladek <pmladek@xxxxxxxx> wrote: > > On Wed 2024-08-07 19:46:31, Song Liu wrote: >> >> >>> On Aug 7, 2024, at 7:58 AM, zhang warden <zhangwarden@xxxxxxxxx> wrote: >>> >>> >>>> In my GCC built, we have suffixes like ".constprop.0", ".part.0", ".isra.0", >>>> and ".isra.0.cold". >>> >>> A fresher's eye, I met sometime when try to build a livepatch module and found some mistake caused by ".constprop.0" ".part.0" which is generated by GCC. >>> >>> These section with such suffixes is special and sometime the symbol st_value is quite different. What is these kind of section (or symbol) use for? >> >> >> IIUC, constprop means const propagation. For example, function >> "foo(int a, int b)" that is called as "foo(a, 10)" will be come >> "foo(int a)" with a hard-coded b = 10 inside. >> >> .part.0 is part of the function, as the other part is inlined in >> the caller. > > Hmm, we should not remove the suffixes like .constprop*, .part*, > .isra*. They implement a special optimized variant of the function. > It is not longer the original full-featured one. > > This is a difference against adding a suffix for a static function. > Such a symbol implements the original full-featured function. Allow tracing without .llvm.<hash> suffixes may target a different function with same name, i.e. func_a.llvm.1 vs. func_a.llvm.2. We can probably detect and report this in the kernel. However, I would rather we just disallow tracing without suffixes. I think Masami also agrees with this. Thanks, Song
