s390: Compile kernel with -fPIC and link with -no-pie

When the kernel is built with CONFIG_PIE_BUILD option enabled it
uses dynamic symbols, for which the linker does not allow more
than 64K number

s390: Compile kernel with -fPIC and link with -no-pie

When the kernel is built with CONFIG_PIE_BUILD option enabled it
uses dynamic symbols, for which the linker does not allow more
than 64K number of entries. This can break features like kpatch.

Hence, whenever possible the kernel is built with CONFIG_PIE_BUILD
option disabled. For that support of unaligned symbols generated by
linker scripts in the compiler is necessary.

However, older compilers might lack such support. In that case the
build process resorts to CONFIG_PIE_BUILD option-enabled build.

Compile object files with -fPIC option and then link the kernel
binary with -no-pie linker option.

As result, the dynamic symbols are not generated and not only kpatch
feature succeeds, but also the whole CONFIG_PIE_BUILD option-enabled
code could be dropped.

[ agordeev: Reworded the commit message ]

Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

mm/treewide: rename CONFIG_HAVE_FAST_GUP to CONFIG_HAVE_GUP_FAST

Nowadays, we call it "GUP-fast", the external interface includes functions
like "get_user_pages_fast()", and we renamed all internal

mm/treewide: rename CONFIG_HAVE_FAST_GUP to CONFIG_HAVE_GUP_FAST

Nowadays, we call it "GUP-fast", the external interface includes functions
like "get_user_pages_fast()", and we renamed all internal functions to
reflect that as well.

Let's make the config option reflect that.

Link: https://lkml.kernel.org/r/20240402125516.223131-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

s390/expoline: Make modules use kernel expolines

Currently, kernel modules contain their own set of expoline thunks. In
the case of EXPOLINE_EXTERN, this involves postlinking of precompiled
expoline

s390/expoline: Make modules use kernel expolines

Currently, kernel modules contain their own set of expoline thunks. In
the case of EXPOLINE_EXTERN, this involves postlinking of precompiled
expoline.o. expoline.o is also necessary for out-of-source tree module
builds.

Now that the kernel modules area is less than 4 GB away from
kernel expoline thunks, make modules use kernel expolines. Also make
EXPOLINE_EXTERN the default if the compiler supports it. This simplifies
build and aligns with the approach adopted by other architectures.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390: Map kernel at fixed location when KASLR is disabled

Since kernel virtual and physical address spaces are
uncoupled the kernel is mapped at the top of the virtual
address space in case KASLR is

s390: Map kernel at fixed location when KASLR is disabled

Since kernel virtual and physical address spaces are
uncoupled the kernel is mapped at the top of the virtual
address space in case KASLR is disabled.

That does not pose any issue with regard to the kernel
booting and operation, but makes it difficult to use a
generated vmlinux with some debugging tools (e.g. gdb),
because the exact location of the kernel image in virtual
memory is unknown. Make that location known and introduce
CONFIG_KERNEL_IMAGE_BASE configuration option.

A custom CONFIG_KERNEL_IMAGE_BASE value that would break
the virtual memory layout leads to a build error.

The kernel image size is defined by KERNEL_IMAGE_SIZE
macro and set to 512 MB, by analogy with x86.

Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/boot: Uncouple virtual and physical kernel offsets

This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.

Currently __kaslr_offset is the kernel offset in both

s390/boot: Uncouple virtual and physical kernel offsets

This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.

Currently __kaslr_offset is the kernel offset in both
physical memory on boot and in virtual memory after DAT
mode is enabled.

Uncouple these offsets and rename the physical address
space variant to __kaslr_offset_phys while keep the name
__kaslr_offset for the offset in virtual address space.

Do not use __kaslr_offset_phys after DAT mode is enabled
just yet, but still make it a persistent boot variable
for later use.

Use __kaslr_offset and __kaslr_offset_phys offsets in
proper contexts and alter handle_relocs() function to
distinguish between the two.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: rename ap debug configuration option

The configuration option ZCRYPT_DEBUG is used only in ap queue code,
so rename it to AP_DEBUG. It also no longer depends on ZCRYPT but on
AP. While at i

s390/ap: rename ap debug configuration option

The configuration option ZCRYPT_DEBUG is used only in ap queue code,
so rename it to AP_DEBUG. It also no longer depends on ZCRYPT but on
AP. While at it, also update the help text.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: modularize ap bus

There is no hard requirement to have the ap bus statically in the
kernel, so add an option to compile it as module.

Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pa

s390/ap: modularize ap bus

There is no hard requirement to have the ap bus statically in the
kernel, so add an option to compile it as module.

Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support

Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:

- Trying to translate a

s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support

Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:

- Trying to translate a vmalloc or module address to a physical address

- Translating a supposed to be ZONE_DMA virtual address into a physical
address, and the resulting physical address is larger than two GiB

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

arch: define CONFIG_PAGE_SIZE_*KB on all architectures

Most architectures only support a single hardcoded page size. In order
to ensure that each one of these sets the corresponding Kconfig symbols,

arch: define CONFIG_PAGE_SIZE_*KB on all architectures

Most architectures only support a single hardcoded page size. In order
to ensure that each one of these sets the corresponding Kconfig symbols,
change over the PAGE_SHIFT definition to the common one and allow
only the hardware page size to be selected.

Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

show more ...

s390: enable MHP_MEMMAP_ON_MEMORY

Enable MHP_MEMMAP_ON_MEMORY to support "memmap on memory".
memory_hotplug.memmap_on_memory=true kernel parameter should be set in
kernel boot option to enable the f

s390: enable MHP_MEMMAP_ON_MEMORY

Enable MHP_MEMMAP_ON_MEMORY to support "memmap on memory".
memory_hotplug.memmap_on_memory=true kernel parameter should be set in
kernel boot option to enable the feature.

Link: https://lkml.kernel.org/r/20240108132747.3238763-6-sumanthk@linux.ibm.com
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

s390: compile relocatable kernel without -fPIE

On s390, currently kernel uses the '-fPIE' compiler flag for compiling
vmlinux. This has a few problems:

- It uses dynamic symbols (.dynsym), for w

s390: compile relocatable kernel without -fPIE

On s390, currently kernel uses the '-fPIE' compiler flag for compiling
vmlinux. This has a few problems:

- It uses dynamic symbols (.dynsym), for which the linker refuses to
allow more than 64k sections. This can break features which use
'-ffunction-sections' and '-fdata-sections', including kpatch-build
[1] and Function Granular KASLR.

- It unnecessarily uses GOT relocations, adding an extra layer of
indirection for many memory accesses.

Instead of using '-fPIE', resolve all the relocations at link time and
then manually adjust any absolute relocations (R_390_64) during boot.

This is done by first telling the linker to preserve all relocations
during the vmlinux link. (Note this is harmless: they are later
stripped in the vmlinux.bin link.)

Then use the 'relocs' tool to find all absolute relocations (R_390_64)
which apply to allocatable sections. The offsets of those relocations
are saved in a special section which is then used to adjust the
relocations during boot.

(Note: For some reason, Clang occasionally creates a GOT reference, even
without '-fPIE'. So Clang-compiled kernels have a GOT, which needs to
be adjusted.)

On my mostly-defconfig kernel, this reduces kernel text size by ~1.3%.

[1] https://github.com/dynup/kpatch/issues/1284
[2] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html
[3] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html

Compiler consideration:

Gcc recently implemented an optimization [2] for loading symbols without
explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates
symbols to reside on a 2-byte boundary, enabling the use of the larl
instruction. However, kernel linker scripts may still generate unaligned
symbols. To address this, a new -munaligned-symbols option has been
introduced [3] in recent gcc versions. This option has to be used with
future gcc versions.

Older Clang lacks support for handling unaligned symbols generated
by kernel linker scripts when the kernel is built without -fPIE. However,
future versions of Clang will include support for the -munaligned-symbols
option. When the support is unavailable, compile the kernel with -fPIE
to maintain the existing behavior.

In addition to it:
move vmlinux.relocs to safe relocation

When the kernel is built with CONFIG_KERNEL_UNCOMPRESSED, the entire
uncompressed vmlinux.bin is positioned in the bzImage decompressor
image at the default kernel LMA of 0x100000, enabling it to be executed
in-place. However, the size of .vmlinux.relocs could be large enough to
cause an overlap with the uncompressed kernel at the address 0x100000.
To address this issue, .vmlinux.relocs is positioned after the
.rodata.compressed in the bzImage. Nevertheless, in this configuration,
vmlinux.relocs will overlap with the .bss section of vmlinux.bin. To
overcome that, move vmlinux.relocs to a safe location before clearing
.bss and handling relocs.

Compile warning fix from Sumanth Korikkar:

When kernel is built with CONFIG_LD_ORPHAN_WARN and -fno-PIE, there are
several warnings:

ld: warning: orphan section `.rela.iplt' from
`arch/s390/kernel/head64.o' being placed in section `.rela.dyn'
ld: warning: orphan section `.rela.head.text' from
`arch/s390/kernel/head64.o' being placed in section `.rela.dyn'
ld: warning: orphan section `.rela.init.text' from
`arch/s390/kernel/head64.o' being placed in section `.rela.dyn'
ld: warning: orphan section `.rela.rodata.cst8' from
`arch/s390/kernel/head64.o' being placed in section `.rela.dyn'

Orphan sections are sections that exist in an object file but don't have
a corresponding output section in the final executable. ld raises a
warning when it identifies such sections.

Eliminate the warning by placing all .rela orphan sections in .rela.dyn
and raise an error when size of .rela.dyn is greater than zero. i.e.
Dont just neglect orphan sections.

This is similar to adjustment performed in x86, where kernel is built
with -fno-PIE.
commit 5354e84598f2 ("x86/build: Add asserts for unwanted sections")

[sumanthk@linux.ibm.com: rebased Josh Poimboeuf patches and move
vmlinux.relocs to safe location]
[hca@linux.ibm.com: merged compile warning fix from Sumanth]
Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Link: https://lore.kernel.org/r/20240219132734.22881-4-sumanthk@linux.ibm.com
Link: https://lore.kernel.org/r/20240219132734.22881-5-sumanthk@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390: don't allow CONFIG_COMPAT with LD=ld.lld

When building 'ARCH=s390 defconfig compat.config' with GCC and
LD=ld.lld, there is an error when attempting to link the compat vDSO:

ld.lld: error:

s390: don't allow CONFIG_COMPAT with LD=ld.lld

When building 'ARCH=s390 defconfig compat.config' with GCC and
LD=ld.lld, there is an error when attempting to link the compat vDSO:

ld.lld: error: unknown emulation: elf_s390
make[4]: *** [arch/s390/kernel/vdso32/Makefile:48: arch/s390/kernel/vdso32/vdso32.so.dbg] Error 1

Much like clang, ld.lld only supports the 64-bit s390 emulation. Add a
dependency on not using LLD to CONFIG_COMPAT to avoid breaking the build
with this toolchain combination.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240214-s390-compat-lld-dep-v1-1-abf1f4b5e514@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390: select CONFIG_ARCH_WANT_LD_ORPHAN_WARN

Now that all sections have been properly accounted for in the s390
linker scripts, select CONFIG_ARCH_WANT_LD_ORPHAN_WARN so that
'--orphan-handling' is

s390: select CONFIG_ARCH_WANT_LD_ORPHAN_WARN

Now that all sections have been properly accounted for in the s390
linker scripts, select CONFIG_ARCH_WANT_LD_ORPHAN_WARN so that
'--orphan-handling' is added to LDFLAGS to catch any future sections
that are added without being described in linker scripts.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-10-8a665b3346ab@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

treewide: remove CONFIG_HAVE_KVM

It has no users anymore.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

ubsan: Remove CONFIG_UBSAN_SANITIZE_ALL

For simplicity in splitting out UBSan options into separate rules,
remove CONFIG_UBSAN_SANITIZE_ALL, effectively defaulting to "y", which
is how it is general

ubsan: Remove CONFIG_UBSAN_SANITIZE_ALL

For simplicity in splitting out UBSan options into separate rules,
remove CONFIG_UBSAN_SANITIZE_ALL, effectively defaulting to "y", which
is how it is generally used anyway. (There are no ":= y" cases beyond
where a specific file is enabled when a top-level ":= n" is in effect.)

Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

show more ...

s390/kexec: do not automatically select KEXEC option

Following commit dccf78d39f10 ("kernel/Kconfig.kexec: drop
select of KEXEC for CRASH_DUMP") also drop automatic KEXEC
selection for s390 while se

s390/kexec: do not automatically select KEXEC option

Following commit dccf78d39f10 ("kernel/Kconfig.kexec: drop
select of KEXEC for CRASH_DUMP") also drop automatic KEXEC
selection for s390 while set CONFIG_KEXEC=y explicitly for
defconfig and debug_defconfig targets. zfcpdump_defconfig
target gets CONFIG_KEXEC unset as result, which is right
and consistent with CONFIG_KEXEC_FILE besides.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/compat: change default for CONFIG_COMPAT to "n"

31 bit support has been removed from the kernel more than eight years
ago. The last 31 bit distribution is many years older. There shouldn't be
a

s390/compat: change default for CONFIG_COMPAT to "n"

31 bit support has been removed from the kernel more than eight years
ago. The last 31 bit distribution is many years older. There shouldn't be
any 31 bit code around anymore.

Therefore avoid providing an unused and only partially tested user space
interface and change the default for CONFIG_COMPAT from "yes" to "no".

Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

kexec: fix KEXEC_FILE dependencies

The cleanup for the CONFIG_KEXEC Kconfig logic accidentally changed the
'depends on CRYPTO=y' dependency to a plain 'depends on CRYPTO', which
causes a link failur

kexec: fix KEXEC_FILE dependencies

The cleanup for the CONFIG_KEXEC Kconfig logic accidentally changed the
'depends on CRYPTO=y' dependency to a plain 'depends on CRYPTO', which
causes a link failure when all the crypto support is in a loadable module
and kexec_file support is built-in:

x86_64-linux-ld: vmlinux.o: in function `__x64_sys_kexec_file_load':
(.text+0x32e30a): undefined reference to `crypto_alloc_shash'
x86_64-linux-ld: (.text+0x32e58e): undefined reference to `crypto_shash_update'
x86_64-linux-ld: (.text+0x32e6ee): undefined reference to `crypto_shash_final'

Both s390 and x86 have this problem, while ppc64 and riscv have the
correct dependency already. On riscv, the dependency is only used for the
purgatory, not for the kexec_file code itself, which may be a bit
surprising as it means that with CONFIG_CRYPTO=m, it is possible to enable
KEXEC_FILE but then the purgatory code is silently left out.

Move this into the common Kconfig.kexec file in a way that is correct
everywhere, using the dependency on CRYPTO_SHA256=y only when the
purgatory code is available. This requires reversing the dependency
between ARCH_SUPPORTS_KEXEC_PURGATORY and KEXEC_FILE, but the effect
remains the same, other than making riscv behave like the other ones.

On s390, there is an additional dependency on CRYPTO_SHA256_S390, which
should technically not be required but gives better performance. Remove
this dependency here, noting that it was not present in the initial
Kconfig code but was brought in without an explanation in commit
71406883fd357 ("s390/kexec_file: Add kexec_file_load system call").

[arnd@arndb.de: fix riscv build]
Link: https://lkml.kernel.org/r/67ddd260-d424-4229-a815-e3fcfb864a77@app.fastmail.com
Link: https://lkml.kernel.org/r/20231023110308.1202042-1-arnd@kernel.org
Fixes: 6af5138083005 ("x86/kexec: refactor for kernel/Kconfig.kexec")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric DeVolder <eric_devolder@yahoo.com>
Tested-by: Eric DeVolder <eric_devolder@yahoo.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Conor Dooley <conor@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support

s390 selects ARCH_WANTS_DYNAMIC_TASK_STRUCT in order to make the size of
the task structure dependent on the availability of the vector
facili

s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support

s390 selects ARCH_WANTS_DYNAMIC_TASK_STRUCT in order to make the size of
the task structure dependent on the availability of the vector
facility. This doesn't make sense anymore because since many years all
machines provide the vector facility.

Therefore simplify the code a bit and remove s390 support for
ARCH_WANTS_DYNAMIC_TASK_STRUCT.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

mm/slab: remove CONFIG_SLAB from all Kconfig and Makefile

Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and
everything in Kconfig files and mm/Makefile that depends on those. Since
S

mm/slab: remove CONFIG_SLAB from all Kconfig and Makefile

Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and
everything in Kconfig files and mm/Makefile that depends on those. Since
SLUB is the only remaining allocator, remove the allocator choice, make
CONFIG_SLUB a "def_bool y" for now and remove all explicit dependencies
on SLUB or SLAB as it's now always enabled. Make every option's verbose
name and description refer to "the slab allocator" without refering to
the specific implementation. Do not rename the CONFIG_ option names yet.

Everything under #ifdef CONFIG_SLAB, and mm/slab.c is now dead code, all
code under #ifdef CONFIG_SLUB is now always compiled.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

show more ...

s390: add USER_STACKTRACE support

Use the perf_callchain_user() code as blueprint to also add support for
USER_STACKTRACE. To describe how to use this cite the commit message of the
LoongArch implem

s390: add USER_STACKTRACE support

Use the perf_callchain_user() code as blueprint to also add support for
USER_STACKTRACE. To describe how to use this cite the commit message of the
LoongArch implementation which came with commit 4d7bf939df08 ("LoongArch:
Add USER_STACKTRACE support"), but replace -fno-omit-frame-pointer option
with the s390 specific -mbackchain option:
====================================================================== To
get the best stacktrace output, you can compile your userspace programs
with frame pointers (at least glibc + the app you are tracing).

1, export "CC = gcc -mbackchain";
2, compile your programs with "CC";
3, use uprobe to get stacktrace output.

...
echo 'p:malloc /usr/lib64/libc.so.6:0x0a4704 size=%r2:u64' > uprobe_events
echo 'p:free /usr/lib64/libc.so.6:0x0a4d50 ptr=%r2:u64' >> uprobe_events
echo 'comm == "demo"' > ./events/uprobes/malloc/filter
echo 'comm == "demo"' > ./events/uprobes/free/filter
echo 1 > ./options/userstacktrace
echo 1 > ./options/sym-userobj
...
======================================================================

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

show more ...

s390: add support for DCACHE_WORD_ACCESS

Implement load_unaligned_zeropad() and enable DCACHE_WORD_ACCESS to
speed up string operations in fs/dcache.c and fs/namei.c.

Reviewed-by: Sven Schnelle <sv

s390: add support for DCACHE_WORD_ACCESS

Implement load_unaligned_zeropad() and enable DCACHE_WORD_ACCESS to
speed up string operations in fs/dcache.c and fs/namei.c.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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remove ARCH_DEFAULT_KEXEC from Kconfig.kexec

This patch is a minor cleanup to the series "refactor Kconfig to
consolidate KEXEC and CRASH options".

In that series, a new option ARCH_DEFAULT_KEXEC w

remove ARCH_DEFAULT_KEXEC from Kconfig.kexec

This patch is a minor cleanup to the series "refactor Kconfig to
consolidate KEXEC and CRASH options".

In that series, a new option ARCH_DEFAULT_KEXEC was introduced in order to
obtain the equivalent behavior of s390 original Kconfig settings for
KEXEC. As it turns out, this new option did not fully provide the
equivalent behavior, rather a "select KEXEC" did.

As such, the ARCH_DEFAULT_KEXEC is not needed anymore, so remove it.

Link: https://lkml.kernel.org/r/20230802161750.2215-1-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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kexec: rename ARCH_HAS_KEXEC_PURGATORY

The Kconfig refactor to consolidate KEXEC and CRASH options utilized
option names of the form ARCH_SUPPORTS_<option>. Thus rename the
ARCH_HAS_KEXEC_PURGATORY

kexec: rename ARCH_HAS_KEXEC_PURGATORY

The Kconfig refactor to consolidate KEXEC and CRASH options utilized
option names of the form ARCH_SUPPORTS_<option>. Thus rename the
ARCH_HAS_KEXEC_PURGATORY to ARCH_SUPPORTS_KEXEC_PURGATORY to follow
the same.

Link: https://lkml.kernel.org/r/20230712161545.87870-15-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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s390/kexec: refactor for kernel/Kconfig.kexec

The kexec and crash kernel options are provided in the common
kernel/Kconfig.kexec. Utilize the common options and provide
the ARCH_SUPPORTS_ and ARCH_S

s390/kexec: refactor for kernel/Kconfig.kexec

The kexec and crash kernel options are provided in the common
kernel/Kconfig.kexec. Utilize the common options and provide
the ARCH_SUPPORTS_ and ARCH_SELECTS_ entries to recreate the
equivalent set of KEXEC and CRASH options.

Link: https://lkml.kernel.org/r/20230712161545.87870-13-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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