On Thu, Feb 06, 2025 at 10:11:29AM -0800, Kees Cook wrote: > In preparation for adding stricter type checking to the str/mem*() > helpers, provide a way to check that a variable is a character array > via __must_be_char_array(). > > Signed-off-by: Kees Cook <k...@kernel.org>
Suggested-by? :) > --- > include/linux/compiler.h | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > index 7af999a131cb..a577fe0b1f8a 100644 > --- a/include/linux/compiler.h > +++ b/include/linux/compiler.h > @@ -221,7 +221,13 @@ void ftrace_likely_update(struct ftrace_likely_data *f, > int val, > #endif /* __CHECKER__ */ > > /* &a[0] degrades to a pointer: a different type from an array */ > -#define __must_be_array(a) __BUILD_BUG_ON_ZERO_MSG(__same_type((a), > &(a)[0]), "must be array") > +#define __is_array(a) (!__same_type((a), &(a)[0])) > +#define __must_be_array(a) __BUILD_BUG_ON_ZERO_MSG(!__is_array(a), \ > + "must be array") > + > +#define __is_char_array(a) (__is_array(a) && sizeof((a)[0]) == 1) > +#define __must_be_char_array(a) > __BUILD_BUG_ON_ZERO_MSG(!__is_char_array(a), \ > + "must be byte array") > > /* Require C Strings (i.e. NUL-terminated) lack the "nonstring" attribute. */ > #define __must_be_cstr(p) \ > -- > 2.34.1 >
