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>

3 files changed, 7 insertions, 13 deletions

diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h
index 3b19eba1bc8e..66641624d8a5 100644
--- a/arch/riscv/include/asm/futex.h
+++ b/arch/riscv/include/asm/futex.h
@@ -95,7 +95,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	u32 val;
 	uintptr_t tmp;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+	if (!access_ok(uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	__enable_user_access();
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index 8c3e3e3c8be1..637b896894fc 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -54,14 +54,8 @@ static inline void set_fs(mm_segment_t fs)
 #define user_addr_max()	(get_fs())
 
 
-#define VERIFY_READ	0
-#define VERIFY_WRITE	1
-
 /**
  * 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
  *
@@ -76,7 +70,7 @@ static inline void set_fs(mm_segment_t fs)
  * checks that the pointer is in the user space range - after calling
  * this function, memory access functions may still return -EFAULT.
  */
-#define access_ok(type, addr, size) ({					\
+#define access_ok(addr, size) ({					\
 	__chk_user_ptr(addr);						\
 	likely(__access_ok((unsigned long __force)(addr), (size)));	\
 })
@@ -258,7 +252,7 @@ do {								\
 ({								\
 	const __typeof__(*(ptr)) __user *__p = (ptr);		\
 	might_fault();						\
-	access_ok(VERIFY_READ, __p, sizeof(*__p)) ?		\
+	access_ok(__p, sizeof(*__p)) ?		\
 		__get_user((x), __p) :				\
 		((x) = 0, -EFAULT);				\
 })
@@ -386,7 +380,7 @@ do {								\
 ({								\
 	__typeof__(*(ptr)) __user *__p = (ptr);			\
 	might_fault();						\
-	access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ?		\
+	access_ok(__p, sizeof(*__p)) ?		\
 		__put_user((x), __p) :				\
 		-EFAULT;					\
 })
@@ -421,7 +415,7 @@ static inline
 unsigned long __must_check clear_user(void __user *to, unsigned long n)
 {
 	might_fault();
-	return access_ok(VERIFY_WRITE, to, n) ?
+	return access_ok(to, n) ?
 		__clear_user(to, n) : n;
 }
 
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index f9b5e7e352ef..837e1646091a 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -115,7 +115,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 
 	frame = (struct rt_sigframe __user *)regs->sp;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
@@ -187,7 +187,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	long err = 0;
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame));
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		return -EFAULT;
 
 	err |= copy_siginfo_to_user(&frame->info, &ksig->info);