On Tue, Oct 25, 2022 at 6:22 AM Alexander Potapenko <glider@xxxxxxxxxx> wrote: > > KMSAN adds a lot of instrumentation to the code, which results in > increased stack usage (up to 2048 bytes and more in some cases). > It's hard to predict how big the stack frames can be, so we disable > the warnings for KMSAN instead. > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx> > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Cc: linux-kbuild@xxxxxxxxxxxxxxx > Link: https://github.com/google/kmsan/issues/89 > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> > --- > lib/Kconfig.debug | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 3fc7abffc7aa2..29280072dc0e4 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -400,8 +400,9 @@ config FRAME_WARN > default 1536 if (!64BIT && XTENSA) > default 1024 if !64BIT > default 2048 if 64BIT > + default 0 if KMSAN This is wrong. Kconfig picks up the first default entry which has true 'if' condition. Since (!64BIT || 64BIT) covers all the possible cases, this patch is just adding dead code. > help > - Tell gcc to warn at build time for stack frames larger than this. > + Tell the compiler to warn at build time for stack frames larger than this. > Setting this too low will cause a lot of warnings. > Setting it to 0 disables the warning. > > -- > 2.38.0.135.g90850a2211-goog > -- Best Regards Masahiro Yamada
