Similar to other architectures such as arm64, x86, riscv and so on, use
offsets relative to the exception table entry values rather than their
absolute addresses for both the exception location and the fixup.

However, LoongArch label difference because it will actually produce two
relocations, a pair of R_LARCH_ADD32 and R_LARCH_SUB32. Take simple code
below for example:

$ cat test_ex_table.S
.section .text
1:
        nop
.section __ex_table,"a"
        .balign 4
        .long (1b - .)
.previous

$ loongarch64-unknown-linux-gnu-gcc -c test_ex_table.S
$ loongarch64-unknown-linux-gnu-readelf -Wr test_ex_table.o

Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
    Offset            Info             Type         Symbol's Value   Symbol's Name + Addend
0000000000000000 0000000600000032 R_LARCH_ADD32    0000000000000000  .L1^B1 + 0
0000000000000000 0000000500000037 R_LARCH_SUB32    0000000000000000  L0^A + 0

The modpost will complain the R_LARCH_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.
Signed-off-by: NYouling Tang <tangyouling@loongson.cn>
Signed-off-by: NHuacai Chen <chenhuacai@loongson.cn>

Add rust argument at TAR_CONTENT in
scripts/Makefile.package script with alphabetical order.
Signed-off-by: NParan Lee <p4ranlee@gmail.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Since 2df8220c ("kbuild: build init/built-in.a just once"),
generating Debian packages using 'make bindeb-pkg' results in
packages that are stuck to the same .version, leading to unexpected
behaviours (multiple packages with the same version).

That's because the mkdebian script samples the build version
before building the kernel, and forces the use of that version
number for the actual build.

Restore the previous behaviour by calling init/build-version
instead of reading the .version file. This is likely to result
in too many .version bumps, but this is what was happening before
(although the bump was affecting builds made after the current one).

Fixes: 2df8220c ("kbuild: build init/built-in.a just once")
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Commit 1d1a0e7c ("scripts/faddr2line: Fix overlapping text section
failures") can cause faddr2line to fail on ppc64le on some
distributions, while it works fine on other distributions. The failure
can be attributed to differences in the readelf output.

  $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
  no match for find_busiest_group+0x00

On ppc64le, readelf adds the localentry tag before the symbol name on
some distributions, and adds the localentry tag after the symbol name on
other distributions. This problem has been discussed previously:

  https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/

This problem can be overcome by filtering out the localentry tags in the
readelf output. Similar fixes are already present in the kernel by way
of the following commits:

  1fd6cee1 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
  aa915931 ("libbpf: Fix readelf output parsing for Fedora")

[jpoimboe: rework commit log]

Fixes: 1d1a0e7c ("scripts/faddr2line: Fix overlapping text section failures")
Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: NThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Link: https://lore.kernel.org/r/20220927075211.897152-1-srikar@linux.vnet.ibm.comSigned-off-by: NJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>

Before version 15.0.0 llvm's integrated assembler may silently
generate corrupted code on s390. See e.g. commit e9953b72
("s390/boot: workaround llvm IAS bug") for further details.

While there have been workarounds applied for all known existing
locations, there is nothing that prevents that new code with
problematic patterns will be added.

Therefore raise the minimum clang version to 15.0.0. Note that llvm
commit e547b04d5b2c ("[SystemZ] Bugfix for symbolic displacements."),
which is included in 15.0.0, fixes the broken code generation.
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Acked-by: NNathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20221031123456.3872220-1-hca@linux.ibm.comSigned-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>

Since commit d05377e1 ("kconfig: Create links to main menu items
in search"), menuconfig shows a jump key next to "Main menu" if the
nearest visible parent is the rootmenu. If you press that jump key,
menuconfig crashes with a segmentation fault.

For example, do this:

  $ make ARCH=arm64 allnoconfig menuconfig

Press '/' to search for the string "ACPI". Press '1' to choose
"(1) Main menu". Then, menuconfig crashed with a segmentation fault.

The following code in search_conf()

    conf(targets[i]->parent, targets[i]);

results in NULL pointer dereference because targets[i] is the rootmenu,
which does not have a parent.

Commit d05377e1 tried to fix the issue of top-level items not having
a jump key, but adding the "Main menu" was not the right fix.

The correct fix is to show the searched item itself. This fixes another
weird behavior described in the comment block.

Fixes: d05377e1 ("kconfig: Create links to main menu items in search")
Reported-by: NJohannes Zink <j.zink@pengutronix.de>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NBagas Sanjaya <bagasdotme@gmail.com>
Tested-by: NJohannes Zink <j.zink@pengutronix.de>

Commit f73edc89 ("kbuild: unify two modpost invocations") introduced
a typo (moudle.symvers-if-present) which results in the kernel's
Module.symvers to not be included as a prerequisite for
$(KBUILD_EXTMOD)/Module.symvers. Fix the typo to restore the intended
functionality.

Fixes: f73edc89 ("kbuild: unify two modpost invocations")
Signed-off-by: NWill McVicker <willmcvicker@google.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

When debugging LLVM IR, it can be handy for clang to not discard value
names used for local variables and parameters. Compare the generated IR.

-fdiscard-value-names:
  define i32 @core_sys_select(i32 %0, ptr %1, ptr %2, ptr %3, ptr %4) {
    %6 = alloca i64
    %7 = alloca %struct.poll_wqueues
    %8 = alloca [64 x i32]

-fno-discard-value-names:
  define i32 @core_sys_select(i32 %n, ptr %inp, ptr %outp, ptr %exp,
                              ptr %end_time) {
    %expire.i = alloca i64
    %table.i = alloca %struct.poll_wqueues
    %stack_fds = alloca [64 x i32]

The rule for generating human readable LLVM IR (.ll) is only useful as a
debugging feature:

$ make LLVM=1 fs/select.ll

As Fangrui notes:
  A LLVM_ENABLE_ASSERTIONS=off build of Clang defaults to
  -fdiscard-value-names.

  A LLVM_ENABLE_ASSERTIONS=on build of Clang defaults to
  -fno-discard-value-names.

Explicitly enable -fno-discard-value-names so that the IR always contains
value names regardless of whether assertions were enabled or not.
Assertions generally are not enabled in releases of clang packaged by
distributions.

Link: https://github.com/ClangBuiltLinux/linux/issues/1467Reviewed-by: NNathan Chancellor <nathan@kernel.org>
Reviewed-by: NFangrui Song <maskray@google.com>
Signed-off-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Convert list of clang-tidy arguments to a list for ease of adding to
them and extending them as required.
Signed-off-by: NGuru Das Srinagesh <quic_gurus@quicinc.com>
Suggested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

The musl implementation of getopt stops looking for options after the
first non-option argument. Put the options before the non-option
argument so environments using musl can still build the kernel and
modules.

Fixes: f73edc89 ("kbuild: unify two modpost invocations")
Link: https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt.c?h=dc9285ad1dc19349c407072cc48ba70dab86de45#n44Signed-off-by: NRichard Acayan <mailingradian@gmail.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

vmlinux.bz2 was added to the rpm packages in 2009 in the
fc370ecf ("kbuild: add vmlinux to kernel rpm") but seemingly hasn't
been used since.

Originally this should have been split up in a seperate debugging
package because it massively increases the size of the generated rpm's
e.g. kernel rpm built using binrpm-pkg on Fedora 36 default 5.19.8 kernel
config and localmodconfig is ~255MB with vmlinux.bz2 and only ~65MB
without it.

Make the kernel built rpms about 4x smaller by not including the unused
vmlinux.bz2 in them.
Signed-off-by: NZack Rusin <zackr@vmware.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Add a warning for fixes tags that does not follow community conventions.

Link: https://lkml.kernel.org/r/20220914100255.1048460-1-niklas.soderlund@corigine.comSigned-off-by: NNiklas Söderlund <niklas.soderlund@corigine.com>
Reviewed-by: NSimon Horman <simon.horman@corigine.com>
Reviewed-by: NLouis Peens <louis.peens@corigine.com>
Reviewed-by: NPhilippe Schenker <philippe.schenker@toradex.com>
Acked-by: NDwaipayan Ray <dwaipayanray1@gmail.com>
Reviewed-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

For each memory location KernelMemorySanitizer maintains two types of
metadata:

1. The so-called shadow of that location - а byte:byte mapping describing
   whether or not individual bits of memory are initialized (shadow is 0)
   or not (shadow is 1).
2. The origins of that location - а 4-byte:4-byte mapping containing
   4-byte IDs of the stack traces where uninitialized values were
   created.

Each struct page now contains pointers to two struct pages holding KMSAN
metadata (shadow and origins) for the original struct page.  Utility
routines in mm/kmsan/core.c and mm/kmsan/shadow.c handle the metadata
creation, addressing, copying and checking.  mm/kmsan/report.c performs
error reporting in the cases an uninitialized value is used in a way that
leads to undefined behavior.

KMSAN compiler instrumentation is responsible for tracking the metadata
along with the kernel memory.  mm/kmsan/instrumentation.c provides the
implementation for instrumentation hooks that are called from files
compiled with -fsanitize=kernel-memory.

To aid parameter passing (also done at instrumentation level), each
task_struct now contains a struct kmsan_task_state used to track the
metadata of function parameters and return values for that task.

Finally, this patch provides CONFIG_KMSAN that enables KMSAN, and declares
CFLAGS_KMSAN, which are applied to files compiled with KMSAN.  The
KMSAN_SANITIZE:=n Makefile directive can be used to completely disable
KMSAN instrumentation for certain files.

Similarly, KMSAN_ENABLE_CHECKS:=n disables KMSAN checks and makes newly
created stack memory initialized.

Users can also use functions from include/linux/kmsan-checks.h to mark
certain memory regions as uninitialized or initialized (this is called
"poisoning" and "unpoisoning") or check that a particular region is
initialized.

Link: https://lkml.kernel.org/r/20220915150417.722975-12-glider@google.comSigned-off-by: NAlexander Potapenko <glider@google.com>
Acked-by: NMarco Elver <elver@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

When include/linux/export-internal.h is updated, .vmlinux.export.o
must be rebuilt, but it does not happen because its rule is hidden
behind scripts/link-vmlinux.sh.

Move it out of the shell script, so that Make can see the dependency
between vmlinux and .vmlinux.export.o.

Move the vmlinux rule to scripts/Makefile.vmlinux.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.

There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Every EXPORT_SYMBOL creates __kstrtab_* and __kstrtabns_*, which
consumes 15-20% of the kallsyms entries.

For example, on the system built from the x86_64 defconfig,

  $ cat /proc/kallsyms | wc
     129527    388581   5685465
  $ cat /proc/kallsyms | grep __kstrtab | wc
      23489     70467   1187932

We already ignore __crc_* symbols populated by EXPORT_SYMBOL, so it
should be fine to ignore __kstrtab_* and __kstrtabns_* as well.

This makes vmlinux a bit smaller.

  $ size vmlinux.before vmlinux.after
     text    data     bss     dec     hex filename
  22785374        8559694 1413328 32758396        1f3da7c vmlinux.before
  22785374        8137806 1413328 32336508        1ed6a7c vmlinux.after
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

This gets rid of the pipe operator connected with 'cat'.

Also use getopt_long() to parse the command line.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Now that kallsyms.c parses the output from mksysmap, some symbols have
already been dropped.

Move comments to scripts/mksysmap. Also, make the grep command readable.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

scripts/mksysmap internally runs ${NM} (dropping some symbols).

When CONFIG_KALLSYMS=y, mksysmap creates .tmp_System.map, but it is
almost the same as the output from the ${NM} invocation in kallsyms().
It is true scripts/mksysmap drops some symbols, but scripts/kallsyms.c
ignores more anyway.

Keep the mksysmap output as *.syms, and reuse it for kallsyms and
'cmp -s'. It saves one ${NM} invocation.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Since commit 7b453719 ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), __crc_* symbols never become
absolute.

Keep ignoring __crc_*, but update the comment.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.

A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.

I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.

I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

The objects placed at the head of vmlinux need special treatments:

 - arch/$(SRCARCH)/Makefile adds them to head-y in order to place
   them before other archives in the linker command line.

 - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
   obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

We enable -Wcast-function-type globally in the kernel to warn about
mismatching types in function pointer casts. Compilers currently
warn only about ABI incompability with this flag, but Clang 16 will
enable a stricter version of the check by default that checks for an
exact type match. This will be very noisy in the kernel, so disable
-Wcast-function-type-strict without W=1 until the new warnings have
been addressed.

Cc: stable@vger.kernel.org
Link: https://reviews.llvm.org/D134831
Link: https://github.com/ClangBuiltLinux/linux/issues/1724Suggested-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NSami Tolvanen <samitolvanen@google.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220930203310.4010564-1-samitolvanen@google.com

checkpatch does not point out that VM_BUG_ON() and friends should be
avoided, however, Linus notes:

    VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally
    no different, the only difference is "we can make the code smaller
    because these are less important". [1]

So let's warn on VM_BUG_ON() and other BUG variants as well. While at it,
make it clearer that the kernel really shouldn't be crashed.

As there are some subsystem BUG macros that actually don't end up crashing
the kernel -- for example, KVM_BUG_ON() -- exclude these manually.

[1] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@mail.gmail.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20220923113426.52871-3-david@redhat.comSigned-off-by: NJonathan Corbet <corbet@lwn.net>

This one file should not really be in the top-level documentation
directory.  core-api/ may not be a perfect fit but seems to be best, so
move it there.  Adjust a couple of internal document references to make
them location-independent, and point checkpatch.pl at the new location.

Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: NDavid Vernet <void@manifault.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-6-corbet@lwn.netSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Modpost generates .vmlinux.export.c and *.mod.c, which are prerequisites
of vmlinux and modules, respectively.

The modpost stage should be re-run when the modpost code is updated.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Currently, modpost is executed twice; first for vmlinux, second
for modules.

This commit merges them.

Current build flow
==================

  1) build obj-y and obj-m objects
    2) link vmlinux.o
      3) modpost for vmlinux
        4) link vmlinux
          5) modpost for modules
            6) link modules (*.ko)

The build steps 1) through 6) are serialized, that is, modules are
built after vmlinux. You do not get benefits of parallel builds when
scripts/link-vmlinux.sh is being run.

New build flow
==============

  1) build obj-y and obj-m objects
    2) link vmlinux.o
      3) modpost for vmlinux and modules
        4a) link vmlinux
        4b) link modules (*.ko)

In the new build flow, modpost is invoked just once.

vmlinux and modules are built in parallel. One exception is
CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

Move the build rules of vmlinux.o out of scripts/link-vmlinux.sh to
clearly separate 1) pre-modpost, 2) modpost, 3) post-modpost stages.
This will make further refactoring possible.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

.vmlinux.objs is used by modpost, so scripts/Makefile.modpost is
a better place to generate it.

It is used only when CONFIG_MODVERSIONS=y. It should be guarded
by "ifdef CONFIG_MODVERSIONS".
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

Use the ordinary obj-y syntax to list subdirectories.

Note1:
Previously, the link order of lib-y depended on CONFIG_MODULES; lib-y
was linked before drivers-y when CONFIG_MODULES=y, otherwise after
drivers-y. This was a bug of commit 7273ad2b ("kbuild: link lib-y
objects to vmlinux forcibly when CONFIG_MODULES=y"), but it was not a
big deal after all. Now, all objects listed in lib-y are linked last,
irrespective of CONFIG_MODULES.

Note2:
Finally, the single target build in arch/*/lib/ works correctly. There was
a bug report about this. [1]

  $ make ARCH=arm arch/arm/lib/findbit.o
    CALL    scripts/checksyscalls.sh
    AS      arch/arm/lib/findbit.o

[1]: https://lore.kernel.org/linux-kbuild/YvUQOwL6lD4%2F5%2FU6@shell.armlinux.org.uk/Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNicolas Schier <nicolas@fjasle.eu>

cc-ifversion is GCC specific. Replace it with compiler specific
variants. Update the users of cc-ifversion to use these new macros.

Link: https://github.com/ClangBuiltLinux/linux/issues/350
Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/Suggested-by: NBill Wendling <morbo@google.com>
Reviewed-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Doing make V=1 binrpm-pkg results in:

 Executing(%install): /bin/sh -e /var/tmp/rpm-tmp.EgV6qJ
 + umask 022
 + cd .
 + /bin/rm -rf /home/scgl/rpmbuild/BUILDROOT/kernel-6.0.0_rc5+-1.s390x
 + /bin/mkdir -p /home/scgl/rpmbuild/BUILDROOT
 + /bin/mkdir /home/scgl/rpmbuild/BUILDROOT/kernel-6.0.0_rc5+-1.s390x
 + mkdir -p /home/scgl/rpmbuild/BUILDROOT/kernel-6.0.0_rc5+-1.s390x/boot
 + make -f ./Makefile image_name
 + cp test -e include/generated/autoconf.h -a -e include/config/auto.conf || ( \ echo >&2; \ echo >&2 " ERROR: Kernel configuration is invalid."; \ echo >&2 " include/generated/autoconf.h or include/config/auto.conf are missing.";\ echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \ echo >&2 ; \ /bin/false) arch/s390/boot/bzImage /home/scgl/rpmbuild/BUILDROOT/kernel-6.0.0_rc5+-1.s390x/boot/vmlinuz-6.0.0-rc5+
 cp: invalid option -- 'e'
 Try 'cp --help' for more information.
 error: Bad exit status from /var/tmp/rpm-tmp.EgV6qJ (%install)

Because the make call to get the image name is verbose and prints
additional information.

Fixes: 993bdde9 ("kbuild: add image_name to no-sync-config-targets")
Signed-off-by: NJanis Schoetterl-Glausch <scgl@linux.ibm.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Remove unused function argument, and there is
no logic changes.
Signed-off-by: NZeng Heng <zengheng4@huawei.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

sym_set_choice_value could be removed and directly call
sym_set_tristate_value instead.
Signed-off-by: NZeng Heng <zengheng4@huawei.com>
Suggested-by: NMasahiro Yamada <masahiroy@kernel.org>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Based on Linus' patch. Refactor scripts/Makefile.vmlinux_o as well.

Link: https://lore.kernel.org/lkml/CAHk-=wgjTMQgiKzBZTmb=uWGDEQxDdyF1+qxBkODYciuNsmwnw@mail.gmail.com/Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>

The single target build has a subtle bug for the combination for
an individual file and a subdirectory.

[1] 'make kernel/fork.i' builds only kernel/fork.i

  $ make kernel/fork.i
    CALL    scripts/checksyscalls.sh
    DESCEND objtool
    CPP     kernel/fork.i

[2] 'make kernel/' builds only under the kernel/ directory.

  $ make kernel/
    CALL    scripts/checksyscalls.sh
    DESCEND objtool
    CC      kernel/fork.o
    CC      kernel/exec_domain.o
       [snip]
    CC      kernel/rseq.o
    AR      kernel/built-in.a

But, if you try to do [1] and [2] in a single command, you will get
only [1] with a weird log:

  $ make kernel/fork.i kernel/
    CALL    scripts/checksyscalls.sh
    DESCEND objtool
    CPP     kernel/fork.i
  make[2]: Nothing to be done for 'kernel/'.

With 'make kernel/fork.i kernel/', you should get both [1] and [2].

Rewrite the single target build.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Remove the bash build dependency for those who otherwise do not
have it installed. This also provides a significant speedup:

$ make defconfig
$ make yes2modconfig

...

$ find  .  -name "*.o" | grep -v vmlinux | wc
     3169      3169     89615
$ export NM=nm
$ time sh -c 'find . -name "*.o" | grep -v vmlinux | xargs -n1
./scripts/check-local-export'

Without patch:
    0m15.90s real     0m12.17s user     0m05.28s system

With patch:
dash + nawk
    0m02.16s real     0m02.92s user     0m00.34s system

dash + busybox awk
    0m02.36s real     0m03.36s user     0m00.34s system

dash + gawk
    0m02.07s real     0m03.26s user     0m00.32s system

bash + gawk
    0m03.55s real     0m05.00s user     0m00.54s system
Signed-off-by: NOwen Rafferty <owen@owenrafferty.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

This reverts commit [1] in the pre-git era.

I do not know what problem happened in the script when sh != bash
because there is no commit message.

Now that this script is much simpler than it used to be, let's revert
it, and let' see. (If this turns out to be problematic, fix the code
with proper commit description.)

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=11acbbbb8a50f4de7dbe4bc1b5acc440dfe81810Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Minimize the scope of LC_ALL=C like before commit 87c94bfb ("kbuild:
override build timestamp & version").

Give LC_ALL=C to '$LD -v' to get the consistent version output, as commit
bcbcf50f ("kbuild: fix ld-version.sh to not be affected by locale")
mentioned the LD version is affected by locale.

While I was here, I merged two sed invocations.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Kbuild builds init/built-in.a twice; first during the ordinary
directory descending, second from scripts/link-vmlinux.sh.

We do this because UTS_VERSION contains the build version and the
timestamp. We cannot update it during the normal directory traversal
since we do not yet know if we need to update vmlinux. UTS_VERSION is
temporarily calculated, but omitted from the update check. Otherwise,
vmlinux would be rebuilt every time.

When Kbuild results in running link-vmlinux.sh, it increments the
version number in the .version file and takes the timestamp at that
time to really fix UTS_VERSION.

However, updating the same file twice is a footgun. To avoid nasty
timestamp issues, all build artifacts that depend on init/built-in.a
are atomically generated in link-vmlinux.sh, where some of them do not
need rebuilding.

To fix this issue, this commit changes as follows:

[1] Split UTS_VERSION out to include/generated/utsversion.h from
    include/generated/compile.h

    include/generated/utsversion.h is generated just before the
    vmlinux link. It is generated under include/generated/ because
    some decompressors (s390, x86) use UTS_VERSION.

[2] Split init_uts_ns and linux_banner out to init/version-timestamp.c
    from init/version.c

    init_uts_ns and linux_banner contain UTS_VERSION. During the ordinary
    directory descending, they are compiled with __weak and used to
    determine if vmlinux needs relinking. Just before the vmlinux link,
    they are compiled without __weak to embed the real version and
    timestamp.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>