sparc/vdso: Always reject undefined references during linking

Instead of using a custom script to detect and fail on undefined
references, use --no-undefined for all VDSO linker invocations.

Drop t

sparc/vdso: Always reject undefined references during linking

Instead of using a custom script to detect and fail on undefined
references, use --no-undefined for all VDSO linker invocations.

Drop the now unused checkundef.sh script.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Andreas Larsson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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sparc/build: Put usage of -fcall-used* flags behind cc-option

Place -fcall-used* flags behind cc-option so that clang (which doesn't
support them) can still compile the kernel.

This is a safe chang

sparc/build: Put usage of -fcall-used* flags behind cc-option

Place -fcall-used* flags behind cc-option so that clang (which doesn't
support them) can still compile the kernel.

This is a safe change, the reasoning is as follows:

In the (normal) 32-bit ABI, %g5 and %g7 is normally reserved, and in
the 64-bit ABI, %g7 is the reserved one.
Linux turns them into volatile registers by the way of -fcall-used-*,
but on the other hand, omitting the flags shouldn't be harmful;
compilers will now simply refuse to touch them, and any assembly
code that happens to touch them would still work like usual (because
Linux' conventions already treats them as volatile anyway).

Signed-off-by: Koakuma <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Reviewed-by: Andreas Larsson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andreas Larsson <[email protected]>

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Makefile: remove redundant tool coverage variables

Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.

Remove redundant variables.

Note:

This commit changes the covera

Makefile: remove redundant tool coverage variables

Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.

Remove redundant variables.

Note:

This commit changes the coverage for some objects:

- include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV
- include arch/sparc/vdso/vdso-image-*.o into UBSAN
- include arch/sparc/vdso/vma.o into UBSAN
- include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
- include arch/x86/entry/vdso/vma.o into GCOV, KCOV
- include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV

I believe these are positive effects because all of them are kernel
space objects.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Tested-by: Roberto Sassu <[email protected]>

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kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention withou

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

$(obj) - directory in the object tree
$(src) - directory in the source tree (changed by this commit)
$(objtree) - the top of the kernel object tree
$(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>

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sparc: vdso: Disable UBSAN instrumentation

The UBSAN instrumentation cannot work in the vDSO since it is executing
in userspace, so disable it in the Makefile. Fixes the build failures
such as:

arc

sparc: vdso: Disable UBSAN instrumentation

The UBSAN instrumentation cannot work in the vDSO since it is executing
in userspace, so disable it in the Makefile. Fixes the build failures
such as:

arch/sparc/vdso/vclock_gettime.c:217: undefined reference to `__ubsan_handle_shift_out_of_bounds'

Acked-by: Sam Ravnborg <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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sparc: vdso: use $(addprefix ) instead of $(foreach )

$(addprefix ) is slightly shorter and more intuitive.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Sam Ravnborg <sam@ravnbor

sparc: vdso: use $(addprefix ) instead of $(foreach )

$(addprefix ) is slightly shorter and more intuitive.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>

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sparc: vdso: simplify obj-y addition

Add objects to obj-y in a more straightforward way.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>

sparc: vdso: clean up build artifacts in arch/sparc/vdso/

Currently, vdso-image-*.c, vdso*.so, vdso*.so.dbg are not cleaned
because 'make clean' does not include include/config/auto.conf,
resulting

sparc: vdso: clean up build artifacts in arch/sparc/vdso/

Currently, vdso-image-*.c, vdso*.so, vdso*.so.dbg are not cleaned
because 'make clean' does not include include/config/auto.conf,
resulting in $(vdso_img-y) being empty.

Add the build artifacts to 'targets' unconditionally.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>

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kbuild: unify vdso_install rules

Currently, there is no standard implementation for vdso_install,
leading to various issues:

1. Code duplication

Many architectures duplicate similar code just

kbuild: unify vdso_install rules

Currently, there is no standard implementation for vdso_install,
leading to various issues:

1. Code duplication

Many architectures duplicate similar code just for copying files
to the install destination.

Some architectures (arm, sparc, x86) create build-id symlinks,
introducing more code duplication.

2. Unintended updates of in-tree build artifacts

The vdso_install rule depends on the vdso files to install.
It may update in-tree build artifacts. This can be problematic,
as explained in commit 19514fc665ff ("arm, kbuild: make
"make install" not depend on vmlinux").

3. Broken code in some architectures

Makefile code is often copied from one architecture to another
without proper adaptation.

'make vdso_install' for parisc does not work.

'make vdso_install' for s390 installs vdso64, but not vdso32.

To address these problems, this commit introduces a generic vdso_install
rule.

Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.

For example, arch/x86/Makefile looks like this:

vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg
vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg
vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg
vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg

These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.

vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.

The following is a snippet from arch/arm64/Makefile.

vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so

This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Sven Schnelle <[email protected]> # s390
Reviewed-by: Nicolas Schier <[email protected]>
Reviewed-by: Guo Ren <[email protected]>
Acked-by: Helge Deller <[email protected]> # parisc
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Russell King (Oracle) <[email protected]>

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randstruct: Split randstruct Makefile and CFLAGS

To enable the new Clang randstruct implementation[1], move
randstruct into its own Makefile and split the CFLAGS from
GCC_PLUGINS_CFLAGS into RANDSTR

randstruct: Split randstruct Makefile and CFLAGS

To enable the new Clang randstruct implementation[1], move
randstruct into its own Makefile and split the CFLAGS from
GCC_PLUGINS_CFLAGS into RANDSTRUCT_CFLAGS.

[1] https://reviews.llvm.org/D121556

Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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treewide: remove DISABLE_LTO

This change removes all instances of DISABLE_LTO from
Makefiles, as they are currently unused, and the preferred
method of disabling LTO is to filter out the flags inste

treewide: remove DISABLE_LTO

This change removes all instances of DISABLE_LTO from
Makefiles, as they are currently unused, and the preferred
method of disabling LTO is to filter out the flags instead.

Note added by Masahiro Yamada:
DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was
not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272)

Suggested-by: Kees Cook <[email protected]>
Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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kbuild: explicitly specify the build id style

ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs tha

kbuild: explicitly specify the build id style

ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs that reference them.

Signed-off-by: Bill Wendling <[email protected]>
Acked-by: David S. Miller <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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kbuild: remove cc-option test of -fno-stack-protector

Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No probl

kbuild: remove cc-option test of -fno-stack-protector

Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>

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kbuild: rename hostprogs-y/always to hostprogs/always-y

In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typica

kbuild: rename hostprogs-y/always to hostprogs/always-y

In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

always -> always-y
hostprogs-y -> hostprogs

So, scripts/Makefile will look like this:

always-$(CONFIG_BUILD_BIN2C) += ...
always-$(CONFIG_KALLSYMS) += ...
...
hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.

Signed-off-by: Masahiro Yamada <[email protected]>

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sparc: vdso: fix build error of vdso32

Since commit 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to
take the path relative to $(obj)"), sparc allmodconfig fails to build
as follows:

CC

sparc: vdso: fix build error of vdso32

Since commit 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to
take the path relative to $(obj)"), sparc allmodconfig fails to build
as follows:

CC arch/sparc/vdso/vdso32/vclock_gettime.o
unrecognized e_machine 18 arch/sparc/vdso/vdso32/vclock_gettime.o
arch/sparc/vdso/vdso32/vclock_gettime.o: failed

The cause of the breakage is that -pg flag not being dropped.

The vdso32 files are located in the vdso32/ subdirectory, but I missed
to update the Makefile.

I removed the meaningless CFLAGS_REMOVE_vdso-note.o since it is only
effective for C file.

vdso-note.o is compiled from assembly file:

arch/sparc/vdso/vdso-note.S
arch/sparc/vdso/vdso32/vdso-note.S

Fixes: 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)")
Reported-by: Anatoly Pugachev <[email protected]>
Reported-by: Guenter Roeck <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Tested-by: Anatoly Pugachev <[email protected]>
Acked-by: David S. Miller <[email protected]>

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kbuild: add --hash-style= and --build-id unconditionally

As commit 1e0221374e30 ("mips: vdso: drop unnecessary cc-ldoption")
explained, these flags are supported by the minimal required version
of b

kbuild: add --hash-style= and --build-id unconditionally

As commit 1e0221374e30 ("mips: vdso: drop unnecessary cc-ldoption")
explained, these flags are supported by the minimal required version
of binutils. They are supported by ld.lld too.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>

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treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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sparc: vdso: add FORCE to the build rule of %.so

$(call if_changed,...) must have FORCE as a prerequisite.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nick Desaulnie

sparc: vdso: add FORCE to the build rule of %.so

$(call if_changed,...) must have FORCE as a prerequisite.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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sparc: vdso: Drop implicit common-page-size linker flag

GNU linker's -z common-page-size's default value is based on the target
architecture. arch/sparc/vdso/Makefile sets it to the architecture
def

sparc: vdso: Drop implicit common-page-size linker flag

GNU linker's -z common-page-size's default value is based on the target
architecture. arch/sparc/vdso/Makefile sets it to the architecture
default, which is implicit and redundant. Drop it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nick Desaulniers <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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sparc: Validate VDSO for undefined symbols.

There should be no undefined symbols in the resulting VDSO image(s).

On sparc, fixed register usage can result in undefined symbols ending
up in the imag

sparc: Validate VDSO for undefined symbols.

There should be no undefined symbols in the resulting VDSO image(s).

On sparc, fixed register usage can result in undefined symbols ending
up in the image. To combat this, we do two things:

1) Define current_thread_info() specially when BUILD_DSO.

2) Ignore "#scratch" register undefined symbols in the output.

Signed-off-by: David S. Miller <[email protected]>

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sparc: Really use linker with LDFLAGS.

Rather than funneling through CC.

Also, use --hash-style=both just like other VDSO architectures and
glibc do.

Signed-off-by: David S. Miller <davem@davemlof

sparc: Really use linker with LDFLAGS.

Rather than funneling through CC.

Also, use --hash-style=both just like other VDSO architectures and
glibc do.

Signed-off-by: David S. Miller <[email protected]>

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sparc: Improve VDSO CFLAGS.

Do not set any special register usage options, use the default which
is exactly what we should use for userspace code.

Make sure we remove the gcc plugin options from th

sparc: Improve VDSO CFLAGS.

Do not set any special register usage options, use the default which
is exactly what we should use for userspace code.

Make sure we remove the gcc plugin options from the 64-bit build.
The 32-bit cflags got it right already.

Signed-off-by: David S. Miller <[email protected]>

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sparc: Set DISABLE_BRANCH_PROFILING in VDSO CFLAGS.

Not in vclock_gettime.c itself.

Signed-off-by: David S. Miller <[email protected]>

sparc: vdso: clean-up vdso Makefile

arch/sparc/vdso/Makefile is a replica of arch/x86/entry/vdso/Makefile.

Clean-up the Makefile in the same way as I did for x86:

- Remove unnecessary export
- P

sparc: vdso: clean-up vdso Makefile

arch/sparc/vdso/Makefile is a replica of arch/x86/entry/vdso/Makefile.

Clean-up the Makefile in the same way as I did for x86:

- Remove unnecessary export
- Put the generated linker script to $(obj)/ instead of $(src)/
- Simplify cmd_vdso2c

The corresponding x86 commits are:

- 61615faf0a89 ("x86/build/vdso: Remove unnecessary export in Makefile")
- 1742ed2088cc ("x86/build/vdso: Put generated linker scripts to $(obj)/")
- c5fcdbf15523 ("x86/build/vdso: Simplify 'cmd_vdso2c'")

Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers

GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.

Example 1) %.dtb.o <- %.dtb.S <- %

kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers

GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.

Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped

A couple of makefiles mark such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.

.SECONDARY
Prerequisites of this special target are treated as intermediate
files but are never automatically deleted.

.PRECIOUS
When make is interrupted during execution, it may delete the target
file it is updating if the file was modified since make started.
If you mark the file as precious, make will never delete the file
if interrupted.

Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.

The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.

Another difference is that .PRECIOUS works with pattern rules whereas
.SECONDARY does not.

.PRECIOUS: $(obj)/%.lex.c

works, but

.SECONDARY: $(obj)/%.lex.c

has no effect. However, for the reason above, I do not want to use
.PRECIOUS which could cause obscure build breakage.

The targets specified as .SECONDARY must be explicit. $(targets)
contains all targets that need to include .*.cmd files. So, the
intermediates you want to keep are mostly in there. Therefore, mark
$(targets) as .SECONDARY. It means primary targets are also marked
as .SECONDARY, but I do not see any drawback for this.

I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This
will make Kbuild search for non-existing .*.cmd files, but this is
not a noticeable performance issue.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Frank Rowand <[email protected]>
Acked-by: Ingo Molnar <[email protected]>

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