RDMA/core: Fix incorrect structure packing for booleans
authorJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Fri, 23 Dec 2016 01:07:52 +0000 (18:07 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 12 Mar 2017 05:41:50 +0000 (06:41 +0100)
commit50fc62d5eeb3392f11161637b5ed4e0d340fed74
treefe22edef3b4f2eb39ba5a1b3e0f4d9b2f8e90d0a
parentfbff994b8a464cd5de50fbb2e0b8341becb70336
RDMA/core: Fix incorrect structure packing for booleans

commit 55efcfcd7776165b294f8b5cd6e05ca00ec89b7c upstream.

The RDMA core uses ib_pack() to convert from unpacked CPU structs
to on-the-wire bitpacked structs.

This process requires that 1 bit fields are declared as u8 in the
unpacked struct, otherwise the packing process does not read the
value properly and the packed result is wired to 0. Several
places wrongly used int.

Crucially this means the kernel has never, set reversible
correctly in the path record request. It has always asked for
irreversible paths even if the ULP requests otherwise.

When the kernel is used with a SM that supports this feature, it
completely breaks communication management if reversible paths are
not properly requested.

The only reason this ever worked is because opensm ignores the
reversible bit.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/rdma/ib_sa.h