| Message ID | 20240905122020.872466-1-ubizjak@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | random: Include <linux/percpu.h> and resolve circular include dependency | expand |
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. > [1] https://lore.kernel.org/lkml/20240812115945.484051-4-ubizjak@gmail.com/
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.
On Thu, Sep 05, 2024 at 03:03:24PM +0200, Uros Bizjak wrote: > 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. Thank you for elaboration, it's all clear now. > Thus, the patch series is only tangentially connected to Ingo's patch series.
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(-)