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, 13 insertions, 16 deletions

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 6b2e63df2739..d82c78a79da5 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -35,7 +35,7 @@ static inline void set_fs(mm_segment_t fs)
 #define segment_eq(a, b) ((a).seg == (b).seg)
 #endif
 
-#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
+#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
 
 /*
  * The architecture should really override this if possible, at least
@@ -78,7 +78,7 @@ static inline int __access_ok(unsigned long addr, unsigned long size)
 ({								\
 	void __user *__p = (ptr);				\
 	might_fault();						\
-	access_ok(VERIFY_WRITE, __p, sizeof(*ptr)) ?		\
+	access_ok(__p, sizeof(*ptr)) ?		\
 		__put_user((x), ((__typeof__(*(ptr)) __user *)__p)) :	\
 		-EFAULT;					\
 })
@@ -140,7 +140,7 @@ extern int __put_user_bad(void) __attribute__((noreturn));
 ({								\
 	const void __user *__p = (ptr);				\
 	might_fault();						\
-	access_ok(VERIFY_READ, __p, sizeof(*ptr)) ?		\
+	access_ok(__p, sizeof(*ptr)) ?		\
 		__get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
 		((x) = (__typeof__(*(ptr)))0,-EFAULT);		\
 })
@@ -175,7 +175,7 @@ __strncpy_from_user(char *dst, const char __user *src, long count)
 static inline long
 strncpy_from_user(char *dst, const char __user *src, long count)
 {
-	if (!access_ok(VERIFY_READ, src, 1))
+	if (!access_ok(src, 1))
 		return -EFAULT;
 	return __strncpy_from_user(dst, src, count);
 }
@@ -196,7 +196,7 @@ strncpy_from_user(char *dst, const char __user *src, long count)
  */
 static inline long strnlen_user(const char __user *src, long n)
 {
-	if (!access_ok(VERIFY_READ, src, 1))
+	if (!access_ok(src, 1))
 		return 0;
 	return __strnlen_user(src, n);
 }
@@ -217,7 +217,7 @@ static inline __must_check unsigned long
 clear_user(void __user *to, unsigned long n)
 {
 	might_fault();
-	if (!access_ok(VERIFY_WRITE, to, n))
+	if (!access_ok(to, n))
 		return n;
 
 	return __clear_user(to, n);
diff --git a/include/linux/regset.h b/include/linux/regset.h
index 494cedaafdf2..a85c1707285c 100644
--- a/include/linux/regset.h
+++ b/include/linux/regset.h
@@ -376,7 +376,7 @@ static inline int copy_regset_to_user(struct task_struct *target,
 	if (!regset->get)
 		return -EOPNOTSUPP;
 
-	if (!access_ok(VERIFY_WRITE, data, size))
+	if (!access_ok(data, size))
 		return -EFAULT;
 
 	return regset->get(target, regset, offset, size, NULL, data);
@@ -402,7 +402,7 @@ static inline int copy_regset_from_user(struct task_struct *target,
 	if (!regset->set)
 		return -EOPNOTSUPP;
 
-	if (!access_ok(VERIFY_READ, data, size))
+	if (!access_ok(data, size))
 		return -EFAULT;
 
 	return regset->set(target, regset, offset, size, NULL, data);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index efe79c1cdd47..bf2523867a02 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -6,9 +6,6 @@
 #include <linux/thread_info.h>
 #include <linux/kasan-checks.h>
 
-#define VERIFY_READ 0
-#define VERIFY_WRITE 1
-
 #define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS)
 
 #include <asm/uaccess.h>
@@ -111,7 +108,7 @@ _copy_from_user(void *to, const void __user *from, unsigned long n)
 {
 	unsigned long res = n;
 	might_fault();
-	if (likely(access_ok(VERIFY_READ, from, n))) {
+	if (likely(access_ok(from, n))) {
 		kasan_check_write(to, n);
 		res = raw_copy_from_user(to, from, n);
 	}
@@ -129,7 +126,7 @@ static inline unsigned long
 _copy_to_user(void __user *to, const void *from, unsigned long n)
 {
 	might_fault();
-	if (access_ok(VERIFY_WRITE, to, n)) {
+	if (access_ok(to, n)) {
 		kasan_check_read(from, n);
 		n = raw_copy_to_user(to, from, n);
 	}
@@ -160,7 +157,7 @@ static __always_inline unsigned long __must_check
 copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
 	might_fault();
-	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
+	if (access_ok(to, n) && access_ok(from, n))
 		n = raw_copy_in_user(to, from, n);
 	return n;
 }
diff --git a/include/net/checksum.h b/include/net/checksum.h
index aef2b2bb6603..0f319e13be2c 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -30,7 +30,7 @@ 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)
@@ -46,7 +46,7 @@ static __inline__ __wsum csum_and_copy_to_user
 {
 	sum = csum_partial(src, len, sum);
 
-	if (access_ok(VERIFY_WRITE, dst, len)) {
+	if (access_ok(dst, len)) {
 		if (copy_to_user(dst, src, len) == 0)
 			return sum;
 	}