On Wed, 2024-01-24 at 22:21 -0800, debug@xxxxxxxxxxxx wrote: > + /* > + * PROT_SHADOWSTACK is a kernel only protection flag on risc- > v. > + * mmap doesn't expect PROT_SHADOWSTACK to be set by user > space. > + * User space can rely on `map_shadow_stack` syscall to > create > + * shadow stack pages. > + */ > + if (unlikely(prot & PROT_SHADOWSTACK)) > + return -EINVAL; Are you sure you need PROT_SHADOWSTACK? Since you are passing VM_SHADOW_STACK into do_mmap() directly.