rlimits: add task_struct to update_rlimit_cpu

Add task_struct as a parameter to update_rlimit_cpu to be able to set
rlimit_cpu of different task than current.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: James Morris <jmorris@namei.org>

include/linux/posix-timers.h

@@ -117,6 +117,6 @@ void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
 
 long clock_nanosleep_restart(struct restart_block *restart_block);
 
-void update_rlimit_cpu(unsigned long rlim_new);
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
 
 #endif

kernel/posix-cpu-timers.c

@@ -16,13 +16,13 @@
  * siglock protection since other code may update expiration cache as
  * well.
  */
-void update_rlimit_cpu(unsigned long rlim_new)
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
 {
 	cputime_t cputime = secs_to_cputime(rlim_new);
 
-	spin_lock_irq(&current->sighand->siglock);
-	set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
-	spin_unlock_irq(&current->sighand->siglock);
+	spin_lock_irq(&task->sighand->siglock);
+	set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
+	spin_unlock_irq(&task->sighand->siglock);
 }
 
 static int check_clock(const clockid_t which_clock)

kernel/sys.c

@@ -1320,7 +1320,7 @@ SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 	if (new_rlim.rlim_cur == RLIM_INFINITY)
 		goto out;
 
-	update_rlimit_cpu(new_rlim.rlim_cur);
+	update_rlimit_cpu(current, new_rlim.rlim_cur);
 out:
 	return 0;
 }

security/selinux/hooks.c

@@ -2338,7 +2338,8 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
 			initrlim = init_task.signal->rlim + i;
 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
 		}
-		update_rlimit_cpu(current->signal->rlim[RLIMIT_CPU].rlim_cur);
+		update_rlimit_cpu(current,
+				current->signal->rlim[RLIMIT_CPU].rlim_cur);
 	}
 }