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authorYann Droneaud <ydroneaud@opteya.com>2014-05-05 19:33:22 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-06 18:59:10 -0700
commit0151759dd37044fd2cb44d6eef8d63bb16b0b47e (patch)
treea0b95303ec472c378c7bea491d63cd8202491c6c
parentbcdd10a31eae267c10fd4c73fa834e74defc936b (diff)
IB/mlx5: add missing padding at end of struct mlx5_ib_create_srq
commit 43bc889380c2ad9aa230eccc03a15cc52cf710d4 upstream. 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 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/infiniband/hw/mlx5/srq.c14
-rw-r--r--drivers/infiniband/hw/mlx5/user.h1
2 files changed, 14 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c
index 210b3eaf188a..384af6dec5eb 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 d44ecd2c2faf..d0ba264ac1ed 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 {