Fixed 2 more fork issues

Added setting of spsr for the new task.
Added newly created task into mm0's global task list.

include/l4/api/syscall.h

@@ -26,6 +26,8 @@
 #define syscalls_end_offset			sys_time_offset
 #define SYSCALLS_TOTAL				((syscalls_end_offset >> 2) + 1)
 
+void print_syscall_context(struct ktcb *t);
+
 int sys_ipc(struct syscall_context *);
 int sys_thread_switch(struct syscall_context *);
 int sys_thread_control(struct syscall_context *);

src/api/syscall.c

@@ -17,6 +17,16 @@
 #include INC_API(syscall.h)
 #include INC_ARCH(exception.h)
 
+void print_syscall_context(struct ktcb *t)
+{
+	syscall_context_t *r = t->syscall_regs;
+
+	printk("Thread id: %d registers: 0x%x, 0x%x, 0x%x, 0x%x, "
+	       "0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
+	       t->tid, r->spsr, r->r0, r->r1, r->r2, r->r3, r->r4,
+	       r->r5, r->r6, r->r7, r->r8, r->sp_usr, r->lr_usr);
+}
+
 int sys_exchange_registers(syscall_context_t *regs)
 {
 	struct ktcb *task;

src/api/thread.c

@@ -6,6 +6,7 @@
 #include <l4/generic/scheduler.h>
 #include INC_API(syscall.h)
 #include <l4/api/thread.h>
+#include <l4/api/syscall.h>
 #include <l4/api/errno.h>
 #include <l4/generic/tcb.h>
 #include <l4/lib/idpool.h>
@@ -61,6 +62,7 @@ int thread_start(struct task_ids *ids)
 	return -EINVAL;
 }
 
+
 extern unsigned int return_from_syscall;
 
 /*
@@ -107,12 +109,14 @@ int arch_setup_new_thread(struct ktcb *new, struct ktcb *orig)
 	new->syscall_regs->r0 = 0;
 
 	/*
-	 * Set up the stack pointer and program counter so that next time
-	 * the new thread schedules, it executes the end part of the system
-	 * call exception where the previous context is restored.
+	 * Set up the stack pointer, saved program status register and program
+	 * counter so that next time the new thread schedules, it executes the
+	 * end part of the system call exception where the previous context is
+	 * restored.
 	 */
-	new->context.sp = (unsigned long)new + syscall_context_offset;
-	new->context.pc = (unsigned long)return_from_syscall;
+	new->context.sp = (unsigned long)new->syscall_regs;
+	new->context.pc = (unsigned long)&return_from_syscall;
+	new->context.spsr = (unsigned long)orig->context.spsr; 
 
 	/* Copy other relevant fields from original ktcb */
 	new->pagerid = orig->pagerid;

tasks/fs0/src/task.c

@@ -121,6 +121,7 @@ int pager_notify_fork(l4id_t sender, l4id_t parid,
 	memcpy(child->fd, parent->fd, TASK_FILES_MAX * sizeof(int));
 
 	l4_ipc_return(0);
+	printf("%s/%s: Exiting...\n", __TASKNAME__, __FUNCTION__);
 
 	return 0;
 }

tasks/mm0/include/task.h

@@ -94,6 +94,7 @@ struct task_data_head {
 };
 
 struct tcb *find_task(int tid);
+void task_add_global(struct tcb *t);
 
 struct initdata;
 void init_pm(struct initdata *initdata);

tasks/mm0/src/clone.c

@@ -158,6 +158,10 @@ int do_fork(struct tcb *parent)
 	/* Notify fs0 about forked process */
 	vfs_notify_fork(child, parent);
 
+	/* Add child to global task list */
+	task_add_global(child);
+
+	printf("%s/%s: Starting forked child.\n", __TASKNAME__, __FUNCTION__);
 	/* Start forked child. */
 	l4_thread_control(THREAD_RUN, &ids);
 

tasks/mm0/src/task.c

@@ -43,6 +43,12 @@ void print_tasks(void)
 	}
 }
 
+void task_add_global(struct tcb *task)
+{
+	list_add_tail(&task->list, &tcb_head.list);
+	tcb_head.total++;
+}
+
 struct tcb *find_task(int tid)
 {
 	struct tcb *t;
@@ -276,8 +282,7 @@ int task_exec(struct vm_file *f, unsigned long task_region_start,
 		return err;
 
 	/* Add the task to the global task list */
-	list_add_tail(&task->list, &tcb_head.list);
-	tcb_head.total++;
+	task_add_global(task);
 
 	/* Add the file to global vm lists */
 	list_del_init(&f->list);