user/sven/linux.git/kernel/panic.c, branch next/HEAD

kernel/panic: mark init_taint_buf as __initdata and panic instead of warning in alloc_taint_buf()

2026-03-28T04:19:33Z

However there's a convention of assuming that __init-time allocations cannot fail. Because if a kmalloc() were to fail at this time, the kernel is hopelessly messed up anyway. So simply panic() if that kmalloc failed, then make that 350-byte buffer __initdata. Link: https://lkml.kernel.org/r/20260223035914.4033-1-rioo.tsukatsukii@gmail.com Signed-off-by: Rio Cc: Joel Granados Cc: Petr Mladek Cc: Wang Jinchao Signed-off-by: Andrew Morton

kernel/panic: allocate taint string buffer dynamically

2026-03-28T04:19:33Z

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 Cc: Joel Granados Cc: Petr Mladek Cc: Wang Jinchao Signed-off-by: Andrew Morton

kernel/panic: increase buffer size for verbose taint logging

2026-03-28T04:19:33Z

The verbose 'Tainted: ...' string in print_tainted_seq can total to 327 characters while the buffer defined in _print_tainted is 320 bytes. Increase its size to 350 characters to hold all flags, along with some headroom. [akpm@linux-foundation.org: fix spello, add comment] Link: https://lkml.kernel.org/r/20260220151500.13585-1-rioo.tsukatsukii@gmail.com Signed-off-by: Rio Cc: Joel Granados Cc: Petr Mladek Cc: Wang Jinchao Signed-off-by: Andrew Morton

panic: add panic_force_cpu= parameter to redirect panic to a specific CPU

2026-02-03T16:21:26Z

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 Reviewed-by: Petr Mladek Cc: Baoquan He Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Mel Gorman Cc: Peter Zijlstra Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Thomas Gleixner Signed-off-by: Andrew Morton

panic: only warn about deprecated panic_print on write access

2026-01-19T20:30:01Z

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: ee13240cd78b ("panic: add note that panic_print sysctl interface is deprecated") Fixes: 2683df6539cb ("panic: add note that 'panic_print' parameter is deprecated") Signed-off-by: Gal Pressman Reviewed-by: Mark Bloch Reviewed-by: Nimrod Oren Cc: Feng Tang Cc: Joel Granados Cc: Petr Mladek Cc: Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-12-06T22:01:20Z

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 ...

Merge branch 'objtool/core'

2025-11-21T10:21:20Z

Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions. Signed-off-by: Peter Zijlstra

panic: sys_info: align constant definition names with parameters

2025-11-20T22:03:40Z

Align constant definition names with parameters to make it easier to map. It's also better to maintain and extend the names while keeping their uniqueness. Link: https://lkml.kernel.org/r/20251030132007.3742368-3-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Reviewed-by: Feng Tang Reviewed-by: Petr Mladek Signed-off-by: Andrew Morton

taint/module: remove unnecessary taint_flag.module field

2025-11-12T18:00:15Z

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 7fd8329ba502 ("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 Acked-by: Petr Mladek Reviewed-by: Randy Dunlap Cc: Aaron Tomlin Cc: Luis Chamberalin Cc: Petr Pavlu Cc: Sami Tolvanen Signed-off-by: Andrew Morton

taint: add reminder about updating docs and scripts

2025-11-12T18:00:15Z

Sometimes people update taint-related pieces of the kernel without updating the supporting documentation or scripts. Add a reminder to do this. Link: https://lkml.kernel.org/r/20251015221626.1126156-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Cc: David Gow Cc: Jonathan Corbet Signed-off-by: Andrew Morton