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Halil Pasic fd0c8b3375 s390/vfio-ccw: Make mdev_types not look like a fake flex array
The vfio-ccw driver and the vfio parent device provided by it (parent)
support just a single mdev_type, and this is not likely to change any
time soon. To match the mdev interfaces nicely initially the choice was
made that mdev_types (which gets passed into mdev_register_parent())
shall be an array of pointers to struct mdev_type with a single element,
and to make things worse it ended up being the last member.

Now the problem with that is that before C99 the usual way to get
something similar to a flexible array member was to use a trailing array
of size 0 or 1. This is what I called fake flex array. For a while now
the community is trying to get rid of fake flex arrays. And while
mdev_types was not a fake flex array but an array of size one, because
it can easily be and probably was mistaken for a fake flex array it got
converted into a real C99 flex array with a compile time known constant
size of one.

As per [1] it was established that "only fake flexible arrays should be
transformed into C99 flex-array members". Since IMHO the entire point of
flex arrays is being flexible about the array size at run time, a C99
flex array is a poor fit for mdev_types.  But an array of a size one is
a poor fit as well for the reason stated above, let us try to get rid of
the flex array without introducing back the one sized array.

So, lets make mdev_types a pointer to struct mdev_type and pass in the
address of that pointer as the 4th formal parameter of
mdev_register_parent().

[1] https://lore.kernel.org/lkml/85863d7a-2d8b-4c1b-b76a-e2f40834a7a8@embeddedor.com/

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20250217100614.3043620-3-pasic@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-02-18 18:53:47 +01:00
Documentation ARM: 2025-02-09 09:41:38 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
arch ARM: 2025-02-09 09:41:38 -08:00
block block-6.14-20250131 2025-01-31 11:49:30 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
drivers s390/vfio-ccw: Make mdev_types not look like a fake flex array 2025-02-18 18:53:47 +01:00
fs four SMB3 client fixes, 3 DFS related 2025-02-07 19:23:06 -08:00
include Kbuild fixes for v6.14 2025-02-09 10:05:32 -08:00
init Kbuild updates for v6.14 2025-01-31 12:07:07 -08:00
io_uring Fix a dangling pointer bug in the futex code used by the 2025-02-08 10:54:11 -08:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel seccomp fix for v6.14-rc2 2025-02-08 14:04:21 -08:00
lib hardening fixes for v6.14-rc2 2025-02-08 14:12:17 -08:00
mm assorted stuff for this merge window 2025-02-01 15:07:56 -08:00
net vfs-6.14-rc2.fixes 2025-02-07 09:22:31 -08:00
rust rust: kbuild: do not export generated KASAN ODR symbols 2025-02-06 19:47:04 +01:00
samples AT_EXECVE_CHECK update for v6.14-rc1 (fix1) 2025-01-31 17:12:31 -08:00
scripts Kbuild fixes for v6.14 2025-02-09 10:05:32 -08:00
security treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
sound sound fixes for 6.14-rc1 2025-01-31 09:17:02 -08:00
tools ARM: 2025-02-09 09:41:38 -08:00
usr kbuild: Drop support for include/asm-<arch> in headers_check.pl 2024-12-21 11:43:17 +09:00
virt KVM: remove kvm_arch_post_init_vm 2025-02-04 11:27:45 -05:00
.clang-format clang-format: Update with v6.11-rc1's `for_each` macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap 21 hotfixes. 8 are cc:stable and the remainder address post-6.13 issues. 2025-02-01 09:49:20 -08:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Pavel to kernel.org address 2025-02-07 09:12:33 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS gpio fixes for v6.14-rc2 2025-02-07 09:50:33 -08:00
Makefile Linux 6.14-rc2 2025-02-09 12:45:03 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

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.