Kernel: Add a way to specify which memory regions can make syscalls

This patch adds sys$msyscall() which is loosely based on an OpenBSD
mechanism for preventing syscalls from non-blessed memory regions.

It works similarly to pledge and unveil, you can call it as many
times as you like, and when you're finished, you call it with a null
pointer and it will stop accepting new regions from then on.

If a syscall later happens and doesn't originate from one of the
previously blessed regions, the kernel will simply crash the process.

1 files changed, 1 insertions, 0 deletions

diff --git a/Kernel/Syscalls/fork.cpp b/Kernel/Syscalls/fork.cpp
index 0f12b412a5..f20859dc5a 100644
--- a/Kernel/Syscalls/fork.cpp
+++ b/Kernel/Syscalls/fork.cpp
@@ -47,6 +47,7 @@ pid_t Process::sys$fork(RegisterState& regs)
     child->m_has_execpromises = m_has_execpromises;
     child->m_veil_state = m_veil_state;
     child->m_unveiled_paths = m_unveiled_paths.deep_copy();
+    child->m_enforces_syscall_regions = m_enforces_syscall_regions;
     child->m_fds = m_fds;
     child->m_sid = m_sid;
     child->m_pg = m_pg;