2007-10-29 05:11:37

by Al Viro

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---
drivers/scsi/aacraid/commctrl.c | 12 ++++++------
drivers/scsi/aacraid/comminit.c | 2 +-
drivers/scsi/aacraid/dpcsup.c | 2 +-
drivers/spi/spidev.c | 6 +++---
include/linux/types.h | 2 ++
5 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
index 72b0393..1e6d7a9 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 3009ad8..8736813 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 fcd25f7..e6032ff 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 c55459c..b3518ca 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 4f0dad2..f4f8d19 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;
--
1.5.3.GIT