s390/hypfs_diag0c: fix virtual vs physical address confusion

Add missing virt_to_phys() translation to diag0c(). This doesn't fix a
bug since virtual and physical addresses are currently the same.

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

s390/diag: fix diag26c() physical vs virtual address confusion

Fix virtual vs physical address confusion (which currently are the same).

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>

s390/diag: handle diag 204 subcode 4 address correctly

Diagnose 204 subcode 4 requires a real (physical) address, but a
virtual address is passed to the inline assembly.

Convert the address to a physical address for only this specific case.

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

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>

s390/diag: replace zero-length array with flexible-array member

Zero-length arrays are deprecated [1] and have to be replaced by C99
flexible-array members.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
on memcpy() and help to make progress towards globally enabling
-fstrict-flex-arrays=3 [2]

Link: https://github.com/KSPP/linux/issues/78 [1]
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [2]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZC7XGpUtVhqlRLhH@work
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/diag: use __packed __aligned

Use __packed __aligned instead of __attribute__((packed, aligned(X)));
to match the rest of the file.

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

s390/tty3270: add support for diag 8c

The current code uses diag210 to infer the 3270 geometry from the
model number when running on z/VM. This doesn't work well as almost
all 3270 software clients report as 3279-2 with a custom resolution.
tty3270 assumes it has a 80x24 terminal connected because of the -2
suffix. Use diag 8c to fetch the realy geometry from z/VM.

Note that this doesn't allow dynamic resizing, i.e. reconnecting to
a z/VM session with a different geometry.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/extable: move EX_TABLE define to asm-extable.h

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h
which is a lot less generic than the current linkage.h.

Also make sure that all files which contain EX_TABLE usages actually
include the new header file. This should make sure that the files
always compile and there won't be any random compile breakage due to
other header file dependencies.

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

s390/diag: use pfn_to_phys() instead of open coding

Use pfn_to_phys() instead of open coding to make it
clear what the code is doing.

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

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>

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>

s390/setup: diag 318: refactor struct

The diag 318 struct introduced in include/asm/diag.h can be
reused in KVM, so let's condense the version code fields in the
diag318_info struct for easier usage and simplify it until we
can determine how the data should be formatted.

Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20200622154636.5499-2-walling@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

s390/kernel: introduce .dma sections

With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.

The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.

The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/setup: set control program code via diag 318

The s390x diagnose 318 instruction sets the control program name code (CPNC)
and control program version code (CPVC) to provide useful information
regarding the OS during debugging. The CPNC is explicitly set to 4 to
indicate a Linux/KVM environment.

The CPVC is a 7-byte value containing:

- 3-byte Linux version code, currently set to 0
- 3-byte unique value, currently set to 0
- 1-byte trailing null

Signed-off-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <1544135405-22385-2-git-send-email-walling@linux.ibm.com>
[set version code to 0 until the structure is fully defined]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/diag: add diag26c support for VNIC info

With subcode 0x24, diag26c returns all sorts of VNIC-related information.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

s390/diag: add diag26c support

Implement support for the hypervisor diagnose 0x26c
('Access Certain System Information').
It passes a request buffer and a subfunction code, and receives
a response buffer and a return code.

Also add the scaffolding for the 'MAC Services' subfunction.
It may be used by network devices to obtain a hypervisor-managed
MAC address.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390: avoid extable collisions

We have some inline assemblies where the extable entry points to a
label at the end of an inline assembly which is not followed by an
instruction.

On the other hand we have also inline assemblies where the extable
entry points to the first instruction of an inline assembly.

If a first type inline asm (extable point to empty label at the end)
would be directly followed by a second type inline asm (extable points
to first instruction) then we would have two different extable entries
that point to the same instruction but would have a different target
address.

This can lead to quite random behaviour, depending on sorting order.

I verified that we currently do not have such collisions within the
kernel. However to avoid such subtle bugs add a couple of nop
instructions to those inline assemblies which contain an extable that
points to an empty label.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

KVM: s390: Add sthyi emulation

Store Hypervisor Information is an emulated z/VM instruction that
provides a guest with basic information about the layers it is running
on. This includes information about the cpu configuration of both the
machine and the lpar, as well as their names, machine model and
machine type. This information enables an application to determine the
maximum capacity of CPs and IFLs available to software.

The instruction is available whenever the facility bit 74 is set,
otherwise executing it results in an operation exception.

It is important to check the validity flags in the sections before
using data from any structure member. It is not guaranteed that all
members will be valid on all machines / machine configurations.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

KVM: s390: Extend diag 204 fields

The new store hypervisor information instruction, which we are going
to introduce, needs previously unused fields in diag 204 structures.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

s390: Make diag224 public

Diag204's cpu structures only contain the cpu type by means of an
index in the diag224 name table. Hence, to be able to use diag204 in
any meaningful way, we also need a usable diag224 interface.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

s390: hypfs: Move diag implementation and data definitions

Diag 204 data and function definitions currently live in the hypfs
files. As KVM will be a consumer of this data, we need to make it
publicly available and move it to the appropriate diag.{c,h} files.

__attribute__ ((packed)) occurences were replaced with __packed for
all moved structs.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

s390/diag: add tracepoint for diagnose calls

To be able to analyse problems in regard to hypervisor overhead
add a tracepoing for diagnose calls. It reports the number of
the diagnose issued, e.g.

sshd-1385 [002] .... 42.701431: diagnose: nr=0x9c
<idle>-0 [001] ..s. 43.587528: diagnose: nr=0x9c

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/diag: add a statistic for diagnose calls

Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose
calls have been done by each CPU in the system.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] replace diag10() with diag10_range() function

Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] move include/asm-s390 to arch/s390/include/asm

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>