On Wed, Aug 18, 2021 at 11:40 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > GCC and Clang can use the "alloc_size" attribute to better inform the > results of __builtin_object_size() (for compile-time constant values). > Clang can additionally use alloc_size to inform the results of > __builtin_dynamic_object_size() (for run-time values). > > Because GCC sees the frequent use of struct_size() as an allocator size > argument, and notices it can return SIZE_MAX (the overflow indication), > it complains about these call sites may overflow (since SIZE_MAX is > greater than the default -Walloc-size-larger-than=PTRDIFF_MAX). This > isn't helpful since we already know a SIZE_MAX will be caught at run-time > (this was an intentional design). Instead, just disable this check as > it is both a false positive and redundant. (Clang does not have this > warning option.) Thanks! Reviewed-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Cheers, Miguel
