procfs: Add a procfs

Userland can now interface with processes by writing/reading from
`/proc/<pid>/<entry>`

It can send signals, for example `echo 15 > /proc/1/signal`

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/sched/scheduler.c b/kernel/sched/scheduler.c
index d0452fd..1b36e8a 100644
--- a/kernel/sched/scheduler.c
+++ b/kernel/sched/scheduler.c
@@ -98,6 +98,7 @@ process_t *create_process(process_t *p, u32 esp, u32 eip) {
   if (!r) {
     return NULL;
   }
+  r->reference_count = 1;
   r->tcb = kcalloc(1, sizeof(struct TCB));
   if (!r->tcb) {
     kfree(r);
@@ -147,6 +148,9 @@ process_t *create_process(process_t *p, u32 esp, u32 eip) {
     r->cr3 = get_active_pagedirectory();
   }
   r->parent = p;
+  if (p) {
+    p->reference_count++;
+  }
 
   r->tcb->CR3 = r->cr3->physical_address;
 
@@ -205,6 +209,14 @@ void free_process(process_t *p) {
   mmu_free_pagedirectory(p->cr3);
 }
 
+void process_remove_reference(process_t *p) {
+  assert(0 != p->reference_count);
+  p->reference_count--;
+  if (0 == p->reference_count) {
+    kfree(p);
+  }
+}
+
 void exit_process(process_t *p, int status) {
   assert(p->pid != 1);
   disable_interrupts();