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, 8 insertions, 8 deletions

diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c
index 08e43a32a693..3b69a76d341e 100644
--- a/arch/arm/kernel/perf_callchain.c
+++ b/arch/arm/kernel/perf_callchain.c
@@ -37,7 +37,7 @@ user_backtrace(struct frame_tail __user *tail,
 	struct frame_tail buftail;
 	unsigned long err;
 
-	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+	if (!access_ok(tail, sizeof(buftail)))
 		return NULL;
 
 	pagefault_disable();
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index b908382b69ff..76bb8de6bf6b 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -241,7 +241,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)
 
 	frame = (struct sigframe __user *)regs->ARM_sp;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+	if (!access_ok(frame, sizeof (*frame)))
 		goto badframe;
 
 	if (restore_sigframe(regs, frame))
@@ -271,7 +271,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 
 	frame = (struct rt_sigframe __user *)regs->ARM_sp;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+	if (!access_ok(frame, sizeof (*frame)))
 		goto badframe;
 
 	if (restore_sigframe(regs, &frame->sig))
@@ -355,7 +355,7 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize)
 	/*
 	 * 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/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index a188d5e8ab7f..76f6e6a9736c 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -198,7 +198,7 @@ static int swp_handler(struct pt_regs *regs, unsigned int instr)
 		 destreg, EXTRACT_REG_NUM(instr, RT2_OFFSET), data);
 
 	/* Check access in reasonable access range for both SWP and SWPB */
-	if (!access_ok(VERIFY_WRITE, (address & ~3), 4)) {
+	if (!access_ok((address & ~3), 4)) {
 		pr_debug("SWP{B} emulation: access to %p not allowed!\n",
 			 (void *)address);
 		res = -EFAULT;
diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 40da0872170f..92ab36f38795 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -285,7 +285,7 @@ asmlinkage long sys_oabi_epoll_wait(int epfd,
 			maxevents > (INT_MAX/sizeof(*kbuf)) ||
 			maxevents > (INT_MAX/sizeof(*events)))
 		return -EINVAL;
-	if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents))
+	if (!access_ok(events, sizeof(*events) * maxevents))
 		return -EFAULT;
 	kbuf = kmalloc_array(maxevents, sizeof(*kbuf), GFP_KERNEL);
 	if (!kbuf)
@@ -326,7 +326,7 @@ asmlinkage long sys_oabi_semtimedop(int semid,
 
 	if (nsops < 1 || nsops > SEMOPM)
 		return -EINVAL;
-	if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops))
+	if (!access_ok(tsops, sizeof(*tsops) * nsops))
 		return -EFAULT;
 	sops = kmalloc_array(nsops, sizeof(*sops), GFP_KERNEL);
 	if (!sops)
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 2d668cff8ef4..33af097c454b 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -582,7 +582,7 @@ do_cache_op(unsigned long start, unsigned long end, int flags)
 	if (end < start || flags)
 		return -EINVAL;
 
-	if (!access_ok(VERIFY_READ, start, end - start))
+	if (!access_ok(start, end - start))
 		return -EFAULT;
 
 	return __do_cache_op(start, end);