[PATCH] pacct: avoidance to refer the last thread as a representation of the process

When pacct facility generate an 'ac_flag' field in accounting record, it
refers a task_struct of the thread which died last in the process.  But any
other task_structs are ignored.

Therefore, pacct facility drops ASU flag even if root-privilege operations are
used by any other threads except the last one.  In addition, AFORK flag is
always set when the thread of group-leader didn't die last, although this
process has called execve() after fork().

We have a same matter in ac_exitcode.  The recorded ac_exitcode is an exit
code of the last thread in the process.  There is a possibility this exitcode
is not the group leader's one.
diff --git a/include/linux/acct.h b/include/linux/acct.h
index 5bca9b3..e86bae7 100644
--- a/include/linux/acct.h
+++ b/include/linux/acct.h
@@ -122,16 +122,16 @@
 extern void acct_auto_close_mnt(struct vfsmount *m);
 extern void acct_auto_close(struct super_block *sb);
 extern void acct_init_pacct(struct pacct_struct *pacct);
-extern void acct_collect();
-extern void acct_process(long exitcode);
+extern void acct_collect(long exitcode, int group_dead);
+extern void acct_process(void);
 extern void acct_update_integrals(struct task_struct *tsk);
 extern void acct_clear_integrals(struct task_struct *tsk);
 #else
 #define acct_auto_close_mnt(x)	do { } while (0)
 #define acct_auto_close(x)	do { } while (0)
 #define acct_init_pacct(x)	do { } while (0)
-#define acct_collect()		do { } while (0)
-#define acct_process(x)		do { } while (0)
+#define acct_collect(x,y)	do { } while (0)
+#define acct_process()		do { } while (0)
 #define acct_update_integrals(x)		do { } while (0)
 #define acct_clear_integrals(task)	do { } while (0)
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index abada7c..d8429dc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -359,6 +359,8 @@
 };
 
 struct pacct_struct {
+	int			ac_flag;
+	long			ac_exitcode;
 	unsigned long		ac_mem;
 };