Compiling vmlogrdr with GCC 15 generates this warning:
CC [M] drivers/s390/char/vmlogrdr.o
drivers/s390/char/vmlogrdr.c:126:29: error: initializer-string for array
of ‘char’ is too long [-Werror=unterminated-string-initialization]
126 | { .system_service = "*LOGREC ",
Given that the system_service array intentionally contains a non-null
terminated string use an array initializer, instead of string
initializer to get rid of this warning.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Use the internal_name member of vmlogrdr_priv_t to print error messages
instead of the system_service member. The system_service member is not a
string, but a non-null terminated eight byte character array, which
contains the ASCII representation of a z/VM system service.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
With the switch to GENERIC_CPU_DEVICES an early call to the sclp subsystem
was added to smp_prepare_cpus(). This will usually succeed since the sclp
subsystem is implicitly initialized early enough if an sclp based console
is present.
If no such console is present the initialization happens with an
arch_initcall(); in such cases calls to the sclp subsystem will fail.
For CPU detection this means that the fallback sigp loop will be used
permanently to detect CPUs instead of the preferred READ_CPU_INFO sclp
request.
Fix this by adding an explicit early sclp_init() call via
arch_cpu_finalize_init().
Reported-by: Sheshu Ramanandan <sheshu.ramanandan@ibm.com>
Fixes: 4a39f12e75 ("s390/smp: Switch to GENERIC_CPU_DEVICES")
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The in-kernel disassembler intentionally uses nun-null terminated
strings in order to keep the arrays which contain mnemonics as small
as possible. GCC 15 however warns about this:
./arch/s390/include/generated/asm/dis-defs.h:1662:71: error: initializer-string
for array of ‘char’ is too long [-Werror=unterminated-string-initialization]
1662 | [1261] = { .opfrag = 0xea, .format = INSTR_SS_L0RDRD, .name = "unpka" }, \
Get rid of this warning by using array initializers.
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
GCC changed the default C standard dialect from gnu17 to gnu23,
which should not have impacted the kernel because it explicitly requests
the gnu11 standard in the main Makefile. However, there are certain
places in the s390 code that use their own CFLAGS without a '-std='
value, which break with this dialect change because of the kernel's own
definitions of bool, false, and true conflicting with the C23 reserved
keywords.
include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant
11 | false = 0,
| ^~~~~
include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards
include/linux/types.h:35:33: error: 'bool' cannot be defined via 'typedef'
35 | typedef _Bool bool;
| ^~~~
include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards
Add '-std=gnu11' to the decompressor and purgatory CFLAGS to eliminate
these errors and make the C standard version of these areas match the
rest of the kernel.
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Use the "Q" instead of "R" constraint to correctly reflect the instruction
format of the tm instruction: the first operand is a memory reference
without index register and short displacement. The "R" constraint indicates
a memory reference with index register instead.
This may lead to compile errors like:
arch/s390/include/asm/bitops.h: Assembler messages:
arch/s390/include/asm/bitops.h:60: Error: operand 1: syntax error; missing ')' after base register
arch/s390/include/asm/bitops.h:60: Error: operand 2: syntax error; ')' not allowed here
arch/s390/include/asm/bitops.h:60: Error: junk at end of line: `,4'
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org
Fixes: b2bc1b1a77 ("s390/bitops: Provide optimized arch_test_bit()")
Acked-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>
Since commit 25f39d3dcb ("s390/pci: Ignore RID for isolated VFs") PFs
which are not initially configured but in standby are considered
isolated. That is they create only a single function PCI domain. Due to
the PCI domains being created on discovery, this means that even if they
are configured later on, sibling PFs and their child VFs will not be
added to their PCI domain breaking SR-IOV expectations.
The reason the referenced commit ignored standby PFs for the creation of
multi-function PCI subhierarchies, was to work around a PCI domain
renumbering scenario on reboot. The renumbering would occur after
removing a previously in standby PF, whose domain number is used for its
configured sibling PFs and their child VFs, but which itself remained in
standby. When this is followed by a reboot, the sibling PF is used
instead to determine the PCI domain number of it and its child VFs.
In principle it is not possible to know which standby PFs will be
configured later and which may be removed. The PCI domain and root bus
are pre-requisites for hotplug slots so the decision of which functions
belong to which domain can not be postponed. With the renumbering
occurring only in rare circumstances and being generally benign, accept
it as an oddity and fix SR-IOV for initially standby PFs simply by
allowing them to create PCI domains.
Cc: stable@vger.kernel.org
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Fixes: 25f39d3dcb ("s390/pci: Ignore RID for isolated VFs")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Similar to commit eb6efdfeae ("s390/uaccess: add KMSAN support to
put_user() and get_user()") disable KMSAN instrumention for futex inline
assemblies, which contain dereferenced user pointers. With KMSAN
instrumentation this would lead to accesses of shadows for user pointers,
which should not happen.
Handle the futex operations like they copy a value (old) from user
space to kernel space.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Rename get_put_user_noinstr_attributes to a more generic
uaccess_kmsan_or_inline name. This allows to use it for other non
put_user()/get_user() uaccess functions withour causing confusion.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cleanup the futex_atomic_cmpxchg_inatomic() inline assembly to make it
a bit more readable.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cleanup the futex atomic op inline assembly and generate a function for
each futex atomic op. This makes the code hopefully a bit more readable.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
The s390 implementations of raw_copy_from_user() and raw_copy_to_user() are
never inlined. However INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER are
still set. This leads to the odd situation that only the error handling
(memset to zero of the not copied bytes) of copy_from_user() is inlined,
while the actual fast path code is out-of-line.
This would make sense if raw_copy_from_user() and raw_copy_to_user() were
implemented in assembler files, where inlining is not possible. But the
current s390 setup does not make any sense.
Address this by moving the raw uaccess copy inline assemblies to the
uaccess header file, and remove INLINE_COPY_FROM_USER and
INLINE_COPY_TO_USER definitions. This way the uaccess code, but now
including error handling, is still out-of-line with the common code
_copy_from_user() and _copy_to_user() variants, which inline the raw
uaccess functions via _inline_copy_from_user() and _inline_copy_to_user().
This reduces the size of the kernel image by ~17kb.
(defconfig, gcc 14.2.0)
Acked-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>
Use asm goto if available for put_user() and get_user().
This generates slightly better code.
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>
Remove usage of the operand access control specifier for put_user()
and get_user() (again). Instead hardcode the specifier for both inline
assemblies. This saves one instruction.
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>
Remove EX_TABLE_UA_LOAD_MEM exception handling and replace it with
EX_TABLE_UA_FAULT. Open code the return code check, and also open code
setting of the destination to zero in case of an error. In almost all cases
the compiler is able to optimize the open coded checks away, since all
users of get_users() must check the return code, and are not supposed to
use the result in case of an error.
In addition this allows to change the get_user() inline assembly so that
the "Q" constraint can be used for the destination, instead of only an "a"
constraint. This generates slightly better code.
Acked-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>
Remove superfluous underscores, brackets, and early clobber to make
the code a bit more readable.
Acked-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>
The __put_user_fn() and __get_user_fn() wrappers are leftovers from the
time where the kernel was compiled with or without mvcos support plus they
were later used to workaround the problems that came with asm register
constructs.
Both reasons do not exist anymore, therefore remove the wrappers and
shorten the code.
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>
Use asm goto for __mvc_kernel_nofault() if available. This generates
slightly better code, since the error checking happens implicitly with
the goto (aka exception) and the good path comes without any checks and
branches.
Acked-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>
Use the mvc instruction in order to implement __get_kernel_nofault() and
__put_kernel_nofault(). Both functions have a source and destination
address where the code is supposed to read from and write to. Use the mvc
instruction to copy from source to destination instead of lg/stg like
instructions. This generates slightly better code.
Acked-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>
Rename EX_TABLE_UA_STORE to a more generic EX_TABLE_UA_FAULT
name. This allows to use the extable type also for uaccess inline
assemblies which read from userspace, without causing confusion.
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>
Use the more precise CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS to tell if the
compiler has support for the A, O, and R inline assembly format flags.
This allows recent Clang compilers to generate better code.
Move code around so the good (aka better) case at the top of each ifdef
construct.
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>
Introduce CC_HAS_ASM_AOR_FORMAT_FLAGS Kconfig option. Use this option for
inline assemblies where the A, O, or R format flags are used.
Those flags are not available for Clang versions before 19.1.0.
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>
Config options which can be used to check for compiler bugs and features
have the compiler independent CC prefix in order to avoid duplicating and
having to check config options for multiple compilers. Therefore rename the
config option accordingly.
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>
The fixup section was added again by mistake when test_fp_ctl() was
removed. The reason for the removal of the fixup section is described in
commit 484a8ed8b7 ("s390/extable: add dedicated uaccess handler").
Remove it again for the same reason.
Add an exception handler which handles exceptions when the floating point
control register is attempted to be set to invalid values. The exception
handler sets the floating point control register to zero and continues
execution at the specified address.
The new sfpc inline assembly is open-coded to make back porting a bit
easier.
Fixes: 702644249d ("s390/fpu: get rid of test_fp_ctl()")
Cc: stable@vger.kernel.org
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>
Use a zero identity base when CONFIG_RANDOMIZE_IDENTITY_BASE is off,
slightly optimizing __pa/__va calculations.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Currently, decompression error messages can be very uninformative:
[ 0.029853] startup: read error
[ 0.040507] startup: -- System halted
Improve these messages to make it clear that the error originates from
the decompression code. Additionally, on decompression failures, if
bootdebug is enabled, dump the message ring buffer before halting. This
provides more context for diagnosing startup issues.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add boot_debug() calls to log various memory layout decisions and
randomization details during early startup, improving debugging
capabilities.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reorder the store_ipl_parmblock(), uv_query_info(), and command line
setup calls to occur earlier. This ensures debug printing covers all
memory tracking activities from the start.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Introduce boot_debug() calls to track memory detection, online ranges,
reserved areas, and allocations (except for VMEM allocations, which are
too frequent). Instead introduce dump_physmem_reserved() function which
prints out full memory tracking information. This helps in debugging
early boot memory handling.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
sclp_early_printk() ignores boot console debug settings and prints
unconditionally. It also prints message without any timestamp
or formatting. Convert it to pr_info().
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
When CONFIG_PRINTK_TIME is enabled, add timestamps to boot messages in
the same format as regular printk. Timestamps appear only with earlyprintk
and are stored in the boot messages ring buffer, but are not propagated
to main kernel messages (if earlyprintk is not enabled). This prevents
double timestamps in the output.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Dump the boot message ring buffer when a crash occurs during boot, but
only if bootdebug is enabled. This helps assist in analyzing boot-time
issues by providing additional debugging information.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Enhance boot debugging by allowing the "bootdebug" kernel parameter to
accept an optional comma-separated list of prefixes. Only debug messages
starting with these prefixes will be printed during boot. For example:
bootdebug=startup,vmem
Not specifying a filter for the "bootdebug" parameter prints all debug
messages. The `boot_fmt` macro can be defined to set a common prefix:
#define boot_fmt(fmt) "startup: " fmt
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Suppress decompressor debug messages by default, similar to regular
kernel debug messages that require 'DEBUG' or 'dyndbg' to be enabled
(depending on CONFIG_DYNAMIC_DEBUG). Introduce a 'bootdebug' option to
enable printing these messages when needed.
All messages are still stored in the boot ring buffer regardless.
To enable boot debug messages:
bootdebug debug
Or combine with 'earlyprintk' to print them without delay:
bootdebug debug earlyprintk
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
When earlyprintk is not specified, boot messages are only stored in a
ring buffer to be printed later by printk when console driver is
registered.
Critical messages from boot_emerg() are always printed immediately,
even without earlyprintk.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Collect all boot messages into a ring buffer independent of the current
log level. This allows to retain all boot-time messages, which is
particularly useful for analyzing early crashes.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Now that boot_printk() supports decimal specifiers, update boot_emerg()
messages to use %d and %lu instead of %x and %lx where appropriate.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Replaces boot_printk() calls with appropriate loglevel-specific helpers
such as boot_emerg(), boot_warn(), and boot_debug().
Using functions with explicit log levels improves log clarity and aligns
the boot code with standard kernel logging practices. This makes it
easier to filter and manage boot-time messages based on their severity.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add message severity levels for boot messages, similar to the main
kernel. Support command-line options that control console output
verbosity, including "loglevel," "ignore_loglevel," "debug," and "quiet".
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Enable the boot_printk() function to print decimal values. Add the 'd',
'i', and 'u' conversion specifiers support.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Enhance boot_printk() to support field width and padding across all
argument types for better formatting.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
For KASAN shadow mappings, switch from physmem_alloc_or_die() to
physmem_alloc() and return INVALID_PHYS_ADDR on allocation failure. This
allows gracefully falling back from large pages to smaller pages (1MB
or 4KB) if the allocation of 2GB size/aligned pages cannot be fulfilled.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
