cpu->proc_current cannot be NULL

kernel/amd64/intr.c

@@ -160,6 +160,23 @@ static void intr_exception (struct saved_regs* regs) {
                regs->error, regs->rip, regs->cs, regs->rflags, regs->rsp, regs->ss, cr2, cr3,
                regs->rbx);
 
+  debugprintf ("call stack:\n");
+
+  uint64_t rbp = regs->rbp;
+
+  for (size_t depth = 0; depth < 20; depth++) {
+    if (rbp == 0)
+      break;
+
+    uint64_t rip = *(uint64_t*)(rbp + 8);
+    debugprintf ("  #%d %016lx\n", depth, rip);
+
+    rbp = *(uint64_t*)rbp;
+
+    if (rbp == 0)
+      break;
+  }
+
   if (regs->cs == (GDT_UCODE | 0x03)) {
     struct reschedule_ctx rctx;
     memset (&rctx, 0, sizeof (rctx));
@@ -200,14 +217,12 @@ void intr_handler (void* stack_ptr) {
 
       struct proc* proc_current = thiscpu->proc_current;
 
-      if (proc_current != NULL) {
+      spin_lock (&proc_current->lock, &fpc);
-        spin_lock (&proc_current->lock, &fpc);
+      memcpy (&proc_current->pdata.regs, regs, sizeof (struct saved_regs));
-        memcpy (&proc_current->pdata.regs, regs, sizeof (struct saved_regs));
 
-        fx_save (proc_current->pdata.fx_env);
+      fx_save (proc_current->pdata.fx_env);
 
-        spin_unlock (&proc_current->lock, fpc);
+      spin_unlock (&proc_current->lock, fpc);
-      }
 
       spin_unlock (&thiscpu->lock, ftc);
     }

kernel/build/.gitignore

@@ -1,2 +1,3 @@
 *.elf
 *.json
+*.map

kernel/device/ps2_kb.c

@@ -161,7 +161,7 @@ static void ps2kb_irq (void* arg, void* regs, bool user, struct reschedule_ctx*
 
   struct list_node_link* node = ps2kb_sq.proc_list;
 
-  if (node) {
+  if (node != NULL) {
     struct proc_sq_entry* sq_entry = list_entry (node, struct proc_sq_entry, sq_link);
     struct proc* resumed_proc = sq_entry->proc;
 

kernel/generic/flags.mk

@@ -26,7 +26,8 @@ ifeq ($(buildtype),release)
 endif
 
 ldflags += --nostdlib \
-					 --static
+					 --static \
+					 --Map=build/kernel.map
 
 ifeq ($(buildtype),release)
 	ldflags += --gc-sections \

kernel/proc/mutex.c

@@ -12,12 +12,16 @@
 #include <sys/spin_lock.h>
 
 void proc_mutexes_cleanup (struct proc* proc, struct reschedule_ctx* rctx) {
-  uint64_t fpg, fr;
+  uint64_t fpg, fr, fp;
 
-  spin_lock (&proc->procgroup->lock, &fpg);
+  spin_lock (&proc->lock, &fp);
+  struct procgroup* procgroup = proc->procgroup;
+  spin_unlock (&proc->lock, fp);
+
+  spin_lock (&procgroup->lock, &fpg);
 
   struct rb_node_link* rnode;
-  rbtree_first (&proc->procgroup->resource_tree, rnode);
+  rbtree_first (&procgroup->resource_tree, rnode);
 
   while (rnode) {
     struct rb_node_link* next;
@@ -43,7 +47,7 @@ void proc_mutexes_cleanup (struct proc* proc, struct reschedule_ctx* rctx) {
     spin_unlock (&resource->lock, fr);
   }
 
-  spin_unlock (&proc->procgroup->lock, fpg);
+  spin_unlock (&procgroup->lock, fpg);
 }
 
 void proc_cleanup_resource_mutex (struct proc_resource* resource, struct reschedule_ctx* rctx) {

kernel/proc/proc.c

@@ -234,7 +234,7 @@ static struct proc* proc_find_sched (struct cpu* cpu) {
   if (!cpu->proc_run_q)
     return NULL;
 
-  if (cpu->proc_current && cpu->proc_current->cpu_run_q_link.next)
+  if (cpu->proc_current->cpu_run_q_link.next)
     current = cpu->proc_current->cpu_run_q_link.next;
   else
     current = cpu->proc_run_q;
@@ -282,7 +282,6 @@ retry:
     else
       spin_unlock (&cpu->lock, fc);
   } else {
-    cpu->proc_current = NULL;
     spin_unlock (&cpu->lock, fc);
 
     spin_lock_relax ();
@@ -310,8 +309,6 @@ void proc_kill (struct proc* proc, struct reschedule_ctx* rctx) {
 
   list_remove (cpu->proc_run_q, &proc->cpu_run_q_link);
   cpu->proc_run_q_count--;
-  if (cpu->proc_current == proc)
-    cpu->proc_current = NULL;
 
   rbtree_delete (&proc_tree, &proc->proc_tree_link);
 

kernel/proc/suspension_q.c

@@ -14,7 +14,9 @@ int proc_sq_suspend (struct proc* proc, struct proc_suspension_q* sq, spin_lock_
                      uint64_t lockflags, struct reschedule_ctx* rctx) {
   uint64_t fc, fp, fsq;
 
+  spin_lock (&proc->lock, &fp);
   struct cpu* cpu = proc->cpu;
+  spin_unlock (&proc->lock, fp);
 
   struct proc_sq_entry* sq_entry = malloc (sizeof (*sq_entry));
   if (!sq_entry) {
@@ -44,9 +46,6 @@ int proc_sq_suspend (struct proc* proc, struct proc_suspension_q* sq, spin_lock_
   list_remove (cpu->proc_run_q, &proc->cpu_run_q_link);
   cpu->proc_run_q_count--;
 
-  if (cpu->proc_current == proc)
-    cpu->proc_current = NULL;
-
   int state = proc->state;
 
   spin_unlock (&sq->lock, fsq);
@@ -81,8 +80,6 @@ int proc_sq_resume (struct proc* proc, struct proc_sq_entry* sq_entry,
     proc->state = PROC_READY;
 
   list_append (cpu->proc_run_q, &proc->cpu_run_q_link);
-  if (cpu->proc_current == NULL)
-    cpu->proc_current = proc;
   cpu->proc_run_q_count++;
 
   int state = proc->state;

kernel/syscall/syscall.c

@@ -480,8 +480,6 @@ DEFINE_SYSCALL (sys_exec_partial_fini) {
 
   cpu->proc_run_q_count++;
   list_append (cpu->proc_run_q, &target_proc->cpu_run_q_link);
-  if (cpu->proc_current == NULL)
-    cpu->proc_current = target_proc;
 
   spin_unlock (&target_proc->lock, fp);
   spin_unlock (&cpu->lock, fc);