| From 43bc889380c2ad9aa230eccc03a15cc52cf710d4 Mon Sep 17 00:00:00 2001 |
| From: Yann Droneaud <ydroneaud@opteya.com> |
| Date: Mon, 5 May 2014 19:33:22 +0200 |
| Subject: IB/mlx5: add missing padding at end of struct mlx5_ib_create_srq |
| |
| From: Yann Droneaud <ydroneaud@opteya.com> |
| |
| 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> |
| |
| --- |
| drivers/infiniband/hw/mlx5/srq.c | 14 +++++++++++++- |
| drivers/infiniband/hw/mlx5/user.h | 1 + |
| 2 files changed, 14 insertions(+), 1 deletion(-) |
| |
| --- 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 |
| { |
| 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, |
| --- 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 { |