Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull compat and uaccess updates from Al Viro:

 - {get,put}_compat_sigset() series

 - assorted compat ioctl stuff

 - more set_fs() elimination

 - a few more timespec64 conversions

 - several removals of pointless access_ok() in places where it was
   followed only by non-__ variants of primitives

* 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits)
  coredump: call do_unlinkat directly instead of sys_unlink
  fs: expose do_unlinkat for built-in callers
  ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs()
  ipmi: get rid of pointless access_ok()
  pi433: sanitize ioctl
  cxlflash: get rid of pointless access_ok()
  mtdchar: get rid of pointless access_ok()
  r128: switch compat ioctls to drm_ioctl_kernel()
  selection: get rid of field-by-field copyin
  VT_RESIZEX: get rid of field-by-field copyin
  i2c compat ioctls: move to ->compat_ioctl()
  sched_rr_get_interval(): move compat to native, get rid of set_fs()
  mips: switch to {get,put}_compat_sigset()
  sparc: switch to {get,put}_compat_sigset()
  s390: switch to {get,put}_compat_sigset()
  ppc: switch to {get,put}_compat_sigset()
  parisc: switch to {get,put}_compat_sigset()
  get_compat_sigset()
  get rid of {get,put}_compat_itimerspec()
  io_getevents: Use timespec64 to represent timeouts
  ...

3 files changed, 83 insertions, 107 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index 772e038d04d9..d1cee656a7ed 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -367,24 +367,6 @@ COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
 	return ret;
 }
 
-int get_compat_itimerspec(struct itimerspec *dst,
-			  const struct compat_itimerspec __user *src)
-{
-	if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
-	    __compat_get_timespec(&dst->it_value, &src->it_value))
-		return -EFAULT;
-	return 0;
-}
-
-int put_compat_itimerspec(struct compat_itimerspec __user *dst,
-			  const struct itimerspec *src)
-{
-	if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
-	    __compat_put_timespec(&src->it_value, &dst->it_value))
-		return -EFAULT;
-	return 0;
-}
-
 int get_compat_itimerspec64(struct itimerspec64 *its,
 			const struct compat_itimerspec __user *uits)
 {
@@ -485,27 +467,44 @@ Efault:
 	return -EFAULT;
 }
 
-void
-sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
+int
+get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
 {
+#ifdef __BIG_ENDIAN
+	compat_sigset_t v;
+	if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
+		return -EFAULT;
 	switch (_NSIG_WORDS) {
-	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
-	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
-	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
-	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
+	case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
+	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
+	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
+	case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
 	}
+#else
+	if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
+		return -EFAULT;
+#endif
+	return 0;
 }
-EXPORT_SYMBOL_GPL(sigset_from_compat);
+EXPORT_SYMBOL_GPL(get_compat_sigset);
 
-void
-sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
+int
+put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
+		  unsigned int size)
 {
+	/* size <= sizeof(compat_sigset_t) <= sizeof(sigset_t) */
+#ifdef __BIG_ENDIAN
+	compat_sigset_t v;
 	switch (_NSIG_WORDS) {
-	case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
-	case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
-	case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
-	case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
+	case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
+	case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
+	case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
+	case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
 	}
+	return copy_to_user(compat, &v, size) ? -EFAULT : 0;
+#else
+	return copy_to_user(compat, set, size) ? -EFAULT : 0;
+#endif
 }
 
 #ifdef CONFIG_NUMA
@@ -563,22 +562,6 @@ COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
 }
 #endif
 
-COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
-		       compat_pid_t, pid,
-		       struct compat_timespec __user *, interval)
-{
-	struct timespec t;
-	int ret;
-	mm_segment_t old_fs = get_fs();
-
-	set_fs(KERNEL_DS);
-	ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
-	set_fs(old_fs);
-	if (compat_put_timespec(&t, interval))
-		return -EFAULT;
-	return ret;
-}
-
 /*
  * Allocate user-space memory for the duration of a single system call,
  * in order to marshall parameters inside a compat thunk.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a092f350f3a2..75554f366fd3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -16,6 +16,7 @@
 #include <linux/init_task.h>
 #include <linux/context_tracking.h>
 #include <linux/rcupdate_wait.h>
+#include <linux/compat.h>
 
 #include <linux/blkdev.h>
 #include <linux/kprobes.h>
@@ -5107,13 +5108,11 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
  * Return: On success, 0 and the timeslice is in @interval. Otherwise,
  * an error code.
  */
-SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
-		struct timespec __user *, interval)
+static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
 {
 	struct task_struct *p;
 	unsigned int time_slice;
 	struct rq_flags rf;
-	struct timespec t;
 	struct rq *rq;
 	int retval;
 
@@ -5137,15 +5136,40 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
 	task_rq_unlock(rq, p, &rf);
 
 	rcu_read_unlock();
-	jiffies_to_timespec(time_slice, &t);
-	retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
-	return retval;
+	jiffies_to_timespec64(time_slice, t);
+	return 0;
 
 out_unlock:
 	rcu_read_unlock();
 	return retval;
 }
 
+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+		struct timespec __user *, interval)
+{
+	struct timespec64 t;
+	int retval = sched_rr_get_interval(pid, &t);
+
+	if (retval == 0)
+		retval = put_timespec64(&t, interval);
+
+	return retval;
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
+		       compat_pid_t, pid,
+		       struct compat_timespec __user *, interval)
+{
+	struct timespec64 t;
+	int retval = sched_rr_get_interval(pid, &t);
+
+	if (retval == 0)
+		retval = compat_put_timespec64(&t, interval);
+	return retval;
+}
+#endif
+
 void sched_show_task(struct task_struct *p)
 {
 	unsigned long free = 0;
diff --git a/kernel/signal.c b/kernel/signal.c
index aa1fb9f905db..babb36d3d039 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2599,7 +2599,6 @@ SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
 COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
 		compat_sigset_t __user *, oset, compat_size_t, sigsetsize)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t old_set = current->blocked;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
@@ -2607,38 +2606,22 @@ COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
 		return -EINVAL;
 
 	if (nset) {
-		compat_sigset_t new32;
 		sigset_t new_set;
 		int error;
-		if (copy_from_user(&new32, nset, sizeof(compat_sigset_t)))
+		if (get_compat_sigset(&new_set, nset))
 			return -EFAULT;
-
-		sigset_from_compat(&new_set, &new32);
 		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
 
 		error = sigprocmask(how, &new_set, NULL);
 		if (error)
 			return error;
 	}
-	if (oset) {
-		compat_sigset_t old32;
-		sigset_to_compat(&old32, &old_set);
-		if (copy_to_user(oset, &old32, sizeof(compat_sigset_t)))
-			return -EFAULT;
-	}
-	return 0;
-#else
-	return sys_rt_sigprocmask(how, (sigset_t __user *)nset,
-				  (sigset_t __user *)oset, sigsetsize);
-#endif
+	return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0;
 }
 #endif
 
-static int do_sigpending(void *set, unsigned long sigsetsize)
+static int do_sigpending(sigset_t *set)
 {
-	if (sigsetsize > sizeof(sigset_t))
-		return -EINVAL;
-
 	spin_lock_irq(&current->sighand->siglock);
 	sigorsets(set, &current->pending.signal,
 		  &current->signal->shared_pending.signal);
@@ -2658,7 +2641,12 @@ static int do_sigpending(void *set, unsigned long sigsetsize)
 SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize)
 {
 	sigset_t set;
-	int err = do_sigpending(&set, sigsetsize);
+	int err;
+
+	if (sigsetsize > sizeof(*uset))
+		return -EINVAL;
+
+	err = do_sigpending(&set);
 	if (!err && copy_to_user(uset, &set, sigsetsize))
 		err = -EFAULT;
 	return err;
@@ -2668,20 +2656,16 @@ SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize)
 COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset,
 		compat_size_t, sigsetsize)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t set;
-	int err = do_sigpending(&set, sigsetsize);
-	if (!err) {
-		compat_sigset_t set32;
-		sigset_to_compat(&set32, &set);
-		/* we can get here only if sigsetsize <= sizeof(set) */
-		if (copy_to_user(uset, &set32, sigsetsize))
-			err = -EFAULT;
-	}
+	int err;
+
+	if (sigsetsize > sizeof(*uset))
+		return -EINVAL;
+
+	err = do_sigpending(&set);
+	if (!err)
+		err = put_compat_sigset(uset, &set, sigsetsize);
 	return err;
-#else
-	return sys_rt_sigpending((sigset_t __user *)uset, sigsetsize);
-#endif
 }
 #endif
 
@@ -2915,7 +2899,6 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
 		struct compat_siginfo __user *, uinfo,
 		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
 {
-	compat_sigset_t s32;
 	sigset_t s;
 	struct timespec t;
 	siginfo_t info;
@@ -2924,9 +2907,8 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
 	if (sigsetsize != sizeof(sigset_t))
 		return -EINVAL;
 
-	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
+	if (get_compat_sigset(&s, uthese))
 		return -EFAULT;
-	sigset_from_compat(&s, &s32);
 
 	if (uts) {
 		if (compat_get_timespec(&t, uts))
@@ -3344,15 +3326,11 @@ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t set;
-	int err = do_sigpending(&set, sizeof(set.sig[0]));
+	int err = do_sigpending(&set);
 	if (!err)
 		err = put_user(set.sig[0], set32);
 	return err;
-#else
-	return sys_rt_sigpending((sigset_t __user *)set32, sizeof(*set32));
-#endif
 }
 #endif
 
@@ -3450,7 +3428,6 @@ COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig,
 		compat_size_t, sigsetsize)
 {
 	struct k_sigaction new_ka, old_ka;
-	compat_sigset_t mask;
 #ifdef __ARCH_HAS_SA_RESTORER
 	compat_uptr_t restorer;
 #endif
@@ -3468,19 +3445,18 @@ COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig,
 		ret |= get_user(restorer, &act->sa_restorer);
 		new_ka.sa.sa_restorer = compat_ptr(restorer);
 #endif
-		ret |= copy_from_user(&mask, &act->sa_mask, sizeof(mask));
+		ret |= get_compat_sigset(&new_ka.sa.sa_mask, &act->sa_mask);
 		ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags);
 		if (ret)
 			return -EFAULT;
-		sigset_from_compat(&new_ka.sa.sa_mask, &mask);
 	}
 
 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 	if (!ret && oact) {
-		sigset_to_compat(&mask, &old_ka.sa.sa_mask);
 		ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), 
 			       &oact->sa_handler);
-		ret |= copy_to_user(&oact->sa_mask, &mask, sizeof(mask));
+		ret |= put_compat_sigset(&oact->sa_mask, &old_ka.sa.sa_mask,
+					 sizeof(oact->sa_mask));
 		ret |= put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 #ifdef __ARCH_HAS_SA_RESTORER
 		ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer),
@@ -3660,22 +3636,15 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize)
 {
-#ifdef __BIG_ENDIAN
 	sigset_t newset;
-	compat_sigset_t newset32;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
 	if (sigsetsize != sizeof(sigset_t))
 		return -EINVAL;
 
-	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
+	if (get_compat_sigset(&newset, unewset))
 		return -EFAULT;
-	sigset_from_compat(&newset, &newset32);
 	return sigsuspend(&newset);
-#else
-	/* on little-endian bitmaps don't care about granularity */
-	return sys_rt_sigsuspend((sigset_t __user *)unewset, sigsetsize);
-#endif
 }
 #endif