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: Masahiro 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: Masahiro 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: Masahiro 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: Masahiro 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: Masahiro 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 ${NM} invocation.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit 7b4537199a ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), __crc_* symbols never become
absolute.
Keep ignoring __crc_*, but update the comment.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.
A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.
I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.
I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
The objects placed at the head of vmlinux need special treatments:
- arch/$(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: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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: Masahiro 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: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas 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: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas 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: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas 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 7273ad2b08 ("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: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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: 993bdde945 ("kbuild: add image_name to no-sync-config-targets")
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Remove unused function argument, and there is
no logic changes.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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: Masahiro 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: Owen Rafferty <owen@owenrafferty.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Minimize the scope of LC_ALL=C like before commit 87c94bfb8a ("kbuild:
override build timestamp & version").
Give LC_ALL=C to '$LD -v' to get the consistent version output, as commit
bcbcf50f52 ("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: Masahiro 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: Masahiro Yamada <masahiroy@kernel.org>
The AWK code was added to deduplicate modules.order in case $(obj-m)
contains the same module multiple times, but it is actually unneeded
since commit b2c8855491 ("kbuild: update modules.order only when
contained modules are updated").
The list is already deduplicated before being processed by AWK because
$^ is the deduplicated list of prerequisites.
(Please note the real-prereqs macro uses $^)
Yet, modules.order will contain duplication if two different Makefiles
build the same module:
foo/Makefile:
obj-m += bar/baz.o
foo/bar/Makefile:
obj-m += baz.o
However, the parallel builds cannot properly handle this case in the
first place. So, it is better to let it fail (as already done by
scripts/modules-check.sh).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
It is unneeded to check the sha1sum every time.
Create the timestamp files to manage it.
Add '.' to clean-dirs because 'make clean' must visit ./Kbuild to
clean up the timestamp files.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
My future plan is to list subdirectories in ./Kbuild. When it occurs,
$(vmlinux-alldirs) will not contain all subdirectories.
Let's hard-code the directory list until I get around to implementing
a more sophisticated way for generating a source tarball.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
When receiving some signal, GNU Make automatically deletes the target if
it has already been changed by the interrupted recipe.
If the target is possibly incomplete due to interruption, it must be
deleted so that it will be remade from scratch on the next run of make.
Otherwise, the target would remain corrupted permanently because its
timestamp had already been updated.
Thanks to this behavior of Make, you can stop the build any time by
pressing Ctrl-C, and just run 'make' to resume it.
Kbuild also relies on this feature, but it is equivalently important
for any build systems that make decisions based on timestamps (if you
want to support Ctrl-C reliably).
However, this does not always work as claimed; Make immediately dies
with Ctrl-C if its stderr goes into a pipe.
[Test Makefile]
foo:
echo hello > $@
sleep 3
echo world >> $@
[Test Result]
$ make # hit Ctrl-C
echo hello > foo
sleep 3
^Cmake: *** Deleting file 'foo'
make: *** [Makefile:3: foo] Interrupt
$ make 2>&1 | cat # hit Ctrl-C
echo hello > foo
sleep 3
^C$ # 'foo' is often left-over
The reason is because SIGINT is sent to the entire process group.
In this example, SIGINT kills 'cat', and 'make' writes the message to
the closed pipe, then dies with SIGPIPE before cleaning the target.
A typical bad scenario (as reported by [1], [2]) is to save build log
by using the 'tee' command:
$ make 2>&1 | tee log
This can be problematic for any build systems based on Make, so I hope
it will be fixed in GNU Make. The maintainer of GNU Make stated this is
a long-standing issue and difficult to fix [3]. It has not been fixed
yet as of writing.
So, we cannot rely on Make cleaning the target. We can do it by
ourselves, in signal traps.
As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and
SITERM for the target removal. I added the traps for them, and also for
SIGPIPE just in case cmd_* rule prints something to stdout or stderr
(but I did not observe an actual case where SIGPIPE was triggered).
[Note 1]
The trap handler might be worth explaining.
rm -f $@; trap - $(sig); kill -s $(sig) $$
This lets the shell kill itself by the signal it caught, so the parent
process can tell the child has exited on the signal. Generally, this is
a proper manner for handling signals, in case the calling program (like
Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may
not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT
in WUE and SIGTERM in IUE.
IUE - Immediate Unconditional Exit
WUE - Wait and Unconditional Exit
WCE - Wait and Cooperative Exit
For details, see "Proper handling of SIGINT/SIGQUIT" [4].
[Note 2]
Reverting 392885ee82 ("kbuild: let fixdep directly write to .*.cmd
files") would directly address [1], but it only saves if_changed_dep.
As reported in [2], all commands that use redirection can potentially
leave an empty (i.e. broken) target.
[Note 3]
Another (even safer) approach might be to always write to a temporary
file, and rename it to $@ at the end of the recipe.
<command> > $(tmp-target)
mv $(tmp-target) $@
It would require a lot of Makefile changes, and result in ugly code,
so I did not take it.
[Note 4]
A little more thoughts about a pattern rule with multiple targets (or
a grouped target).
%.x %.y: %.z
<recipe>
When interrupted, GNU Make deletes both %.x and %.y, while this solution
only deletes $@. Probably, this is not a big deal. The next run of make
will execute the rule again to create $@ along with the other files.
[1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/
[2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/
[3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html
[4]: https://www.cons.org/cracauer/sigint.html
Fixes: 392885ee82 ("kbuild: let fixdep directly write to .*.cmd files")
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
There is nowhere calling `menu_get_root_menu` function,
so remove it.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull Kbuild fixes from Masahiro Yamada:
- Remove unused scripts/gcc-ld script
- Add zstd support to scripts/extract-ikconfig
- Check 'make headers' for UML
- Fix scripts/mksysmap to ignore local symbols
* tag 'kbuild-fixes-v6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
mksysmap: Fix the mismatch of 'L0' symbols in System.map
kbuild: disable header exports for UML in a straightforward way
scripts/extract-ikconfig: add zstd compression support
scripts: remove obsolete gcc-ld script
When System.map was generated, the kernel used mksysmap to filter the
kernel symbols, we need to filter "L0" symbols in LoongArch architecture.
$ cat System.map | grep L0
9000000000221540 t L0
The L0 symbol exists in System.map, but not in .tmp_System.map. When
"cmp -s System.map .tmp_System.map" will show "Inconsistent kallsyms
data" error message in link-vmlinux.sh script.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
-Wformat was recently re-enabled for builds with clang, then quickly
re-disabled, due to concerns stemming from the frequency of default
argument promotion related warning instances.
commit 258fafcd06 ("Makefile.extrawarn: re-enable -Wformat for clang")
commit 21f9c8a13b ("Revert "Makefile.extrawarn: re-enable -Wformat for clang"")
ISO WG14 has ratified N2562 to address default argument promotion
explicitly for printf, as part of the upcoming ISO C2X standard.
The behavior of clang was changed in clang-16 to not warn for the cited
cases in all language modes.
Add a version check, so that users of clang-16 now get the full effect
of -Wformat. For older clang versions, re-enable flags under the
-Wformat group that way users still get some useful checks related to
format strings, without noisy default argument promotion warnings. I
intentionally omitted -Wformat-y2k and -Wformat-security from being
re-enabled, which are also part of -Wformat in clang-16.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Link: https://github.com/llvm/llvm-project/issues/57102
Link: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf
Suggested-by: Justin Stitt <jstitt007@gmail.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 8564ed2b38 ("Kbuild, lto: Add a gcc-ld script to let run gcc
as ld") in 2014, there was not specific work on this the gcc-ld script
other than treewide clean-ups.
There are no users within the kernel tree, and probably no out-of-tree
users either, and there is no dedicated maintainer in MAINTAINERS.
Delete this obsolete gcc-ld script.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull Kbuild fixes from Masahiro Yamada:
- Fix module versioning broken on some architectures
- Make dummy-tools enable CONFIG_PPC_LONG_DOUBLE_128
- Remove -Wformat-zero-length, which has no warning instance
- Fix the order between drivers and libs in modules.order
- Fix false-positive warnings in clang-analyzer
* tag 'kbuild-fixes-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
scripts/clang-tools: Remove DeprecatedOrUnsafeBufferHandling check
kbuild: fix the modules order between drivers and libs
scripts/Makefile.extrawarn: Do not disable clang's -Wformat-zero-length
kbuild: dummy-tools: pretend we understand __LONG_DOUBLE_128__
modpost: fix module versioning when a symbol lacks valid CRC
This `clang-analyzer` check flags the use of memset(), suggesting a more
secure version of the API, such as memset_s(), which does not exist in
the kernel:
warning: Call to function 'memset' is insecure as it does not provide
security checks introduced in the C11 standard. Replace with analogous
functions that support length arguments or provides boundary checks such
as 'memset_s' in case of C11
[clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
Signed-off-by: Guru Das Srinagesh <quic_gurus@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There are no instances of this warning in the tree across several
difference architectures and configurations. This was added by
commit 26ea6bb1fe ("kbuild, LLVMLinux: Supress warnings unless W=1-3")
back in 2014, where it might have been necessary, but there are no
instances of it now so stop disabling it to increase warning coverage
for clang.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There is a test in powerpc's Kconfig which checks __LONG_DOUBLE_128__
and sets CONFIG_PPC_LONG_DOUBLE_128 if it is understood by the compiler.
We currently don't handle it, so this results in PPC_LONG_DOUBLE_128 not
being in super-config generated by dummy-tools. So take this into
account in the gcc script and preprocess __LONG_DOUBLE_128__ as "1".
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit 7b4537199a ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), module versioning is broken on
some architectures. Loading a module fails with "disagrees about
version of symbol module_layout".
On such architectures (e.g. ARCH=sparc build with sparc64_defconfig),
modpost shows a warning, like follows:
WARNING: modpost: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
Is "_mcount" prototyped in <asm/asm-prototypes.h>?
Previously, it was a harmless warning (CRC check was just skipped),
but now wrong CRCs are used for comparison because invalid CRCs are
just skipped.
$ sparc64-linux-gnu-nm -n vmlinux
[snip]
0000000000c2cea0 r __ksymtab__kstrtol
0000000000c2ceb8 r __ksymtab__kstrtoul
0000000000c2ced0 r __ksymtab__local_bh_enable
0000000000c2cee8 r __ksymtab__mcount
0000000000c2cf00 r __ksymtab__printk
0000000000c2cf18 r __ksymtab__raw_read_lock
0000000000c2cf30 r __ksymtab__raw_read_lock_bh
[snip]
0000000000c53b34 D __crc__kstrtol
0000000000c53b38 D __crc__kstrtoul
0000000000c53b3c D __crc__local_bh_enable
0000000000c53b40 D __crc__printk
0000000000c53b44 D __crc__raw_read_lock
0000000000c53b48 D __crc__raw_read_lock_bh
Please notice __crc__mcount is missing here.
When the module subsystem looks up a CRC that comes after, it results
in reading out a wrong address. For example, when __crc__printk is
needed, the module subsystem reads 0xc53b44 instead of 0xc53b40.
All CRC entries must be output for correct index accessing. Invalid
CRCs will be unused, but are needed to keep the one-to-one mapping
between __ksymtab_* and __crc_*.
The best is to fix all modpost warnings, but several warnings are still
remaining on less popular architectures.
Fixes: 7b4537199a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS")
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Pull hardening fixes from Kees Cook:
- Also undef LATENT_ENTROPY_PLUGIN for per-file disabling (Andrew
Donnellan)
- Return EFAULT on copy_from_user() failures in LoadPin (Kees Cook)
* tag 'hardening-v6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
LoadPin: Return EFAULT on copy_from_user() failures
Commit 36d4b36b69 ("lib/nodemask: inline next_node_in() and
node_random()") refactored some code by moving node_random() from
lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to
include random.h, which conditionally defines add_latent_entropy()
depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.
This broke the build on powerpc, where nodemask.h is indirectly included
in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that
is excluded from the latent entropy plugin using
DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag
to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN.
This leads to the following:
CC arch/powerpc/kernel/prom_init.o
In file included from ./include/linux/nodemask.h:97,
from ./include/linux/mmzone.h:17,
from ./include/linux/gfp.h:7,
from ./include/linux/xarray.h:15,
from ./include/linux/radix-tree.h:21,
from ./include/linux/idr.h:15,
from ./include/linux/kernfs.h:12,
from ./include/linux/sysfs.h:16,
from ./include/linux/kobject.h:20,
from ./include/linux/pci.h:35,
from arch/powerpc/kernel/prom_init.c:24:
./include/linux/random.h: In function 'add_latent_entropy':
./include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'?
25 | add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
| ^~~~~~~~~~~~~~
| add_latent_entropy
./include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [scripts/Makefile.build:249: arch/powerpc/kernel/prom_init.o] Fehler 1
make[1]: *** [scripts/Makefile.build:465: arch/powerpc/kernel] Fehler 2
make: *** [Makefile:1855: arch/powerpc] Error 2
Change the DISABLE_LATENT_ENTROPY_PLUGIN flags to undefine
LATENT_ENTROPY_PLUGIN for files where the plugin is disabled.
Cc: Yury Norov <yury.norov@gmail.com>
Fixes: 38addce8b6 ("gcc-plugins: Add latent_entropy plugin")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216367
Link: https://lore.kernel.org/linuxppc-dev/alpine.DEB.2.22.394.2208152006320.289321@ramsan.of.borg/
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220816051720.44108-1-ajd@linux.ibm.com
Pull more RISC-V updates from Palmer Dabbelt:
"There's still a handful of new features in here, but there are a lot
of fixes/cleanups as well:
- Support for the Zicbom extension for explicit cache-block
management, along with the necessary bits to make the non-standard
cache management ops on the Allwinner D1 function
- Support for the Zihintpause extension, which codifies a go-slow
instruction used for cpu_relax()
- Support for the Sstc extension for supervisor-mode timer/counter
management
- Many device tree fixes and cleanups, including a large set for the
Canaan device trees
- A handful of fixes and cleanups for the PMU driver"
* tag 'riscv-for-linus-5.20-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (43 commits)
dt-bindings: gpio: sifive: add gpio-line-names
wireguard: selftests: set CONFIG_NONPORTABLE on riscv32
RISC-V: KVM: Support sstc extension
RISC-V: Improve SBI definitions
RISC-V: Move counter info definition to sbi header file
RISC-V: Fix SBI PMU calls for RV32
RISC-V: Update user page mapping only once during start
RISC-V: Fix counter restart during overflow for RV32
RISC-V: Prefer sstc extension if available
RISC-V: Enable sstc extension parsing from DT
RISC-V: Add SSTC extension CSR details
riscv:uprobe fix SR_SPIE set/clear handling
dt-bindings: riscv: fix SiFive l2-cache's cache-sets
riscv: ensure cpu_ops_sbi is declared
RISC-V: cpu_ops_spinwait.c should include head.h
RISC-V: Declare cpu_ops_spinwait in <asm/cpu_ops.h>
riscv: dts: starfive: correct number of external interrupts
riscv: dts: sifive unmatched: Add PWM controlled LEDs
riscv/purgatory: Omit use of bin2c
riscv/purgatory: hard-code obj-y in Makefile
...
The .incbin assembler directive is much faster than bin2c + $(CC).
Do similar refactoring as in commit 4c0f032d49 ("s390/purgatory:
Omit use of bin2c").
Please note the .quad directive matches to size_t in C (both 8 byte)
because the purgatory is compiled only for the 64-bit kernel.
(KEXEC_FILE depends on 64BIT).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20220625223438.835408-2-masahiroy@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This reverts commit 258fafcd06.
The clang -Wformat warning is terminally broken, and the clang people
can't seem to get their act together.
This test program causes a warning with clang:
#include <stdio.h>
int main(int argc, char **argv)
{
printf("%hhu\n", 'a');
}
resulting in
t.c:5:19: warning: format specifies type 'unsigned char' but the argument has type 'int' [-Wformat]
printf("%hhu\n", 'a');
~~~~ ^~~
%d
and apparently clang people consider that a feature, because they don't
want to face the reality of how either C character constants, C
arithmetic, and C varargs functions work.
The rest of the world just shakes their head at that kind of
incompetence, and turns off -Wformat for clang again.
And no, the "you should use a pointless cast to shut this up" is not a
valid answer. That warning should not exist in the first place, or at
least be optinal with some "-Wformat-me-harder" kind of option.
[ Admittedly, there's also very little reason to *ever* use '%hh[ud]' in
C, but what little reason there is is entirely about 'I want to see
only the low 8 bits of the argument'. So I would suggest nobody ever
use that format in the first place, but if they do, the clang
behavious is simply always wrong. Because '%hhu' takes an 'int'. It's
that simple. ]
Reported-by: Sudip Mukherjee (Codethink) <sudipm.mukherjee@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull Kbuild updates from Masahiro Yamada:
- Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3)
- Fix error of rpm-pkg cross-builds
- Support riscv for checkstack tool
- Re-enable -Wformwat warnings for Clang
- Clean up modpost, Makefiles, and misc scripts
* tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
modpost: remove .symbol_white_list field entirely
modpost: remove unneeded .symbol_white_list initializers
modpost: add PATTERNS() helper macro
modpost: shorten warning messages in report_sec_mismatch()
Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"
modpost: use more reliable way to get fromsec in section_rel(a)()
modpost: add array range check to sec_name()
modpost: refactor get_secindex()
kbuild: set EXIT trap before creating temporary directory
modpost: remove unused Elf_Sword macro
Makefile.extrawarn: re-enable -Wformat for clang
kbuild: add dtbs_prepare target
kconfig: Qt5: tell the user which packages are required
modpost: use sym_get_data() to get module device_table data
modpost: drop executable ELF support
checkstack: add riscv support for scripts/checkstack.pl
kconfig: shorten the temporary directory name for cc-option
scripts: headers_install.sh: Update config leak ignore entries
kbuild: error out if $(INSTALL_MOD_PATH) contains % or :
kbuild: error out if $(KBUILD_EXTMOD) contains % or :
...
Pull module updates from Luis Chamberlain:
"For the 6.0 merge window the modules code shifts to cleanup and minor
fixes effort. This becomes much easier to do and review now due to the
code split to its own directory from effort on the last kernel
release. I expect to see more of this with time and as we expand on
test coverage in the future. The cleanups and fixes come from usual
suspects such as Christophe Leroy and Aaron Tomlin but there are also
some other contributors.
One particular minor fix worth mentioning is from Helge Deller, where
he spotted a *forever* incorrect natural alignment on both ELF section
header tables:
* .altinstructions
* __bug_table sections
A lot of back and forth went on in trying to determine the ill effects
of this misalignment being present for years and it has been
determined there should be no real ill effects unless you have a buggy
exception handler. Helge actually hit one of these buggy exception
handlers on parisc which is how he ended up spotting this issue. When
implemented correctly these paths with incorrect misalignment would
just mean a performance penalty, but given that we are dealing with
alternatives on modules and with the __bug_table (where info regardign
BUG()/WARN() file/line information associated with it is stored) this
really shouldn't be a big deal.
The only other change with mentioning is the kmap() with
kmap_local_page() and my only concern with that was on what is done
after preemption, but the virtual addresses are restored after
preemption. This is only used on module decompression.
This all has sit on linux-next for a while except the kmap stuff which
has been there for 3 weeks"
* tag 'modules-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module: Replace kmap() with kmap_local_page()
module: Show the last unloaded module's taint flag(s)
module: Use strscpy() for last_unloaded_module
module: Modify module_flags() to accept show_state argument
module: Move module's Kconfig items in kernel/module/
MAINTAINERS: Update file list for module maintainers
module: Use vzalloc() instead of vmalloc()/memset(0)
modules: Ensure natural alignment for .altinstructions and __bug_table sections
module: Increase readability of module_kallsyms_lookup_name()
module: Fix ERRORs reported by checkpatch.pl
module: Add support for default value for module async_probe
