s390/kexec: make machine_kexec() depend on CONFIG_KEXEC_CORE

Make machine_kexec.o and relocate_kernel.o depend on
CONFIG_KEXEC_CORE option as other architectures do.

Still generate machine_kexec_re

s390/kexec: make machine_kexec() depend on CONFIG_KEXEC_CORE

Make machine_kexec.o and relocate_kernel.o depend on
CONFIG_KEXEC_CORE option as other architectures do.

Still generate machine_kexec_reloc.o unconditionally,
since arch_kexec_do_relocs() function is neded by the
decompressor.

Suggested-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390: add support for user-defined certificates

Enable receiving the user-defined certificates from the s390x
hypervisor via new diagnose 0x320 calls, and make them available to the
Linux root user

s390: add support for user-defined certificates

Enable receiving the user-defined certificates from the s390x
hypervisor via new diagnose 0x320 calls, and make them available to the
Linux root user as 'cert_store_key' type keys in a so-called
'cert_store' keyring.

New user-space interfaces:

/sys/firmware/cert_store/refresh

Writing to this attribute re-fetches certificates via DIAG 0x320

/sys/firmware/cert_store/cs_status

Reading from this attribute returns either of:

"uninitialized"
If no certificate has been retrieved yet
"ok"
If certificates have been successfully retrieved
"failed (<number>)"
If certificate retrieval failed with reason code <number>

New debug trace areas:

/sys/kernel/debug/s390dbf/cert_store_msg

/sys/kernel/debug/s390dbf/cert_store_hexdump

Usage example:

To initiate request for certificates available to the system as root:

$ echo 1 > /sys/firmware/cert_store/refresh

Upon success the '/sys/firmware/cert_store/cs_status' contains
the value 'ok'.

$ cat /sys/firmware/cert_store/cs_status
ok

Get the ID of the keyring 'cert_store':

$ keyctl search @us keyring cert_store
OR
$ keyctl link @us @s; keyctl request keyring cert_store

Obtain list of IDs of certificates:

$ keyctl rlist <cert_store keyring ID>

Display certificate content as hex-dump:

$ keyctl read <certificate ID>

Read certificate contents as binary data:

$ keyctl pipe <certificate ID> >cert_data

Display certificate description:

$ keyctl describe <certificate ID>

The certificate description has the following format:

<64 bytes certificate name in EBCDIC> ':'
<certificate index as obtained from hypervisor> ':'
<certificate store token obtained from hypervisor>

The certificate description in /proc/keys has certificate name
represented in ASCII.

Users can read but cannot update the content of the certificate.

Signed-off-by: Anastasia Eskova <anastasia.eskova@ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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rethook, fprobe: do not trace rethook related functions

These functions are already marked as NOKPROBE to prevent recursion and
we have the same reason to blacklist them if rethook is used with fpro

rethook, fprobe: do not trace rethook related functions

These functions are already marked as NOKPROBE to prevent recursion and
we have the same reason to blacklist them if rethook is used with fprobe,
since they are beyond the recursion-free region ftrace can guard.

Link: https://lore.kernel.org/all/20230517034510.15639-5-zegao@tencent.com/

Fixes: f3a112c0c40d ("x86,rethook,kprobes: Replace kretprobe with rethook on x86")
Signed-off-by: Ze Gao <zegao@tencent.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

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s390/cpum_cf: merge source files for CPU Measurement counter facility

With no in-kernel user, the source files can be merged.

Move all functions and the variable definitions to file perf_cpum_cf.c

s390/cpum_cf: merge source files for CPU Measurement counter facility

With no in-kernel user, the source files can be merged.

Move all functions and the variable definitions to file perf_cpum_cf.c
This file now contains all the necessary functions and definitions
for the CPU Measurement counter facility device driver.

The files cpu_mcf.h and perf_cpum_cf_common.c are deleted.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/kprobes: replace kretprobe with rethook

That's an adaptation of commit f3a112c0c40d ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") to s390.

Replaces the kretprobe code with ret

s390/kprobes: replace kretprobe with rethook

That's an adaptation of commit f3a112c0c40d ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") to s390.

Replaces the kretprobe code with rethook on s390. With this patch,
kretprobe on s390 uses the rethook instead of kretprobe specific
trampoline code.

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

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kbuild: use obj-y instead extra-y for objects placed at the head

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

- arch/$(SRCARCH)/Makefile adds them to head-y in order to place

kbuild: use obj-y instead extra-y for objects placed at the head

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>

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s390/pai: Add support for PAI Extension 1 NNPA counters

PMU device driver perf_paiext supports Processor Activity
Instrumentation Extension (PAIE1), available with IBM z16:
- maps a 512 byte block t

s390/pai: Add support for PAI Extension 1 NNPA counters

PMU device driver perf_paiext supports Processor Activity
Instrumentation Extension (PAIE1), available with IBM z16:
- maps a 512 byte block to lowcore address 0x1508 called PAIE1 control
block.
- maps a 1024 byte block at PAIE1 control block entry with index 2.
- uses control register bit 14 to enable PAIE1 control block lookup.
- turn PAIE1 nnpa counting on and off by setting bit 63 in
PAIE1 control block entry with index 2.
- creates a sample with raw data on each context switch out when
at context switch some mapped counters have a value of nonzero.
This device driver only supports CPU wide context, no task context
is allowed.

Support for counting:
- one or more counters can be specified using
perf stat -e pai_ext/xxx/
where xxx stands for the counter event name. Multiple invocation
of this command is possible. The counter names are listed in
/sys/devices/pai_ext/events directory.
- one special counters can be specified using
perf stat -e pai_ext/NNPA_ALL/
which returns the sum of all incremented nnpa counters.
- multiple counting events can run in parallel.

Support for Sampling:
- one event pai_ext/NNPA_ALL/ is reserved for sampling.
The event collects data at context switch out and saves them in
the ring buffer.
- no multiple invocations are possible.

The PAIE1 nnpa counter events are system wide. No task context is
supported. Therefore some restrictions documented in function
paiext_busy() apply.

Extend qpaci assembly instruction to query supported memory mapped nnpa
counters. It returns the number of counters (no holes allowed in that
range).

PAIE1 nnpa counter events can not be created when a CPU hot plug
add is processed. This means a CPU hot plug add does not get
the necessary PAIE1 event to record PAIE1 nnpa counter increments
on the newly added CPU. CPU hot plug remove removes the event and
terminates the counting of PAIE1 counters immediately.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

show more ...

s390/smp: rework absolute lowcore access

Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework a

s390/smp: rework absolute lowcore access

Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework avoids the prefix page uninstalling and disabling
of normal and machine check interrupts when accessing the absolute
zero memory.

Although memcpy_absolute() routine can access the whole memory, it is
only used to update the absolute zero lowcore. This rework therefore
introduces a new mechanism for the absolute zero lowcore access and
scraps memcpy_absolute() routine for good.

Instead, an area is reserved in the virtual memory that is used for
the absolute lowcore access only. That area holds an array of 8KB
virtual mappings - one per CPU. Whenever a CPU is brought online, the
corresponding item is mapped to the real address of the previously
installed prefix page.

The absolute zero lowcore access works like this: a CPU calls the
new primitive get_abs_lowcore() to obtain its 8KB mapping as a
pointer to the struct lowcore. Virtual address references to that
pointer get translated to the real addresses of the prefix page,
which in turn gets swapped with the absolute zero memory addresses
due to prefixing. Once the pointer is not needed it must be released
with put_abs_lowcore() primitive:

struct lowcore *abs_lc;
unsigned long flags;

abs_lc = get_abs_lowcore(&flags);
abs_lc->... = ...;
put_abs_lowcore(abs_lc, flags);

To ensure the described mechanism works large segment- and region-
table entries must be avoided for the 8KB mappings. Failure to do
so results in usage of Region-Frame Absolute Address (RFAA) or
Segment-Frame Absolute Address (SFAA) large page fields. In that
case absolute addresses would be used to address the prefix page
instead of the real ones and the prefixing would get bypassed.

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

show more ...

Revert "s390/smp: rework absolute lowcore access"

This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8.

This introduced vmem_mutex locking from vmem_map_4k_page()
function called from smp_r

Revert "s390/smp: rework absolute lowcore access"

This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8.

This introduced vmem_mutex locking from vmem_map_4k_page()
function called from smp_reinit_ipl_cpu() with interrupts
disabled. While it is a pre-SMP early initcall no other CPUs
running in parallel nor other code taking vmem_mutex on this
boot stage - it still needs to be fixed.

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

show more ...

s390/smp: rework absolute lowcore access

Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework a

s390/smp: rework absolute lowcore access

Temporary unsetting of the prefix page in memcpy_absolute() routine
poses a risk of executing code path with unexpectedly disabled prefix
page. This rework avoids the prefix page uninstalling and disabling
of normal and machine check interrupts when accessing the absolute
zero memory.

Although memcpy_absolute() routine can access the whole memory, it is
only used to update the absolute zero lowcore. This rework therefore
introduces a new mechanism for the absolute zero lowcore access and
scraps memcpy_absolute() routine for good.

Instead, an area is reserved in the virtual memory that is used for
the absolute lowcore access only. That area holds an array of 8KB
virtual mappings - one per CPU. Whenever a CPU is brought online, the
corresponding item is mapped to the real address of the previously
installed prefix page.

The absolute zero lowcore access works like this: a CPU calls the
new primitive get_abs_lowcore() to obtain its 8KB mapping as a
pointer to the struct lowcore. Virtual address references to that
pointer get translated to the real addresses of the prefix page,
which in turn gets swapped with the absolute zero memory addresses
due to prefixing. Once the pointer is not needed it must be released
with put_abs_lowcore() primitive:

struct lowcore *abs_lc;
unsigned long flags;

abs_lc = get_abs_lowcore(&flags);
abs_lc->... = ...;
put_abs_lowcore(abs_lc, flags);

To ensure the described mechanism works large segment- and region-
table entries must be avoided for the 8KB mappings. Failure to do
so results in usage of Region-Frame Absolute Address (RFAA) or
Segment-Frame Absolute Address (SFAA) large page fields. In that
case absolute addresses would be used to address the prefix page
instead of the real ones and the prefixing would get bypassed.

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

show more ...

s390/cpufeature: rework to allow more than only hwcap bits

Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by

s390/cpufeature: rework to allow more than only hwcap bits

Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by adding a sequential list of cpu feature numbers, where each of them
is mapped to an entry which indicates what this number is about.

Each entry contains a type member, which indicates what feature
name space to look into (e.g. hwcap, or cpu facility). If wanted this
allows also to automatically load modules only in e.g. z/VM
configurations.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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s390: simplify early program check handler

Due to historic reasons the base program check handler calls a
configurable function. Given that there is only the early program
check handler left, simpli

s390: simplify early program check handler

Due to historic reasons the base program check handler calls a
configurable function. Given that there is only the early program
check handler left, simplify the code by directly calling that
function.

The only other user was removed with commit d485235b0054 ("s390:
assume diag308 set always works").

Also rename all functions and the asm file to reflect this.

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

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s390/pai: add support for cryptography counters

PMU device driver perf_pai_crypto supports Processor Activity
Instrumentation (PAI), available with IBM z16:
- maps a full page to lowcore address 0x1

s390/pai: add support for cryptography counters

PMU device driver perf_pai_crypto supports Processor Activity
Instrumentation (PAI), available with IBM z16:
- maps a full page to lowcore address 0x1500.
- uses CR0 bit 13 to turn PAI crypto counting on and off.
- creates a sample with raw data on each context switch out when
at context switch some mapped counters have a value of nonzero.
This device driver only supports CPU wide context, no task context
is allowed.

Support for counting:
- one or more counters can be specified using
perf stat -e pai_crypto/xxx/
where xxx stands for the counter event name. Multiple invocation
of this command is possible. The counter names are listed in
/sys/devices/pai_crypto/events directory.
- one special counters can be specified using
perf stat -e pai_crypto/CRYPTO_ALL/
which returns the sum of all incremented crypto counters.
- one event pai_crypto/CRYPTO_ALL/ is reserved for sampling.
No multiple invocations are possible. The event collects data at
context switch out and saves them in the ring buffer.

Add qpaci assembly instruction to query supported memory mapped crypto
counters. It returns the number of counters (no holes allowed in that
range).

The PAI crypto counter events are system wide and can not be executed
in parallel. Therefore some restrictions documented in function
paicrypt_busy apply.
In particular event CRYPTO_ALL for sampling must run exclusive.
Only counting events can run in parallel.

PAI crypto counter events can not be created when a CPU hot plug
add is processed. This means a CPU hot plug add does not get
the necessary PAI event to record PAI cryptography counter increments
on the newly added CPU. CPU hot plug remove removes the event and
terminates the counting of PAI counters immediately.

Co-developed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20220504062351.2954280-3-tmricht@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/kprobes: Avoid additional kprobe in kretprobe handling

So far, s390 registered a krobe on __kretprobe_trampoline which is
called everytime a kretprobe fires. This kprobe would then determine
th

s390/kprobes: Avoid additional kprobe in kretprobe handling

So far, s390 registered a krobe on __kretprobe_trampoline which is
called everytime a kretprobe fires. This kprobe would then determine
the correct return address and adjust the psw accordingly, such that
the kretprobe would branch to the appropriate address after completion.

Some other archs handle kretprobes without such an additional kprobe.
This approach is adopted to s390 with this patch.
Furthermore, the __kretprobe_trampoline now uses an assembler function
to correctly gather the register and psw content to be passed to the
registered kretprobe handler as struct pt_regs. After completion, the
register content and the psw are set based on the contents of said
pt_regs struct.
Note that a change to the psw address in struct pt_regs will not have
an impact, as the probe will still return to the original return
address of the probed function.
The return address is now recovered by using the appropriate function
arch_kretprobe_fixup_return.

The no longer needed kprobe is removed.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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arch: Make ARCH_STACKWALK independent of STACKTRACE

Make arch_stack_walk() available for ARCH_STACKWALK architectures
without it being entangled in STACKTRACE.

Link: https://lore.kernel.org/lkml/20

arch: Make ARCH_STACKWALK independent of STACKTRACE

Make arch_stack_walk() available for ARCH_STACKWALK architectures
without it being entangled in STACKTRACE.

Link: https://lore.kernel.org/lkml/20211022152104.356586621@infradead.org/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[Mark: rebase, drop unnecessary arm change]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20211129142849.3056714-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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s390: rename dma section to amode31

The dma section name is confusing, since the code which resides within
that section has nothing to do with direct memory access. Instead the
limitation is that t

s390: rename dma section to amode31

The dma section name is confusing, since the code which resides within
that section has nothing to do with direct memory access. Instead the
limitation is that the code has to run in 31 bit addressing mode, and
therefore has to reside below 2GB. So the name was chosen since
ZONE_DMA is the same region.

To reduce confusion rename the section to amode31, which hopefully
describes better what this is about.

Note: this will also change vmcoreinfo strings
- SDMA=... gets renamed to SAMODE31=...
- EDMA=... gets renamed to EAMODE31=...

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/boot: move dma sections from decompressor to decompressed kernel

This change simplifies the task of making the decompressor relocatable.

The decompressor's image contains special DMA sections

s390/boot: move dma sections from decompressor to decompressed kernel

This change simplifies the task of making the decompressor relocatable.

The decompressor's image contains special DMA sections between _sdma and
_edma. This DMA segment is loaded at boot as part of the decompressor and
then simply handed over to the decompressed kernel. The decompressor itself
never uses it in any way. The primary reason for this is the need to keep
the aforementioned DMA segment below 2GB which is required by architecture,
and because the decompressor is always loaded at a fixed low physical
address, it is guaranteed that the DMA region will not cross the 2GB
memory limit. If the DMA region had been placed in the decompressed kernel,
then KASLR would make this guarantee impossible to fulfill or it would
be restricted to the first 2GB of memory address space.

This commit moves all DMA sections between _sdma and _edma from
the decompressor's image to the decompressed kernel's image. The complete
DMA region is placed in the init section of the decompressed kernel and
immediately relocated below 2GB at start-up before it is needed by other
parts of the decompressed kernel. The relocation of the DMA region happens
even if the decompressed kernel is already located below 2GB in order
to keep the first implementation simple. The relocation should not have
any noticeable impact on boot time because the DMA segment is only a couple
of pages.

After relocating the DMA sections, the kernel has to fix all references
which point into it. In order to automate this, place all variables
pointing into the DMA sections in a special .dma.refs section. All such
variables must be defined using the new __dma_ref macro. Only variables
containing addresses within the DMA sections must be placed in the new
.dma.refs section.

Furthermore, move the initialization of control registers from
the decompressor to the decompressed kernel because some control registers
reference tables that must be placed in the DMA data section to
guarantee that their addresses are below 2G. Because the decompressed
kernel relocates the DMA sections at startup, the content of control
registers CR2, CR5 and CR15 must be updated with new addresses after
the relocation. The decompressed kernel initializes all control registers
early at boot and then updates the content of CR2, CR5 and CR15
as soon as the DMA relocation has occurred. This practically reverts
the commit a80313ff91ab ("s390/kernel: introduce .dma sections").

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

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s390/vdso: add minimal compat vdso

Add a small vdso for 31 bit compat application that provides
trampolines for calls to sigreturn,rt_sigreturn,syscall_restart.
This is requird for moving these sysc

s390/vdso: add minimal compat vdso

Add a small vdso for 31 bit compat application that provides
trampolines for calls to sigreturn,rt_sigreturn,syscall_restart.
This is requird for moving these syscalls away from the signal
frame to the vdso. Note that this patch effectively disables
CONFIG_COMPAT when using clang to compile the kernel. clang
doesn't support 31 bit mode.

We want to redirect sigreturn and restart_syscall to the vdso. However,
the kernel cannot parse the ELF vdso file, so we need to generate header
files which contain the offsets of the syscall instructions in the vdso
page.

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

show more ...

s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility

Commit cf6acb8bdb1d ("s390/cpumf: Add support for complete counter set extraction")
allows access to the CPU Measurement Coun

s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility

Commit cf6acb8bdb1d ("s390/cpumf: Add support for complete counter set extraction")
allows access to the CPU Measurement Counter Facility via character
device /dev/hwctr. The access was exclusive via this device or
via perf_event_open() system call. Only one path at a time was
permitted. The CPU Measurement Counter Facility device driver blocked
access to other processes.

This patch removes this restriction and allows concurrent access to
the CPU Measurement Counter Facility from multiple processes at the same
time via perf_event_open() SVC and via /dev/hwctr device. The access
via /dev/hwctr device is still exclusive, only one process is allowed to
access this device.

This patch
- moves the /dev/hwctr device access from file perf_cpum_cf_diag.c.
to file perf_cpum_cf.c.
- use only one trace buffer .../s390dbf/cpum_cf.
- remove cfset_csd structure and includes its members it into the
structure cpu_cf_events. This results in one data structure and
simplifies the access.
- rework function familiy ctr_set_enable, ctr_set_disable, ctr_set_start
and ctr_set_stop which operate on a counter set number.
Now they operate on a counter set bit mask.
- move CF_DIAG event functionality to file perf_cpum_cf.c. It now
contains the complete functionality of the CPU Measurement Counter
Facility:
- Performance measurement support for counters using perf stat.
- Support for complete counter set extraction with device /dev/hwctr.
- Support for counter set extraction event CF_DIAG attached to
samples using perf record.
- removes file perf_cpum_cf_diag.c

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/traps: convert pgm_check.S to C

Convert the program check table to C. Which allows to get rid of yet
another assembler file, and also enables proper type checking for the
table.

Reviewed-by: A

s390/traps: convert pgm_check.S to C

Convert the program check table to C. Which allows to get rid of yet
another assembler file, and also enables proper type checking for the
table.

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

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s390: convert to generic entry

This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.

There are a few special things on s390:

- PIF_PER_TRAP is moved to TIF_PER_TRAP

s390: convert to generic entry

This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.

There are a few special things on s390:

- PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't
know about our PIF flags in exit_to_user_mode_loop().

- The old code had several ways to restart syscalls:

a) PIF_SYSCALL_RESTART, which was only set during execve to force a
restart after upgrading a process (usually qemu-kvm) to pgste page
table extensions.

b) PIF_SYSCALL, which is set by do_signal() to indicate that the
current syscall should be restarted. This is changed so that
do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use
PIF_SYSCALL doesn't work with the generic code, and changing it
to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART
more unique.

- On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by
executing a svc instruction on the process stack which causes a fault.
While handling that fault the fault code sets PIF_SYSCALL to hand over
processing to the syscall code on exit to usermode.

The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets
a return value for a syscall. The s390x ptrace ABI uses r2 both for the
syscall number and return value, so ptrace cannot set the syscall number +
return value at the same time. The flag makes handling that a bit easier.
do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET
is set.

CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY.
CR1/7/13 will be checked both on kernel entry and exit to contain the
correct asces.

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

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s390/kprobes: move insn_page to text segment

Move the in-kernel kprobes insn page to text segment. Rationale:
having that page in rw data segment is suboptimal, since as soon as a
kprobe is set, thi

s390/kprobes: move insn_page to text segment

Move the in-kernel kprobes insn page to text segment. Rationale:
having that page in rw data segment is suboptimal, since as soon as a
kprobe is set, this will split the 1:1 kernel mapping for a single
page which get new permissions.

Note: there is always at least one kprobe present for the kretprobe
trampoline; so the mapping will always be split into smaller 4k
mappings because of this.

Moving the kprobes insn page into text segment makes sure that the
page is mapped RO/X in any case, and avoids that the 1:1 mapping is
split.

The kprobe insn_page is defined as a dummy function which is filled
with "br %r14" instructions.

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

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s390/numa: move code to arch/s390/kernel

Move all code from arch/s390/numa/ to arch/s390/kernel/
since numa.c is the only source file and all others were
deleted with the fake NUMA support removal.

s390/numa: move code to arch/s390/kernel

Move all code from arch/s390/numa/ to arch/s390/kernel/
since numa.c is the only source file and all others were
deleted with the fake NUMA support removal.

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

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s390: ptrace: hard-code "s390x" instead of UTS_MACHINE

s390 uses the UTS_MACHINE defined arch/s390/Makefile as follows:

UTS_MACHINE := s390x

We do not need to pass the fixed string from the

s390: ptrace: hard-code "s390x" instead of UTS_MACHINE

s390 uses the UTS_MACHINE defined arch/s390/Makefile as follows:

UTS_MACHINE := s390x

We do not need to pass the fixed string from the command line.
Hard-code user_regset_view::name, like many other architectures do.

Link: https://lkml.kernel.org/r/20200413013113.8529-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390: remove broken hibernate / power management support

Hibernation is known to be broken for many years on s390. Given that
there aren't any real use cases, remove the code instead of spending
tim

s390: remove broken hibernate / power management support

Hibernation is known to be broken for many years on s390. Given that
there aren't any real use cases, remove the code instead of spending
time to fix and maintain it.

Without hibernate support it doesn't make too much sense to keep power
management support; therefore remove it completely.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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