[PATCH 4.19 3/7] IB/qib: Use struct_size() helper

From: Greg Kroah-Hartman
Date: Thu Nov 04 2021 - 10:17:28 EST


From: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

commit 829ca44ecf60e9b6f83d0161a6ef10c1304c5060 upstream.

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(*pkt) + sizeof(pkt->addr[0])*n

with:

struct_size(pkt, addr, n)

Also, notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Cc: Mile Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/hw/qib/qib_user_sdma.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/qib/qib_user_sdma.c
+++ b/drivers/infiniband/hw/qib/qib_user_sdma.c
@@ -908,10 +908,11 @@ static int qib_user_sdma_queue_pkts(cons
}

if (frag_size) {
- int pktsize, tidsmsize, n;
+ int tidsmsize, n;
+ size_t pktsize;

n = npages*((2*PAGE_SIZE/frag_size)+1);
- pktsize = sizeof(*pkt) + sizeof(pkt->addr[0])*n;
+ pktsize = struct_size(pkt, addr, n);

/*
* Determine if this is tid-sdma or just sdma.