soc: qcom: smp2p: Correct addressing of outgoing value

commit 63af8e44 upstream.

The valid_entries index should not be incremented until after we have
acquired the pointer to the value, or we will read and write data one
item off.

Fixes: 50e99641 ("soc: qcom: smp2p: Qualcomm Shared Memory Point to Point")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/soc/qcom/smp2p.c

@@ -344,11 +344,12 @@ static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
 	/* Allocate an entry from the smem item */
 	strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
 	memcpy_toio(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
-	out->valid_entries++;
 
 	/* Make the logical entry reference the physical value */
 	entry->value = &out->entries[out->valid_entries].value;
 
+	out->valid_entries++;
+
 	entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
 	if (IS_ERR(entry->state)) {
 		dev_err(smp2p->dev, "failed to register qcom_smem_state\n");