Commit Graph

4263 Commits

Author SHA1 Message Date
Linus Torvalds
25a01b5155 Merge tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:

 - Use CIO device online variable instead of the internal FSM state to
   determine device availability during purge operations

 - Remove extra check of task_stack_page() because try_get_task_stack()
   already takes care of that when reading /proc/<pid>/wchan

 - Allow user-space to use the new SCLP action qualifier 4 for to
   provide NVMe SMART log data to the platform.

 - Send AP CHANGE uevents on successful bind and successful association
   to notify user-space about SE operations on AP queue devices

 - Add an s390dbf kernel parameter to configure debug log levels and
   area sizes during early boot

 - On arm64 the empty zero page is going to be mapped read-only. Do the
   same for s390 with an explicit set_memory_ro() call

 - Improve s390-specific bcr_serialize() and cpu_relax() implementations

 - Remove all unused variables to avoid allmodconfig W=1 build fails
   with latest clang-23

 - Cleanup default Kconfig values for s390 selftests

 - Add a s390-tod trace clock to allow comparing trace timestamps
   between different systems or virtual machines on s390

 - Remove the s390 implementation of strlcat() in favor of the generic
   variant

 - Make consistent the calling order between
   page_table_check_pte_clear() and secure page conversion across all
   code paths

 - Rearrange some fields within AP and zcrypt structs to reduce memory
   consumption and unused holes

 - Shorten GR_NUM and VX_NUM macros and move them to a separate header

 - Replace __get_free_page() with kmalloc() in few sources

 - Introduce an infrastructure for more efficient this_cpu operations.
   Eliminate conditional branches when PREEMPT_NONE is removed

 - Enable Rust support

 - Use z10 as minimum architecture level, similar to the boot code, to
   enforce a defined architecture level set

 - Improve and convert various mem*() helper functions to C. For that
   add .noinstr.text section to avoid orphaned warnings from the linker

 - Fix the function pointer type in __ret_from_fork() to correct the
   indirect call to match kernel thread return type of int

 - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
   loop on read from donated Ultravisor pages at unaligned addresses

* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
  s390: Revert support for DCACHE_WORD_ACCESS
  s390/process: Fix kernel thread function pointer type
  s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
  s390/memmove: Optimize backward copy case
  s390/string: Convert memset(16|32|64)() to C
  s390/string: Convert memcpy() to C
  s390/string: Convert memset() to C
  s390/string: Convert memmove() to C
  s390/string: Add -ffreestanding compile option to string.o
  s390: Add .noinstr.text to boot and purgatory linker scripts
  s390/purgatory: Enforce z10 minimum architecture level
  s390: Enable Rust support
  s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
  rust: helpers: Add memchr wrapper for string operations
  rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
  s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
  s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
  s390/ap: Fix locking issue in SE bind and associate sysfs functions
  s390/percpu: Provide arch_this_cpu_write() implementation
  s390/percpu: Provide arch_this_cpu_read() implementation
  ...
2026-06-16 05:08:13 +05:30
Heiko Carstens
d0478f5d3c s390/process: Fix kernel thread function pointer type
In case of a kernel thread __ret_from_fork() calls the specified function
indirectly. Fix the kernel thread function pointer, since kernel threads
return an int instead of void.

Fixes: 56e62a7370 ("s390: convert to generic entry")
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>
2026-06-11 17:45:35 +02:00
Heiko Carstens
a737737cdb s390/percpu: Infrastructure for more efficient this_cpu operations
With the intended removal of PREEMPT_NONE this_cpu operations based on
atomic instructions, guarded with preempt_disable()/preempt_enable() pairs
become more expensive: the preempt_disable() / preempt_enable() pairs are
not optimized away anymore during compile time.

In particular the conditional call to preempt_schedule_notrace() after
preempt_enable() adds additional code and register pressure.

E.g. this simple C code sequence

DEFINE_PER_CPU(long, foo);
long bar(long a) { return this_cpu_add_return(foo, a); }

generates this code:

  11a976:       eb af f0 68 00 24       stmg    %r10,%r15,104(%r15)
  11a97c:       b9 04 00 ef             lgr     %r14,%r15
  11a980:       b9 04 00 b2             lgr     %r11,%r2
  11a984:       e3 f0 ff c8 ff 71       lay     %r15,-56(%r15)
  11a98a:       e3 e0 f0 98 00 24       stg     %r14,152(%r15)
  11a990:       eb 01 03 a8 00 6a       asi     936,1            <- __preempt_count_add(1)
  11a996:       c0 10 00 d2 ac b5       larl    %r1,1b70300      <- address of percpu var
  11a9a0:       e3 10 23 b8 00 08       ag      %r1,952          <- add percpu offset
  11a9a6:       eb ab 10 00 00 e8       laag    %r10,%r11,0(%r1) <- atomic op
  11a9ac:       eb ff 03 a8 00 6e       alsi    936,-1           <- __preempt_count_dec_and_test()
  11a9b2:       a7 54 00 05             jnhe    11a9bc <bar+0x4c>
  11a9b6:       c0 e5 00 76 d1 bd       brasl   %r14,ff4d30 <preempt_schedule_notrace>
  11a9bc:       b9 e8 b0 2a             agrk    %r2,%r10,%r11
  11a9c0:       eb af f0 a0 00 04       lmg     %r10,%r15,160(%r15)
  11a9c6        07 fe                   br      %r14

Even though the above example is more or less the worst case, since the
branch to preempt_schedule_notrace() requires a stackframe, which
otherwise wouldn't be necessary, there is also the conditional jnhe branch
instruction.

Get rid of the conditional branch with the following code sequence:

  11a8e6:       c0 30 00 d0 c5 0d       larl    %r3,1b33300
  11a8ec:       b9 04 00 43             lgr     %r4,%r3
  11a8f0:       eb 00 43 c0 00 52       mviy    960,4
  11a8f6:       e3 40 03 b8 00 08       ag      %r4,952
  11a8fc:       eb 52 40 00 00 e8       laag    %r5,%r2,0(%r4)
  11a902:       eb 00 03 c0 00 52       mviy    960,0
  11a908:       b9 08 00 25             agr     %r2,%r5
  11a90c        07 fe                   br      %r14

The general idea is that this_cpu operations based on atomic instructions
are guarded with mviy instructions:

- The first mviy instruction writes the register number, which contains
  the percpu address variable to lowcore. This also indicates that a
  percpu code section is executed.

- The first instruction following the mviy instruction must be the ag
  instruction which adds the percpu offset to the percpu address register.

- Afterwards the atomic percpu operation follows.

- Then a second mviy instruction writes a zero to lowcore, which indicates
  the end of the percpu code section.

- In case of an interrupt/exception/nmi the register number which was
  written to lowcore is copied to the exception frame (pt_regs), and a zero
  is written to lowcore.

- On return to the previous context it is checked if a percpu code section
  was executed (saved register number not zero), and if the process was
  migrated to a different cpu. If the percpu offset was already added to
  the percpu address register (instruction address does _not_ point to the
  ag instruction) the content of the percpu address register is adjusted so
  it points to percpu variable of the new cpu.

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>
2026-06-03 15:32:46 +02:00
Frederic Weisbecker
ad5a9e14ec s390/time: Prepare to stop elapsing in dynticks-idle
Currently the tick subsystem stores the idle cputime accounting in private
fields, allowing cohabitation with architecture idle vtime accounting. The
former is fetched on online CPUs, the latter on offline CPUs.

For consolidation purposes, architecture vtime accounting will continue to
account the cputime but will make a break when the idle tick is
stopped. The dyntick cputime accounting will then be relayed by the tick
subsystem so that the idle cputime is still seen advancing coherently even
when the tick isn't there to flush the idle vtime.

Prepare for that and introduce three new APIs which will be used in
subsequent patches:

  - vtime_dynticks_start() is deemed to be called when idle enters in
    dyntick mode. The idle cputime that elapsed so far is accumulated
    and accounted. Also idle time accounting is ignored.

  - vtime_dynticks_stop() is deemed to be called when idle exits from
    dyntick mode. The vtime entry clocks are fast-forward to current time
    so that idle accounting restarts elapsing from now. Also idle time
    accounting is resumed.

  - vtime_reset() is deemed to be called from dynticks idle IRQ entry to
    fast-forward the clock to current time so that the IRQ time is still
    accounted by vtime while nohz cputime is paused.

Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid
accounting twice the idle cputime, along with nohz accounting.

Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-7-frederic@kernel.org
2026-06-02 21:27:25 +02:00
Sven Schnelle
29eb8a7b6e s390/tracing: Add s390-tod clock
In order to allow comparing trace timestamps between different
systems or virtual machines on s390, add a s390-tod trace clock.
This clock just uses the returned TOD clock value from stcke
directly.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-26 08:15:41 +02:00
Heiko Carstens
3f90f58eb7 s390/debug: Remove s390dbf_sysctl_header variable
allmodconfig with clang W=1 points out an unused global variable:

arch/s390/kernel/debug.c:1237:33: error: variable
 's390dbf_sysctl_header' set but not used [-Werror,-Wunused-but-set-global]

Just remove the variable. There is no point in adding error handling for a
failing register_sysctl() call.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-26 08:15:39 +02:00
Alexandra Winter
540f4a4f6e s390/topology: Use zero-based numbering for containing entities
Start the numbering scheme for higher-level topology structures (like
socket, book, drawer) at zero, matching the convention for other hardware
identifiers like e.g. CPU numbers.

Hardware documentation, the Hardware Management Console and other tools
like zmemtopo also use zero-based numbering for these containing entities.
Aligning the numbering in sysfs, procfs, and tools like lscpu improves
user experience by making it easier to correlate topology information
across different interfaces.

If available, Linux on s390 derives this physical topology information from
the stsi function code 15 store_topology instruction, which is defined to
start at 1 for the lowest numbered container id. Subtract one, so
drawer_id, book_id and socket_id in cpu_topology[] start with 0 for the
lowest numbered entity; and /proc/cpuinfo and tools like 'lscpu -ye'
display the expected values.

Display only, no functional change intended.

Example: In a partition with 3 cores in a system with
8 cores per socket; 2 sockets per book; 4 books per dawer; and 4 drawers:
Before this fix:
$ lscpu -ye
CPU NODE DRAWER BOOK SOCKET CORE L1d:L1i:L2 ONLINE CONFIGURED POLARIZATION ADDRESS
  0    0      2    4      1    0 0:0:0         yes yes        vert-high    0
  1    0      2    4      1    0 1:1:1         yes yes        vert-high    1
  2    0      2    4      1    1 2:2:2         yes yes        vert-medium  2
  3    0      2    4      1    1 3:3:3         yes yes        vert-medium  3
  4    0      2    4      2    3 4:4:4         yes yes        vert-low     4
  5    0      2    4      2    3 5:5:5         yes yes        vert-low     5
After this fix:
$ lscpu -ye
CPU NODE DRAWER BOOK SOCKET CORE L1d:L1i:L2 ONLINE CONFIGURED POLARIZATION ADDRESS
  0    0      1    3      0    0 0:0:0         yes yes        vert-high    0
  1    0      1    3      0    0 1:1:1         yes yes        vert-high    1
  2    0      1    3      0    1 2:2:2         yes yes        vert-medium  2
  3    0      1    3      0    1 3:3:3         yes yes        vert-medium  3
  4    0      1    3      1    3 4:4:4         yes yes        vert-low     4
  5    0      1    3      1    3 5:5:5         yes yes        vert-low     5

For KVM guests, qemu emulates the stsi FC15 store_topology instruction.
This emulation currently erroneously starts id numbering at 0. A qemu fix
is proposed that makes this emulation compliant to the stsi architecture.
In case a guest with this patch is running on a qemu without the other fix,
it can happen that ids of 255 are displayed erroneously.

z/VM currently does not provide or emulate physical topology information to
its guests. So this patch does not change anything for z/VM guests.

Fixes: 10d3858950 ("[S390] topology: expose core identifier")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-20 09:39:24 +02:00
Peter Oberparleiter
a2cec68637 s390/debug: Add s390dbf kernel parameter
Problem determination using s390dbf logging sometimes requires changing
the default logging level or log area size. While this is possible
using sysfs interfaces, there is no easy way to adjust these parameters
for early boot code that emits logs before userspace is available.

Add an s390dbf kernel parameter to address this shortcoming. The
parameter can be used to specify log level and area size (in units of
pages). A level of '-' turns logging off for an area. Logs can be
identified by name or a shell-style pattern.

Parameter format:

  s390dbf=<name|pattern>:[<level>|-]:[<pages>][,...]

Example:

  s390dbf=cio*:6:128,sclp_err::2

Specified parameters are applied immediately during debug area
registration for regular log areas. For early, static debug areas,
log levels are changed during early_param() parsing, while size
changes are applied at arch_initcall-time.

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-11 16:42:31 +02:00
Thomas Richter
99269799bf s390/pai: Fix missing PAI counter increments under heavy load
Machines with a larger number of CPUs and under heavy load sometimes
loose PAI counter increments during recording using events
-e CRYPTO_ÂLL or -e NNPA_ALL. Counting is not affected.
This happens when several PAI crypto counters are incremented during
the same cryptographic operation.

During schedule out the functions

paiXXX_sched_task() (with XXX either crypt or ext)
+--> pai_have_samples()
   +--> pai_have_sample()
	+--> pai_copy()
	+--> pai_push_sample()

are called to read out PAI counter values.
In pai_copy() the current values of PAI counters are read from the
PMU memory mapped page and compared to the values read during last
schedule out operation, which have been saved in a backup page
named PAI_SAVE_AREA(event). For each PAI counter a delta is calculated
and when the delta is positive, that PAI counter was incremented by
hardware. This positve delta is reported as raw data record attached
to a sample.
After all deltas have been calculated, the new PAI counter values
are saved in the backup page PAI_SAVE_AREA(event). However this is
done in pai_push_sample(), leaving a small window for missing hardware
triggered updates. Here is one scenario:

  PAI counter idx:   0   1   2   3   4   5   6   7  ....  N
                   +---+---+---+---+---+---+---+---+    +---+
  PAI counter page:|   |   | X |   |   |   |   |   |....| Y |
                   +---+---+---+---+---+---+---+---+    +---+

In pai_copy() each PAI counter value is read and compared
to its old value. This is done in a loop. When PAI counter indexed
N is read, the hardware might increment PAI counter indexed 2 again,
updating its value from X to X+1.
Later pai_push_sample() simply mem-copies the complete PAI counter
page to a backup page and the increment of X+1 is lost, because the
backup page now contains the new value.

Read each PAI counter and save this value in the backup page when
there is a positive delta. This omits any time window between read
and store. This also reduced the work load as only modified PAI
counters are saved.

Cc: stable@vger.kernel.org
Fixes: fe861b0c8d ("s390/pai: save PAI counter value page in event structure")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-11 16:00:04 +02:00
Maninder Singh
a59b9cb859 s390: Remove extra check of task_stack_page()
There is no need to call task_stack_page(),
because try_get_task_stack() already takes care of that.

Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-05-05 10:12:47 +02:00
Thomas Richter
3fe7ecab1a s390/pai: Disable duplicate read of kernel PAI counter value
The PAI crypto counter design allows for user space and kernel space
PAI counter increment recording. This is achieved by splitting the
recording page in half. The upper part of the 4KB page records user
space increments of PAI crypto counter and the lower half records
kernel space increments. The page itself looks like:

 lowcore ptr ---> ++++++++++++++++++++++++
                  |user space area       |
                  +----------------------+
                  |kernel space area     |
                  ++++++++++++++++++++++++

User space and kernel space entries are handled via a kernel_offset
value when wrting. For PAI crypto counters this offset is 2048 or
half of a page size.

For PAI NNPA counter design this distinction was not needed. There is
no user and kernel space part for the page pointed to by lowcore.
The set up is:

 lowcore ptr ---> ++++++++++++++++++++++++
                  |user + kernel space   |
                  |area                  |
                  |                      |
                  ++++++++++++++++++++++++

There is always only one counter value recorded and saved.

Depending on number of CPUs and machine load, the number of PAI NNPA
counter increment differs between counting (perf stat) and recording
(perf record). The number reported by sampling was double the number
shown by counting.

This was caused by a double read of the PAI NNPA values in function
pai_copy(). The first part of that function reads the kernel space part.
The offset into the kernel page part must be larger than zero.
The second part of that function reads the user space part, which
begins of offset zero. This works fine for PAI crypto counters.

It fails for PAI NNPA counters because the PMU device driver does
not support that feature and has a kernel_offset value of 0x0.
Executing both user and kernel space read out might end up reading
user space value twice.
For the PAI NNPA PMU prohibit the kernel space part read out.

Cc: stable@vger.kernel.org
Fixes: f124735413 ("s390/pai_crypto: Rename paicrypt_copy() to pai_copy()")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-04-30 18:57:15 +02:00
Vasily Gorbik
e14622a758 s390/debug: Reject zero-length input in debug_input_flush_fn()
debug_input_flush_fn() always copies one byte from the userspace buffer
with copy_from_user() regardless of the supplied write length. A
zero-length write therefore reads one byte beyond the caller's buffer.
If the stale byte happens to be '-' or a digit the debug log is
silently flushed. With an unmapped buffer the call returns -EFAULT.

Reject zero-length writes before copying from userspace.

Cc: stable@vger.kernel.org # v5.10+
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-04-28 14:45:02 +02:00
Pengpeng Hou
c366a7b5ed s390/debug: Reject zero-length input before trimming a newline
debug_get_user_string() duplicates the userspace buffer with
memdup_user_nul() and then unconditionally looks at buffer[user_len - 1]
to strip a trailing newline.

A zero-length write reaches this helper unchanged, so the newline trim
reads before the start of the allocated buffer.

Reject empty writes before accessing the last input byte.

Fixes: 66a464dbc8 ("[PATCH] s390: debug feature changes")
Cc: stable@vger.kernel.org
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260417073530.96002-1-pengpeng@iscas.ac.cn
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-04-28 14:45:02 +02:00
Linus Torvalds
9cdca33667 Merge tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
 "There are two main changes, one feature removal, some code cleanup,
  and a number of bug fixes.

  Main changes:
   - Detecting secure boot mode was limited to IMA. Make detecting
     secure boot mode accessible to EVM and other LSMs
   - IMA sigv3 support was limited to fsverity. Add IMA sigv3 support
     for IMA regular file hashes and EVM portable signatures

  Remove:
   - Remove IMA support for asychronous hash calculation originally
     added for hardware acceleration

  Cleanup:
   - Remove unnecessary Kconfig CONFIG_MODULE_SIG and CONFIG_KEXEC_SIG
     tests
   - Add descriptions of the IMA atomic flags

  Bug fixes:
   - Like IMA, properly limit EVM "fix" mode
   - Define and call evm_fix_hmac() to update security.evm
   - Fallback to using i_version to detect file change for filesystems
     that do not support STATX_CHANGE_COOKIE
   - Address missing kernel support for configured (new) TPM hash
     algorithms
   - Add missing crypto_shash_final() return value"

* tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  evm: Enforce signatures version 3 with new EVM policy 'bit 3'
  integrity: Allow sigv3 verification on EVM_XATTR_PORTABLE_DIGSIG
  ima: add support to require IMA sigv3 signatures
  ima: add regular file data hash signature version 3 support
  ima: Define asymmetric_verify_v3() to verify IMA sigv3 signatures
  ima: remove buggy support for asynchronous hashes
  integrity: Eliminate weak definition of arch_get_secureboot()
  ima: Add code comments to explain IMA iint cache atomic_flags
  ima_fs: Correctly create securityfs files for unsupported hash algos
  ima: check return value of crypto_shash_final() in boot aggregate
  ima: Define and use a digest_size field in the ima_algo_desc structure
  powerpc/ima: Drop unnecessary check for CONFIG_MODULE_SIG
  ima: efi: Drop unnecessary check for CONFIG_MODULE_SIG/CONFIG_KEXEC_SIG
  ima: fallback to using i_version to detect file change
  evm: fix security.evm for a file with IMA signature
  s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
  evm: Don't enable fix mode when secure boot is enabled
  integrity: Make arch_ima_get_secureboot integrity-wide
2026-04-17 15:42:01 -07:00
Linus Torvalds
f5ad410100 Merge tag 'bpf-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:

 - Welcome new BPF maintainers: Kumar Kartikeya Dwivedi, Eduard
   Zingerman while Martin KaFai Lau reduced his load to Reviwer.

 - Lots of fixes everywhere from many first time contributors. Thank you
   All.

 - Diff stat is dominated by mechanical split of verifier.c into
   multiple components:

    - backtrack.c: backtracking logic and jump history
    - states.c:    state equivalence
    - cfg.c:       control flow graph, postorder, strongly connected
                   components
    - liveness.c:  register and stack liveness
    - fixups.c:    post-verification passes: instruction patching, dead
                   code removal, bpf_loop inlining, finalize fastcall

   8k line were moved. verifier.c still stands at 20k lines.

   Further refactoring is planned for the next release.

 - Replace dynamic stack liveness with static stack liveness based on
   data flow analysis.

   This improved the verification time by 2x for some programs and
   equally reduced memory consumption. New logic is in liveness.c and
   supported by constant folding in const_fold.c (Eduard Zingerman,
   Alexei Starovoitov)

 - Introduce BTF layout to ease addition of new BTF kinds (Alan Maguire)

 - Use kmalloc_nolock() universally in BPF local storage (Amery Hung)

 - Fix several bugs in linked registers delta tracking (Daniel Borkmann)

 - Improve verifier support of arena pointers (Emil Tsalapatis)

 - Improve verifier tracking of register bounds in min/max and tnum
   domains (Harishankar Vishwanathan, Paul Chaignon, Hao Sun)

 - Further extend support for implicit arguments in the verifier (Ihor
   Solodrai)

 - Add support for nop,nop5 instruction combo for USDT probes in libbpf
   (Jiri Olsa)

 - Support merging multiple module BTFs (Josef Bacik)

 - Extend applicability of bpf_kptr_xchg (Kaitao Cheng)

 - Retire rcu_trace_implies_rcu_gp() (Kumar Kartikeya Dwivedi)

 - Support variable offset context access for 'syscall' programs (Kumar
   Kartikeya Dwivedi)

 - Migrate bpf_task_work and dynptr to kmalloc_nolock() (Mykyta
   Yatsenko)

 - Fix UAF in in open-coded task_vma iterator (Puranjay Mohan)

* tag 'bpf-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (241 commits)
  selftests/bpf: cover short IPv4/IPv6 inputs with adjust_room
  bpf: reject short IPv4/IPv6 inputs in bpf_prog_test_run_skb
  selftests/bpf: Use memfd_create instead of shm_open in cgroup_iter_memcg
  selftests/bpf: Add test for cgroup storage OOB read
  bpf: Fix OOB in pcpu_init_value
  selftests/bpf: Fix reg_bounds to match new tnum-based refinement
  selftests/bpf: Add tests for non-arena/arena operations
  bpf: Allow instructions with arena source and non-arena dest registers
  bpftool: add missing fsession to the usage and docs of bpftool
  docs/bpf: add missing fsession attach type to docs
  bpf: add missing fsession to the verifier log
  bpf: Move BTF checking logic into check_btf.c
  bpf: Move backtracking logic to backtrack.c
  bpf: Move state equivalence logic to states.c
  bpf: Move check_cfg() into cfg.c
  bpf: Move compute_insn_live_regs() into liveness.c
  bpf: Move fixup/post-processing logic from verifier.c into fixups.c
  bpf: Simplify do_check_insn()
  bpf: Move checks for reserved fields out of the main pass
  bpf: Delete unused variable
  ...
2026-04-14 18:04:04 -07:00
Linus Torvalds
88b29f3f57 Merge tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull module updates from Sami Tolvanen:
 "Kernel symbol flags:

   - Replace the separate *_gpl symbol sections (__ksymtab_gpl and
     __kcrctab_gpl) with a unified symbol table and a new __kflagstab
     section.

     This section stores symbol flags, such as the GPL-only flag, as an
     8-bit bitset for each exported symbol. This is a cleanup that
     simplifies symbol lookup in the module loader by avoiding table
     fragmentation and will allow a cleaner way to add more flags later
     if needed.

  Module signature UAPI:

   - Move struct module_signature to the UAPI headers to allow reuse by
     tools outside the kernel proper, such as kmod and
     scripts/sign-file.

     This also renames a few constants for clarity and drops unused
     signature types as preparation for hash-based module integrity
     checking work that's in progress.

  Sysfs:

   - Add a /sys/module/<module>/import_ns sysfs attribute to show the
     symbol namespaces imported by loaded modules.

     This makes it easier to verify driver API access at runtime on
     systems that care about such things (e.g. Android).

  Cleanups and fixes:

   - Force sh_addr to 0 for all sections in module.lds. This prevents
     non-zero section addresses when linking modules with 'ld.bfd -r',
     which confused elfutils.

   - Fix a memory leak of charp module parameters on module unload when
     the kernel is configured with CONFIG_SYSFS=n.

   - Override the -EEXIST error code returned by module_init() to
     userspace. This prevents confusion with the errno reserved by the
     module loader to indicate that a module is already loaded.

   - Simplify the warning message and drop the stack dump on positive
     returns from module_init().

   - Drop unnecessary extern keywords from function declarations and
     synchronize parse_args() arguments with their implementation"

* tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (23 commits)
  module: Simplify warning on positive returns from module_init()
  module: Override -EEXIST module return
  documentation: remove references to *_gpl sections
  module: remove *_gpl sections from vmlinux and modules
  module: deprecate usage of *_gpl sections in module loader
  module: use kflagstab instead of *_gpl sections
  module: populate kflagstab in modpost
  module: add kflagstab section to vmlinux and modules
  module: define ksym_flags enumeration to represent kernel symbol flags
  selftests/bpf: verify_pkcs7_sig: Use 'struct module_signature' from the UAPI headers
  sign-file: use 'struct module_signature' from the UAPI headers
  tools uapi headers: add linux/module_signature.h
  module: Move 'struct module_signature' to UAPI
  module: Give MODULE_SIG_STRING a more descriptive name
  module: Give 'enum pkey_id_type' a more specific name
  module: Drop unused signature types
  extract-cert: drop unused definition of PKEY_ID_PKCS7
  docs: symbol-namespaces: mention sysfs attribute
  module: expose imported namespaces via sysfs
  module: Remove extern keyword from param prototypes
  ...
2026-04-14 17:16:38 -07:00
Linus Torvalds
d568788baa Merge tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:

 - randomize_kstack: Improve implementation across arches (Ryan Roberts)

 - lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test

 - refcount: Remove unused __signed_wrap function annotations

* tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test
  refcount: Remove unused __signed_wrap function annotations
  randomize_kstack: Unify random source across arches
  randomize_kstack: Maintain kstack_offset per task
2026-04-13 17:52:29 -07:00
Linus Torvalds
3719114091 Merge tag 's390-7.0-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:

 - Fix a memory leak in the zcrypt driver where the AP message buffer
   for clear key RSA requests was allocated twice, once by the caller
   and again locally, causing the first allocation to never be freed

 - Fix the cpum_sf perf sampling rate overflow adjustment to clamp the
   recalculated rate to the hardware maximum, preventing exceptions on
   heavily loaded systems running with HZ=1000

* tag 's390-7.0-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: Fix memory leak with CCA cards used as accelerator
  s390/cpum_sf: Cap sampling rate to prevent lsctl exception
2026-04-03 17:50:24 -07:00
Alexei Starovoitov
891a05ccba Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc6+
Cross-merge BPF and other fixes after downstream PR.

Minor conflict in kernel/bpf/verifier.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-04-03 08:14:13 -07:00
Linus Torvalds
e522b75c44 Merge tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:

 - Add array_index_nospec() to syscall dispatch table lookup to prevent
   limited speculative out-of-bounds access with user-controlled syscall
   number

 - Mark array_index_mask_nospec() __always_inline since GCC may emit an
   out-of-line call instead of the inline data dependency sequence the
   mitigation relies on

 - Clear r12 on kernel entry to prevent potential speculative use of
   user value in system_call, ext/io/mcck interrupt handlers

* tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/entry: Scrub r12 register on kernel entry
  s390/syscalls: Add spectre boundary for syscall dispatch table
  s390/barrier: Make array_index_mask_nospec() __always_inline
2026-03-28 09:50:11 -07:00
Vasily Gorbik
0738d395aa s390/entry: Scrub r12 register on kernel entry
Before commit f33f2d4c7c ("s390/bp: remove TIF_ISOLATE_BP"),
all entry handlers loaded r12 with the current task pointer
(lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That
commit removed TIF_ISOLATE_BP, dropping both the branch prediction
macros and the r12 load, but did not add r12 to the register clearing
sequence.

Add the missing xgr %r12,%r12 to make the register scrub consistent
across all entry points.

Fixes: f33f2d4c7c ("s390/bp: remove TIF_ISOLATE_BP")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-28 00:43:39 +01:00
Greg Kroah-Hartman
48b8814e25 s390/syscalls: Add spectre boundary for syscall dispatch table
The s390 syscall number is directly controlled by userspace, but does
not have an array_index_nospec() boundary to prevent access past the
syscall function pointer tables.

Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Fixes: 56e62a7370 ("s390: convert to generic entry")
Cc: stable@kernel.org
Assisted-by: gkh_clanker_2000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/2026032404-sterling-swoosh-43e6@gregkh
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-28 00:43:39 +01:00
Ryan Roberts
a96ef5848c randomize_kstack: Unify random source across arches
Previously different architectures were using random sources of
differing strength and cost to decide the random kstack offset. A number
of architectures (loongarch, powerpc, s390, x86) were using their
timestamp counter, at whatever the frequency happened to be. Other
arches (arm64, riscv) were using entropy from the crng via
get_random_u16().

There have been concerns that in some cases the timestamp counters may
be too weak, because they can be easily guessed or influenced by user
space. And get_random_u16() has been shown to be too costly for the
level of protection kstack offset randomization provides.

So let's use a common, architecture-agnostic source of entropy; a
per-cpu prng, seeded at boot-time from the crng. This has a few
benefits:

  - We can remove choose_random_kstack_offset(); That was only there to
    try to make the timestamp counter value a bit harder to influence
    from user space [*].

  - The architecture code is simplified. All it has to do now is call
    add_random_kstack_offset() in the syscall path.

  - The strength of the randomness can be reasoned about independently
    of the architecture.

  - Arches previously using get_random_u16() now have much faster
    syscall paths, see below results.

[*] Additionally, this gets rid of some redundant work on s390 and x86.
Before this patch, those architectures called
choose_random_kstack_offset() under arch_exit_to_user_mode_prepare(),
which is also called for exception returns to userspace which were *not*
syscalls (e.g. regular interrupts). Getting rid of
choose_random_kstack_offset() avoids a small amount of redundant work
for the non-syscall cases.

In some configurations, add_random_kstack_offset() will now call
instrumentable code, so for a couple of arches, I have moved the call a
bit later to the first point where instrumentation is allowed. This
doesn't impact the efficacy of the mechanism.

There have been some claims that a prng may be less strong than the
timestamp counter if not regularly reseeded. But the prng has a period
of about 2^113. So as long as the prng state remains secret, it should
not be possible to guess. If the prng state can be accessed, we have
bigger problems.

Additionally, we are only consuming 6 bits to randomize the stack, so
there are only 64 possible random offsets. I assert that it would be
trivial for an attacker to brute force by repeating their attack and
waiting for the random stack offset to be the desired one. The prng
approach seems entirely proportional to this level of protection.

Performance data are provided below. The baseline is v6.18 with rndstack
on for each respective arch. (I)/(R) indicate statistically significant
improvement/regression. arm64 platform is AWS Graviton3 (m7g.metal).
x86_64 platform is AWS Sapphire Rapids (m7i.24xlarge):

+-----------------+--------------+---------------+---------------+
| Benchmark       | Result Class |  per-cpu-prng |  per-cpu-prng |
|                 |              | arm64 (metal) |   x86_64 (VM) |
+=================+==============+===============+===============+
| syscall/getpid  | mean (ns)    |    (I) -9.50% |   (I) -17.65% |
|                 | p99 (ns)     |   (I) -59.24% |   (I) -24.41% |
|                 | p99.9 (ns)   |   (I) -59.52% |   (I) -28.52% |
+-----------------+--------------+---------------+---------------+
| syscall/getppid | mean (ns)    |    (I) -9.52% |   (I) -19.24% |
|                 | p99 (ns)     |   (I) -59.25% |   (I) -25.03% |
|                 | p99.9 (ns)   |   (I) -59.50% |   (I) -28.17% |
+-----------------+--------------+---------------+---------------+
| syscall/invalid | mean (ns)    |   (I) -10.31% |   (I) -18.56% |
|                 | p99 (ns)     |   (I) -60.79% |   (I) -20.06% |
|                 | p99.9 (ns)   |   (I) -61.04% |   (I) -25.04% |
+-----------------+--------------+---------------+---------------+

I tested an earlier version of this change on x86 bare metal and it
showed a smaller but still significant improvement. The bare metal
system wasn't available this time around so testing was done in a VM
instance. I'm guessing the cost of rdtsc is higher for VMs.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://patch.msgid.link/20260303150840.3789438-3-ryan.roberts@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-24 21:12:03 -07:00
Thomas Weißschuh
2ae4ea2d9a module: Give MODULE_SIG_STRING a more descriptive name
The purpose of the constant it is not entirely clear from its name.

As this constant is going to be exposed in a UAPI header, give it a more
specific name for clarity. As all its users call it 'marker', use that
wording in the constant itself.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2026-03-24 21:42:37 +00:00
Thomas Weißschuh
acd87264af module: Give 'enum pkey_id_type' a more specific name
This enum originates in generic cryptographic code and has a very
generic name. Nowadays it is only used for module signatures.

As this enum is going to be exposed in a UAPI header, give it a more
specific name for clarity and consistency.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2026-03-24 21:42:37 +00:00
Thomas Richter
57ad0d4a00 s390/cpum_sf: Cap sampling rate to prevent lsctl exception
commit fcc43a7e29 ("s390/configs: Set HZ=1000") changed the interrupt
frequency of the system. On machines with heavy load and many perf event
overflows, this might lead to an exception. Dmesg displays these entries:
  [112.242542] cpum_sf: Loading sampling controls failed: op 1 err -22
One line per CPU online.

The root cause is the CPU Measurement sampling facility overflow
adjustment. Whenever an overflow (too much samples per tick) occurs, the
sampling rate is adjusted and increased. This was done without observing
the maximum sampling rate limit. When the current sampling interval is
higher than the maximum sampling rate limit, the lsctl instruction raises
an exception. The error messages is the result of such an exception.
Observe the upper limit when the new sampling rate is recalculated.

Cc: stable@vger.kernel.org
Fixes: 39d4a501a9 ("s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-24 20:57:31 +01:00
Paolo Bonzini
12fd965871 Merge tag 'kvm-s390-master-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Fixes for 7.0

- fix deadlock in new memory management
- handle kernel faults on donated memory properly
- fix bounds checking for irq routing + selftest
- fix invalid machine checks + logging
2026-03-24 17:32:13 +01:00
Alexei Starovoitov
bfec8e88ff Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc5
Cross-merge BPF and other fixes after downstream PR.

Minor conflicts in:
  tools/testing/selftests/bpf/progs/exceptions_fail.c
  tools/testing/selftests/bpf/progs/verifier_bounds.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-22 19:33:29 -07:00
Christian Borntraeger
ab5119735e KVM: s390: vsie: Avoid injecting machine check on signal
The recent XFER_TO_GUEST_WORK change resulted in a situation, where the
vsie code would interpret a signal during work as a machine check during
SIE as both use the EINTR return code.
The exit_reason of the sie64a function has nothing to do with the
kvm_run exit_reason. Rename it and define a specific code for machine
checks instead of abusing -EINTR.
rename exit_reason into sie_return to avoid the naming conflict
and change the code flow in vsie.c to have a separate variable for rc
and sie_return.

Fixes: 2bd1337a12 ("KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-03-16 16:56:39 +01:00
Linus Torvalds
8d9968859c Merge tag 's390-7.0-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:

 - Revert IRQ entry/exit path optimization that incorrectly cleared
   some PSW bits before irqentry_exit(), causing boot failures with
   linux-next and HRTIMER_REARM_DEFERRED (which only uncovered the
   problem)

 - Fix zcrypt code to show CCA card serial numbers even when the
   default crypto domain is offline by selecting any domain available,
   preventing empty sysfs entries

* tag 's390-7.0-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: Enable AUTOSEL_DOM for CCA serialnr sysfs attribute
  s390: Revert "s390/irq/idle: Remove psw bits early"
2026-03-13 14:18:13 -07:00
Nathan Chancellor
7caedbb5ad integrity: Eliminate weak definition of arch_get_secureboot()
security/integrity/secure_boot.c contains a single __weak function,
which breaks recordmcount when building with clang:

  $ make -skj"$(nproc)" ARCH=powerpc LLVM=1 ppc64_defconfig security/integrity/secure_boot.o
  Cannot find symbol for section 2: .text.
  security/integrity/secure_boot.o: failed

Introduce a Kconfig symbol, CONFIG_HAVE_ARCH_GET_SECUREBOOT, to indicate
that an architecture provides a definition of arch_get_secureboot().
Provide a static inline stub when this symbol is not defined to achieve
the same effect as the __weak function, allowing secure_boot.c to be
removed altogether. Move the s390 definition of arch_get_secureboot()
out of the CONFIG_KEXEC_FILE block to ensure it is always available, as
it does not actually depend on KEXEC_FILE.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 31a6a07eef ("integrity: Make arch_ima_get_secureboot integrity-wide")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-13 11:37:13 -04:00
Alexei Starovoitov
099bded752 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc3
Cross-merge BPF and other fixes after downstream PR.

No conflicts.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-08 17:46:38 -07:00
Heiko Carstens
75aa996ea6 s390: Revert "s390/irq/idle: Remove psw bits early"
This reverts commit d8b5cf9c63.

Mikhail Zaslonko reported that linux-next doesn't boot anymore [2]. Reason
for this is recent change [2] was supposed to slightly optimize the irq
entry/exit path by removing some psw bits early in case of an idle exit.

This however is incorrect since irqentry_exit() requires the correct old
psw state at irq entry. Otherwise the embedded regs_irqs_disabled() will
not provide the correct result.

With linux-next and HRTIMER_REARM_DEFERRED this leads to the observed boot
problems, however the commit is broken in any case.

Revert the commit which introduced this.

Thanks to Peter Zijlstra for pointing out that this is a bug in the s390
entry code.

Fixes: d8b5cf9c63 ("s390/irq/idle: Remove psw bits early") [1]
Reported-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Closes: https://lore.kernel.org/r/af549a19-db99-4b16-8511-bf315177a13e@linux.ibm.com/ [2]
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260306111919.362559-1-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-07 22:41:10 +01:00
Linus Torvalds
4ae12d8bd9 Merge tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild fixes from Nathan Chancellor:

 - Split out .modinfo section from ELF_DETAILS macro, as that macro may
   be used in other areas that expect to discard .modinfo, breaking
   certain image layouts

 - Adjust genksyms parser to handle optional attributes in certain
   declarations, necessary after commit 07919126ec ("netfilter:
   annotate NAT helper hook pointers with __rcu")

 - Include resolve_btfids in external module build created by
   scripts/package/install-extmod-build when it may be run on external
   modules

 - Avoid removing objtool binary with 'make clean', as it is required
   for external module builds

* tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: Leave objtool binary around with 'make clean'
  kbuild: install-extmod-build: Package resolve_btfids if necessary
  genksyms: Fix parsing a declarator with a preceding attribute
  kbuild: Split .modinfo out from ELF_DETAILS
2026-03-06 20:27:13 -08:00
Coiby Xu
a2e507afd9 s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
Commit b5ca117365 ("ima: prevent kexec_load syscall based on runtime
secureboot flag") and commit 268a784049 ("s390/kexec_file: Disable
kexec_load when IPLed secure") disabled the kexec_load syscall based
on the secureboot mode. Commit 9e2b4be377 ("ima: add a new CONFIG
for loading arch-specific policies") needed to detect the secure boot
mode, not to load an IMA architecture specific policy. Since there is
the new CONFIG_INTEGRITY_SECURE_BOOT, drop
CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT for s390.

Signed-off-by: Coiby Xu <coxu@redhat.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
[Vasily Gorbik: Fix missing arch_get_secureboot() prototype warning]
link: https://lore.kernel.org/linux-integrity/c00-01.ttbfdx5@ub.hpns/
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-05 11:15:10 -05:00
Coiby Xu
31a6a07eef integrity: Make arch_ima_get_secureboot integrity-wide
EVM and other LSMs need the ability to query the secure boot status of
the system, without directly calling the IMA arch_ima_get_secureboot
function. Refactor the secure boot status check into a general function
named arch_get_secureboot.

Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-05 11:10:08 -05:00
Ilya Leoshkevich
6fe54677bc s390: Introduce bpf_get_lowcore() kfunc
Implementing BPF version of preempt_count() requires accessing lowcore
from BPF. Since lowcore can be relocated, open-coding
(struct lowcore *)0 does not work, so add a kfunc.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20260217160813.100855-2-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-03 08:35:07 -08:00
Nathan Chancellor
8678591b47 kbuild: Split .modinfo out from ELF_DETAILS
Commit 3e86e4d74c ("kbuild: keep .modinfo section in
vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it
from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and
ELF_DETAILS was present in all architecture specific vmlinux linker
scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and
COMMON_DISCARDS may be used by other linker scripts, such as the s390
and x86 compressed boot images, which may not expect to have a .modinfo
section. In certain circumstances, this could result in a bootloader
failing to load the compressed kernel [1].

Commit ddc6cbef3e ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with
SecureBoot trailer") recently addressed this for the s390 bzImage but
the same bug remains for arm, parisc, and x86. The presence of .modinfo
in the x86 bzImage was the root cause of the issue worked around with
commit d50f210913 ("kbuild: align modinfo section for Secureboot
Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes
lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its
MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition.

Split .modinfo out from ELF_DETAILS into its own macro and handle it in
all vmlinux linker scripts. Discard .modinfo in the places where it was
previously being discarded from being in COMMON_DISCARDS, as it has
never been necessary in those uses.

Cc: stable@vger.kernel.org
Fixes: 3e86e4d74c ("kbuild: keep .modinfo section in vmlinux.unstripped")
Reported-by: Ed W <lists@wildgooses.com>
Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1]
Tested-by: Ed W <lists@wildgooses.com> # x86_64
Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-02-26 11:50:19 -07:00
Vasily Gorbik
1623a554c6 s390/kexec: Disable stack protector in s390_reset_system()
s390_reset_system() calls set_prefix(0), which switches back to the
absolute lowcore. At that point the stack protector canary no longer
matches the canary from the lowcore the function was entered with, so
the stack check fails.

Mark s390_reset_system() __no_stack_protector. This is safe here since
its callers (__do_machine_kdump() and __do_machine_kexec()) are
effectively no-return and fall back to disabled_wait() on failure.

Fixes: f5730d44e0 ("s390: Add stackprotector support")
Reported-by: Nikita Dubrovskii <nikita@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 17:00:25 +01:00
Heiko Carstens
80f63fd09e s390/vtime: Use lockdep_assert_irqs_disabled() instead of BUG_ON()
Use lockdep_assert_irqs_disabled() instead of BUG_ON(). This avoids
crashing the kernel, and generates better code if CONFIG_PROVE_LOCKING
is disabled.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
e282ccd308 s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE()
do_account_vtime() runs always with interrupts disabled, therefore use
__this_cpu_read() instead of this_cpu_read() to get rid of a pointless
preempt_disable() / preempt_enable() pair.

Also there are no concurrent writers to the cpu time accounting fields
in lowcore. Therefore get rid of READ_ONCE() usages.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
d8b5cf9c63 s390/irq/idle: Remove psw bits early
Remove wait, io, external interrupt bits early in do_io_irq()/do_ext_irq()
when previous context was idle. This saves one conditional branch and is
closer to the original old assembly code.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
257c14e5a1 s390/idle: Inline update_timer_idle()
Inline update_timer_idle() again to avoid an extra function call. This
way the generated code is close to old assembler version again.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
00d8b035eb s390/idle: Slightly optimize idle time accounting
Slightly optimize account_idle_time_irq() and update_timer_idle():

- Use fast single instruction __atomic64() primitives to update per
  cpu idle_time and idle_count, instead of READ_ONCE() / WRITE_ONCE()
  pairs

- stcctm() is an inline assembly with a full memory barrier. This
  leads to a not necessary extra dereference of smp_cpu_mtid in
  update_timer_idle(). Avoid this and read smp_cpu_mtid into a
  variable

- Use __this_cpu_add() instead of this_cpu_add() to avoid disabling /
  enabling of preemption several times in a loop in update_timer_idle().

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
aefa6ec890 s390/idle: Add comment for non obvious code
Add a comment to update_timer_idle() which describes why wall time (not
steal time) is added to steal_timer. This is not obvious and was reported
by Frederic Weisbecker.

Reported-by: Frederic Weisbecker <frederic@kernel.org>
Closes: https://lore.kernel.org/all/aXEVM-04lj0lntMr@localhost.localdomain/
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
dbc0fb3567 s390/vtime: Fix virtual timer forwarding
Since delayed accounting of system time [1] the virtual timer is
forwarded by do_account_vtime() but also vtime_account_kernel(),
vtime_account_softirq(), and vtime_account_hardirq(). This leads
to double accounting of system, guest, softirq, and hardirq time.

Remove accounting from the vtime_account*() family to restore old behavior.

There is only one user of the vtimer interface, which might explain
why nobody noticed this so far.

Fixes: b7394a5f4c ("sched/cputime, s390: Implement delayed accounting of system time") [1]
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Heiko Carstens
0d785e2c32 s390/idle: Fix cpu idle exit cpu time accounting
With the conversion to generic entry [1] cpu idle exit cpu time accounting
was converted from assembly to C. This introduced an reversed order of cpu
time accounting.

On cpu idle exit the current accounting happens with the following call
chain:

-> do_io_irq()/do_ext_irq()
 -> irq_enter_rcu()
  -> account_hardirq_enter()
   -> vtime_account_irq()
    -> vtime_account_kernel()

vtime_account_kernel() accounts the passed cpu time since last_update_timer
as system time, and updates last_update_timer to the current cpu timer
value.

However the subsequent call of

 -> account_idle_time_irq()

will incorrectly subtract passed cpu time from timer_idle_enter to the
updated last_update_timer value from system_timer. Then last_update_timer
is updated to a sys_enter_timer, which means that last_update_timer goes
back in time.

Subsequently account_hardirq_exit() will account too much cpu time as
hardirq time. The sum of all accounted cpu times is still correct, however
some cpu time which was previously accounted as system time is now
accounted as hardirq time, plus there is the oddity that last_update_timer
goes back in time.

Restore previous behavior by extracting cpu time accounting code from
account_idle_time_irq() into a new update_timer_idle() function and call it
before irq_enter_rcu().

Fixes: 56e62a7370 ("s390: convert to generic entry") [1]
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25 16:46:07 +01:00
Kees Cook
189f164e57 Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch && !(file in "tools") && !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-22 08:26:33 -08:00
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00