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author | Yann Droneaud <ydroneaud@opteya.com> | 2014-05-05 19:33:22 +0200 |
---|---|---|
committer | Roland Dreier <roland@purestorage.com> | 2014-05-27 11:53:16 -0700 |
commit | 43bc889380c2ad9aa230eccc03a15cc52cf710d4 (patch) | |
tree | f435c4c7a947a84a9c711840322910e607ea2149 /drivers/infiniband/hw | |
parent | a8237b32a3faab155a5dc8f886452147ce73da3e (diff) | |
download | op-kernel-dev-43bc889380c2ad9aa230eccc03a15cc52cf710d4.zip op-kernel-dev-43bc889380c2ad9aa230eccc03a15cc52cf710d4.tar.gz |
IB/mlx5: add missing padding at end of struct mlx5_ib_create_srq
The i386 ABI disagrees with most other ABIs regarding alignment of
data type larger than 4 bytes: on most ABIs a padding must be added at
end of the structures, while it is not required on i386.
So for most ABIs struct mlx5_ib_create_srq gets implicitly padded to be
aligned on a 8 bytes multiple, while for i386, such padding is not
added.
Tool pahole could be used to find such implicit padding:
$ pahole --anon_include \
--nested_anon_include \
--recursive \
--class_name mlx5_ib_create_srq \
drivers/infiniband/hw/mlx5/mlx5_ib.o
Then, structure layout can be compared between i386 and x86_64:
+++ obj-i386/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-28 11:43:07.386413682 +0100
--- obj-x86_64/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-27 13:06:17.788472721 +0100
@@ -69,7 +68,6 @@ struct mlx5_ib_create_srq {
__u64 db_addr; /* 8 8 */
__u32 flags; /* 16 4 */
- /* size: 20, cachelines: 1, members: 3 */
- /* last cacheline: 20 bytes */
+ /* size: 24, cachelines: 1, members: 3 */
+ /* padding: 4 */
+ /* last cacheline: 24 bytes */
};
ABI disagreement will make an x86_64 kernel try to read past
the buffer provided by an i386 binary.
When boundary check will be implemented, the x86_64 kernel will
refuse to read past the i386 userspace provided buffer and the
uverb will fail.
Anyway, if the structure lay in memory on a page boundary and
next page is not mapped, ib_copy_from_udata() will fail and the
uverb will fail.
This patch makes create_srq_user() takes care of the input
data size to handle the case where no padding was provided.
This way, x86_64 kernel will be able to handle struct mlx5_ib_create_srq
as sent by unpatched and patched i386 libmlx5.
Link: http://marc.info/?i=cover.1399309513.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Fixes: e126ba97dba9e ("mlx5: Add driver for Mellanox Connect-IB adapter")
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband/hw')
-rw-r--r-- | drivers/infiniband/hw/mlx5/srq.c | 14 | ||||
-rw-r--r-- | drivers/infiniband/hw/mlx5/user.h | 1 |
2 files changed, 14 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c index 210b3ea..384af6d 100644 --- a/drivers/infiniband/hw/mlx5/srq.c +++ b/drivers/infiniband/hw/mlx5/srq.c @@ -35,6 +35,7 @@ #include <linux/mlx5/srq.h> #include <linux/slab.h> #include <rdma/ib_umem.h> +#include <rdma/ib_user_verbs.h> #include "mlx5_ib.h" #include "user.h" @@ -78,16 +79,27 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq, { struct mlx5_ib_dev *dev = to_mdev(pd->device); struct mlx5_ib_create_srq ucmd; + size_t ucmdlen; int err; int npages; int page_shift; int ncont; u32 offset; - if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) { + ucmdlen = + (udata->inlen - sizeof(struct ib_uverbs_cmd_hdr) < + sizeof(ucmd)) ? (sizeof(ucmd) - + sizeof(ucmd.reserved)) : sizeof(ucmd); + + if (ib_copy_from_udata(&ucmd, udata, ucmdlen)) { mlx5_ib_dbg(dev, "failed copy udata\n"); return -EFAULT; } + + if (ucmdlen == sizeof(ucmd) && + ucmd.reserved != 0) + return -EINVAL; + srq->wq_sig = !!(ucmd.flags & MLX5_SRQ_FLAG_SIGNATURE); srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr, buf_size, diff --git a/drivers/infiniband/hw/mlx5/user.h b/drivers/infiniband/hw/mlx5/user.h index d44ecd2..d0ba264 100644 --- a/drivers/infiniband/hw/mlx5/user.h +++ b/drivers/infiniband/hw/mlx5/user.h @@ -110,6 +110,7 @@ struct mlx5_ib_create_srq { __u64 buf_addr; __u64 db_addr; __u32 flags; + __u32 reserved; /* explicit padding (optional on i386) */ }; struct mlx5_ib_create_srq_resp { |