riscv: Remove duplicate CONFIG_PAGE_OFFSET definition

This definition is already provided by include/generated/autoconf.h,
so it does not need to be provided on the command line.

Signed-off-by: Sam

riscv: Remove duplicate CONFIG_PAGE_OFFSET definition

This definition is already provided by include/generated/autoconf.h,
so it does not need to be provided on the command line.

Signed-off-by: Samuel Holland <[email protected]>
Reviewed-by: Jesse Taube <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch spec

kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch specific tools
consume these static relocations in order to construct relocation tables
for KASLR.

The fact that vmlinux is created, consumed and subsequently updated goes
against the typical, declarative paradigm used by Make, which is based
on rules and dependencies. So as a first step towards cleaning this up,
introduce a Kconfig symbol to declare that the arch wants to consume the
static relocations emitted into vmlinux. This will be wired up further
in subsequent patches.

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

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kbuild: add $(objtree)/ prefix to some in-kernel build artifacts

$(objtree) refers to the top of the output directory of kernel builds.

This commit adds the explicit $(objtree)/ prefix to build art

kbuild: add $(objtree)/ prefix to some in-kernel build artifacts

$(objtree) refers to the top of the output directory of kernel builds.

This commit adds the explicit $(objtree)/ prefix to build artifacts
needed for building external modules.

This change has no immediate impact, as the top-level Makefile
currently defines:

objtree := .

This commit prepares for supporting the building of external modules
in a different directory.

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

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riscv: Implement cmpxchg8/16() using Zabha

This adds runtime support for Zabha in cmpxchg8/16() operations.

Note that in the absence of Zacas support in the toolchain, CAS
instructions from Zabha w

riscv: Implement cmpxchg8/16() using Zabha

This adds runtime support for Zabha in cmpxchg8/16() operations.

Note that in the absence of Zacas support in the toolchain, CAS
instructions from Zabha won't be used.

Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Reviewed-by: Andrea Parri <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Implement cmpxchg32/64() using Zacas

This adds runtime support for Zacas in cmpxchg operations.

Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Andrew Jones <ajones@vent

riscv: Implement cmpxchg32/64() using Zacas

This adds runtime support for Zacas in cmpxchg operations.

Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Reviewed-by: Andrea Parri <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: boot: add Image.xz support

The Image.* targets existed for other compressors already. Bootloader
support is needed for decompression.

This is for CONFIG_EFI_ZBOOT=n. With CONFIG_EFI_ZBOOT=y

riscv: boot: add Image.xz support

The Image.* targets existed for other compressors already. Bootloader
support is needed for decompression.

This is for CONFIG_EFI_ZBOOT=n. With CONFIG_EFI_ZBOOT=y, XZ was already
available.

Comparision with Linux 6.10 RV64GC tinyconfig (in KiB):

1027 Image
594 Image.gz
541 Image.zst
510 Image.lzma
474 Image.xz

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Lasse Collin <[email protected]>
Reviewed-by: Emil Renner Berthing <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Jules Maselbas <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Joel Stanley <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jubin Zhong <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Rui Li <[email protected]>
Cc: Sam James <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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riscv: Provide a definition for 'pause'

If we're going to provide the encoding for 'pause' in cpu_relax()
anyway, then we can drop the toolchain checks and just always use
it. The advantage of doing

riscv: Provide a definition for 'pause'

If we're going to provide the encoding for 'pause' in cpu_relax()
anyway, then we can drop the toolchain checks and just always use
it. The advantage of doing this is that other code that need
pause don't need to also define it (yes, another use is coming).
Add the definition to insn-def.h since it's an instruction
definition and also because insn-def.h doesn't include much, so
it's safe to include from asm/vdso/processor.h without concern for
circular dependencies.

Signed-off-by: Andrew Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: show help string for riscv-specific targets

Define the archhelp variable so that 'make ACRH=riscv help' will show
the targets specific to building a RISC-V kernel like other
architectures.

T

riscv: show help string for riscv-specific targets

Define the archhelp variable so that 'make ACRH=riscv help' will show
the targets specific to building a RISC-V kernel like other
architectures.

Tested-by: Björn Töpel <[email protected]>
Signed-off-by: Emil Renner Berthing <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: make image compression configurable

Previously the build process would always set KBUILD_IMAGE to the
uncompressed Image file (unless XIP_KERNEL or EFI_ZBOOT was enabled) and
unconditionally

riscv: make image compression configurable

Previously the build process would always set KBUILD_IMAGE to the
uncompressed Image file (unless XIP_KERNEL or EFI_ZBOOT was enabled) and
unconditionally compress it into Image.gz. However there are already
build targets for Image.bz2, Image.lz4, Image.lzma, Image.lzo and
Image.zstd, so let's make use of those, make the compression method
configurable and set KBUILD_IMAGE accordingly so that targets like
'make install' and 'make bindeb-pkg' will use the chosen image.

Tested-by: Björn Töpel <[email protected]>
Signed-off-by: Emil Renner Berthing <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: add support for kernel-mode FPU

This is motivated by the amdgpu DRM driver, which needs floating-point
code to support recent hardware. That code is not performance-critical,
so only provide

riscv: add support for kernel-mode FPU

This is motivated by the amdgpu DRM driver, which needs floating-point
code to support recent hardware. That code is not performance-critical,
so only provide a minimal non-preemptible implementation for now.

Support is limited to riscv64 because riscv32 requires runtime (libgcc)
assistance to convert between doubles and 64-bit integers.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Samuel Holland <[email protected]>
Acked-by: Palmer Dabbelt <[email protected]>
Reviewed-by: Palmer Dabbelt <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nicolas Schier <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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RISC-V: enable building 64-bit kernels with rust support

The rust modules work on 64-bit RISC-V, with no twiddling required.
Select HAVE_RUST and provide the required flags to kbuild so that the
mod

RISC-V: enable building 64-bit kernels with rust support

The rust modules work on 64-bit RISC-V, with no twiddling required.
Select HAVE_RUST and provide the required flags to kbuild so that the
modules can be used. The Makefile and Kconfig changes are lifted from
work done by Miguel in the Rust-for-Linux tree, hence his authorship.
Following the rabbit hole, the Makefile changes originated in a script,
created based on config files originally added by Gary, hence his
co-authorship.

32-bit is broken in core rust code, so support is limited to 64-bit:
ld.lld: error: undefined symbol: __udivdi3

As 64-bit RISC-V is now supported, add it to the arch support table.

Co-developed-by: Gary Guo <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Co-developed-by: Conor Dooley <[email protected]>
Signed-off-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/20240409-silencer-book-ce1320f06aab@spud
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Kconfig.socs: Split ARCH_CANAAN and SOC_CANAAN_K210

Since SOC_FOO should be deprecated from patch [1], and cleanup for other
SoCs is already in the mailing list [2,3,4], we remove the use of

riscv: Kconfig.socs: Split ARCH_CANAAN and SOC_CANAAN_K210

Since SOC_FOO should be deprecated from patch [1], and cleanup for other
SoCs is already in the mailing list [2,3,4], we remove the use of
SOC_CANAAN and use ARCH_CANAAN for SoCs vendored by Canaan instead from now
on. And allows ARCH_CANAAN to be selected for other Canaan SoCs. However,
we should keep the config SOC_CANAAN and use def_bool to redirect the
symbol temporarily to avoid potential conflict.

Since we now have Canaan Kendryte K230 with MMU, ARCH_CANAAN is no longer
referred to as K210. There are some special features for K210, like M-Mode
No MMU and loader.bin in arch/riscv/Makefile. If we keep ARCH_CANAAN for
other Canaan SoCs and remove the K210, the depends on !MMU in Kconfig may
confuse some users who try to boot Kernel with MMU on K210, as Damien
mentioned in the list [5]. Thus, we introduce a new symbol SOC_CANAAN_K210
for any conditional code or driver selection specific to the K210, so users
will not try to build some K210-specific things when MMU is enabled and see
it fails to boot on K210.

[1] https://lore.kernel.org/linux-riscv/[email protected]/
[2] https://lore.kernel.org/linux-riscv/20240305-praying-clad-c4fbcaa7ed0a@spud/
[3] https://lore.kernel.org/linux-riscv/20240305-fled-undrilled-41dc0c46bb29@spud/
[4] https://lore.kernel.org/linux-riscv/20240305-stress-earflap-d7ddb8655a4d@spud/
[5] https://lore.kernel.org/linux-riscv/[email protected]/

Signed-off-by: Yangyu Chen <[email protected]>
Signed-off-by: Conor Dooley <[email protected]>

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riscv: merge two if-blocks for KBUILD_IMAGE

In arch/riscv/Makefile, KBUILD_IMAGE is assigned in two separate
if-blocks.

When CONFIG_XIP_KERNEL is disabled, the decision made by the first
if-block i

riscv: merge two if-blocks for KBUILD_IMAGE

In arch/riscv/Makefile, KBUILD_IMAGE is assigned in two separate
if-blocks.

When CONFIG_XIP_KERNEL is disabled, the decision made by the first
if-block is overwritten by the second one, which is redundant and
unreadable.

Merge the two if-blocks.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Alexandre Ghiti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: compat_vdso: install compat_vdso.so.dbg to /lib/modules/*/vdso/

'make vdso_install' installs debug vdso files to /lib/modules/*/vdso/.

Only for the compat vdso on riscv, the installation des

riscv: compat_vdso: install compat_vdso.so.dbg to /lib/modules/*/vdso/

'make vdso_install' installs debug vdso files to /lib/modules/*/vdso/.

Only for the compat vdso on riscv, the installation destination differs;
compat_vdso.so.dbg is installed to /lib/module/*/compat_vdso/.

To follow the standard install destination and simplify the vdso_install
logic, change the install destination to standard /lib/modules/*/vdso/.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Alexandre Ghiti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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RISC-V: build: Allow LTO to be selected

Allow LTO to be selected for RISC-V, only when LLD >= 14, since there is
an issue [1] in prior LLD versions that prevents LLD to generate proper
machine code

RISC-V: build: Allow LTO to be selected

Allow LTO to be selected for RISC-V, only when LLD >= 14, since there is
an issue [1] in prior LLD versions that prevents LLD to generate proper
machine code for RISC-V when writing `nop`s.

To avoid boot failures in QEMU [2], '-mattr=+c' and '-mattr=+relax'
need to be passed via '-mllvm' to ld.lld, as there appears to be an
issue with LLVM's target-features and LTO [3], which can result in
incorrect relocations to branch targets [4]. Once this is fixed in LLVM,
it can be made conditional on affected ld.lld versions.

Disable LTO for arch/riscv/kernel/pi, as llvm-objcopy expects an ELF
object file when manipulating the files in that subfolder, rather than
LLVM bitcode.

[1] https://github.com/llvm/llvm-project/issues/50505, resolved by LLVM
commit e63455d5e0e5 ("[MC] Use local MCSubtargetInfo in writeNops")
[2] https://github.com/ClangBuiltLinux/linux/issues/1942
[3] https://github.com/llvm/llvm-project/issues/59350
[4] https://github.com/llvm/llvm-project/issues/65090

Tested-by: Wende Tan <[email protected]>
Signed-off-by: Wende Tan <[email protected]>
Co-developed-by: Nathan Chancellor <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: add dependency among Image(.gz), loader(.bin), and vmlinuz.efi

A common issue in Makefile is a race in parallel building.

You need to be careful to prevent multiple threads from writing to t

riscv: add dependency among Image(.gz), loader(.bin), and vmlinuz.efi

A common issue in Makefile is a race in parallel building.

You need to be careful to prevent multiple threads from writing to the
same file simultaneously.

Commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not
generate invalid images") addressed such a bad scenario.

A similar symptom occurs with the following command:

$ make -j$(nproc) ARCH=riscv Image Image.gz loader loader.bin vmlinuz.efi
[ snip ]
SORTTAB vmlinux
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
GZIP arch/riscv/boot/Image.gz
AS arch/riscv/boot/loader.o
AS arch/riscv/boot/loader.o
Kernel: arch/riscv/boot/Image is ready
PAD arch/riscv/boot/vmlinux.bin
GZIP arch/riscv/boot/vmlinuz
Kernel: arch/riscv/boot/loader is ready
OBJCOPY arch/riscv/boot/loader.bin
Kernel: arch/riscv/boot/loader.bin is ready
Kernel: arch/riscv/boot/Image.gz is ready
OBJCOPY arch/riscv/boot/vmlinuz.o
LD arch/riscv/boot/vmlinuz.efi.elf
OBJCOPY arch/riscv/boot/vmlinuz.efi
Kernel: arch/riscv/boot/vmlinuz.efi is ready

The log "OBJCOPY arch/riscv/boot/Image" is displayed 5 times.
(also "AS arch/riscv/boot/loader.o" twice.)

It indicates that 5 threads simultaneously enter arch/riscv/boot/
and write to arch/riscv/boot/Image.

It occasionally leads to a build failure:

$ make -j$(nproc) ARCH=riscv Image Image.gz loader loader.bin vmlinuz.efi
[ snip ]
SORTTAB vmlinux
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
OBJCOPY arch/riscv/boot/Image
PAD arch/riscv/boot/vmlinux.bin
truncate: Invalid number: 'arch/riscv/boot/vmlinux.bin'
make[2]: *** [drivers/firmware/efi/libstub/Makefile.zboot:13: arch/riscv/boot/vmlinux.bin] Error 1
make[2]: *** Deleting file 'arch/riscv/boot/vmlinux.bin'
make[1]: *** [arch/riscv/Makefile:167: vmlinuz.efi] Error 2
make[1]: *** Waiting for unfinished jobs....
Kernel: arch/riscv/boot/Image is ready
GZIP arch/riscv/boot/Image.gz
AS arch/riscv/boot/loader.o
AS arch/riscv/boot/loader.o
Kernel: arch/riscv/boot/loader is ready
OBJCOPY arch/riscv/boot/loader.bin
Kernel: arch/riscv/boot/loader.bin is ready
Kernel: arch/riscv/boot/Image.gz is ready
make: *** [Makefile:234: __sub-make] Error 2

Image.gz, loader, vmlinuz.efi depend on Image. loader.bin depends
on loader. Such dependencies are not specified in arch/riscv/Makefile.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Samuel Holland <[email protected]>
Tested-by: Samuel Holland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Hoist linker relaxation disabling logic into Kconfig

Certain configurations may need to be disabled if linker relaxation is
in use, such as DWARF5 with ld.lld < 18. Hoist the logic of whether

riscv: Hoist linker relaxation disabling logic into Kconfig

Certain configurations may need to be disabled if linker relaxation is
in use, such as DWARF5 with ld.lld < 18. Hoist the logic of whether or
not linker relaxation is in use into Kconfig so decisions can be made at
configuration time.

Reviewed-by: Fangrui Song <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: introduce RISCV_EFFICIENT_UNALIGNED_ACCESS

Some riscv implementations such as T-HEAD's C906, C908, C910 and C920
support efficient unaligned access, for performance reason we want
to enable H

riscv: introduce RISCV_EFFICIENT_UNALIGNED_ACCESS

Some riscv implementations such as T-HEAD's C906, C908, C910 and C920
support efficient unaligned access, for performance reason we want
to enable HAVE_EFFICIENT_UNALIGNED_ACCESS on these platforms. To
avoid performance regressions on other non efficient unaligned access
platforms, HAVE_EFFICIENT_UNALIGNED_ACCESS can't be globally selected.

To solve this problem, runtime code patching based on the detected
speed is a good solution. But that's not easy, it involves lots of
work to modify vairous subsystems such as net, mm, lib and so on.
This can be done step by step.

So let's take an easier solution: add support to efficient unaligned
access and hide the support under NONPORTABLE.

Now let's introduce RISCV_EFFICIENT_UNALIGNED_ACCESS which depends on
NONPORTABLE, if users know during config time that the kernel will be
only run on those efficient unaligned access hw platforms, they can
enable it. Obviously, generic unified kernel Image shouldn't enable it.

Signed-off-by: Jisheng Zhang <[email protected]>
Reviewed-by: Charlie Jenkins <[email protected]>
Reviewed-by: Eric Biggers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[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]>

show more ...

riscv: Implement Shadow Call Stack

Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the
compiler injects instructions to all non-leaf C functions to
store the return address to the shado

riscv: Implement Shadow Call Stack

Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the
compiler injects instructions to all non-leaf C functions to
store the return address to the shadow stack and unconditionally
load it again before returning, which makes it harder to corrupt
the return address through a stack overflow, for example.

The active shadow call stack pointer is stored in the gp
register, which makes SCS incompatible with gp relaxation. Use
--no-relax-gp to ensure gp relaxation is disabled and disable
global pointer loading. Add SCS pointers to struct thread_info,
implement SCS initialization, and task switching

Signed-off-by: Sami Tolvanen <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

show more ...

riscv: Remove duplicate objcopy flag

There are two duplicate `-O binary` flags when objcopying from vmlinux
to Image/xipImage.

RISC-V set `-O binary` flag in both OBJCOPYFLAGS in the top-level risc

riscv: Remove duplicate objcopy flag

There are two duplicate `-O binary` flags when objcopying from vmlinux
to Image/xipImage.

RISC-V set `-O binary` flag in both OBJCOPYFLAGS in the top-level riscv
Makefile and OBJCOPYFLAGS_* in the boot/Makefile, and the objcopy cmd
in Kbuild would join them together.

The `-O binary` flag is only needed for objcopying Image, so remove the
OBJCOPYFLAGS in the top-level riscv Makefile.

Fixes: c0fbcd991860 ("RISC-V: Build flat and compressed kernel images")
Signed-off-by: Song Shuai <[email protected]>
Reviewed-by: Palmer Dabbelt <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Cc: [email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Require FRAME_POINTER for some configurations

Some V configurations implicitly turn on '-fno-omit-frame-pointer',
but leaving FRAME_POINTER disabled. This makes it hard to reason about
the FR

riscv: Require FRAME_POINTER for some configurations

Some V configurations implicitly turn on '-fno-omit-frame-pointer',
but leaving FRAME_POINTER disabled. This makes it hard to reason about
the FRAME_POINTER config, and also triggers build failures introduced
in by the commit in the Fixes: tag.

Select FRAME_POINTER explicitly for these configurations.

Fixes: ebc9cb03b21e ("riscv: stack: Fixup independent softirq stack for CONFIG_FRAME_POINTER=n")
Signed-off-by: Björn Töpel <[email protected]>
Tested-by: Randy Dunlap <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Enable Vector code to be built

This patch adds configs for building Vector code. First it detects the
reqired toolchain support for building the code. Then it provides an
option setting wheth

riscv: Enable Vector code to be built

This patch adds configs for building Vector code. First it detects the
reqired toolchain support for building the code. Then it provides an
option setting whether Vector is implicitly enabled to userspace.

Signed-off-by: Guo Ren <[email protected]>
Co-developed-by: Greentime Hu <[email protected]>
Signed-off-by: Greentime Hu <[email protected]>
Co-developed-by: Andy Chiu <[email protected]>
Signed-off-by: Andy Chiu <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Allow to downgrade paging mode from the command line

Add 2 early command line parameters that allow to downgrade satp mode
(using the same naming as x86):
- "no5lvl": use a 4-level page table

riscv: Allow to downgrade paging mode from the command line

Add 2 early command line parameters that allow to downgrade satp mode
(using the same naming as x86):
- "no5lvl": use a 4-level page table (down from sv57 to sv48)
- "no4lvl": use a 3-level page table (down from sv57/sv48 to sv39)

Note that going through the device tree to get the kernel command line
works with ACPI too since the efi stub creates a device tree anyway with
the command line.

In KASAN kernels, we can't use the libfdt that early in the boot process
since we are not ready to execute instrumented functions. So instead of
using the "generic" libfdt, we compile our own versions of those functions
that are not instrumented and that are prefixed so that they do not
conflict with the generic ones. We also need the non-instrumented versions
of the string functions and the prefixed versions of memcpy/memmove.

This is largely inspired by commit aacd149b6238 ("arm64: head: avoid
relocating the kernel twice for KASLR") from which I removed compilation
flags that were not relevant to RISC-V at the moment (LTO, SCS). Also
note that we have to link with -z norelro to avoid ld.lld to throw a
warning with the new .got sections, like in commit 311bea3cb9ee ("arm64:
link with -z norelro for LLD or aarch64-elf").

Signed-off-by: Alexandre Ghiti <[email protected]>
Tested-by: Björn Töpel <[email protected]>
Reviewed-by: Björn Töpel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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riscv: Use --emit-relocs in order to move .rela.dyn in init

To circumvent an issue where placing the relocations inside the init
sections produces empty relocations, use --emit-relocs. But to avoid

riscv: Use --emit-relocs in order to move .rela.dyn in init

To circumvent an issue where placing the relocations inside the init
sections produces empty relocations, use --emit-relocs. But to avoid
carrying those relocations in vmlinux, use an intermediate
vmlinux.relocs file which is a copy of vmlinux *before* stripping its
relocations.

Suggested-by: Björn Töpel <[email protected]>
Suggested-by: Nick Desaulniers <[email protected]>
Signed-off-by: Alexandre Ghiti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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