Subject: [PATCH v2 12/18] uaccess: fix type mismatch warnings from access_ok()

From: Arnd Bergmann <[email-masked]>
Date: Wed, 16 Feb 2022 14:13:26 +0100

From: Arnd Bergmann <[email-masked]>

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 <[email-masked]>
Signed-off-by: Arnd Bergmann <[email-masked]>
---
 arch/arc/kernel/process.c           |  2 +-
 arch/arm/kernel/swp_emulate.c       |  2 +-
 arch/arm/kernel/traps.c             |  2 +-
 arch/csky/kernel/signal.c           |  2 +-
 arch/mips/sibyte/common/sb_tbprof.c |  6 +++---
 arch/nios2/kernel/signal.c          | 20 +++++++++++---------
 arch/powerpc/lib/sstep.c            |  4 ++--
 arch/riscv/kernel/perf_callchain.c  |  2 +-
 arch/sparc/kernel/signal_32.c       |  2 +-
 lib/test_lockup.c                   |  4 ++--
 10 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 8e90052f6f05..5f7f5aab361f 100644
--- a/arch/arc/kernel/process.c
+++ b/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;
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index 6166ba38bf99..b74bfcf94fb1 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/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;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index da04ed85855a..26c8c8276297 100644
--- a/arch/arm/kernel/traps.c
+++ b/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);
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index c7b763d2f526..8867ddf3e6c7 100644
--- a/arch/csky/kernel/signal.c
+++ b/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));
diff --git a/arch/mips/sibyte/common/sb_tbprof.c b/arch/mips/sibyte/common/sb_tbprof.c
index f80d7a710333..01d00b87d0f5 100644
--- a/arch/mips/sibyte/common/sb_tbprof.c
+++ b/arch/mips/sibyte/common/sb_tbprof.c
@@ -437,13 +437,13 @@ static int sbprof_tb_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static ssize_t sbprof_tb_read(struct file *filp, char *buf,
+static ssize_t sbprof_tb_read(struct file *filp, char __user *buf,
 			      size_t size, loff_t *offp)
 {
 	int cur_sample, sample_off, cur_count, sample_left;
 	char *src;
 	int   count   =	 0;
-	char *dest    =	 buf;
+	char __user *dest = buf;
 	long  cur_off = *offp;
 
 	if (!access_ok(buf, size))
@@ -512,7 +512,7 @@ static long sbprof_tb_ioctl(struct file *filp,
 		if (err)
 			break;
 
-		err = put_user(TB_FULL, (int *) arg);
+		err = put_user(TB_FULL, (int __user *) arg);
 		break;
 	}
 
diff --git a/arch/nios2/kernel/signal.c b/arch/nios2/kernel/signal.c
index 2009ae2d3c3b..386e46443b60 100644
--- a/arch/nios2/kernel/signal.c
+++ b/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));
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index a94b0cd0bdc5..022d23ae300b 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/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
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index 1fc075b8f764..f0c7bb98119a 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -15,7 +15,7 @@ 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 __user *user_frame_tail =
 			(unsigned long *)(fp - sizeof(struct stackframe));
 
 	/* Check accessibility of one struct frame_tail beyond */
diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c
index ffab16369bea..74f80443b195 100644
--- a/arch/sparc/kernel/signal_32.c
+++ b/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;
diff --git a/lib/test_lockup.c b/lib/test_lockup.c
index 906b598740a7..6a0f329a794a 100644
--- a/lib/test_lockup.c
+++ b/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);
-- 
2.29.2