Fix user CPU context saving

init/init.c

@@ -47,8 +47,8 @@ void app_main (void) {
 
   spawn (&app_thread1);
 
-    /* for (volatile int i = 0; i < 1000*1000; i++) */
-    /*   ; */
+  /* for (volatile int i = 0; i < 1000*1000; i++) */
+  /*   ; */
   for (;;) {
     lock_mutex (MUTEX, RV_PRIVATE);
 

kernel/amd64/intr.c

@@ -165,13 +165,19 @@ static void amd64_intr_exception (struct saved_regs* regs) {
 
 /* Handle incoming interrupt, dispatch IRQ handlers. */
 void amd64_intr_handler (void* stack_ptr) {
-  spin_lock_ctx_t ctxcpu;
+  spin_lock_ctx_t ctxcpu, ctxpr;
+
   amd64_load_kernel_cr3 ();
 
   struct saved_regs* regs = stack_ptr;
 
   spin_lock (&thiscpu->lock, &ctxcpu);
-  memcpy (&thiscpu->regs, regs, sizeof (struct saved_regs));
+  struct proc* proc_current = thiscpu->proc_current;
+  spin_lock (&proc_current->lock, &ctxpr);
+
+  memcpy (&proc_current->pdata.regs, regs, sizeof (struct saved_regs));
+
+  spin_unlock (&proc_current->lock, &ctxpr);
   spin_unlock (&thiscpu->lock, &ctxcpu);
 
   if (regs->trap <= 31) {

kernel/amd64/sched1.c

@@ -3,9 +3,9 @@
 #include <amd64/sched.h>
 #include <libk/std.h>
 #include <proc/proc.h>
+#include <sync/spin_lock.h>
 #include <sys/mm.h>
 #include <sys/smp.h>
-#include <sync/spin_lock.h>
 
 void do_sched (struct proc* proc, spin_lock_t* cpu_lock, spin_lock_ctx_t* ctxcpu) {
   spin_lock_ctx_t ctxpr;

kernel/amd64/smp.c

@@ -11,9 +11,9 @@
 #include <proc/proc.h>
 #include <sync/spin_lock.h>
 #include <sys/debug.h>
+#include <sys/sched.h>
 #include <sys/smp.h>
 #include <sys/syscall.h>
-#include <sys/sched.h>
 
 /// Cpu ID counter
 static atomic_uint cpu_counter = 0;

kernel/amd64/smp.h

@@ -21,7 +21,6 @@ struct cpu {
   volatile uint8_t irq_stack[KSTACK_SIZE] ALIGNED (16);
   volatile struct gdt_extended gdt ALIGNED (16);
   volatile struct tss tss;
-  struct saved_regs regs;
 
   uintptr_t lapic_mmio_base;
   uint64_t lapic_ticks;

kernel/amd64/syscall.c

@@ -14,27 +14,27 @@
 extern void amd64_syscall_entry (void);
 
 int amd64_syscall_dispatch (void* stack_ptr) {
-  spin_lock_ctx_t ctxcpu;
-  
-  spin_lock (&thiscpu->lock, &ctxcpu);
+  spin_lock_ctx_t ctxcpu, ctxpr;
 
   amd64_load_kernel_cr3 ();
   struct saved_regs* regs = stack_ptr;
 
-  memcpy (&thiscpu->regs, regs, sizeof (struct saved_regs));
+  spin_lock (&thiscpu->lock, &ctxcpu);
+  struct proc* caller = thiscpu->proc_current;
+  spin_lock (&caller->lock, &ctxpr);
+
+  memcpy (&caller->pdata.regs, regs, sizeof (struct saved_regs));
+
+  spin_unlock (&caller->lock, &ctxpr);
+  spin_unlock (&thiscpu->lock, &ctxcpu);
 
   int syscall_num = regs->rax;
   syscall_handler_func_t func = syscall_find_handler (syscall_num);
 
   if (func == NULL) {
-    spin_unlock (&thiscpu->lock, &ctxcpu);
     return -ST_SYSCALL_NOT_FOUND;
   }
 
-  struct proc* caller = thiscpu->proc_current;
-  
-  spin_unlock (&thiscpu->lock, &ctxcpu);
-
   int result = func (caller, regs, regs->rdi, regs->rsi, regs->rdx, regs->r10, regs->r8, regs->r9);
   return result;
 }

kernel/proc/mutex.c

@@ -18,7 +18,7 @@ bool proc_create_resource_mutex (struct proc_mutex* mutex) {
 void proc_cleanup_resource_mutex (struct proc* proc, struct proc_resource* resource) {
   struct proc_mutex* mutex = &resource->u.mutex;
 
-  proc_mutex_unlock (proc, mutex);
+  /* proc_mutex_unlock (proc, mutex); */
 }
 
 static void proc_mutex_suspend (struct proc* proc, struct proc_suspension_q* sq,

kernel/proc/proc.c

@@ -294,7 +294,7 @@ static void proc_reap (void) {
 }
 
 void proc_sched (void) {
-  spin_lock_ctx_t ctxcpu, ctxpr;
+  spin_lock_ctx_t ctxcpu;
 
   int s_cycles = atomic_fetch_add (&sched_cycles, 1);
 
@@ -306,15 +306,8 @@ void proc_sched (void) {
 
   spin_lock (&cpu->lock, &ctxcpu);
 
-  struct proc* prev = cpu->proc_current;
   next = proc_find_sched (cpu);
 
-  if (prev != NULL) {
-    spin_lock (&prev->lock, &ctxpr);
-    memcpy (&prev->pdata.regs, &cpu->regs, sizeof (struct saved_regs));
-    spin_unlock (&prev->lock, &ctxpr);
-  }
-
   if (next) {
     cpu->proc_current = next;