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@xxxxxxxxx/ Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: x86@xxxxxxxxxx Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Cc: Tvrtko Ursulin <tursulin@xxxxxxxxxxx> Cc: David Airlie <airlied@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: Hans Verkuil <hverkuil@xxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> Cc: Richard Weinberger <richard@xxxxxx> Cc: Vignesh Raghavendra <vigneshr@xxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: "Theodore Y. Ts'o" <tytso@xxxxxxx> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Cc: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Hannes Reinecke <hare@xxxxxxx> Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Cc: John Fastabend <john.fastabend@xxxxxxxxx> Cc: Andrii Nakryiko <andrii@xxxxxxxxxx> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx> Cc: Eduard Zingerman <eddyz87@xxxxxxxxx> Cc: Song Liu <song@xxxxxxxxxx> Cc: Yonghong Song <yonghong.song@xxxxxxxxx> Cc: KP Singh <kpsingh@xxxxxxxxxx> Cc: Stanislav Fomichev <sdf@xxxxxxxxxxx> Cc: Hao Luo <haoluo@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx> Cc: David Gow <davidgow@xxxxxxxxxx> Cc: Rae Moar <rmoar@xxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> Cc: Jiri Pirko <jiri@xxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Cc: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> Cc: Jamal Hadi Salim <jhs@xxxxxxxxxxxx> Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx> Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx> --- 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:. 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> instead of <linux/random.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(-) -- 2.46.0