The buffer used to hold the taint string is statically allocated, which
requires updating whenever a new taint flag is added.
Instead, allocate the exact required length at boot once the allocator is
available in an init function. The allocation sums the string lengths in
taint_flags[], along with space for separators and formatting.
print_tainted() is switched to use this dynamically allocated buffer.
If allocation fails, print_tainted() warns about the failure and continues
to use the original static buffer as a fallback.
Link: https://lkml.kernel.org/r/20260222140804.22225-1-rioo.tsukatsukii@gmail.com
Signed-off-by: Rio <rioo.tsukatsukii@gmail.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Wang Jinchao <wangjinchao600@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some platforms require panic handling to execute on a specific CPU for
crash dump to work reliably. This can be due to firmware limitations,
interrupt routing constraints, or platform-specific requirements where
only a single CPU is able to safely enter the crash kernel.
Add the panic_force_cpu= kernel command-line parameter to redirect panic
execution to a designated CPU. When the parameter is provided, the CPU
that initially triggers panic forwards the panic context to the target CPU
via IPI, which then proceeds with the normal panic and kexec flow.
The IPI delivery is implemented as a weak function
(panic_smp_redirect_cpu) so architectures with NMI support can override it
for more reliable delivery.
If the specified CPU is invalid, offline, or a panic is already in
progress on another CPU, the redirection is skipped and panic continues on
the current CPU.
[pnina.feder@mobileye.com: fix unused variable warning]
Link: https://lkml.kernel.org/r/20260126122618.2967950-1-pnina.feder@mobileye.com
Link: https://lkml.kernel.org/r/20260122102457.1154599-1-pnina.feder@mobileye.com
Signed-off-by: Pnina Feder <pnina.feder@mobileye.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The panic_print_deprecated() warning is being triggered on both read and
write operations to the panic_print parameter.
This causes spurious warnings when users run 'sysctl -a' to list all
sysctl values, since that command reads /proc/sys/kernel/panic_print and
triggers the deprecation notice.
Modify the handlers to only emit the deprecation warning when the
parameter is actually being set:
- sysctl_panic_print_handler(): check 'write' flag before warning.
- panic_print_get(): remove the deprecation call entirely.
This way, users are only warned when they actively try to use the
deprecated parameter, not when passively querying system state.
Link: https://lkml.kernel.org/r/20260106163321.83586-1-gal@nvidia.com
Fixes: ee13240cd7 ("panic: add note that panic_print sysctl interface is deprecated")
Fixes: 2683df6539 ("panic: add note that 'panic_print' parameter is deprecated")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Cc: Feng Tang <feng.tang@linux.alibaba.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull non-MM updates from Andrew Morton:
- "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
fixes a build issue and does some cleanup in ib/sys_info.c
- "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
enhances the 64-bit math code on behalf of a PWM driver and beefs up
the test module for these library functions
- "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
makes BPF symbol names, sizes, and line numbers available to the GDB
debugger
- "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
adds a sysctl which can be used to cause additional info dumping when
the hung-task and lockup detectors fire
- "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
adds a general base64 encoder/decoder to lib/ and migrates several
users away from their private implementations
- "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
makes TCP a little faster
- "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
reworks the KEXEC Handover interfaces in preparation for Live Update
Orchestrator (LUO), and possibly for other future clients
- "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
increases the flexibility of KEXEC Handover. Also preparation for LUO
- "Live Update Orchestrator" (Pasha Tatashin)
is a major new feature targeted at cloud environments. Quoting the
cover letter:
This series introduces the Live Update Orchestrator, a kernel
subsystem designed to facilitate live kernel updates using a
kexec-based reboot. This capability is critical for cloud
environments, allowing hypervisors to be updated with minimal
downtime for running virtual machines. LUO achieves this by
preserving the state of selected resources, such as memory,
devices and their dependencies, across the kernel transition.
As a key feature, this series includes support for preserving
memfd file descriptors, which allows critical in-memory data, such
as guest RAM or any other large memory region, to be maintained in
RAM across the kexec reboot.
Mike Rappaport merits a mention here, for his extensive review and
testing work.
- "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
moves the kexec and kdump sysfs entries from /sys/kernel/ to
/sys/kernel/kexec/ and adds back-compatibility symlinks which can
hopefully be removed one day
- "kho: fixes for vmalloc restoration" (Mike Rapoport)
fixes a BUG which was being hit during KHO restoration of vmalloc()
regions
* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
calibrate: update header inclusion
Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
vmcoreinfo: track and log recoverable hardware errors
kho: fix restoring of contiguous ranges of order-0 pages
kho: kho_restore_vmalloc: fix initialization of pages array
MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
init: replace simple_strtoul with kstrtoul to improve lpj_setup
KHO: fix boot failure due to kmemleak access to non-PRESENT pages
Documentation/ABI: new kexec and kdump sysfs interface
Documentation/ABI: mark old kexec sysfs deprecated
kexec: move sysfs entries to /sys/kernel/kexec
test_kho: always print restore status
kho: free chunks using free_page() instead of kfree()
selftests/liveupdate: add kexec test for multiple and empty sessions
selftests/liveupdate: add simple kexec-based selftest for LUO
selftests/liveupdate: add userspace API selftests
docs: add documentation for memfd preservation via LUO
mm: memfd_luo: allow preserving memfd
liveupdate: luo_file: add private argument to store runtime state
mm: shmem: export some functions to internal.h
...
Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
The TAINT_RANDSTRUCT and TAINT_FWCTL flags are mistakenly set in the
taint_flags table as per-module flags. While this can be trivially
corrected, the issue can be avoided altogether by removing the
taint_flag.module field.
This is possible because, since commit 7fd8329ba5 ("taint/module: Clean
up global and module taint flags handling") in 2016, the handling of
module taint flags has been fully generic. Specifically,
module_flags_taint() can print all flags, and the required output buffer
size is properly defined in terms of TAINT_FLAGS_COUNT. The actual
per-module flags are always those added to module.taints by calls to
add_taint_module().
Link: https://lkml.kernel.org/r/20251022082938.26670-1-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Resolve conflicts with this commit that was developed in parallel
during the merge window:
8c8efa93db ("x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust")
Conflicts:
arch/riscv/include/asm/bug.h
arch/x86/include/asm/bug.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull non-MM updates from Andrew Morton:
"Significant patch series in this pull request:
- "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
us closer to being able to remove page->mapping
- "relayfs: misc changes" (Jason Xing) does some maintenance and
minor feature addition work in relayfs
- "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
us from static preallocation of the kdump crashkernel's working
memory over to dynamic allocation. So the difficulty of a-priori
estimation of the second kernel's needs is removed and the first
kernel obtains extra memory
- "generalize panic_print's dump function to be used by other
kernel parts" (Feng Tang) implements some consolidation and
rationalization of the various ways in which a failing kernel
splats information at the operator
* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
tools/getdelays: add backward compatibility for taskstats version
kho: add test for kexec handover
delaytop: enhance error logging and add PSI feature description
samples: Kconfig: fix spelling mistake "instancess" -> "instances"
fat: fix too many log in fat_chain_add()
scripts/spelling.txt: add notifer||notifier to spelling.txt
xen/xenbus: fix typo "notifer"
net: mvneta: fix typo "notifer"
drm/xe: fix typo "notifer"
cxl: mce: fix typo "notifer"
KVM: x86: fix typo "notifer"
MAINTAINERS: add maintainers for delaytop
ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
ucount: fix atomic_long_inc_below() argument type
kexec: enable CMA based contiguous allocation
stackdepot: make max number of pools boot-time configurable
lib/xxhash: remove unused functions
init/Kconfig: restore CONFIG_BROKEN help text
lib/raid6: update recov_rvv.c zero page usage
docs: update docs after introducing delaytop
...
Pull runtime verification updates from Steven Rostedt:
- Added Linear temporal logic monitors for RT application
Real-time applications may have design flaws causing them to have
unexpected latency. For example, the applications may raise page
faults, or may be blocked trying to take a mutex without priority
inheritance.
However, while attempting to implement DA monitors for these
real-time rules, deterministic automaton is found to be inappropriate
as the specification language. The automaton is complicated, hard to
understand, and error-prone.
For these cases, linear temporal logic is found to be more suitable.
The LTL is more concise and intuitive.
- Make printk_deferred() public
The new monitors needed access to printk_deferred(). Make them
visible for the entire kernel.
- Add a vpanic() to allow for va_list to be passed to panic.
- Add rtapp container monitor.
A collection of monitors that check for common problems with
real-time applications that cause unexpected latency.
- Add page fault tracepoints to risc-v
These tracepoints are necessary to for the RV monitor to run on
risc-v.
- Fix the behaviour of the rv tool with -s and idle tasks.
- Allow the rv tool to gracefully terminate with SIGTERM
- Adjusts dot2c not to create lines over 100 columns
- Properly order nested monitors in the RV Kconfig file
- Return the registration error in all DA monitor instead of 0
- Update and add new sched collection monitors
Replace tss and sncid monitors with more complete sts:
Not only prove that switches occur in scheduling context and scheduling
needs interrupt disabled but also that each call to the scheduler
disables interrupts to (optionally) switch.
New monitor: nrp
Preemption requires need resched which is cleared by any switch
(includes a non optimal workaround for /nested/ preemptions)
New monitor: sssw
suspension requires setting the task to sleepable and, after the
switch occurs, the task requires a wakeup to come back to runnable
New monitor: opid
waking and need-resched operations occur with interrupts and
preemption disabled or in IRQ without explicitly disabling
preemption"
* tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits)
rv: Add opid per-cpu monitor
rv: Add nrp and sssw per-task monitors
rv: Replace tss and sncid monitors with more complete sts
sched: Adapt sched tracepoints for RV task model
rv: Retry when da monitor detects race conditions
rv: Adjust monitor dependencies
rv: Use strings in da monitors tracepoints
rv: Remove trailing whitespace from tracepoint string
rv: Add da_handle_start_run_event_ to per-task monitors
rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()
rv: Fix wrong type cast in monitors_show()
rv: Remove struct rv_monitor::reacting
rv: Remove rv_reactor's reference counter
rv: Merge struct rv_reactor_def into struct rv_reactor
rv: Merge struct rv_monitor_def into struct rv_monitor
rv: Remove unused field in struct rv_monitor_def
rv: Return init error when registering monitors
verification/rvgen: Organise Kconfig entries for nested monitors
tools/dot2c: Fix generated files going over 100 column limit
tools/rv: Stop gracefully also on SIGTERM
...
With the introduction of the condition string as part of the 'file'
string output of kernel warnings, the first line has become a bit
harder to read:
WARNING: CPU: 0 PID: 0 at [ptr == 0 && 1] kernel/sched/core.c:8511 sched_init+0x20/0x410
Re-order the fields by importance (higher to lower), make the 'at' meaningful
again, and add '->comm[]' output which is often more valuable than a PID.
Also, remove the 'PID' prefix - in combination with comm it's clear what it is.
These changes make the output only slightly longer:
WARNING: [ptr == 0 && 1] kernel/sched/core.c:8511 at sched_init+0x20/0x410 CPU#0: swapper/0
While adding more information and making it better organized.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org> # Rebased ancestor commits
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20250515124644.2958810-16-mingo@kernel.org
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Move the ctl_table with the "tainted" proc_name into kernel/panic.c.
With it moves the proc_tainted helper function.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
RioandAndrew Morton
Pnina FederandAndrew Morton
Gal PressmanandAndrew Morton
Linus Torvalds
Peter Zijlstra
Andy ShevchenkoandAndrew Morton
Petr PavluandAndrew Morton
Randy DunlapandAndrew Morton
Johannes BergandAndrew Morton
Sergey SenozhatskyandAndrew Morton
Jinchao WangandAndrew Morton
Petr MladekandAndrew Morton
Feng TangandAndrew Morton
Ingo Molnar
Joel Granados