On Fri, Sep 04, 2026 at 11:14:19AM -0700, Bill Wendling wrote: > Hi Kees, > > On Thu, Sep 3, 2026 at 4:24 PM Kees Cook <[email protected]> wrote: > > > > find_bad_casts() reports a cast between two randomized structure pointer > > types with inform(), which renders as a "note:". It has done so since > > the plugin was originally added, while using error() freely for attribute > > misuse, UAPI structs, and version mismatches. > > > > Clang's implementation of the same check has always been stricter: > > it rejects such a cast as a full error. There is no reason for the GCC > > side to be effectively silent about the same problem. > > > > Build tested ARCH=x86_64 with CONFIG_RANDSTRUCT_FULL=y and GCC 14.2.0: > > allmodconfig clean, and defconfig clean under three different random > > seeds. A deliberate bad cast is still reported, now as a warning, at the > > correct line and column. > > > > Signed-off-by: Kees Cook <[email protected]> > > --- > > scripts/gcc-plugins/randomize_layout_plugin.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c > > b/scripts/gcc-plugins/randomize_layout_plugin.c > > index e2bd9ba08089..1e66f45fe29b 100644 > > --- a/scripts/gcc-plugins/randomize_layout_plugin.c > > +++ b/scripts/gcc-plugins/randomize_layout_plugin.c > > @@ -22,7 +22,7 @@ > > #define ORIG_TYPE_NAME(node) \ > > (TYPE_NAME(TYPE_MAIN_VARIANT(node)) != NULL_TREE ? ((const unsigned > > char *)IDENTIFIER_POINTER(TYPE_NAME(TYPE_MAIN_VARIANT(node)))) : (const > > unsigned char *)"anonymous") > > > > -#define INFORM(loc, msg, ...) inform(loc, "randstruct: " msg, > > ##__VA_ARGS__) > > +#define INFORM(loc, msg, ...) warning_at(loc, 0, "randstruct: " msg, > > ##__VA_ARGS__) > > Why not make this an error instead of a warning?
Yeah, it seems odd to mention that Clang's implementation has always treated this as an error then not match its behavior. If this cannot be made an error, I think the commit message should call out why. -- Cheers, Nathan
