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path: root/drivers/infiniband/hw/ipath/ipath_diag.c
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Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_diag.c')
-rw-r--r--drivers/infiniband/hw/ipath/ipath_diag.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_diag.c b/drivers/infiniband/hw/ipath/ipath_diag.c
index 0f13a2182cc7..63e8368b0e95 100644
--- a/drivers/infiniband/hw/ipath/ipath_diag.c
+++ b/drivers/infiniband/hw/ipath/ipath_diag.c
@@ -296,7 +296,7 @@ static int ipath_diag_open(struct inode *in, struct file *fp)
}
fp->private_data = dd;
- ipath_diag_inuse = 1;
+ ipath_diag_inuse = -2;
diag_set_link = 0;
ret = 0;
@@ -461,6 +461,8 @@ static ssize_t ipath_diag_read(struct file *fp, char __user *data,
else if ((count % 4) || (*off % 4))
/* address or length is not 32-bit aligned, hence invalid */
ret = -EINVAL;
+ else if (ipath_diag_inuse < 1 && (*off || count != 8))
+ ret = -EINVAL; /* prevent cat /dev/ipath_diag* */
else if ((count % 8) || (*off % 8))
/* address or length not 64-bit aligned; do 32-bit reads */
ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
@@ -470,6 +472,8 @@ static ssize_t ipath_diag_read(struct file *fp, char __user *data,
if (ret >= 0) {
*off += count;
ret = count;
+ if (ipath_diag_inuse == -2)
+ ipath_diag_inuse++;
}
return ret;
@@ -489,6 +493,9 @@ static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
else if ((count % 4) || (*off % 4))
/* address or length is not 32-bit aligned, hence invalid */
ret = -EINVAL;
+ else if ((ipath_diag_inuse == -1 && (*off || count != 8)) ||
+ ipath_diag_inuse == -2) /* read qw off 0, write qw off 0 */
+ ret = -EINVAL; /* before any other write allowed */
else if ((count % 8) || (*off % 8))
/* address or length not 64-bit aligned; do 32-bit writes */
ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
@@ -498,6 +505,8 @@ static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
if (ret >= 0) {
*off += count;
ret = count;
+ if (ipath_diag_inuse == -1)
+ ipath_diag_inuse = 1; /* all read/write OK now */
}
return ret;