Changeset 408 for trunk/kernel/syscalls/sys_exec.c

Timestamp:

Dec 5, 2017, 4:20:07 PM (6 years ago)

Author:

alain

Message:

Fix several bugs in the fork() syscall.

File:

• trunk/kernel/syscalls/sys_exec.c (modified) (8 diffs)

trunk/kernel/syscalls/sys_exec.c

@@ -150 +150 @@
 // Implementation note:
 // This function build an exec_info_t structure containing all informations
-// required to create the new process descriptor and the associated thread.
+// required to initialize the new process descriptor and the associated thread.
+// It includes the process PID (unchanged), main() arguments, environment variables, 
+// and the pathname to the new process .elf file. 
 // It calls the process_exec_get_strings() functions to copy the main() arguments and 
 // the environment variables from user buffers to the exec_info_t structure, allocate
 // and call the process_make_exec() function.
-// Finally, it destroys the calling thread and process. 
+// As it must destroy all parent process copies, and all parent threads in all clusters,
+// the process_make_exec() function must be executed in the parent owner cluster, 
+// and this sys_exec() function uses a RPC to access the owner cluster if required. 
+// 
 // TODO : the args & envs arguments are not supported yet : both must be NULL 
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -169 +174 @@
         tm_start = hal_get_cycles();
 
-    // get pointers on parent process and thread
+    // get parent process pid
     thread_t   * this    = CURRENT_THREAD;
     process_t  * process = this->process;
@@ -177 +182 @@
 __FUNCTION__, local_cxy, this->core->lid, pid, (uint32_t)hal_get_cycles() );
 
-sched_display( 0 );
+    // get owner cluster
+    cxy_t  owner_cxy = CXY_FROM_PID( pid );
 
     // check pathname length
@@ -189 +195 @@
     // copy pathname in exec_info structure (kernel space)
     hal_strcpy_from_uspace( exec_info.path , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
+
     // check args argument
     assert( (args == NULL) , __FUNCTION__ , 
@@ -196 +203 @@
     assert( (envs == NULL) , __FUNCTION__ , 
     "args not supported yet\n" );
-
-    // compute client_cxy (local cluster) and server_cxy (target cluster)
-    cxy_t     cxy_server = CXY_FROM_PID( pid );
-    cxy_t     cxy_client = local_cxy;
-
-    // register parent process in exec_info
-    exec_info.parent_xp   = process->ref_xp;
-
-    // new process keep the parent process PID
-    exec_info.keep_pid   = true;
 
     // check and store args in exec_info structure if required
@@ -229 +226 @@
     }
 
+    // register PID in exec_info
+    exec_info.pid = pid;
+
     // call process_make_exec (local or remote)
-    if( cxy_server == cxy_client )
+    if( owner_cxy == local_cxy )
     {
         error = process_make_exec( &exec_info );
@@ -236 +236 @@
     else
     {
-        rpc_process_exec_client( cxy_server , &exec_info , &error );
+        rpc_process_make_exec_client( owner_cxy,
+                                      &exec_info,
+                                      &error );
     }
 
@@ -242 +244 @@
     {
         printk("\n[ERROR] in %s : cannot create new process %x in cluster %x\n",
-        __FUNCTION__, pid, cxy_server );
+        __FUNCTION__, pid, owner_cxy );
         this->errno = error;
         return -1;
     }
-
-    // FIXME delete the local process descriptor
-    // process_kill( process );
 
     tm_end = hal_get_cycles();