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From: Sedat Dilek <sedat.dilek@gmail.com>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nicolas Schier <nicolas@fjasle.eu>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-modules <linux-modules@vger.kernel.org>,
	clang-built-linux <llvm@lists.linux.dev>,
	Ard Biesheuvel <ardb@kernel.org>,
	Sami Tolvanen <samitolvanen@google.com>
Subject: Re: [PATCH v6 00/10] kbuild: yet another series of cleanups (modpost, LTO, MODULE_REL_CRCS, export.h)
Date: Mon, 23 May 2022 00:34:51 +0200	[thread overview]
Message-ID: <CA+icZUU8EAKpuXB996B+BNUcnRzsm5DvrtX-MtXcRm5aX2X8Lg@mail.gmail.com> (raw)
In-Reply-To: <CA+icZUXMWVr-zXm09zV2=pbLMFFOt=phHVT3B0CXVLBG=k8HWQ@mail.gmail.com>

On Sun, May 22, 2022 at 6:18 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Sun, May 22, 2022 at 6:10 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> >
> > On Sun, May 22, 2022 at 11:16 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> > >
> > > On Sun, May 22, 2022 at 11:45 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> > > >
> > > > On Sun, May 22, 2022 at 8:50 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > > > >
> > > > > On Sun, May 22, 2022 at 10:45 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
> > > > > >
> > > > > > On Fri, May 13, 2022 at 4:31 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > > > > > >
> > > > > > > On Fri, May 13, 2022 at 8:42 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > This is the third batch of cleanups in this development cycle.
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > This series is available at
> > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
> > > > > > >  lto-cleanup-v6
> > > > > > >
> > > > > >
> > > > > > Hi Masahiro,
> > > > > >
> > > > > > I cloned the repository on top of latest Linus Git.
> > > > > >
> > > > > > Not able to boot in Quemu - Not able to boot on bare metal.
> > > > > >
> > > > > > $ grep module_layout log_quemu-5.18.0-rc7-2-amd64-clang14-lto.txt
> > > > > > 366:[    2.173265] floppy: disagrees about version of symbol module_layout
> > > > > > 367:[    2.198746] scsi_common: disagrees about version of symbol module_layout
> > > > > > 368:[    2.205573] i2c_piix4: disagrees about version of symbol module_layout
> > > > > > 369:[    2.210610] psmouse: disagrees about version of symbol module_layout
> > > > > > 370:[    2.225138] scsi_common: disagrees about version of symbol module_layout
> > > > > > 371:[    2.235536] scsi_common: disagrees about version of symbol module_layout
> > > > > > 375:Begin: Running /scripts/local-premount ... [    2.298555]
> > > > > > crc32c_intel: disagrees about version of symbol module_layout
> > > > > > 376:[    2.303335] crc32c_generic: disagrees about version of symbol
> > > > > > module_layout
> > > > > > 377:[    2.306667] libcrc32c: disagrees about version of symbol module_layout
> > > > > >
> > > > > > Infos: LLVM-14 + CONFIG_LTO_CLANG_THIN=y
> > > > > >
> > > > > > My linux-config and qemu-log are attached.
> > > > > >
> > > > >
> > > > >
> > > > > Thanks for your testing.
> > > > >
> > > > > I was also able to reproduce this issue.
> > > > >
> > > > >
> > > > > The problematic parts are:
> > > > >
> > > > > [    2.298555] crc32c_intel: disagrees about version of symbol module_layout
> > > > > [    2.303335] crc32c_generic: disagrees about version of symbol module_layout
> > > > > [    2.306667] libcrc32c: disagrees about version of symbol module_layout
> > > > >
> > > > >
> > > > >
> > > > > When CONFIG_LTO_CLANG_THIN=y,
> > > > > I cannot see any __crc_* symbols in "nm  vmlinux".
> > > > >
> > > > > Perhaps, LTO might have discarded all the __crc_* symbols
> > > > > from vmlinux, but I am still checking the details...
> > > > >
> > > >
> > > > Thanks for taking care.
> > > >
> > > > Just for the records:
> > > >
> > > > $ grep CONFIG_MODVERSIONS /boot/config-5.18.0-rc7-2-amd64-clang14-lto
> > > > CONFIG_MODVERSIONS=y
> > > >
> > >
> > > Did not try CONFIG_MODVERSIONS=n.
> > >
> > > We have a new file:
> > >
> > > [ include/linux/export-internal.h ]
> > > /* SPDX-License-Identifier: GPL-2.0-only */
> > > /*
> > > * Please do not include this explicitly.
> > > * This is used by C files generated by modpost.
> > > */
> > >
> > > #ifndef __LINUX_EXPORT_INTERNAL_H__
> > > #define __LINUX_EXPORT_INTERNAL_H__
> > >
> > > #include <linux/compiler.h>
> > > #include <linux/types.h>
> > >
> > > #define SYMBOL_CRC(sym, crc, sec)   \
> > >        u32 __section("___kcrctab" sec "+" #sym) __crc_##sym = crc
> > >
> > > #endif /* __LINUX_EXPORT_INTERNAL_H__ */
> > >
> > > But we discard __kcrctab in scripts/module.lds.S file.
> >
> >
> > No.
> > scripts/module.lds.S keeps __kcrctab.
> >
> >
> > The discarded sections are specified a few lines above:
> >
> > /DISCARD/ : {
> >          *(.discard)
> >          *(.discard.*)
> >          SANITIZER_DISCARDS
> > }
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > Maybe we need:
> >
> >
> > No.
> >
> > The problem is __crc_* symbols are dropped from vmlinux
> > when CONFIG_LTO_CLANG=y.
> >
> >
> > Please try this fixup:
> > https://lore.kernel.org/linux-kbuild/20220522160117.599023-1-masahiroy@kernel.org/T/#u
> >
>
> Thanks!
>
> Will give it a try - will report in a few hours.
>
> -Sedat-

I was able to build and boot on bare metal.

Feel free to add my...

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)

-Sedat-

>
> >
> >
> >
> >
> >
> > >
> > > $ git diff scripts/module.lds.S
> > > diff --git a/scripts/module.lds.S b/scripts/module.lds.S
> > > index 1d0e1e4dc3d2..c04b596c364b 100644
> > > --- a/scripts/module.lds.S
> > > +++ b/scripts/module.lds.S
> > > @@ -21,8 +21,6 @@ SECTIONS {
> > >
> > >        __ksymtab               0 : { *(SORT(___ksymtab+*)) }
> > >        __ksymtab_gpl           0 : { *(SORT(___ksymtab_gpl+*)) }
> > > -       __kcrctab               0 : { *(SORT(___kcrctab+*)) }
> > > -       __kcrctab_gpl           0 : { *(SORT(___kcrctab_gpl+*)) }
> > >
> > >        .ctors                  0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
> > >        .init_array             0 : ALIGN(8) { *(SORT(.init_array.*))
> > > *(.init_array) }
> > >
> > > Or even?
> > >
> > > $ git diff scripts/kallsyms.c
> > > diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
> > > index 8caabddf817c..fb3601fe8aa3 100644
> > > --- a/scripts/kallsyms.c
> > > +++ b/scripts/kallsyms.c
> > > @@ -109,7 +109,6 @@ static bool is_ignored_symbol(const char *name, char type)
> > >        static const char * const ignored_prefixes[] = {
> > >                "$",                    /* local symbols for ARM, MIPS, etc. */
> > >                ".L",                   /* local labels,
> > > .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
> > > -               "__crc_",               /* modversions */
> > >                "__efistub_",           /* arm64 EFI stub namespace */
> > >                "__kvm_nvhe_",          /* arm64 non-VHE KVM namespace */
> > >                "__AArch64ADRPThunk_",  /* arm64 lld */
> > >
> > > - Sedat -
> >
> >
> >
> > --
> > Best Regards
> > Masahiro Yamada

  reply	other threads:[~2022-05-22 22:35 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-13 11:39 [PATCH v6 00/10] kbuild: yet another series of cleanups (modpost, LTO, MODULE_REL_CRCS, export.h) Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 01/10] modpost: extract symbol versions from *.cmd files Masahiro Yamada
2022-05-28 22:47   ` Guenter Roeck
2022-05-29  4:27     ` Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 02/10] kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS Masahiro Yamada
2022-08-20 10:02   ` Build/boot problem with 7b4537199a4a (Re: [PATCH v6 02/10] kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS) Christophe Leroy
2022-08-20 12:05     ` Sedat Dilek
2022-08-20 14:10       ` Christophe Leroy
2022-08-20 12:51     ` Masahiro Yamada
2022-08-20 14:15       ` Christophe Leroy
2022-08-20 17:01         ` Masahiro Yamada
2022-08-20 17:51           ` Christophe Leroy
2022-05-13 11:39 ` [PATCH v6 03/10] kbuild: stop merging *.symversions Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 04/10] genksyms: adjust the output format to modpost Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 05/10] kbuild: do not create *.prelink.o for Clang LTO or IBT Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 06/10] kbuild: check static EXPORT_SYMBOL* by script instead of modpost Masahiro Yamada
2022-05-25  8:31   ` Guenter Roeck
2022-05-25 10:51     ` Masahiro Yamada
2022-06-07 14:22   ` Jon Hunter
2022-06-07 14:25     ` Nathan Chancellor
2022-06-07 14:34       ` Jon Hunter
2022-05-13 11:39 ` [PATCH v6 07/10] kbuild: make built-in.a rule robust against too long argument error Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 08/10] kbuild: make *.mod " Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 09/10] kbuild: add cmd_and_savecmd macro Masahiro Yamada
2022-05-13 11:39 ` [PATCH v6 10/10] kbuild: rebuild multi-object modules when objtool is updated Masahiro Yamada
2022-05-13 12:20 ` [PATCH v6 00/10] kbuild: yet another series of cleanups (modpost, LTO, MODULE_REL_CRCS, export.h) Masahiro Yamada
     [not found]   ` <CA+icZUUWww3fXvjQcefgFuq=tPO6+FYDbHE2E5PmL-BSJg4+cw@mail.gmail.com>
2022-05-22  6:49     ` Masahiro Yamada
2022-05-22  9:45       ` Sedat Dilek
2022-05-22 14:15         ` Sedat Dilek
2022-05-22 16:09           ` Masahiro Yamada
2022-05-22 16:18             ` Sedat Dilek
2022-05-22 22:34               ` Sedat Dilek [this message]
     [not found]   ` <2c496d24174e63b27ec047f383df6700@matoro.tk>
2022-08-06  7:23     ` Sedat Dilek
2022-08-06 13:12       ` matoro
2022-08-08  5:54     ` Masahiro Yamada
2022-08-08 13:26       ` matoro
2022-08-08 17:36         ` Masahiro Yamada
2022-08-08 18:42           ` matoro
2022-08-09 15:20             ` Masahiro Yamada

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