From 7185795a62589292015484985635b4a38029a2b9 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Mon, 15 Jun 2015 17:25:34 +0800 Subject: powerpc/powernv: fix construction of opal PRD messages We currently have a bug in the PRD code, where the contents of an incoming message (beyond the header) will be overwritten by the list item manipulations when adding to to the prd_msg_queue. This change reorders struct opal_prd_msg_queue_item, so that the message body doesn't overlap the list_head. We also clarify the memcpy of the message, as we're copying unnecessary bytes at the end of the message data. Signed-off-by: Jeremy Kerr Acked-by: Stewart Smith Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/opal-prd.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c index d9e72bde79f5..46cb3feb0a13 100644 --- a/arch/powerpc/platforms/powernv/opal-prd.c +++ b/arch/powerpc/platforms/powernv/opal-prd.c @@ -32,9 +32,13 @@ #include +/** + * The msg member must be at the end of the struct, as it's followed by the + * message data. + */ struct opal_prd_msg_queue_item { - struct opal_prd_msg_header msg; struct list_head list; + struct opal_prd_msg_header msg; }; static struct device_node *prd_node; @@ -351,22 +355,23 @@ static int opal_prd_msg_notifier(struct notifier_block *nb, struct opal_prd_msg_queue_item *item; struct opal_prd_msg_header *hdr; struct opal_msg *msg = _msg; + int msg_size, item_size; unsigned long flags; - int size; if (msg_type != OPAL_MSG_PRD) return 0; - /* Calculate total size of the item we need to store. The 'size' field - * in the header includes the header itself. */ + /* Calculate total size of the message and item we need to store. The + * 'size' field in the header includes the header itself. */ hdr = (void *)msg->params; - size = (sizeof(*item) - sizeof(item->msg)) + be16_to_cpu(hdr->size); + msg_size = be16_to_cpu(hdr->size); + item_size = msg_size + sizeof(*item) - sizeof(item->msg); - item = kzalloc(size, GFP_ATOMIC); + item = kzalloc(item_size, GFP_ATOMIC); if (!item) return -ENOMEM; - memcpy(&item->msg, msg->params, size); + memcpy(&item->msg, msg->params, msg_size); spin_lock_irqsave(&opal_prd_msg_queue_lock, flags); list_add_tail(&item->list, &opal_prd_msg_queue); -- cgit v1.2.3