| Message ID | 20240905122020.872466-1-ubizjak@gmail.com |
|---|---|
| Headers | show |
| Series | random: Include <linux/percpu.h> and resolve circular include dependency | expand |
On Thu, Sep 5, 2024 at 2:41 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Thu, Sep 05, 2024 at 02:17:08PM +0200, Uros Bizjak wrote: > > 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 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-- > > > > __percpu tag is currently defined in include/linux/compiler_types.h, > > so there is no direct need for the inclusion of <linux/percpu.h>. > > However, in [1] we would like to repurpose __percpu tag as a named > > address space qualifier, where __percpu macro uses defines from > > <linux/percpu.h>. > > > > This patch series is the "nice cleanup" part, and allows us to finally > > include <linux/percpu.h> in prandom.h. > > > > 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. > > Obvious question(s) is(are): > 1) have you seen the Ingo's gigantic patch series towards resolving issues with > the headers? > 2) if not, please look at the preliminary work and take something from there, I > believe there are many useful changes already waiting for a couple of years to > be applied. > > Because I haven't found any references nor mentions of that in the cover letter > here and explanation why it was not taking into consideration. I am aware of the series, but the patch takes only a small bite of it and specifically resolves the inclusion of <linux/prandom.h> from linux/random.h. The series fixes the missing inclusion of <linux/prandom.h> in files that use pseudo-random function and it was not meant to be a general header cleanup. The end goal is to allow us to include <linux/percpu.h> in linux/prandom.h - which uses __percpu tag without the correct include. Thus, the patch series is only tangentially connected to Ingo's patch series. Best regards, Uros.
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 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-- __percpu tag is currently defined in include/linux/compiler_types.h, so there is no direct need for the inclusion of <linux/percpu.h>. However, in [1] we would like to repurpose __percpu tag as a named address space qualifier, where __percpu macro uses defines from <linux/percpu.h>. This patch series is the "nice cleanup" part, and allows us to finally include <linux/percpu.h> in prandom.h. 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: x86@kernel.org 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: Uros Bizjak <ubizjak@gmail.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: linux-media@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-fscrypt@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: kunit-dev@googlegroups.com Uros Bizjak (18): x86/kaslr: 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/prandom.h> instead of <linux/random.h> 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> prandom: Include <linux/percpu.h> arch/x86/mm/kaslr.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 | 2 +- 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 + 22 files changed, 21 insertions(+), 24 deletions(-)