fix abuses of ptrdiff_t

Use of ptrdiff_t in places like

-                       if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+                       if (!access_ok(VERIFY_WRITE, (u8 __user *)
+                                               (ptrdiff_t) u_tmp->rx_buf,
+                                               u_tmp->len))

is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general
we are not even promised that ptrdiff_t is large enough to hold a pointer,
just enough to hold a difference between two pointers within the same object).
For another, it confuses the fsck out of sparse.

Use unsigned long or uintptr_t instead.  There are several places misusing
ptrdiff_t; fixed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 13 insertions, 11 deletions

diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
index 72b0393b4596..1e6d7a9c75bf 100644
--- a/drivers/scsi/aacraid/commctrl.c
+++ b/drivers/scsi/aacraid/commctrl.c
@@ -391,7 +391,7 @@ static int close_getadapter_fib(struct aac_dev * dev, void __user *arg)
                 /*
                  *      Extract the fibctx from the input parameters
                  */
-                if (fibctx->unique == (u32)(ptrdiff_t)arg) /* We found a winner */
+                if (fibctx->unique == (u32)(uintptr_t)arg) /* We found a winner */
                         break;
                 entry = entry->next;
                 fibctx = NULL;
@@ -590,7 +590,7 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
                                 }
                                 addr = (u64)upsg->sg[i].addr[0];
                                 addr += ((u64)upsg->sg[i].addr[1]) << 32;
-                                sg_user[i] = (void __user *)(ptrdiff_t)addr;
+                                sg_user[i] = (void __user *)(uintptr_t)addr;
                                 sg_list[i] = p; // save so we can clean up later
                                 sg_indx = i;
 
@@ -633,7 +633,7 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
                                         rcode = -ENOMEM;
                                         goto cleanup;
                                 }
-                                sg_user[i] = (void __user *)(ptrdiff_t)usg->sg[i].addr;
+                                sg_user[i] = (void __user *)(uintptr_t)usg->sg[i].addr;
                                 sg_list[i] = p; // save so we can clean up later
                                 sg_indx = i;
 
@@ -664,7 +664,7 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
                 if (actual_fibsize64 == fibsize) {
                         struct user_sgmap64* usg = (struct user_sgmap64 *)upsg;
                         for (i = 0; i < upsg->count; i++) {
-                                u64 addr;
+                                uintptr_t addr;
                                 void* p;
                                 /* Does this really need to be GFP_DMA? */
                                 p = kmalloc(usg->sg[i].count,GFP_KERNEL|__GFP_DMA);
@@ -676,7 +676,7 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
                                 }
                                 addr = (u64)usg->sg[i].addr[0];
                                 addr += ((u64)usg->sg[i].addr[1]) << 32;
-                                sg_user[i] = (void __user *)(ptrdiff_t)addr;
+                                sg_user[i] = (void __user *)addr;
                                 sg_list[i] = p; // save so we can clean up later
                                 sg_indx = i;
 
@@ -704,7 +704,7 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
                                         rcode = -ENOMEM;
                                         goto cleanup;
                                 }
-                                sg_user[i] = (void __user *)(ptrdiff_t)upsg->sg[i].addr;
+                                sg_user[i] = (void __user *)(uintptr_t)upsg->sg[i].addr;
                                 sg_list[i] = p; // save so we can clean up later
                                 sg_indx = i;
 
diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index 3009ad8c4073..8736813a0296 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -110,7 +110,7 @@ static int aac_alloc_comm(struct aac_dev *dev, void **commaddr, unsigned long co
         /*
          *      Align the beginning of Headers to commalign
          */
-        align = (commalign - ((ptrdiff_t)(base) & (commalign - 1)));
+        align = (commalign - ((uintptr_t)(base) & (commalign - 1)));
         base = base + align;
         phys = phys + align;
         /*
diff --git a/drivers/scsi/aacraid/dpcsup.c b/drivers/scsi/aacraid/dpcsup.c
index fcd25f7d0bc6..e6032ffc66a6 100644
--- a/drivers/scsi/aacraid/dpcsup.c
+++ b/drivers/scsi/aacraid/dpcsup.c
@@ -254,7 +254,7 @@ unsigned int aac_intr_normal(struct aac_dev * dev, u32 Index)
                         kfree (fib);
                         return 1;
                 }
-                memcpy(hw_fib, (struct hw_fib *)(((ptrdiff_t)(dev->regs.sa)) +
+                memcpy(hw_fib, (struct hw_fib *)(((uintptr_t)(dev->regs.sa)) +
                   (index & ~0x00000002L)), sizeof(struct hw_fib));
                 INIT_LIST_HEAD(&fib->fiblink);
                 fib->type = FSAFS_NTC_FIB_CONTEXT;
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index c55459c592b8..b3518ca9f04e 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -184,14 +184,14 @@ static int spidev_message(struct spidev_data *spidev,
                 if (u_tmp->rx_buf) {
                         k_tmp->rx_buf = buf;
                         if (!access_ok(VERIFY_WRITE, (u8 __user *)
-                                                (ptrdiff_t) u_tmp->rx_buf,
+                                                (uintptr_t) u_tmp->rx_buf,
                                                 u_tmp->len))
                                 goto done;
                 }
                 if (u_tmp->tx_buf) {
                         k_tmp->tx_buf = buf;
                         if (copy_from_user(buf, (const u8 __user *)
-                                                (ptrdiff_t) u_tmp->tx_buf,
+                                                (uintptr_t) u_tmp->tx_buf,
                                         u_tmp->len))
                                 goto done;
                 }
@@ -224,7 +224,7 @@ static int spidev_message(struct spidev_data *spidev,
         for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
                 if (u_tmp->rx_buf) {
                         if (__copy_to_user((u8 __user *)
-                                        (ptrdiff_t) u_tmp->rx_buf, buf,
+                                        (uintptr_t) u_tmp->rx_buf, buf,
                                         u_tmp->len)) {
                                 status = -EFAULT;
                                 goto done;
diff --git a/include/linux/types.h b/include/linux/types.h
index 4f0dad21c917..f4f8d19158e4 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -37,6 +37,8 @@ typedef __kernel_gid32_t	gid_t;
 typedef __kernel_uid16_t        uid16_t;
 typedef __kernel_gid16_t        gid16_t;
 
+typedef unsigned long           uintptr_t;
+
 #ifdef CONFIG_UID16
 /* This is defined by include/asm-{arch}/posix_types.h */
 typedef __kernel_old_uid_t      old_uid_t;