Remove 'type' argument from access_ok() function

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 9 insertions, 13 deletions

diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index e8161e4dfde7..dcebaaf8c862 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -63,7 +63,7 @@ static inline
 __wsum csum_and_copy_from_user(const void __user *src, void *dst,
 			       int len, __wsum sum, int *err_ptr)
 {
-	if (access_ok(VERIFY_READ, src, len))
+	if (access_ok(src, len))
 		return csum_partial_copy_from_user(src, dst, len, sum,
 						   err_ptr);
 	if (len)
@@ -81,7 +81,7 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
 			     __wsum sum, int *err_ptr)
 {
 	might_fault();
-	if (access_ok(VERIFY_WRITE, dst, len)) {
+	if (access_ok(dst, len)) {
 		if (uaccess_kernel())
 			return __csum_partial_copy_kernel(src,
 							  (__force void *)dst,
diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h
index 8eff134b3a43..c14d798f3888 100644
--- a/arch/mips/include/asm/futex.h
+++ b/arch/mips/include/asm/futex.h
@@ -129,7 +129,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	int ret = 0;
 	u32 val;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+	if (!access_ok(uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	if (cpu_has_llsc && R10000_LLSC_WAR) {
diff --git a/arch/mips/include/asm/termios.h b/arch/mips/include/asm/termios.h
index ce2d72e34274..bc29eeacc55a 100644
--- a/arch/mips/include/asm/termios.h
+++ b/arch/mips/include/asm/termios.h
@@ -32,7 +32,7 @@ static inline int user_termio_to_kernel_termios(struct ktermios *termios,
 	unsigned short iflag, oflag, cflag, lflag;
 	unsigned int err;
 
-	if (!access_ok(VERIFY_READ, termio, sizeof(struct termio)))
+	if (!access_ok(termio, sizeof(struct termio)))
 		return -EFAULT;
 
 	err = __get_user(iflag, &termio->c_iflag);
@@ -61,7 +61,7 @@ static inline int kernel_termios_to_user_termio(struct termio __user *termio,
 {
 	int err;
 
-	if (!access_ok(VERIFY_WRITE, termio, sizeof(struct termio)))
+	if (!access_ok(termio, sizeof(struct termio)))
 		return -EFAULT;
 
 	err = __put_user(termios->c_iflag, &termio->c_iflag);
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 06629011a434..d43c1dc6ef15 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -109,9 +109,6 @@ static inline bool eva_kernel_access(void)
 
 /*
  * access_ok: - Checks if a user space pointer is valid
- * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
- *	  %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
- *	  to write to a block, it is always safe to read from it.
  * @addr: User space pointer to start of block to check
  * @size: Size of block to check
  *
@@ -134,7 +131,7 @@ static inline int __access_ok(const void __user *p, unsigned long size)
 	return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
 }
 
-#define access_ok(type, addr, size)					\
+#define access_ok(addr, size)					\
 	likely(__access_ok((addr), (size)))
 
 /*
@@ -304,7 +301,7 @@ do {									\
 	const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);		\
 									\
 	might_fault();							\
-	if (likely(access_ok(VERIFY_READ,  __gu_ptr, size))) {		\
+	if (likely(access_ok( __gu_ptr, size))) {		\
 		if (eva_kernel_access())				\
 			__get_kernel_common((x), size, __gu_ptr);	\
 		else							\
@@ -446,7 +443,7 @@ do {									\
 	int __pu_err = -EFAULT;						\
 									\
 	might_fault();							\
-	if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {	\
+	if (likely(access_ok( __pu_addr, size))) {	\
 		if (eva_kernel_access())				\
 			__put_kernel_common(__pu_addr, size);		\
 		else							\
@@ -691,8 +688,7 @@ __clear_user(void __user *addr, __kernel_size_t size)
 ({									\
 	void __user * __cl_addr = (addr);				\
 	unsigned long __cl_size = (n);					\
-	if (__cl_size && access_ok(VERIFY_WRITE,			\
-					__cl_addr, __cl_size))		\
+	if (__cl_size && access_ok(__cl_addr, __cl_size))		\
 		__cl_size = __clear_user(__cl_addr, __cl_size);		\
 	__cl_size;							\
 })