1 files changed, 25 insertions, 41 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_diag.c b/drivers/infiniband/hw/ipath/ipath_diag.c
index 714293b78518..e2f9a51f4a38 100644
--- a/drivers/infiniband/hw/ipath/ipath_diag.c
+++ b/drivers/infiniband/hw/ipath/ipath_diag.c
@@ -326,7 +326,7 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
                                    size_t count, loff_t *off)
 {
         u32 __iomem *piobuf;
-        u32 plen, clen, pbufn;
+        u32 plen, pbufn, maxlen_reserve;
         struct ipath_diag_pkt odp;
         struct ipath_diag_xpkt dp;
         u32 *tmpbuf = NULL;
@@ -335,51 +335,29 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
         u64 val;
         u32 l_state, lt_state; /* LinkState, LinkTrainingState */
 
-        if (count < sizeof(odp)) {
-                ret = -EINVAL;
-                goto bail;
-        }
 
         if (count == sizeof(dp)) {
                 if (copy_from_user(&dp, data, sizeof(dp))) {
                         ret = -EFAULT;
                         goto bail;
                 }
-        } else if (copy_from_user(&odp, data, sizeof(odp))) {
-                ret = -EFAULT;
+        } else if (count == sizeof(odp)) {
+                if (copy_from_user(&odp, data, sizeof(odp))) {
+                        ret = -EFAULT;
+                        goto bail;
+                }
+        } else {
+                ret = -EINVAL;
                 goto bail;
         }
 
-        /*
-         * Due to padding/alignment issues (lessened with new struct)
-         * the old and new structs are the same length. We need to
-         * disambiguate them, which we can do because odp.len has never
-         * been less than the total of LRH+BTH+DETH so far, while
-         * dp.unit (same offset) unit is unlikely to get that high.
-         * Similarly, dp.data, the pointer to user at the same offset
-         * as odp.unit, is almost certainly at least one (512byte)page
-         * "above" NULL. The if-block below can be omitted if compatibility
-         * between a new driver and older diagnostic code is unimportant.
-         * compatibility the other direction (new diags, old driver) is
-         * handled in the diagnostic code, with a warning.
-         */
-        if (dp.unit >= 20 && dp.data < 512) {
-                /* very probable version mismatch. Fix it up */
-                memcpy(&odp, &dp, sizeof(odp));
-                /* We got a legacy dp, copy elements to dp */
-                dp.unit = odp.unit;
-                dp.data = odp.data;
-                dp.len = odp.len;
-                dp.pbc_wd = 0; /* Indicate we need to compute PBC wd */
-        }
-
         /* send count must be an exact number of dwords */
         if (dp.len & 3) {
                 ret = -EINVAL;
                 goto bail;
         }
 
-        clen = dp.len >> 2;
+        plen = dp.len >> 2;
 
         dd = ipath_lookup(dp.unit);
         if (!dd || !(dd->ipath_flags & IPATH_PRESENT) ||
@@ -422,16 +400,22 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
                 goto bail;
         }
 
-        /* need total length before first word written */
-        /* +1 word is for the qword padding */
-        plen = sizeof(u32) + dp.len;
-
-        if ((plen + 4) > dd->ipath_ibmaxlen) {
+        /*
+         * need total length before first word written, plus 2 Dwords. One Dword
+         * is for padding so we get the full user data when not aligned on
+         * a word boundary. The other Dword is to make sure we have room for the
+         * ICRC which gets tacked on later.
+         */
+        maxlen_reserve = 2 * sizeof(u32);
+        if (dp.len > dd->ipath_ibmaxlen - maxlen_reserve) {
                 ipath_dbg("Pkt len 0x%x > ibmaxlen %x\n",
-                          plen - 4, dd->ipath_ibmaxlen);
+                          dp.len, dd->ipath_ibmaxlen);
                 ret = -EINVAL;
-                goto bail;      /* before writing pbc */
+                goto bail;
         }
+
+        plen = sizeof(u32) + dp.len;
+
         tmpbuf = vmalloc(plen);
         if (!tmpbuf) {
                 dev_info(&dd->pcidev->dev, "Unable to allocate tmp buffer, "
@@ -473,11 +457,11 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
          */
         if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
                 ipath_flush_wc();
-                __iowrite32_copy(piobuf + 2, tmpbuf, clen - 1);
+                __iowrite32_copy(piobuf + 2, tmpbuf, plen - 1);
                 ipath_flush_wc();
-                __raw_writel(tmpbuf[clen - 1], piobuf + clen + 1);
+                __raw_writel(tmpbuf[plen - 1], piobuf + plen + 1);
         } else
-                __iowrite32_copy(piobuf + 2, tmpbuf, clen);
+                __iowrite32_copy(piobuf + 2, tmpbuf, plen);
 
         ipath_flush_wc();