uaccess: fix type mismatch warnings from access_ok()

On some architectures, access_ok() does not do any argument type
checking, so replacing the definition with a generic one causes
a few warnings for harmless issues that were never caught before.

Fix the ones that I found either through my own test builds or
that were reported by the 0-day bot.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arc/kernel/process.c

@@ -43,7 +43,7 @@ SYSCALL_DEFINE0(arc_gettls)
 	return task_thread_info(current)->thr_ptr;
 }
 
-SYSCALL_DEFINE3(arc_usr_cmpxchg, int *, uaddr, int, expected, int, new)
+SYSCALL_DEFINE3(arc_usr_cmpxchg, int __user *, uaddr, int, expected, int, new)
 {
 	struct pt_regs *regs = current_pt_regs();
 	u32 uval;

arch/arm/kernel/swp_emulate.c

@@ -195,7 +195,7 @@ 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((address & ~3), 4)) {
+	if (!access_ok((void __user *)(address & ~3), 4)) {
 		pr_debug("SWP{B} emulation: access to %p not allowed!\n",
 			 (void *)address);
 		res = -EFAULT;

arch/arm/kernel/traps.c

@@ -576,7 +576,7 @@ do_cache_op(unsigned long start, unsigned long end, int flags)
 	if (end < start || flags)
 		return -EINVAL;
 
-	if (!access_ok(start, end - start))
+	if (!access_ok((void __user *)start, end - start))
 		return -EFAULT;
 
 	return __do_cache_op(start, end);

arch/csky/kernel/perf_callchain.c

@@ -49,7 +49,7 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry,
 {
 	struct stackframe buftail;
 	unsigned long lr = 0;
-	unsigned long *user_frame_tail = (unsigned long *)fp;
+	unsigned long __user *user_frame_tail = (unsigned long __user *)fp;
 
 	/* Check accessibility of one struct frame_tail beyond */
 	if (!access_ok(user_frame_tail, sizeof(buftail)))

arch/csky/kernel/signal.c

@@ -136,7 +136,7 @@ static inline void __user *get_sigframe(struct ksignal *ksig,
 static int
 setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 {
-	struct rt_sigframe *frame;
+	struct rt_sigframe __user *frame;
 	int err = 0;
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame));

arch/nios2/kernel/signal.c

@@ -36,10 +36,10 @@ struct rt_sigframe {
 
 static inline int rt_restore_ucontext(struct pt_regs *regs,
 					struct switch_stack *sw,
-					struct ucontext *uc, int *pr2)
+					struct ucontext __user *uc, int *pr2)
 {
 	int temp;
-	unsigned long *gregs = uc->uc_mcontext.gregs;
+	unsigned long __user *gregs = uc->uc_mcontext.gregs;
 	int err;
 
 	/* Always make any pending restarted system calls return -EINTR */
@@ -102,10 +102,11 @@ asmlinkage int do_rt_sigreturn(struct switch_stack *sw)
 {
 	struct pt_regs *regs = (struct pt_regs *)(sw + 1);
 	/* Verify, can we follow the stack back */
-	struct rt_sigframe *frame = (struct rt_sigframe *) regs->sp;
+	struct rt_sigframe __user *frame;
 	sigset_t set;
 	int rval;
 
+	frame = (struct rt_sigframe __user *) regs->sp;
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
@@ -124,10 +125,10 @@ asmlinkage int do_rt_sigreturn(struct switch_stack *sw)
 	return 0;
 }
 
-static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
+static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
 {
 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
-	unsigned long *gregs = uc->uc_mcontext.gregs;
+	unsigned long __user *gregs = uc->uc_mcontext.gregs;
 	int err = 0;
 
 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
@@ -162,8 +163,9 @@ static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
 	return err;
 }
 
-static inline void *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
-				 size_t frame_size)
+static inline void __user *get_sigframe(struct ksignal *ksig,
+					struct pt_regs *regs,
+					size_t frame_size)
 {
 	unsigned long usp;
 
@@ -174,13 +176,13 @@ static inline void *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	usp = sigsp(usp, ksig);
 
 	/* Verify, is it 32 or 64 bit aligned */
-	return (void *)((usp - frame_size) & -8UL);
+	return (void __user *)((usp - frame_size) & -8UL);
 }
 
 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 			  struct pt_regs *regs)
 {
-	struct rt_sigframe *frame;
+	struct rt_sigframe __user *frame;
 	int err = 0;
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame));

arch/powerpc/lib/sstep.c

@@ -112,9 +112,9 @@ static nokprobe_inline long address_ok(struct pt_regs *regs,
 {
 	if (!user_mode(regs))
 		return 1;
-	if (__access_ok(ea, nb))
+	if (access_ok((void __user *)ea, nb))
 		return 1;
-	if (__access_ok(ea, 1))
+	if (access_ok((void __user *)ea, 1))
 		/* Access overlaps the end of the user region */
 		regs->dar = TASK_SIZE_MAX - 1;
 	else

arch/riscv/kernel/perf_callchain.c

@@ -15,8 +15,8 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry,
 {
 	struct stackframe buftail;
 	unsigned long ra = 0;
-	unsigned long *user_frame_tail =
-			(unsigned long *)(fp - sizeof(struct stackframe));
+	unsigned long __user *user_frame_tail =
+		(unsigned long __user *)(fp - sizeof(struct stackframe));
 
 	/* Check accessibility of one struct frame_tail beyond */
 	if (!access_ok(user_frame_tail, sizeof(buftail)))

arch/sparc/kernel/signal_32.c

@@ -65,7 +65,7 @@ struct rt_signal_frame {
  */
 static inline bool invalid_frame_pointer(void __user *fp, int fplen)
 {
-	if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
+	if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen))
 		return true;
 
 	return false;

lib/test_lockup.c

@@ -417,8 +417,8 @@ static bool test_kernel_ptr(unsigned long addr, int size)
 		return false;
 
 	/* should be at least readable kernel address */
-	if (access_ok(ptr, 1) ||
-	    access_ok(ptr + size - 1, 1) ||
+	if (access_ok((void __user *)ptr, 1) ||
+	    access_ok((void __user *)ptr + size - 1, 1) ||
 	    get_kernel_nofault(buf, ptr) ||
 	    get_kernel_nofault(buf, ptr + size - 1)) {
 		pr_err("invalid kernel ptr: %#lx\n", addr);