mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-01 00:36:40 +09:00
4c70ac7639
I had originally asked Stefan Schake to drop the pad field from the syncobj changes that just landed, because I couldn't come up with a reason to align to 64 bits. Talking with Dave Airlie about the new v3d driver's submit ioctl, we came up with a reason: sizeof() on 64-bit platforms may align to 64 bits, in which case the userspace will be submitting the aligned size and the final 32 bits won't be zero-padded by the kernel. If userspace doesn't zero-fill, then a future ABI change adding a 32-bit field at the end could potentially cause the kernel to read undefined data from old userspace (our userspace happens to use structure initialization that zero-fills, but as a general rule we try not to rely on that in the kernel). Signed-off-by: Eric Anholt <eric@anholt.net> Link: https://patchwork.freedesktop.org/patch/msgid/20180430235927.28712-1-eric@anholt.net Reviewed-by: Stefan Schake <stschake@gmail.com>
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.