s390/uaccess: remove pointless access_ok() checks

access_ok() always returns 'true' on s390. Therefore all calls
are quite pointless and can be removed.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/futex.h

@@ -16,9 +16,6 @@ static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
-		return -EFAULT;
-
 	pagefault_disable();
 	ret = uaccess.futex_atomic_op(op, uaddr, oparg, &oldval);
 	pagefault_enable();
@@ -40,9 +37,6 @@ static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 						u32 oldval, u32 newval)
 {
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
-		return -EFAULT;
-
 	return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval);
 }
 

arch/s390/include/asm/uaccess.h

@@ -252,9 +252,7 @@ static inline unsigned long __must_check
 copy_to_user(void __user *to, const void *from, unsigned long n)
 {
 	might_fault();
-	if (access_ok(VERIFY_WRITE, to, n))
-		n = __copy_to_user(to, from, n);
-	return n;
+	return __copy_to_user(to, from, n);
 }
 
 /**
@@ -315,11 +313,7 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
 		copy_from_user_overflow();
 		return n;
 	}
-	if (access_ok(VERIFY_READ, from, n))
-		n = __copy_from_user(to, from, n);
-	else
-		memset(to, 0, n);
-	return n;
+	return __copy_from_user(to, from, n);
 }
 
 static inline unsigned long __must_check
@@ -332,9 +326,7 @@ static inline unsigned long __must_check
 copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
 	might_fault();
-	if (__access_ok(from,n) && __access_ok(to,n))
-		n = __copy_in_user(to, from, n);
-	return n;
+	return __copy_in_user(to, from, n);
 }
 
 /*
@@ -343,11 +335,8 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
 static inline long __must_check
 strncpy_from_user(char *dst, const char __user *src, long count)
 {
-        long res = -EFAULT;
 	might_fault();
-        if (access_ok(VERIFY_READ, src, 1))
-		res = uaccess.strncpy_from_user(count, src, dst);
-        return res;
+	return uaccess.strncpy_from_user(count, src, dst);
 }
 
 static inline unsigned long
@@ -387,9 +376,7 @@ static inline unsigned long __must_check
 clear_user(void __user *to, unsigned long n)
 {
 	might_fault();
-	if (access_ok(VERIFY_WRITE, to, n))
-		n = uaccess.clear_user(n, to);
-	return n;
+	return uaccess.clear_user(n, to);
 }
 
 extern int copy_to_user_real(void __user *dest, void *src, size_t count);

arch/s390/kernel/compat_signal.c

@@ -53,9 +53,6 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
 {
 	int err;
 
-	if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
-		return -EFAULT;
-
 	/* If you change siginfo_t structure, please be sure
 	   this code is fixed accordingly.
 	   It should never copy any pad contained in the structure
@@ -110,9 +107,6 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 	int err;
 	u32 tmp;
 
-	if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
-		return -EFAULT;
-
 	err = __get_user(to->si_signo, &from->si_signo);
 	err |= __get_user(to->si_errno, &from->si_errno);
 	err |= __get_user(to->si_code, &from->si_code);
@@ -244,8 +238,6 @@ asmlinkage long sys32_sigreturn(void)
 	sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
 	sigset_t set;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
-		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
 		goto badframe;
 	set_current_blocked(&set);
@@ -265,8 +257,6 @@ asmlinkage long sys32_rt_sigreturn(void)
 	rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
 	sigset_t set;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
-		goto badframe;
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
 	set_current_blocked(&set);
@@ -325,8 +315,6 @@ static int setup_frame32(int sig, struct k_sigaction *ka,
 			sigset_t *set, struct pt_regs * regs)
 {
 	sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32)))
-		goto give_sigsegv;
 
 	if (frame == (void __user *) -1UL)
 		goto give_sigsegv;
@@ -391,8 +379,6 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 {
 	int err = 0;
 	rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32)))
-		goto give_sigsegv;
 
 	if (frame == (void __user *) -1UL)
 		goto give_sigsegv;

arch/s390/kernel/signal.c

@@ -116,8 +116,6 @@ SYSCALL_DEFINE0(sigreturn)
 	sigframe __user *frame = (sigframe __user *)regs->gprs[15];
 	sigset_t set;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
-		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
 		goto badframe;
 	set_current_blocked(&set);
@@ -135,8 +133,6 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
 	sigset_t set;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
-		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
 	set_current_blocked(&set);
@@ -195,8 +191,6 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 	sigframe __user *frame;
 
 	frame = get_sigframe(ka, regs, sizeof(sigframe));
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
-		goto give_sigsegv;
 
 	if (frame == (void __user *) -1UL)
 		goto give_sigsegv;
@@ -264,8 +258,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	rt_sigframe __user *frame;
 
 	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
-		goto give_sigsegv;
 
 	if (frame == (void __user *) -1UL)
 		goto give_sigsegv;