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The design of the uAPI had intended all structs to share the same layout on 32 and 64 bit compiles. Unfortunately over the years some errors have crept in. This series fixes all the incompatabilities. It goes along with a userspace rdma-core series that causes the providers to use these structs directly and then does various self-checks on the command formation. Those checks were combined with output from pahole on 32 and 64 bit compiles to confirm that the structure layouts are the same. This series does not make implicit padding explicit, as long as the implicit padding is the same on 32 and 64 bit compiles. Finally, the issue is put to rest by using __aligned_u64 in the uapi headers, if new code copies that type, and is checked in userspace, it is unlikely we will see problems in future. There are two patches that break the ABI for a 32 bit kernel, one for rxe and one for mlx4. Both patches have notes, but the overall feeling from Doug and I is that providing compat is just too difficult and not necessary since there is no real user of a 32 bit userspace and 32 bit kernel for various good reasons. The 32 bit userspace / 64 bit kernel case however does seem to have some real users and does need to work as designed. * 32compat: RDMA: Change all uapi headers to use __aligned_u64 instead of __u64 RDMA/rxe: Fix uABI structure layouts for 32/64 compat RDMA/mlx4: Fix uABI structure layouts for 32/64 compat RDMA/qedr: Fix uABI structure layouts for 32/64 compat RDMA/ucma: Fix uABI structure layouts for 32/64 compat RDMA: Remove minor pahole differences between 32/64
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.