Merge branch 'work.sys_wait' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull wait syscall updates from Al Viro:
 "Consolidating sys_wait* and compat counterparts.

  Gets rid of set_fs()/double-copy mess, simplifies the whole thing
  (lifting the copyouts to the syscalls means less headache in the part
  that does actual work - fewer failure exits, to start with), gets rid
  of the overhead of field-by-field __put_user()"

* 'work.sys_wait' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  osf_wait4: switch to kernel_wait4()
  waitid(): switch copyout of siginfo to unsafe_put_user()
  wait_task_zombie: consolidate info logics
  kill wait_noreap_copyout()
  lift getrusage() from wait_noreap_copyout()
  waitid(2): leave copyout of siginfo to syscall itself
  kernel_wait4()/kernel_waitid(): delay copying status to userland
  wait4(2)/waitid(2): separate copying rusage to userland
  move compat wait4 and waitid next to native variants

6 files changed, 187 insertions, 259 deletions

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index ce93124a850b..b23d6fbbb225 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1183,48 +1183,23 @@ SYSCALL_DEFINE2(osf_getrusage, int, who, struct rusage32 __user *, ru)
 SYSCALL_DEFINE4(osf_wait4, pid_t, pid, int __user *, ustatus, int, options,
 		struct rusage32 __user *, ur)
 {
-	struct rusage r;
-	long ret, err;
 	unsigned int status = 0;
-	mm_segment_t old_fs;
-
+	struct rusage r;
+	long err = kernel_wait4(pid, &status, options, &r);
+	if (err <= 0)
+		return err;
+	if (put_user(status, ustatus))
+		return -EFAULT;
 	if (!ur)
-		return sys_wait4(pid, ustatus, options, NULL);
-
-	old_fs = get_fs();
-		
-	set_fs (KERNEL_DS);
-	ret = sys_wait4(pid, (unsigned int __user *) &status, options,
-			(struct rusage __user *) &r);
-	set_fs (old_fs);
-
-	if (!access_ok(VERIFY_WRITE, ur, sizeof(*ur)))
+		return err;
+	if (put_tv32(&ur->ru_utime, &r.ru_utime))
 		return -EFAULT;
-
-	err = put_user(status, ustatus);
-	if (ret < 0)
-		return err ? err : ret;
-
-	err |= __put_user(r.ru_utime.tv_sec, &ur->ru_utime.tv_sec);
-	err |= __put_user(r.ru_utime.tv_usec, &ur->ru_utime.tv_usec);
-	err |= __put_user(r.ru_stime.tv_sec, &ur->ru_stime.tv_sec);
-	err |= __put_user(r.ru_stime.tv_usec, &ur->ru_stime.tv_usec);
-	err |= __put_user(r.ru_maxrss, &ur->ru_maxrss);
-	err |= __put_user(r.ru_ixrss, &ur->ru_ixrss);
-	err |= __put_user(r.ru_idrss, &ur->ru_idrss);
-	err |= __put_user(r.ru_isrss, &ur->ru_isrss);
-	err |= __put_user(r.ru_minflt, &ur->ru_minflt);
-	err |= __put_user(r.ru_majflt, &ur->ru_majflt);
-	err |= __put_user(r.ru_nswap, &ur->ru_nswap);
-	err |= __put_user(r.ru_inblock, &ur->ru_inblock);
-	err |= __put_user(r.ru_oublock, &ur->ru_oublock);
-	err |= __put_user(r.ru_msgsnd, &ur->ru_msgsnd);
-	err |= __put_user(r.ru_msgrcv, &ur->ru_msgrcv);
-	err |= __put_user(r.ru_nsignals, &ur->ru_nsignals);
-	err |= __put_user(r.ru_nvcsw, &ur->ru_nvcsw);
-	err |= __put_user(r.ru_nivcsw, &ur->ru_nivcsw);
-
-	return err ? err : ret;
+	if (put_tv32(&ur->ru_stime, &r.ru_stime))
+		return -EFAULT;
+	if (copy_to_user(&ur->ru_maxrss, &r.ru_maxrss,
+	      sizeof(struct rusage32) - offsetof(struct rusage32, ru_maxrss)))
+		return -EFAULT;
+	return err;
 }
 
 /*
diff --git a/include/linux/resource.h b/include/linux/resource.h
index 5bc3116e649c..277afdad6589 100644
--- a/include/linux/resource.h
+++ b/include/linux/resource.h
@@ -6,7 +6,7 @@
 
 struct task_struct;
 
-int getrusage(struct task_struct *p, int who, struct rusage __user *ru);
+void getrusage(struct task_struct *p, int who, struct rusage *ru);
 int do_prlimit(struct task_struct *tsk, unsigned int resource,
 		struct rlimit *new_rlim, struct rlimit *old_rlim);
 
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index f0f065c5afcf..c97e5f096927 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -9,6 +9,7 @@
 #include <linux/sched.h>
 
 struct task_struct;
+struct rusage;
 union thread_union;
 
 /*
@@ -74,6 +75,7 @@ extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *,
 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
 struct task_struct *fork_idle(int);
 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
+extern long kernel_wait4(pid_t, int *, int, struct rusage *);
 
 extern void free_task(struct task_struct *tsk);
 
diff --git a/kernel/compat.c b/kernel/compat.c
index ebd8bdc3fd68..9ce1d4876e60 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -396,72 +396,6 @@ int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
 	return 0;
 }
 
-COMPAT_SYSCALL_DEFINE4(wait4,
-	compat_pid_t, pid,
-	compat_uint_t __user *, stat_addr,
-	int, options,
-	struct compat_rusage __user *, ru)
-{
-	if (!ru) {
-		return sys_wait4(pid, stat_addr, options, NULL);
-	} else {
-		struct rusage r;
-		int ret;
-		unsigned int status;
-		mm_segment_t old_fs = get_fs();
-
-		set_fs (KERNEL_DS);
-		ret = sys_wait4(pid,
-				(stat_addr ?
-				 (unsigned int __user *) &status : NULL),
-				options, (struct rusage __user *) &r);
-		set_fs (old_fs);
-
-		if (ret > 0) {
-			if (put_compat_rusage(&r, ru))
-				return -EFAULT;
-			if (stat_addr && put_user(status, stat_addr))
-				return -EFAULT;
-		}
-		return ret;
-	}
-}
-
-COMPAT_SYSCALL_DEFINE5(waitid,
-		int, which, compat_pid_t, pid,
-		struct compat_siginfo __user *, uinfo, int, options,
-		struct compat_rusage __user *, uru)
-{
-	siginfo_t info;
-	struct rusage ru;
-	long ret;
-	mm_segment_t old_fs = get_fs();
-
-	memset(&info, 0, sizeof(info));
-
-	set_fs(KERNEL_DS);
-	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
-			 uru ? (struct rusage __user *)&ru : NULL);
-	set_fs(old_fs);
-
-	if ((ret < 0) || (info.si_signo == 0))
-		return ret;
-
-	if (uru) {
-		/* sys_waitid() overwrites everything in ru */
-		if (COMPAT_USE_64BIT_TIME)
-			ret = copy_to_user(uru, &ru, sizeof(ru));
-		else
-			ret = put_compat_rusage(&ru, uru);
-		if (ret)
-			return -EFAULT;
-	}
-
-	BUG_ON(info.si_code & __SI_MASK);
-	info.si_code |= __SI_CHLD;
-	return copy_siginfo_to_user32(uinfo, &info);
-}
-
 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
 				    unsigned len, struct cpumask *new_mask)
 {
diff --git a/kernel/exit.c b/kernel/exit.c
index c63226283aef..b0cc86a2d00b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -62,6 +62,7 @@
 #include <linux/kcov.h>
 #include <linux/random.h>
 #include <linux/rcuwait.h>
+#include <linux/compat.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -982,14 +983,21 @@ SYSCALL_DEFINE1(exit_group, int, error_code)
 	return 0;
 }
 
+struct waitid_info {
+	pid_t pid;
+	uid_t uid;
+	int status;
+	int cause;
+};
+
 struct wait_opts {
 	enum pid_type		wo_type;
 	int			wo_flags;
 	struct pid		*wo_pid;
 
-	struct siginfo __user	*wo_info;
-	int __user		*wo_stat;
-	struct rusage __user	*wo_rusage;
+	struct waitid_info	*wo_info;
+	int			wo_stat;
+	struct rusage		*wo_rusage;
 
 	wait_queue_entry_t		child_wait;
 	int			notask_error;
@@ -1036,34 +1044,6 @@ eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
 	return 1;
 }
 
-static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
-				pid_t pid, uid_t uid, int why, int status)
-{
-	struct siginfo __user *infop;
-	int retval = wo->wo_rusage
-		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
-
-	put_task_struct(p);
-	infop = wo->wo_info;
-	if (infop) {
-		if (!retval)
-			retval = put_user(SIGCHLD, &infop->si_signo);
-		if (!retval)
-			retval = put_user(0, &infop->si_errno);
-		if (!retval)
-			retval = put_user((short)why, &infop->si_code);
-		if (!retval)
-			retval = put_user(pid, &infop->si_pid);
-		if (!retval)
-			retval = put_user(uid, &infop->si_uid);
-		if (!retval)
-			retval = put_user(status, &infop->si_status);
-	}
-	if (!retval)
-		retval = pid;
-	return retval;
-}
-
 /*
  * Handle sys_wait4 work for one task in state EXIT_ZOMBIE.  We hold
  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
@@ -1072,30 +1052,23 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
  */
 static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 {
-	int state, retval, status;
+	int state, status;
 	pid_t pid = task_pid_vnr(p);
 	uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
-	struct siginfo __user *infop;
+	struct waitid_info *infop;
 
 	if (!likely(wo->wo_flags & WEXITED))
 		return 0;
 
 	if (unlikely(wo->wo_flags & WNOWAIT)) {
-		int exit_code = p->exit_code;
-		int why;
-
+		status = p->exit_code;
 		get_task_struct(p);
 		read_unlock(&tasklist_lock);
 		sched_annotate_sleep();
-
-		if ((exit_code & 0x7f) == 0) {
-			why = CLD_EXITED;
-			status = exit_code >> 8;
-		} else {
-			why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
-			status = exit_code & 0x7f;
-		}
-		return wait_noreap_copyout(wo, p, pid, uid, why, status);
+		if (wo->wo_rusage)
+			getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+		put_task_struct(p);
+		goto out_info;
 	}
 	/*
 	 * Move the task's state to DEAD/TRACE, only one thread can do this.
@@ -1168,38 +1141,11 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 		spin_unlock_irq(&current->sighand->siglock);
 	}
 
-	retval = wo->wo_rusage
-		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
+	if (wo->wo_rusage)
+		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
 	status = (p->signal->flags & SIGNAL_GROUP_EXIT)
 		? p->signal->group_exit_code : p->exit_code;
-	if (!retval && wo->wo_stat)
-		retval = put_user(status, wo->wo_stat);
-
-	infop = wo->wo_info;
-	if (!retval && infop)
-		retval = put_user(SIGCHLD, &infop->si_signo);
-	if (!retval && infop)
-		retval = put_user(0, &infop->si_errno);
-	if (!retval && infop) {
-		int why;
-
-		if ((status & 0x7f) == 0) {
-			why = CLD_EXITED;
-			status >>= 8;
-		} else {
-			why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
-			status &= 0x7f;
-		}
-		retval = put_user((short)why, &infop->si_code);
-		if (!retval)
-			retval = put_user(status, &infop->si_status);
-	}
-	if (!retval && infop)
-		retval = put_user(pid, &infop->si_pid);
-	if (!retval && infop)
-		retval = put_user(uid, &infop->si_uid);
-	if (!retval)
-		retval = pid;
+	wo->wo_stat = status;
 
 	if (state == EXIT_TRACE) {
 		write_lock_irq(&tasklist_lock);
@@ -1216,7 +1162,21 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 	if (state == EXIT_DEAD)
 		release_task(p);
 
-	return retval;
+out_info:
+	infop = wo->wo_info;
+	if (infop) {
+		if ((status & 0x7f) == 0) {
+			infop->cause = CLD_EXITED;
+			infop->status = status >> 8;
+		} else {
+			infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+			infop->status = status & 0x7f;
+		}
+		infop->pid = pid;
+		infop->uid = uid;
+	}
+
+	return pid;
 }
 
 static int *task_stopped_code(struct task_struct *p, bool ptrace)
@@ -1252,8 +1212,8 @@ static int *task_stopped_code(struct task_struct *p, bool ptrace)
 static int wait_task_stopped(struct wait_opts *wo,
 				int ptrace, struct task_struct *p)
 {
-	struct siginfo __user *infop;
-	int retval, exit_code, *p_code, why;
+	struct waitid_info *infop;
+	int exit_code, *p_code, why;
 	uid_t uid = 0; /* unneeded, required by compiler */
 	pid_t pid;
 
@@ -1298,34 +1258,21 @@ unlock_sig:
 	why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
 	read_unlock(&tasklist_lock);
 	sched_annotate_sleep();
+	if (wo->wo_rusage)
+		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+	put_task_struct(p);
 
-	if (unlikely(wo->wo_flags & WNOWAIT))
-		return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);
-
-	retval = wo->wo_rusage
-		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
-	if (!retval && wo->wo_stat)
-		retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
+	if (likely(!(wo->wo_flags & WNOWAIT)))
+		wo->wo_stat = (exit_code << 8) | 0x7f;
 
 	infop = wo->wo_info;
-	if (!retval && infop)
-		retval = put_user(SIGCHLD, &infop->si_signo);
-	if (!retval && infop)
-		retval = put_user(0, &infop->si_errno);
-	if (!retval && infop)
-		retval = put_user((short)why, &infop->si_code);
-	if (!retval && infop)
-		retval = put_user(exit_code, &infop->si_status);
-	if (!retval && infop)
-		retval = put_user(pid, &infop->si_pid);
-	if (!retval && infop)
-		retval = put_user(uid, &infop->si_uid);
-	if (!retval)
-		retval = pid;
-	put_task_struct(p);
-
-	BUG_ON(!retval);
-	return retval;
+	if (infop) {
+		infop->cause = why;
+		infop->status = exit_code;
+		infop->pid = pid;
+		infop->uid = uid;
+	}
+	return pid;
 }
 
 /*
@@ -1336,7 +1283,7 @@ unlock_sig:
  */
 static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
 {
-	int retval;
+	struct waitid_info *infop;
 	pid_t pid;
 	uid_t uid;
 
@@ -1361,22 +1308,20 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
 	get_task_struct(p);
 	read_unlock(&tasklist_lock);
 	sched_annotate_sleep();
+	if (wo->wo_rusage)
+		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+	put_task_struct(p);
 
-	if (!wo->wo_info) {
-		retval = wo->wo_rusage
-			? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
-		put_task_struct(p);
-		if (!retval && wo->wo_stat)
-			retval = put_user(0xffff, wo->wo_stat);
-		if (!retval)
-			retval = pid;
+	infop = wo->wo_info;
+	if (!infop) {
+		wo->wo_stat = 0xffff;
 	} else {
-		retval = wait_noreap_copyout(wo, p, pid, uid,
-					     CLD_CONTINUED, SIGCONT);
-		BUG_ON(retval == 0);
+		infop->cause = CLD_CONTINUED;
+		infop->pid = pid;
+		infop->uid = uid;
+		infop->status = SIGCONT;
 	}
-
-	return retval;
+	return pid;
 }
 
 /*
@@ -1604,8 +1549,8 @@ end:
 	return retval;
 }
 
-SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
-		infop, int, options, struct rusage __user *, ru)
+static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
+			  int options, struct rusage *ru)
 {
 	struct wait_opts wo;
 	struct pid *pid = NULL;
@@ -1643,38 +1588,46 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
 	wo.wo_pid	= pid;
 	wo.wo_flags	= options;
 	wo.wo_info	= infop;
-	wo.wo_stat	= NULL;
 	wo.wo_rusage	= ru;
 	ret = do_wait(&wo);
 
-	if (ret > 0) {
+	if (ret > 0)
 		ret = 0;
-	} else if (infop) {
-		/*
-		 * For a WNOHANG return, clear out all the fields
-		 * we would set so the user can easily tell the
-		 * difference.
-		 */
-		if (!ret)
-			ret = put_user(0, &infop->si_signo);
-		if (!ret)
-			ret = put_user(0, &infop->si_errno);
-		if (!ret)
-			ret = put_user(0, &infop->si_code);
-		if (!ret)
-			ret = put_user(0, &infop->si_pid);
-		if (!ret)
-			ret = put_user(0, &infop->si_uid);
-		if (!ret)
-			ret = put_user(0, &infop->si_status);
-	}
 
 	put_pid(pid);
 	return ret;
 }
 
-SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
-		int, options, struct rusage __user *, ru)
+SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
+		infop, int, options, struct rusage __user *, ru)
+{
+	struct rusage r;
+	struct waitid_info info = {.status = 0};
+	long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
+
+	if (!err) {
+		if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
+			return -EFAULT;
+	}
+	if (!infop)
+		return err;
+
+	user_access_begin();
+	unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+	unsafe_put_user(0, &infop->si_errno, Efault);
+	unsafe_put_user((short)info.cause, &infop->si_code, Efault);
+	unsafe_put_user(info.pid, &infop->si_pid, Efault);
+	unsafe_put_user(info.uid, &infop->si_uid, Efault);
+	unsafe_put_user(info.status, &infop->si_status, Efault);
+	user_access_end();
+	return err;
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+
+long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
+		  struct rusage *ru)
 {
 	struct wait_opts wo;
 	struct pid *pid = NULL;
@@ -1702,14 +1655,29 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
 	wo.wo_pid	= pid;
 	wo.wo_flags	= options | WEXITED;
 	wo.wo_info	= NULL;
-	wo.wo_stat	= stat_addr;
+	wo.wo_stat	= 0;
 	wo.wo_rusage	= ru;
 	ret = do_wait(&wo);
 	put_pid(pid);
+	if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
+		ret = -EFAULT;
 
 	return ret;
 }
 
+SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
+		int, options, struct rusage __user *, ru)
+{
+	struct rusage r;
+	long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
+
+	if (err > 0) {
+		if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
+			return -EFAULT;
+	}
+	return err;
+}
+
 #ifdef __ARCH_WANT_SYS_WAITPID
 
 /*
@@ -1722,3 +1690,56 @@ SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
 }
 
 #endif
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(wait4,
+	compat_pid_t, pid,
+	compat_uint_t __user *, stat_addr,
+	int, options,
+	struct compat_rusage __user *, ru)
+{
+	struct rusage r;
+	long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
+	if (err > 0) {
+		if (ru && put_compat_rusage(&r, ru))
+			return -EFAULT;
+	}
+	return err;
+}
+
+COMPAT_SYSCALL_DEFINE5(waitid,
+		int, which, compat_pid_t, pid,
+		struct compat_siginfo __user *, infop, int, options,
+		struct compat_rusage __user *, uru)
+{
+	struct rusage ru;
+	struct waitid_info info = {.status = 0};
+	long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
+
+	if (!err && uru) {
+		/* kernel_waitid() overwrites everything in ru */
+		if (COMPAT_USE_64BIT_TIME)
+			err = copy_to_user(uru, &ru, sizeof(ru));
+		else
+			err = put_compat_rusage(&ru, uru);
+		if (err)
+			return -EFAULT;
+	}
+
+	if (!infop)
+		return err;
+
+	user_access_begin();
+	unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+	unsafe_put_user(0, &infop->si_errno, Efault);
+	unsafe_put_user((short)info.cause, &infop->si_code, Efault);
+	unsafe_put_user(info.pid, &infop->si_pid, Efault);
+	unsafe_put_user(info.uid, &infop->si_uid, Efault);
+	unsafe_put_user(info.status, &infop->si_status, Efault);
+	user_access_end();
+	return err;
+Efault:
+	user_access_end();
+	return -EFAULT;
+}
+#endif
diff --git a/kernel/sys.c b/kernel/sys.c
index 8a94b4eabcaa..dab1a0658a92 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1552,7 +1552,7 @@ static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
 	r->ru_oublock += task_io_get_oublock(t);
 }
 
-static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
+void getrusage(struct task_struct *p, int who, struct rusage *r)
 {
 	struct task_struct *t;
 	unsigned long flags;
@@ -1626,20 +1626,16 @@ out:
 	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
 }
 
-int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
+SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
 {
 	struct rusage r;
 
-	k_getrusage(p, who, &r);
-	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
-}
-
-SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
-{
 	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
 	    who != RUSAGE_THREAD)
 		return -EINVAL;
-	return getrusage(current, who, ru);
+
+	getrusage(current, who, &r);
+	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
 }
 
 #ifdef CONFIG_COMPAT
@@ -1651,7 +1647,7 @@ COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
 	    who != RUSAGE_THREAD)
 		return -EINVAL;
 
-	k_getrusage(current, who, &r);
+	getrusage(current, who, &r);
 	return put_compat_rusage(&r, ru);
 }
 #endif