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>

5 files changed, 10 insertions, 10 deletions

diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 92be1d12d590..e52e7280884a 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -402,7 +402,7 @@ static int swp_handler(struct pt_regs *regs, u32 instr)
 
 	/* Check access in reasonable access range for both SWP and SWPB */
 	user_ptr = (const void __user *)(unsigned long)(address & ~3);
-	if (!access_ok(VERIFY_WRITE, user_ptr, 4)) {
+	if (!access_ok(user_ptr, 4)) {
 		pr_debug("SWP{B} emulation: access to 0x%08x not allowed!\n",
 			address);
 		goto fault;
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index a34c26afacb0..61d983f5756f 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -39,7 +39,7 @@ user_backtrace(struct frame_tail __user *tail,
 	unsigned long lr;
 
 	/* Also check accessibility of one struct frame_tail beyond */
-	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+	if (!access_ok(tail, sizeof(buftail)))
 		return NULL;
 
 	pagefault_disable();
@@ -86,7 +86,7 @@ compat_user_backtrace(struct compat_frame_tail __user *tail,
 	unsigned long err;
 
 	/* Also check accessibility of one struct frame_tail beyond */
-	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+	if (!access_ok(tail, sizeof(buftail)))
 		return NULL;
 
 	pagefault_disable();
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 5dcc942906db..867a7cea70e5 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -470,7 +470,7 @@ static int parse_user_sigframe(struct user_ctxs *user,
 			offset = 0;
 			limit = extra_size;
 
-			if (!access_ok(VERIFY_READ, base, limit))
+			if (!access_ok(base, limit))
 				goto invalid;
 
 			continue;
@@ -556,7 +556,7 @@ 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 (restore_sigframe(regs, frame))
@@ -730,7 +730,7 @@ static int get_sigframe(struct rt_sigframe_user_layout *user,
 	/*
 	 * Check that we can actually write to the signal frame.
 	 */
-	if (!access_ok(VERIFY_WRITE, user->sigframe, sp_top - sp))
+	if (!access_ok(user->sigframe, sp_top - sp))
 		return -EFAULT;
 
 	return 0;
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 24b09003f821..cb7800acd19f 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -303,7 +303,7 @@ COMPAT_SYSCALL_DEFINE0(sigreturn)
 
 	frame = (struct compat_sigframe __user *)regs->compat_sp;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+	if (!access_ok(frame, sizeof (*frame)))
 		goto badframe;
 
 	if (compat_restore_sigframe(regs, frame))
@@ -334,7 +334,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 
 	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+	if (!access_ok(frame, sizeof (*frame)))
 		goto badframe;
 
 	if (compat_restore_sigframe(regs, &frame->sig))
@@ -365,7 +365,7 @@ static void __user *compat_get_sigframe(struct ksignal *ksig,
 	/*
 	 * Check that we can actually write to the signal frame.
 	 */
-	if (!access_ok(VERIFY_WRITE, frame, framesize))
+	if (!access_ok(frame, framesize))
 		frame = NULL;
 
 	return frame;
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 32653d156747..21005dfe8406 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -58,7 +58,7 @@ do_compat_cache_op(unsigned long start, unsigned long end, int flags)
 	if (end < start || flags)
 		return -EINVAL;
 
-	if (!access_ok(VERIFY_READ, (const void __user *)start, end - start))
+	if (!access_ok((const void __user *)start, end - start))
 		return -EFAULT;
 
 	return __do_compat_cache_op(start, end);