From bfb972c5e1cba88c93912f271ed5ecc114e31431 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 26 Oct 2020 17:15:39 +0100 Subject: IB/verbs: avoid nested container_of() Nested container_of() calls work correctly but cause a warning when building with W=2. Invoking it from an inline function like in drivers/infiniband/hw/mlx5/mlx5_ib.h means we get hundreds of warnings like: include/linux/kernel.h:852:8: warning: declaration of '__mptr' shadows a previous local [-Wshadow] 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ include/rdma/uverbs_ioctl.h:651:11: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ include/rdma/uverbs_ioctl.h:651:24: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ drivers/infiniband/hw/mthca/mthca_qp.c:564:35: note: in expansion of macro 'rdma_udata_to_drv_context' 564 | struct mthca_ucontext *context = rdma_udata_to_drv_context( | ^~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kernel.h:852:8: note: shadowed declaration is here 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ include/rdma/uverbs_ioctl.h:651:11: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ drivers/infiniband/hw/mthca/mthca_qp.c:564:35: note: in expansion of macro 'rdma_udata_to_drv_context' 564 | struct mthca_ucontext *context = rdma_udata_to_drv_context( | ^~~~~~~~~~~~~~~~~~~~~~~~~ In file included from : include/linux/kernel.h:852:8: warning: declaration of '__mptr' shadows a previous local [-Wshadow] 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ Rewrite the macro to use an inline function internally, which makes it more readable and reduces the amount of useless output from make W=2. Fixes: 730623f4a56f ("IB/verbs: Add helper function rdma_udata_to_drv_context") Link: https://lore.kernel.org/r/20201026161549.3709175-1-arnd@kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Jason Gunthorpe --- include/rdma/uverbs_ioctl.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'include/rdma/uverbs_ioctl.h') diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h index b00270c72740..bf167ef6c688 100644 --- a/include/rdma/uverbs_ioctl.h +++ b/include/rdma/uverbs_ioctl.h @@ -647,12 +647,15 @@ static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_b * 'ucontext'. * */ -#define rdma_udata_to_drv_context(udata, drv_dev_struct, member) \ - (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ - driver_udata) \ - ->context, \ - drv_dev_struct, member) : \ - (drv_dev_struct *)NULL) +static inline struct uverbs_attr_bundle * +rdma_udata_to_uverbs_attr_bundle(struct ib_udata *udata) +{ + return container_of(udata, struct uverbs_attr_bundle, driver_udata); +} + +#define rdma_udata_to_drv_context(udata, drv_dev_struct, member) \ + (udata ? container_of(rdma_udata_to_uverbs_attr_bundle(udata)->context, \ + drv_dev_struct, member) : (drv_dev_struct *)NULL) #define IS_UVERBS_COPY_ERR(_ret) ((_ret) && (_ret) != -ENOENT) -- cgit v1.2.3-59-g8ed1b