RDMA/core: Fix incorrect structure packing for booleans
authorJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Fri, 23 Dec 2016 01:07:52 +0000 (18:07 -0700)
committerJiri Slaby <jslaby@suse.cz>
Mon, 13 Mar 2017 20:40:35 +0000 (21:40 +0100)
commit600bfb438cd9ab51f952bc44364c20e82d184fa4
treead566f754485a71e45da732d65ac4f66619aa3a7
parent3ee3990aefa1860fca0c00bf1a03ebaab993550e
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: Jiri Slaby <jslaby@suse.cz>
include/rdma/ib_sa.h