Implement environment variables

kernel/amd64/proc.c

@@ -11,6 +11,7 @@
 #include <limine/requests.h>
 #include <mm/malloc.h>
 #include <mm/pmm.h>
+#include <proc/env.h>
 #include <proc/mutex.h>
 #include <proc/proc.h>
 #include <proc/procgroup.h>
@@ -138,6 +139,8 @@ void proc_cleanup (struct proc* proc, struct reschedule_ctx* rctx) {
   proc_sqs_cleanup (proc);
   proc_mutexes_cleanup (proc, rctx);
 
+  proc_env_cleanup (proc);
+
   pmm_free (proc->pdata.kernel_stack, KSTACK_SIZE / PAGE_SIZE);
   procgroup_unmap (proc->procgroup, proc->pdata.tls_vaddr, proc->procgroup->tls.tls_tmpl_pages);