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

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;
 }
 
 /*

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);
 

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);
 

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)
 {

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 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 	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