Commit Graph

420 Commits

Author SHA1 Message Date
Heiko Carstens
c3a589fd9f s390/boot: Fix ESSA detection
The cmma_test_essa() inline assembly uses tmp as input and output, however
tmp is specified as output only, which allows the compiler to optimize the
initialization of tmp away.

Therefore the ESSA detection may or may not work depending on previous
contents of the register that the compiler selected for tmp.

Fix this by using the correct constraint modifier.

Fixes: 468a3bc2b7 ("s390/cmma: move parsing of cmma kernel parameter to early boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-02-18 18:49:24 +01:00
Linus Torvalds
b731bc5f49 Merge tag 's390-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Alexander Gordeev:

 - The rework that uncoupled physical and virtual address spaces
   inadvertently prevented KASAN shadow mappings from using large pages.
   Restore large page mappings for KASAN shadows

 - Add decompressor routine physmem_alloc() that may fail, unlike
   physmem_alloc_or_die(). This allows callers to implement fallback
   paths

 - Allow falling back from large pages to smaller pages (1MB or 4KB) if
   the allocation of 2GB pages in the decompressor can not be fulfilled

 - Add to the decompressor boot print support of "%%" format string,
   width and padding hadnling, length modifiers and decimal conversion
   specifiers

 - Add to the decompressor message severity levels similar to kernel
   ones. Support command-line options that control console output
   verbosity

 - Replaces boot_printk() calls with appropriate loglevel- specific
   helpers such as boot_emerg(), boot_warn(), and boot_debug().

 - Collect all boot messages into a ring buffer independent of the
   current log level. This is particularly useful for early crash
   analysis

 - If 'earlyprintk' command line parameter is not specified, store
   decompressor boot messages in a ring buffer to be printed later by
   the kernel, once the console driver is registered

 - Add 'bootdebug' command line parameter to enable printing of
   decompressor debug messages when needed. That parameters allows
   message suppressing and filtering

 - Dump boot messages on a decompressor crash, but only if 'bootdebug'
   command line parameter is enabled

 - When CONFIG_PRINTK_TIME is enabled, add timestamps to boot messages
   in the same format as regular printk()

 - Dump physical memory tracking information on boot: online ranges,
   reserved areas and vmem allocations

 - Dump virtual memory layout and randomization details

 - Improve decompression error reporting and dump the message ring
   buffer in case the boot failed and system halted

 - Add an exception handler which handles exceptions when FPU control
   register is attempted to be set to an invalid value. Remove '.fixup'
   section as result of this change

 - Use 'A', 'O', and 'R' inline assembly format flags, which allows
   recent Clang compilers to generate better FPU code

 - Rework uaccess code so it reads better and generates more efficient
   code

 - Cleanup futex inline assembly code

 - Disable KMSAN instrumention for futex inline assemblies, which
   contain dereferenced user pointers. Otherwise, shadows for the user
   pointers would be accessed

 - PFs which are not initially configured but in standby create only a
   single-function PCI domain. If they are configured later on, sibling
   PFs and their child VFs will not be added to their PCI domain
   breaking SR-IOV expectations.

   Fix that by allowing initially configured but in standby PFs create
   multi-function PCI domains

 - Add '-std=gnu11' to decompressor and purgatory CFLAGS to avoid
   compile errors caused by kernel's own definitions of 'bool', 'false',
   and 'true' conflicting with the C23 reserved keywords

 - Fix sclp subsystem failure when a sclp console is not present

 - Fix misuse of non-NULL terminated strings in vmlogrdr driver

 - Various other small improvements, cleanups and fixes

* tag 's390-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (53 commits)
  s390/vmlogrdr: Use array instead of string initializer
  s390/vmlogrdr: Use internal_name for error messages
  s390/sclp: Initialize sclp subsystem via arch_cpu_finalize_init()
  s390/tools: Use array instead of string initializer
  s390/vmem: Fix null-pointer-arithmetic warning in vmem_map_init()
  s390: Add '-std=gnu11' to decompressor and purgatory CFLAGS
  s390/bitops: Use correct constraint for arch_test_bit() inline assembly
  s390/pci: Fix SR-IOV for PFs initially in standby
  s390/futex: Avoid KMSAN instrumention for user pointers
  s390/uaccess: Rename get_put_user_noinstr_attributes to uaccess_kmsan_or_inline
  s390/futex: Cleanup futex_atomic_cmpxchg_inatomic()
  s390/futex: Generate futex atomic op functions
  s390/uaccess: Remove INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER
  s390/uaccess: Use asm goto for put_user()/get_user()
  s390/uaccess: Remove usage of the oac specifier
  s390/uaccess: Replace EX_TABLE_UA_LOAD_MEM exception handling
  s390/uaccess: Cleanup noinstr __put_user()/__get_user() inline assembly constraints
  s390/uaccess: Remove __put_user_fn()/__get_user_fn() wrappers
  s390/uaccess: Move put_user() / __put_user() close to put_user() asm code
  s390/uaccess: Use asm goto for __mvc_kernel_nofault()
  ...
2025-01-30 10:48:17 -08:00
Vasily Gorbik
f684b7954e s390/ipl_report: Remove unused 'size' variable
Remove unused since commit f913a66004 ("s390/boot: rework decompressor
reserved tracking") 'size' variable from get_cert_comp_list_size().

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>
2025-01-26 17:24:04 +01:00
Vasily Gorbik
d7bebcb4a8 s390: Optimize __pa/__va when RANDOMIZE_IDENTITY_BASE is off
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>
2025-01-26 17:24:03 +01:00
Vasily Gorbik
9af310ef10 s390/boot: Improve decompression error reporting
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>
2025-01-26 17:24:03 +01:00
Vasily Gorbik
ec6f9f7e5b s390/boot: Add startup debugging support
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>
2025-01-26 17:24:03 +01:00
Vasily Gorbik
418b4d5e61 s390/boot: Add vmem debugging support
Introduce boot_debug() calls in vmem code to log page table mappings
including KASAN shadow mappings for improved early boot debugging.

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>
2025-01-26 17:24:03 +01:00
Vasily Gorbik
a56827e5a5 s390/boot: Move command line parsing earlier
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>
2025-01-26 17:24:02 +01:00
Vasily Gorbik
9688b17b4a s390/boot: Add physmem tracking debug support
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>
2025-01-26 17:24:02 +01:00
Vasily Gorbik
70309dc776 s390/boot: Add timestamps to early boot messages
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>
2025-01-26 17:24:02 +01:00
Vasily Gorbik
b2a992a55f s390/boot: Dump message ring buffer on crash with bootdebug
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>
2025-01-26 17:24:01 +01:00
Vasily Gorbik
b79015ae63 s390/boot: Add prefix filtering to bootdebug messages
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>
2025-01-26 17:24:01 +01:00
Vasily Gorbik
d20d8e5133 s390/boot: Add bootdebug option to control debug messages
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>
2025-01-26 17:24:01 +01:00
Vasily Gorbik
c09f8d0ad6 s390/boot: Defer boot messages when earlyprintk is not enabled
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>
2025-01-26 17:24:01 +01:00
Vasily Gorbik
847e5a4c71 s390/boot: Make boot_printk() return int
Modify boot_printk() to return int, aligning it with printk().

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>
2025-01-26 17:24:01 +01:00
Vasily Gorbik
816b5feaed s390/boot: Introduce ring buffer for boot messages
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>
2025-01-26 17:24:00 +01:00
Vasily Gorbik
bbbaf06123 s390/boot: Use decimal format specifiers in boot messages
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>
2025-01-26 17:24:00 +01:00
Vasily Gorbik
42fc158c7e s390/boot: Replace boot_printk() with loglevel-specific helpers
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>
2025-01-26 17:24:00 +01:00
Vasily Gorbik
d538fdc49a s390/boot: Add support for boot messages loglevels
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>
2025-01-26 17:24:00 +01:00
Vasily Gorbik
92b712fa7d s390/boot: Add decimal conversion specifiers to boot_printk()
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>
2025-01-26 17:23:59 +01:00
Vasily Gorbik
3d846daafb s390/boot: Add field width and padding handling to boot_printk()
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>
2025-01-26 17:23:59 +01:00
Vasily Gorbik
9291d572fe s390/boot: Add length modifiers to boot_printk()
Add support for the 'l', 'h', 'hh', and 'z' length modifiers.

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>
2025-01-26 17:23:59 +01:00
Vasily Gorbik
dccac2b22b s390/boot: Add %% support to boot_printk()
Add "%%" support for the boot_printk() format string.

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>
2025-01-26 17:23:59 +01:00
Vasily Gorbik
490a5e99ea s390/boot: Allow KASAN mapping to fallback to small pages
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>
2025-01-26 17:23:59 +01:00
Vasily Gorbik
aeb4358a52 s390/boot: Add physmem_alloc()
Add physmem_alloc() as a variant of physmem_alloc_or_die() that can return
an error instead of triggering a panic on OOM. This allows callers to
implement alternative fallback paths.

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>
2025-01-26 17:23:58 +01:00
Vasily Gorbik
02415f1cf4 s390/boot: Rename physmem_alloc_top_down() to physmem_alloc_or_die()
The new name better reflects the function's behavior, emphasizing that
it will terminate execution if allocation fails.

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>
2025-01-26 17:23:58 +01:00
Vasily Gorbik
e70452c4ba s390/mm: Allow large pages for KASAN shadow mapping
Commit c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address
spaces") introduced a large_allowed() helper that restricts which mapping
modes can use large pages. This change unintentionally prevented KASAN
shadow mappings from using large pages, despite there being no reason
to avoid them. In fact, large pages are preferred for performance.

Since commit d8073dc6bc ("s390/mm: Allow large pages only for aligned
physical addresses"), both can_large_pud() and can_large_pmd() call _pa()
to check if large page physical addresses are aligned. However, _pa()
has a side effect: it allocates memory in POPULATE_KASAN_MAP_SHADOW
mode.

Rename large_allowed() to large_page_mapping_allowed() and add
POPULATE_KASAN_MAP_SHADOW to the allowed list to restore large page
mappings for KASAN shadows.

While large_page_mapping_allowed() isn't strictly necessary with current
mapping modes since disallowed modes either don't map anything or fail
alignment and size checks, keep it for clarity.

Rename _pa() to resolve_pa_may_alloc() for clarity and to emphasize
existing side effect. Rework can_large_pud()/can_large_pmd() to take
the side effect into consideration and actually return physical address
instead of just checking conditions.

Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
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>
2025-01-26 17:23:58 +01:00
Linus Torvalds
4f42d0bf72 Merge tag 's390-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:

 - Select config option KASAN_VMALLOC if KASAN is enabled

 - Select config option VMAP_STACK unconditionally

 - Implement arch_atomic_inc() / arch_atomic_dec() functions which
   result in a single instruction if compiled for z196 or newer
   architectures

 - Make layering between atomic.h and atomic_ops.h consistent

 - Comment s390 preempt_count implementation

 - Remove pre MARCH_HAS_Z196_FEATURES preempt count implementation

 - GCC uses the number of lines of an inline assembly to calculate
   number of instructions and decide on inlining. Therefore remove
   superfluous new lines from a couple of inline assemblies.

 - Provide arch_atomic_*_and_test() implementations that allow the
   compiler to generate slightly better code.

 - Optimize __preempt_count_dec_and_test()

 - Remove __bootdata annotations from declarations in header files

 - Add missing include of <linux/smp.h> in abs_lowcore.h to provide
   declarations for get_cpu() and put_cpu() used in the code

 - Fix suboptimal kernel image base when running make kasan.config

 - Remove huge_pte_none() and huge_pte_none_mostly() as are identical to
   the generic variants

 - Remove unused PAGE_KERNEL_EXEC, SEGMENT_KERNEL_EXEC, and
   REGION3_KERNEL_EXEC defines

 - Simplify noexec page protection handling and change the page, segment
   and region3 protection definitions automatically if the instruction
   execution-protection facility is not available

 - Save one instruction and prefer EXRL instruction over EX in string,
   xor_*(), amode31 and other functions

 - Create /dev/diag misc device to fetch diagnose specific information
   from the kernel and provide it to userspace

 - Retrieve electrical power readings using DIAGNOSE 0x324 ioctl

 - Make ccw_device_get_ciw() consistent and use array indices instead of
   pointer arithmetic

 - s390/qdio: Move memory alloc/pointer arithmetic for slib and sl into
   one place

 - The sysfs core now allows instances of 'struct bin_attribute' to be
   moved into read-only memory. Make use of that in s390 code

 - Add missing TLB range adjustment in pud_free_tlb()

 - Improve topology setup by adding early polarization detection

 - Fix length checks in codepage_convert() function

 - The generic bitops implementation is nearly identical to the s390
   one. Switch to the generic variant and decrease a bit the kernel
   image size

 - Provide an optimized arch_test_bit() implementation which makes use
   of flag output constraint. This generates slightly better code

 - Provide memory topology information obtanied with DIAGNOSE 0x310
   using ioctl.

 - Various other small improvements, fixes, and cleanups

Also, some changes came in through a merge of 'pci-device-recovery'
branch:

 - Add PCI error recovery status mechanism

 - Simplify and document debug_next_entry() logic

 - Split private data allocation and freeing out of debug file open()
   and close() operations

 - Add debug_dump() function that gets a textual representation of a
   debug info (e.g. PCI recovery hardware error logs)

 - Add formatted content of pci_debug_msg_id to the PCI report

* tag 's390-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
  s390/futex: Fix FUTEX_OP_ANDN implementation
  s390/diag: Add memory topology information via diag310
  s390/bitops: Provide optimized arch_test_bit()
  s390/bitops: Switch to generic bitops
  s390/ebcdic: Fix length decrement in codepage_convert()
  s390/ebcdic: Fix length check in codepage_convert()
  s390/ebcdic: Use exrl instead of ex
  s390/amode31: Use exrl instead of ex
  s390/stackleak: Use exrl instead of ex in __stackleak_poison()
  s390/lib: Use exrl instead of ex in xor functions
  s390/topology: Improve topology detection
  s390/tlb: Add missing TLB range adjustment
  s390/pkey: Constify 'struct bin_attribute'
  s390/sclp: Constify 'struct bin_attribute'
  s390/pci: Constify 'struct bin_attribute'
  s390/ipl: Constify 'struct bin_attribute'
  s390/crypto/cpacf: Constify 'struct bin_attribute'
  s390/qdio: Move memory alloc/pointer arithmetic for slib and sl into one place
  s390/cio: Use array indices instead of pointer arithmetic
  s390/qdio: Rename feature flag aif_osa to aif_qdio
  ...
2025-01-20 21:14:49 -08:00
Heiko Carstens
f8107a8be0 s390/mm: Simplify noexec page protection handling
By default page protection definitions like PAGE_RX have the _PAGE_NOEXEC
bit set. For older machines without the instruction execution protection
facility this bit is not allowed to be used in page table entries, and
therefore must be removed.

This is done at a couple of page table walkers, but also at some but not
all page table modification functions like ptep_modify_prot_commit(). Avoid
all of this and change the page, segment and region3 protection definitions
so that the noexec bit is masked out automatically if the instruction
execution-protection facility is not available. This is similar to what
also various other architectures do which had to solve the same problem.

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
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>
2024-12-17 12:46:13 +01:00
Vasily Gorbik
282da38b46 s390/mm: Consider KMSAN modules metadata for paging levels
The calculation determining whether to use three- or four-level paging
didn't account for KMSAN modules metadata. Include this metadata in the
virtual memory size calculation to ensure correct paging mode selection
and avoiding potentially unnecessary physical memory size limitations.

Fixes: 65ca73f9fb ("s390/mm: define KMSAN metadata for vmalloc and modules")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-12-15 23:35:09 +01:00
Heiko Carstens
e7256acac3 s390/Kconfig: Select KASAN_VMALLOC if KASAN is enabled
Reduce the number of to be considered config options and select
KASAN_VMALLOC if KASAN is enabled.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-12-10 15:41:58 +01:00
Heiko Carstens
41856638e6 s390/mm: Fix DirectMap accounting
With uncoupling of physical and virtual address spaces population of
the identity mapping was changed to use the type POPULATE_IDENTITY
instead of POPULATE_DIRECT. This breaks DirectMap accounting:

> cat /proc/meminfo
DirectMap4k:       55296 kB
DirectMap1M:    18446744073709496320 kB

Adjust all locations of update_page_count() in vmem.c to use
POPULATE_IDENTITY instead of POPULATE_DIRECT as well. With this
accounting is correct again:

> cat /proc/meminfo
DirectMap4k:       54264 kB
DirectMap1M:     8334336 kB

Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
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>
2024-12-10 15:40:41 +01:00
Heiko Carstens
d80888232e s390/boot/physmem: Convert to use flag output macros
Use flag output macros in inline asm to allow for better code generation if
the compiler has support for the flag output constraint.

Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13 14:31:33 +01:00
David Hildenbrand
63938e1708 s390/physmem_info: Query diag500(STORAGE LIMIT) to support QEMU/KVM memory devices
To support memory devices under QEMU/KVM, such as virtio-mem,
we have to prepare our kernel virtual address space accordingly and
have to know the highest possible physical memory address we might see
later: the storage limit. The good old SCLP interface is not suitable for
this use case.

In particular, memory owned by memory devices has no relationship to
storage increments, it is always detected using the device driver, and
unaware OSes (no driver) must never try making use of that memory.
Consequently this memory is located outside of the "maximum storage
increment"-indicated memory range.

Let's use our new diag500 STORAGE_LIMIT subcode to query this storage
limit that can exceed the "maximum storage increment", and use the
existing interfaces (i.e., SCLP) to obtain information about the initial
memory that is not owned+managed by memory devices.

If a hypervisor does not support such memory devices, the address exposed
through diag500 STORAGE_LIMIT will correspond to the maximum storage
increment exposed through SCLP.

To teach kdump on s390 to include memory owned by memory devices, there
will be ways to query the relevant memory ranges from the device via a
driver running in special kdump mode (like virtio-mem already implements
to filter /proc/vmcore access so we don't end up reading from unplugged
device blocks).

Update setup_ident_map_size(), to clarify that there can be more than
just online and standby memory.

Tested-by: Mario Casquero <mcasquer@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20241025141453.1210600-4-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07 10:26:24 +01:00
Steffen Eiden
f00469a642 s390/uv: Retrieve UV secrets sysfs support
Reflect the updated content in the query information UVC to the sysfs at
/sys/firmware/query

* new UV-query sysfs entry for the maximum number of retrievable
  secrets the UV can store for one secure guest.
* new UV-query sysfs entry for the maximum number of association
  secrets the UV can store for one secure guest.
* max_secrets contains the sum of max association and max retrievable
  secrets.

Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20241024062638.1465970-7-seiden@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29 11:17:17 +01:00
Steffen Eiden
da59c71cc7 s390/uv: Use a constant for more-data rc
Add a define for the UVC rc 0x0100 that indicates that a UV-call was
successful but may serve more data if called with a larger buffer
again.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20241024062638.1465970-2-seiden@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29 11:17:16 +01:00
Heiko Carstens
e6ebf0d651 s390: Fix various typos
Run codespell on arch/s390 and drivers/s390 and fix all typos.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-25 16:03:23 +02:00
Linus Torvalds
1ec6d09789 Merge tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:

 - Optimize ftrace and kprobes code patching and avoid stop machine for
   kprobes if sequential instruction fetching facility is available

 - Add hiperdispatch feature to dynamically adjust CPU capacity in
   vertical polarization to improve scheduling efficiency and overall
   performance. Also add infrastructure for handling warning track
   interrupts (WTI), allowing for graceful CPU preemption

 - Rework crypto code pkey module and split it into separate,
   independent modules for sysfs, PCKMO, CCA, and EP11, allowing modules
   to load only when the relevant hardware is available

 - Add hardware acceleration for HMAC modes and the full AES-XTS cipher,
   utilizing message-security assist extensions (MSA) 10 and 11. It
   introduces new shash implementations for HMAC-SHA224/256/384/512 and
   registers the hardware-accelerated AES-XTS cipher as the preferred
   option. Also add clear key token support

 - Add MSA 10 and 11 processor activity instrumentation counters to perf
   and update PAI Extension 1 NNPA counters

 - Cleanup cpu sampling facility code and rework debug/WARN_ON_ONCE
   statements

 - Add support for SHA3 performance enhancements introduced with MSA 12

 - Add support for the query authentication information feature of MSA
   13 and introduce the KDSA CPACF instruction. Provide query and query
   authentication information in sysfs, enabling tools like cpacfinfo to
   present this data in a human-readable form

 - Update kernel disassembler instructions

 - Always enable EXPOLINE_EXTERN if supported by the compiler to ensure
   kpatch compatibility

 - Add missing warning handling and relocated lowcore support to the
   early program check handler

 - Optimize ftrace_return_address() and avoid calling unwinder

 - Make modules use kernel ftrace trampolines

 - Strip relocs from the final vmlinux ELF file to make it roughly 2
   times smaller

 - Dump register contents and call trace for early crashes to the
   console

 - Generate ptdump address marker array dynamically

 - Fix rcu_sched stalls that might occur when adding or removing large
   amounts of pages at once to or from the CMM balloon

 - Fix deadlock caused by recursive lock of the AP bus scan mutex

 - Unify sync and async register save areas in entry code

 - Cleanup debug prints in crypto code

 - Various cleanup and sanitizing patches for the decompressor

 - Various small ftrace cleanups

* tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (84 commits)
  s390/crypto: Display Query and Query Authentication Information in sysfs
  s390/crypto: Add Support for Query Authentication Information
  s390/crypto: Rework RRE and RRF CPACF inline functions
  s390/crypto: Add KDSA CPACF Instruction
  s390/disassembler: Remove duplicate instruction format RSY_RDRU
  s390/boot: Move boot_printk() code to own file
  s390/boot: Use boot_printk() instead of sclp_early_printk()
  s390/boot: Rename decompressor_printk() to boot_printk()
  s390/boot: Compile all files with the same march flag
  s390: Use MARCH_HAS_*_FEATURES defines
  s390: Provide MARCH_HAS_*_FEATURES defines
  s390/facility: Disable compile time optimization for decompressor code
  s390/boot: Increase minimum architecture to z10
  s390/als: Remove obsolete comment
  s390/sha3: Fix SHA3 selftests failures
  s390/pkey: Add AES xts and HMAC clear key token support
  s390/cpacf: Add MSA 10 and 11 new PCKMO functions
  s390/mm: Add cond_resched() to cmm_alloc/free_pages()
  s390/pai_ext: Update PAI extension 1 counters
  s390/pai_crypto: Add support for MSA 10 and 11 pai counters
  ...
2024-09-21 09:02:54 -07:00
Heiko Carstens
5c9a274202 s390/boot: Move boot_printk() code to own file
Keep the printk code separate from the program check code and move
boot_printk() and helper functions to own printk.c file.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:43 +02:00
Heiko Carstens
dc71555507 s390/boot: Use boot_printk() instead of sclp_early_printk()
Consistently use boot_printk() everywhere instead of sclp_early_printk() at
some places. For some places it was required (e.g. als.c), in order to stay
in code compiled for the same architecture level, for other places it is
not obvious why sclp_early_printk() was used instead of
decompressor_printk().

Given that the whole decompressor code is compiled for the same
architecture level, there is no requirement left to use different
printk functions.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:43 +02:00
Heiko Carstens
bfda610814 s390/boot: Rename decompressor_printk() to boot_printk()
Rename decompressor_printk() to boot_printk() just to have a shorter
function name, which also makes the code more readable.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:42 +02:00
Heiko Carstens
fccb175bc8 s390/boot: Compile all files with the same march flag
Only a couple of files of the decompressor are compiled with the
minimum architecture level. This is problematic for potential function
calls between compile units, especially if a target function is within
a compile until compiled for a higher architecture level, since that
may lead to an unexpected operation exception.

Therefore compile all files of the decompressor for the same (minimum)
architecture level.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:42 +02:00
Heiko Carstens
db545f5387 s390/boot: Increase minimum architecture to z10
The decompressor code is partially compiled with march=z900 so it is
possible to print an error message in case a kernel is booted on a
machine which misses facilities to execute the kernel.

Given that the decompressor code also includes header files from the
core kernel this causes problems for inline assemblies and other code
where the minimum assumed architecture level is set to z10 in the
meantime. If such code is also used in the decompressor (e.g. inline
functions) z900 support must be implemented again.

In order to avoid this and to keep things simple just raise the
minimum architecture level to z10 for the decompressor just like for
the kernel.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:42 +02:00
Heiko Carstens
6fa7aea6a9 s390/als: Remove obsolete comment
The bss section of the decompressor is part of the compressed kernel image
since commit 980d5f9ab3 ("s390/boot: enable .bss section for compressed
kernel").

Remove a now incorrect comment that states that the bss section must not be
accessed.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07 17:12:41 +02:00
Sven Schnelle
ee3daf7c05 s390/entry: Unify save_area_sync and save_area_async
In the past two save areas existed because interrupt handlers
and system call / program check handlers where entered with
interrupts enabled. To prevent a handler from overwriting the
save areas from the previous handler, interrupts used the async
save area, while system call and program check handler used the
sync save area.

Since the removal of critical section cleanup from entry.S, handlers are
entered with interrupts disabled. When the interrupts are re-enabled,
the save area is no longer need. Therefore merge both save areas into one.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29 22:56:34 +02:00
Jens Remus
57216cc985 s390/build: Avoid relocation information in final vmlinux
Since commit 778666df60 ("s390: compile relocatable kernel without
-fPIE") the kernel vmlinux ELF file is linked with --emit-relocs to
preserve all relocations, so that all absolute relocations can be
extracted using the 'relocs' tool to adjust them during boot.

Port and adapt Petr Pavlu's x86 commit 9d9173e9ce ("x86/build: Avoid
relocation information in final vmlinux") to s390 to strip all
relocations from the final vmlinux ELF file to optimize its size.
Following is his original commit message with minor adaptions for s390:

The Linux build process on s390 roughly consists of compiling all input
files, statically linking them into a vmlinux ELF file, and then taking
and turning this file into an actual bzImage bootable file.

vmlinux has in this process two main purposes:
1) It is an intermediate build target on the way to produce the final
   bootable image.
2) It is a file that is expected to be used by debuggers and standard
   ELF tooling to work with the built kernel.

For the second purpose, a vmlinux file is typically collected by various
package build recipes, such as distribution spec files, including the
kernel's own tar-pkg target.

When building the kernel vmlinux contains also relocation information
produced by using the --emit-relocs linker option. This is utilized by
subsequent build steps to create relocs.S and produce a relocatable
image. However, the information is not needed by debuggers and other
standard ELF tooling.

The issue is then that the collected vmlinux file and hence distribution
packages end up unnecessarily large because of this extra data. The
following is a size comparison of vmlinux v6.10 with and without the
relocation information:

  | Configuration      | With relocs | Stripped relocs |
  | defconfig          |      696 MB |          320 MB |
  | -CONFIG_DEBUG_INFO |       48 MB |           32 MB |

Optimize a resulting vmlinux by adding a postlink step that splits the
relocation information into relocs.S and then strips it from the vmlinux
binary.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-27 20:16:48 +02:00
Alexander Gordeev
1642285e51 s390/boot: Fix KASLR base offset off by __START_KERNEL bytes
Symbol offsets to the KASLR base do not match symbol address in
the vmlinux image. That is the result of setting the KASLR base
to the beginning of .text section as result of an optimization.

Revert that optimization and allocate virtual memory for the
whole kernel image including __START_KERNEL bytes as per the
linker script. That allows keeping the semantics of the KASLR
base offset in sync with other architectures.

Rename __START_KERNEL to TEXT_OFFSET, since it represents the
offset of the .text section within the kernel image, rather than
a virtual address.

Still skip mapping TEXT_OFFSET bytes to save memory on pgtables
and provoke exceptions in case an attempt to access this area is
made, as no kernel symbol may reside there.

In case CONFIG_KASAN is enabled the location counter might exceed
the value of TEXT_OFFSET, while the decompressor linker script
forcefully resets it to TEXT_OFFSET, which leads to a sections
overlap link failure. Use MAX() expression to avoid that.

Reported-by: Omar Sandoval <osandov@osandov.com>
Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/
Fixes: 56b1069c40 ("s390/boot: Rework deployment of the kernel image")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-22 19:24:13 +02:00
Alexander Gordeev
d7fd2941ae s390/boot: Avoid possible physmem_info segment corruption
When physical memory for the kernel image is allocated it does not
consider extra memory required for offsetting the image start to
match it with the lower 20 bits of KASLR virtual base address. That
might lead to kernel access beyond its memory range.

Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 693d41f7c9 ("s390/mm: Restore mapping of kernel image using large pages")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-22 19:24:13 +02:00
Alexander Gordeev
32db401965 s390/mm: Pin identity mapping base to zero
SIE instruction performs faster when the virtual address of
SIE block matches the physical one. Pin the identity mapping
base to zero for the benefit of SIE and other instructions
that have similar performance impact. Still, randomize the
base when DEBUG_VM kernel configuration option is enabled.

Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-21 16:14:45 +02:00
Linus Torvalds
65ad409e63 Merge tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Vasily Gorbik:

 - Fix KMSAN build breakage caused by the conflict between s390 and
   mm-stable trees

 - Add KMSAN page markers for ptdump

 - Add runtime constant support

 - Fix __pa/__va for modules under non-GPL licenses by exporting
   necessary vm_layout struct with EXPORT_SYMBOL to prevent linkage
   problems

 - Fix an endless loop in the CF_DIAG event stop in the CPU Measurement
   Counter Facility code when the counter set size is zero

 - Remove the PROTECTED_VIRTUALIZATION_GUEST config option and enable
   its functionality by default

 - Support allocation of multiple MSI interrupts per device and improve
   logging of architecture-specific limitations

 - Add support for lowcore relocation as a debugging feature to catch
   all null ptr dereferences in the kernel address space, improving
   detection beyond the current implementation's limited write access
   protection

 - Clean up and rework CPU alternatives to allow for callbacks and early
   patching for the lowcore relocation

* tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
  s390: Remove protvirt and kvm config guards for uv code
  s390/boot: Add cmdline option to relocate lowcore
  s390/kdump: Make kdump ready for lowcore relocation
  s390/entry: Make system_call() ready for lowcore relocation
  s390/entry: Make ret_from_fork() ready for lowcore relocation
  s390/entry: Make __switch_to() ready for lowcore relocation
  s390/entry: Make restart_int_handler() ready for lowcore relocation
  s390/entry: Make mchk_int_handler() ready for lowcore relocation
  s390/entry: Make int handlers ready for lowcore relocation
  s390/entry: Make pgm_check_handler() ready for lowcore relocation
  s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macro
  s390/entry: Add base register to SIEEXIT macro
  s390/entry: Add base register to MBEAR macro
  s390/entry: Make __sie64a() ready for lowcore relocation
  s390/head64: Make startup code ready for lowcore relocation
  s390: Add infrastructure to patch lowcore accesses
  s390/atomic_ops: Disable flag outputs constraint for GCC versions below 14.2.0
  s390/entry: Move SIE indicator flag to thread info
  s390/nmi: Simplify ptregs setup
  s390/alternatives: Remove alternative facility list
  ...
2024-07-26 10:47:53 -07:00