[PATCH v3 00/19] random: Resolve circular include dependency and include <linux/percpu.h>

* [PATCH v3 00/19] random: Resolve circular include dependency and include <linux/percpu.h>
@ 2024-09-30 12:33 Uros Bizjak
  2024-09-30 12:33 ` [PATCH v3 01/19] x86/kaslr: Include <linux/prandom.h> instead of <linux/random.h> Uros Bizjak
                   ` (19 more replies)
  0 siblings, 20 replies; 23+ messages in thread
From: Uros Bizjak @ 2024-09-30 12:33 UTC (permalink / raw)
  To: x86, linux-crypto, intel-gfx, dri-devel, linux-media, linux-mtd,
	linux-fscrypt, linux-scsi, bpf, linux-kselftest, kunit-dev,
	linux-kernel
  Cc: Uros Bizjak, Dave Hansen, Andy Lutomirski, Peter Zijlstra,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin,
	Jani Nikula, Joonas Lahtinen, Rodrigo Vivi, Tvrtko Ursulin,
	David Airlie, Daniel Vetter, Maarten Lankhorst, Maxime Ripard,
	Thomas Zimmermann, Hans Verkuil, Mauro Carvalho Chehab,
	Miquel Raynal, Richard Weinberger, Vignesh Raghavendra,
	Eric Biggers, Theodore Y. Ts'o, Jaegeuk Kim,
	Jason A. Donenfeld, Linus Torvalds, Hannes Reinecke,
	James E.J. Bottomley, Martin K. Petersen, Alexei Starovoitov,
	Daniel Borkmann, John Fastabend, Andrii Nakryiko,
	Martin KaFai Lau, Eduard Zingerman, Song Liu, Yonghong Song,
	KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, Andrew Morton,
	Brendan Higgins, David Gow, Rae Moar, David S. Miller,
	Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jiri Pirko,
	Petr Mladek, Steven Rostedt, Andy Shevchenko, Rasmus Villemoes,
	Sergey Senozhatsky, Stephen Hemminger, Jamal Hadi Salim,
	Cong Wang, Kent Overstreet

There were several attempts to resolve circular include dependency
after the addition of percpu.h: 1c9df907da83 ("random: fix circular
include dependency on arm64 after addition of percpu.h"), c0842fbc1b18
("random32: move the pseudo-random 32-bit definitions to prandom.h") and
finally d9f29deb7fe8 ("prandom: Remove unused include") that completely
removes the inclusion of <linux/percpu.h>.

Due to legacy reasons, <linux/random.h> includes <linux/prandom.h>, but
with the commit entry remark:

--quote--
A further cleanup step would be to remove this from <linux/random.h>
entirely, and make people who use the prandom infrastructure include
just the new header file.  That's a bit of a churn patch, but grepping
for "prandom_" and "next_pseudo_random32" "struct rnd_state" should
catch most users.

But it turns out that that nice cleanup step is fairly painful, because
a _lot_ of code currently seems to depend on the implicit include of
<linux/random.h>, which can currently come in a lot of ways, including
such fairly core headfers as <linux/net.h>.

So the "nice cleanup" part may or may never happen.
--/quote--

We would like to include <linux/percpu.h> in <linux/prandom.h>.
In [1] we would like to repurpose __percpu tag as a named address space
qualifier, where __percpu macro uses defines from <linux/percpu.h>.

The major roadblock to inclusion of <linux/percpu.h> is the above
mentioned legacy inclusion of <linux/prandom.h> in <linux/random.h> that
causes circular include dependency that prevents <linux/percpu.h>
inclusion.

This patch series is the "nice cleanup" part that:

a) Substitutes the inclusion of <linux/random.h> with the
inclusion of <linux/prandom.h> where needed (patches 1 - 17).

b) Removes legacy inclusion of <linux/prandom.h> from
<linux/random.h> (patch 18).

c) Includes <linux/percpu.h> in <linux/prandom.h> (patch 19).

The whole series was tested by compiling the kernel for x86_64 allconfig
and some popular architectures, namely arm64 defconfig, powerpc defconfig
and loongarch defconfig.

[1] https://lore.kernel.org/lkml/20240812115945.484051-4-ubizjak@gmail.com/

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
---
v2: - Reword commit messages to mention the removal of legacy inclusion
      of <linux/prandom.h> from <linux/random.h>
    - Add missing substitution in crypto/testmgr.c
      (reported by kernel test robot)
    - Add Acked-by: tags.
v3: - Update to linux 6.12rc1.
    - Add more Acked-by: tags.

Uros Bizjak (19):
  x86/kaslr: Include <linux/prandom.h> instead of <linux/random.h>
  crypto: testmgr: Include <linux/prandom.h> instead of <linux/random.h>
  drm/i915/selftests: Include <linux/prandom.h> instead of
    <linux/random.h>
  drm/lib: Include <linux/prandom.h> instead of <linux/random.h>
  media: vivid: Include <linux/prandom.h> in vivid-vid-cap.c
  mtd: tests: Include <linux/prandom.h> instead of <linux/random.h>
  fscrypt: Include <linux/once.h> in fs/crypto/keyring.c
  scsi: libfcoe: Include <linux/prandom.h> instead of <linux/random.h>
  bpf: Include <linux/prandom.h> instead of <linux/random.h>
  lib/interval_tree_test.c: Include <linux/prandom.h> instead of
    <linux/random.h>
  kunit: string-stream-test: Include <linux/prandom.h>
  random32: Include <linux/prandom.h> instead of <linux/random.h>
  lib/rbtree-test: Include <linux/prandom.h> instead of <linux/random.h>
  bpf/tests: Include <linux/prandom.h> instead of <linux/random.h>
  lib/test_parman: Include <linux/prandom.h> instead of <linux/random.h>
  lib/test_scanf: Include <linux/prandom.h> instead of <linux/random.h>
  netem: Include <linux/prandom.h> in sch_netem.c
  random: Do not include <linux/prandom.h> in <linux/random.h>
  prandom: Include <linux/percpu.h> in <linux/prandom.h>

 arch/x86/mm/kaslr.c                              | 2 +-
 crypto/testmgr.c                                 | 2 +-
 drivers/gpu/drm/i915/selftests/i915_gem.c        | 2 +-
 drivers/gpu/drm/i915/selftests/i915_random.h     | 2 +-
 drivers/gpu/drm/i915/selftests/scatterlist.c     | 2 +-
 drivers/gpu/drm/lib/drm_random.h                 | 2 +-
 drivers/media/test-drivers/vivid/vivid-vid-cap.c | 1 +
 drivers/mtd/tests/oobtest.c                      | 2 +-
 drivers/mtd/tests/pagetest.c                     | 2 +-
 drivers/mtd/tests/subpagetest.c                  | 2 +-
 fs/crypto/keyring.c                              | 1 +
 include/linux/prandom.h                          | 1 +
 include/linux/random.h                           | 7 -------
 include/scsi/libfcoe.h                           | 2 +-
 kernel/bpf/core.c                                | 2 +-
 lib/interval_tree_test.c                         | 2 +-
 lib/kunit/string-stream-test.c                   | 1 +
 lib/random32.c                                   | 2 +-
 lib/rbtree_test.c                                | 2 +-
 lib/test_bpf.c                                   | 2 +-
 lib/test_parman.c                                | 2 +-
 lib/test_scanf.c                                 | 2 +-
 net/sched/sch_netem.c                            | 1 +
 23 files changed, 22 insertions(+), 24 deletions(-)

-- 
2.46.2

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