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authorJason Gunthorpe <jgg@nvidia.com>2021-09-03 16:07:28 +0300
committerJason Gunthorpe <jgg@nvidia.com>2021-09-08 14:32:04 +0300
commit84f969e1c48ed3825986e91a0786e363d57f69d1 (patch)
treefa0df9b7953931d0180dba5e3b507ace303e8909 /drivers/infiniband/hw/qib
parentf4c6f31011eafe027abddf6cee1288a1b5a05b73 (diff)
downloadlinux-84f969e1c48ed3825986e91a0786e363d57f69d1.tar.xz
IB/qib: Fix null pointer subtraction compiler warning
>> drivers/infiniband/hw/qib/qib_sysfs.c:411:1: warning: performing pointer subtraction with a null pointer has undefined behavior +[-Wnull-pointer-subtraction] QIB_DIAGC_ATTR(rc_resends); ^~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/infiniband/hw/qib/qib_sysfs.c:408:51: note: expanded from macro 'QIB_DIAGC_ATTR' .counter = &((struct qib_ibport *)0)->rvp.n_##N - (u64 *)0, \ Use offsetof and accomplish the type check using static_assert. Fixes: 4a7aaf88c89f ("RDMA/qib: Use attributes for the port sysfs") Link: https://lore.kernel.org/r/0-v1-43ae3c759177+65-qib_type_jgg@nvidia.com Reported-by: kernel test robot <lkp@intel.com> Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/hw/qib')
-rw-r--r--drivers/infiniband/hw/qib/qib_sysfs.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/qib/qib_sysfs.c b/drivers/infiniband/hw/qib/qib_sysfs.c
index d57e49de6650..452e2355d24e 100644
--- a/drivers/infiniband/hw/qib/qib_sysfs.c
+++ b/drivers/infiniband/hw/qib/qib_sysfs.c
@@ -403,9 +403,11 @@ static ssize_t diagc_attr_store(struct ib_device *ibdev, u32 port_num,
}
#define QIB_DIAGC_ATTR(N) \
+ static_assert(&((struct qib_ibport *)0)->rvp.n_##N != (u64 *)NULL); \
static struct qib_diagc_attr qib_diagc_attr_##N = { \
.attr = __ATTR(N, 0664, diagc_attr_show, diagc_attr_store), \
- .counter = &((struct qib_ibport *)0)->rvp.n_##N - (u64 *)0, \
+ .counter = \
+ offsetof(struct qib_ibport, rvp.n_##N) / sizeof(u64) \
}
QIB_DIAGC_ATTR(rc_resends);