Add implementation of process_fork(), modify process_create() so that it can be used...

diff --git a/kernel/core/process.c b/kernel/core/process.c
index 8f70ec9f93cbff2cf44eea8bab22699088b10786..306e9bed3884e55ddb779a1bd1691bc4ecc28eb5 100644 (file)
--- a/kernel/core/process.c
+++ b/kernel/core/process.c
@@ -9,6 +9,27 @@
 #include "fd.h"
 #include "sched.h"
 
+/* FIXME: Remove struct stack_frame from process.c */
+struct stack_frame {
+       u32_t cr3;
+       u32_t ds;
+       u32_t edi;
+       u32_t esi;
+       u32_t ebp;
+       u32_t esp;
+       u32_t ebx;
+       u32_t edx;
+       u32_t ecx;
+       u32_t eax;
+       u32_t intn;
+       u32_t error;
+       u32_t eip;
+       u32_t cs;
+       u32_t eflags;
+       u32_t prevesp;
+       u32_t ss;
+} __attribute__((packed));
+
 enum procstate {
        PROC_STATE_INIT = 0,
        PROC_STATE_READY,
@@ -20,6 +41,7 @@ struct process {
        struct task    *p_tasks;
        u32_t          p_privl;
        pid_t          p_id;
+       pid_t          p_pid;
 
        struct {
                struct cxmsg *msg;
@@ -81,13 +103,17 @@ static inline int DQ(process_t *p)
        return(ret_val);
 }
 
+void* task_get_eip3(void);
+
 int process_create(process_t **dst, pid_t pid, u32_t ppl, void *entry)
 {
        int ret_val;
        process_t *proc;
+       pid_t ppid;
 
        ret_val = -ENOMEM;
        proc = NULL;
+       ppid = 1;
 
        /* was a specific pid requested? */
        if(pid != PID_ANY) {
@@ -105,6 +131,16 @@ int process_create(process_t **dst, pid_t pid, u32_t ppl, void *entry)
                }
        }
 
+       if(entry == PROC_ENTRY_FORK ||
+          entry == PROC_ENTRY_VFORK) {
+           task_t *ctask;
+
+               /* inherit the ppl from the current task, in the case of fork and vfork */
+               ctask = task_get_current();
+               ppl = ctask->t_privl;
+               ppid = ctask->t_pid;
+       }
+
        proc = kmalloc(sizeof(*proc));
 
        if(proc) {
@@ -130,6 +166,7 @@ int process_create(process_t **dst, pid_t pid, u32_t ppl, void *entry)
                }
 
                proc->p_privl = ppl;
+               proc->p_pid = ppid;
 
                if(pid == PID_ANY) {
                        /* no specific pid requested */
@@ -138,6 +175,27 @@ int process_create(process_t **dst, pid_t pid, u32_t ppl, void *entry)
                        proc->p_id = pid;
                }
 
+               if(entry == PROC_ENTRY_FORK ||
+                  entry == PROC_ENTRY_VFORK) {
+                       struct stack_frame *stack0;
+                       task_t *ctask;
+
+                       ctask = task_get_current();
+
+                       /*
+                        * In the case of fork() and vfork() we have to get the address that the
+                        * interrupt is supposed to return to. The stack that the address was pushed
+                        * onto is located at ctask->t_kstack.
+                        */
+
+                       stack0 = ((struct stack_frame*)(ctask->t_kstack + CONFIG_KERNEL_STACK_SIZE)) - 1;
+
+                       entry = (void*)stack0->eip;
+                       dbg_printf("entry = 0x%08x\n", (u32_t)entry);
+
+                       for(;;);
+               }
+
                task_prepare(proc->p_tasks, (u32_t)pdbr, (u32_t)entry,
                                         (u32_t)kstack + CONFIG_KERNEL_STACK_SIZE,
                                         (u32_t)ustack + CONFIG_USER_STACK_SIZE, ppl);
@@ -473,3 +531,20 @@ int process_exit(process_t *proc, int status)
 
        return(ret_val);
 }
+
+int process_fork(int v)
+{
+       process_t *proc;
+       int ret_val;
+
+       proc = process_get_current();
+       ret_val = -EFAULT;
+
+       if(proc) {
+               process_t *nproc;
+
+               ret_val = process_create(&nproc, PID_ANY, proc->p_privl, PROC_ENTRY_FORK);
+       }
+
+       return(ret_val);
+}

diff --git a/kernel/include/process.h b/kernel/include/process.h
index 4c3baf303eabec553a2e9ed4ede40e5e48f2d028..480e2e08e7254f6f4ca155650120f007eafa1101 100644 (file)
--- a/kernel/include/process.h
+++ b/kernel/include/process.h
@@ -22,6 +22,9 @@
 #include <corax/types.h>
 #include <corax/ipc.h>
 
+#define PROC_ENTRY_FORK  ((void*)0)
+#define PROC_ENTRY_VFORK ((void*)1)
+
 typedef struct process process_t;
 
 int process_create(process_t**, pid_t, u32_t, void*);
@@ -47,5 +50,6 @@ int           process_signal(pid_t);
 void*         process_get_tasks(process_t*);
 pid_t         process_get_id(process_t*);
 int           process_exit(process_t*, int);
+int           process_fork(int);
 
 #endif /* __PROCESS_H */