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2025-09-28panic: remove CONFIG_PANIC_ON_OOPS_VALUEJohannes Berg1-1/+1
There's really no need for this since it's 0 or 1 when CONFIG_PANIC_ON_OOPS is disabled/enabled, so just use IS_ENABLED() instead. The extra symbol goes back to the original code adding it in commit 2a01bb3885c9 ("panic: Make panic_on_oops configurable"). Link: https://lkml.kernel.org/r/20250924094303.18521-2-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: remove redundant panic-cpu backtraceSergey Senozhatsky1-9/+21
Backtraces from all CPUs are printed during panic() when SYS_INFO_ALL_CPU_BT is set. It shows the backtrace for the panic-CPU even when it has already been explicitly printed before. Do not change the legacy code which prints the backtrace in various contexts, for example, as part of Oops report, right after panic message. It will always be visible in the crash dump. Instead, remember when the backtrace was printed, and skip it when dumping the optional backtraces on all CPUs. [akpm@linux-foundation.org: make panic_this_cpu_backtrace_printed static] Closes: https://lore.kernel.org/oe-kbuild-all/202509050048.FMpVvh1u-lkp@intel.com/ [pmladek@suse.com: Handle situations when the backtrace was not printed for the panic CPU] Link: https://lkml.kernel.org/r/20250903100418.410026-1-pmladek@suse.com Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Link: https://lore.kernel.org/r/20250731030314.3818040-1-senozhatsky@chromium.org Signed-off-by: Petr Mladek <pmladek@suse.com> Tested-by: Feng Tang <feng.tang@linux.alibaba.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic/printk: replace this_cpu_in_panic() with panic_on_this_cpu()Jinchao Wang1-1/+1
The helper this_cpu_in_panic() duplicated logic already provided by panic_on_this_cpu(). Remove this_cpu_in_panic() and switch all users to panic_on_this_cpu(). This simplifies the code and avoids having two helpers for the same check. Link: https://lkml.kernel.org/r/20250825022947.1596226-8-wangjinchao600@gmail.com Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Doug Anderson <dianders@chromium.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Kees Cook <kees@kernel.org> Cc: Li Huafei <lihuafei1@huawei.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Luo Gengkun <luogengkun@huaweicloud.com> Cc: Max Kellermann <max.kellermann@ionos.com> Cc: Nam Cao <namcao@linutronix.de> Cc: oushixiong <oushixiong@kylinos.cn> Cc: Petr Mladek <pmladek@suse.com> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Sohil Mehta <sohil.mehta@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Thorsten Blum <thorsten.blum@linux.dev> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Cc: Yunhui Cui <cuiyunhui@bytedance.com> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: use panic_try_start() in vpanic()Jinchao Wang1-6/+2
vpanic() had open-coded logic to claim panic_cpu with atomic_try_cmpxchg. This is already handled by panic_try_start(). Switch to panic_try_start() and use panic_on_other_cpu() for the fallback path. This removes duplicate code and makes panic handling consistent across functions. Link: https://lkml.kernel.org/r/20250825022947.1596226-6-wangjinchao600@gmail.com Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Doug Anderson <dianders@chromium.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Kees Cook <kees@kernel.org> Cc: Li Huafei <lihuafei1@huawei.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Luo Gengkun <luogengkun@huaweicloud.com> Cc: Max Kellermann <max.kellermann@ionos.com> Cc: Nam Cao <namcao@linutronix.de> Cc: oushixiong <oushixiong@kylinos.cn> Cc: Petr Mladek <pmladek@suse.com> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Sohil Mehta <sohil.mehta@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Thorsten Blum <thorsten.blum@linux.dev> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Cc: Yunhui Cui <cuiyunhui@bytedance.com> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: use panic_try_start() in nmi_panic()Jinchao Wang1-8/+2
nmi_panic() duplicated the logic to claim panic_cpu with atomic_try_cmpxchg. This is already wrapped in panic_try_start(). Replace the open-coded logic with panic_try_start(), and use panic_on_other_cpu() for the fallback path. This removes duplication and keeps panic handling code consistent. Link: https://lkml.kernel.org/r/20250825022947.1596226-5-wangjinchao600@gmail.com Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Doug Anderson <dianders@chromium.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Kees Cook <kees@kernel.org> Cc: Li Huafei <lihuafei1@huawei.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Luo Gengkun <luogengkun@huaweicloud.com> Cc: Max Kellermann <max.kellermann@ionos.com> Cc: Nam Cao <namcao@linutronix.de> Cc: oushixiong <oushixiong@kylinos.cn> Cc: Petr Mladek <pmladek@suse.com> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Sohil Mehta <sohil.mehta@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Thorsten Blum <thorsten.blum@linux.dev> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Cc: Yunhui Cui <cuiyunhui@bytedance.com> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: introduce helper functions for panic stateJinchao Wang1-0/+53
Patch series "panic: introduce panic status function family", v2. This series introduces a family of helper functions to manage panic state and updates existing code to use them. Before this series, panic state helpers were scattered and inconsistent. For example, panic_in_progress() was defined in printk/printk.c, not in panic.c or panic.h. As a result, developers had to look in unexpected places to understand or re-use panic state logic. Other checks were open- coded, duplicating logic across panic, crash, and watchdog paths. The new helpers centralize the functionality in panic.c/panic.h: - panic_try_start() - panic_reset() - panic_in_progress() - panic_on_this_cpu() - panic_on_other_cpu() Patches 1–8 add the helpers and convert panic/crash and printk/nbcon code to use them. Patch 9 fixes a bug in the watchdog subsystem by skipping checks when a panic is in progress, avoiding interference with the panic CPU. Together, this makes panic state handling simpler, more discoverable, and more robust. This patch (of 9): This patch introduces four new helper functions to abstract the management of the panic_cpu variable. These functions will be used in subsequent patches to refactor existing code. The direct use of panic_cpu can be error-prone and ambiguous, as it requires manual checks to determine which CPU is handling the panic. The new helpers clarify intent: panic_try_start(): Atomically sets the current CPU as the panicking CPU. panic_reset(): Reset panic_cpu to PANIC_CPU_INVALID. panic_in_progress(): Checks if a panic has been triggered. panic_on_this_cpu(): Returns true if the current CPU is the panic originator. panic_on_other_cpu(): Returns true if a panic is on another CPU. This change lays the groundwork for improved code readability and robustness in the panic handling subsystem. Link: https://lkml.kernel.org/r/20250825022947.1596226-1-wangjinchao600@gmail.com Link: https://lkml.kernel.org/r/20250825022947.1596226-2-wangjinchao600@gmail.com Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Doug Anderson <dianders@chromium.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Kees Cook <kees@kernel.org> Cc: Li Huafei <lihuafei1@huawei.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Luo Gengkun <luogengkun@huaweicloud.com> Cc: Max Kellermann <max.kellermann@ionos.com> Cc: Nam Cao <namcao@linutronix.de> Cc: oushixiong <oushixiong@kylinos.cn> Cc: Petr Mladek <pmladek@suse.com> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Sohil Mehta <sohil.mehta@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Thorsten Blum <thorsten.blum@linux.dev> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Cc: Yunhui Cui <cuiyunhui@bytedance.com> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>b Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: clean up message about deprecated 'panic_print' parameterPetr Mladek1-3/+8
Remove duplication of the message about deprecated 'panic_print' parameter. Also make the wording more direct. Make it clear that the new parameters already exist and should be used instead. Link: https://lkml.kernel.org/r/20250825025701.81921-5-feng.tang@linux.alibaba.com Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Feng Tang <feng.tang@linux.alibaba.com> Cc: Askar Safin <safinaskar@zohomail.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13panic: add note that 'panic_print' parameter is deprecatedFeng Tang1-1/+18
Just like for 'panic_print's systcl interface, add similar note for setup of kernel cmdline parameter and parameter under /sys/module/kernel/. Also add __core_param_cb() macro, which enables to add special get/set operation for a kernel parameter. Link: https://lkml.kernel.org/r/20250825025701.81921-4-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Askar Safin <safinaskar@zohomail.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-08-03Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of ↵Linus Torvalds1-39/+32
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 ...
2025-07-30Merge tag 'trace-rv-6.17' of ↵Linus Torvalds1-5/+13
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 ...
2025-07-23sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.cJoel Granados1-0/+10
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>
2025-07-23sysctl: Move tainted ctl_table into kernel/panic.cJoel Granados1-0/+50
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>
2025-07-19panic: add note that panic_print sysctl interface is deprecatedFeng Tang1-8/+13
Add a dedicated core parameter 'panic_console_replay' for controlling console replay, and add note that 'panic_print' sysctl interface will be obsoleted by 'panic_sys_info' and 'panic_console_replay'. When it happens, the SYS_INFO_PANIC_CONSOLE_REPLAY can be removed as well. Link: https://lkml.kernel.org/r/20250703021004.42328-6-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19panic: add 'panic_sys_info=' setup option for kernel cmdlineFeng Tang1-0/+9
'panic_sys_info=' sysctl interface is already added for runtime setting. Add counterpart kernel cmdline option for boottime setting. Link: https://lkml.kernel.org/r/20250703021004.42328-5-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19panic: add 'panic_sys_info' sysctl to take human readable string parameterFeng Tang1-0/+7
Bitmap definition for 'panic_print' is hard to remember and decode. Add 'panic_sys_info='sysctl to take human readable string like "tasks,mem,timers,locks,ftrace,..." and translate it into bitmap. The detailed mapping is: SYS_INFO_TASKS "tasks" SYS_INFO_MEM "mem" SYS_INFO_TIMERS "timers" SYS_INFO_LOCKS "locks" SYS_INFO_FTRACE "ftrace" SYS_INFO_ALL_CPU_BT "all_bt" SYS_INFO_BLOCKED_TASKS "blocked_tasks" [nathan@kernel.org: add __maybe_unused to sys_info_avail] Link: https://lkml.kernel.org/r/20250708-fix-clang-sys_info_avail-warning-v1-1-60d239eacd64@kernel.org Link: https://lkml.kernel.org/r/20250703021004.42328-4-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19panic: generalize panic_print's function to show sys infoFeng Tang1-32/+4
'panic_print' was introduced to help debugging kernel panic by dumping different kinds of system information like tasks' call stack, memory, ftrace buffer, etc. Actually this function could also be used to help debugging other cases like task-hung, soft/hard lockup, etc. where user may need the snapshot of system info at that time. Extract system info dump function related code from panic.c to separate file sys_info.[ch], for wider usage by other kernel parts for debugging. Also modify the macro names about singulars/plurals. Link: https://lkml.kernel.org/r/20250703021004.42328-3-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19panic: clean up code for console replayFeng Tang1-9/+9
Patch series "generalize panic_print's dump function to be used by other kernel parts", v3. When working on kernel stability issues, panic, task-hung and software/hardware lockup are frequently met. And to debug them, user may need lots of system information at that time, like task call stacks, lock info, memory info etc. panic case already has panic_print_sys_info() for this purpose, and has a 'panic_print' bitmask to control what kinds of information is needed, which is also helpful to debug other task-hung and lockup cases. So this patchset extracts the function out to a new file 'lib/sys_info.c', and makes it available for other cases which also need to dump system info for debugging. Also as suggested by Petr Mladek, add 'panic_sys_info=' interface to take human readable string like "tasks,mem,locks,timers,ftrace,....", and eventually obsolete the current 'panic_print' bitmap interface. In RFC and V1 version, hung_task and SW/HW watchdog modules are enabled with the new sys_info dump interface. In v2, they are kept out for better review of current change, and will be posted later. Locally these have been used in our bug chasing for stability issues and was proven helpful. Many thanks to Petr Mladek for great suggestions on both the code and architectures! This patch (of 5): Currently the panic_print_sys_info() was called twice with different parameters to handle console replay case, which is kind of confusing. Add panic_console_replay() explicitly and rename 'PANIC_PRINT_ALL_PRINTK_MSG' to 'PANIC_CONSOLE_REPLAY', to make the code straightforward. The related kernel document is also updated. Link: https://lkml.kernel.org/r/20250703021004.42328-1-feng.tang@linux.alibaba.com Link: https://lkml.kernel.org/r/20250703021004.42328-2-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-11panic: Fix up description of vpanic()Nam Cao1-1/+1
The description above vpanic() has the wrong function name. Fix it up. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/23a7e8add6546b155371b7e0fbb37bb1def13d6e.1752232374.git.namcao@linutronix.de Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/lkml/20250711183802.2d8c124d@canb.auug.org.au/ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09panic: Add vpanic()Nam Cao1-4/+12
vpanic() is useful for implementing runtime verification reactors. Add it. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-05-31Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of ↵Linus Torvalds1-5/+3
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...
2025-05-21kernel/panic.c: format kernel-doc commentsSravan Kumar Gundu1-5/+3
kernel-doc function comment don't follows documentation commenting style misinterpreting arguments description with function description. Please see latest docs generated before applying this patch https://docs.kernel.org/driver-api/basics.html#c.panic Link: https://lkml.kernel.org/r/20250516174031.2937-1-sravankumarlpu@gmail.com Signed-off-by: Sravan Kumar Gundu <sravankumarlpu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jani Nikula <jani.nikula@intel.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-09panic: Move panic ctl tables into panic.cJoel Granados1-0/+30
Move panic, panic_on_oops, panic_print, panic_on_warn into kerne/panic.c. 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. Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-04-02Merge tag 'objtool-urgent-2025-04-01' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool fixes from Ingo Molnar: "These are objtool fixes and updates by Josh Poimboeuf, centered around the fallout from the new CONFIG_OBJTOOL_WERROR=y feature, which, despite its default-off nature, increased the profile/impact of objtool warnings: - Improve error handling and the presentation of warnings/errors - Revert the new summary warning line that some test-bot tools interpreted as new regressions - Fix a number of objtool warnings in various drivers, core kernel code and architecture code. About half of them are potential problems related to out-of-bounds accesses or potential undefined behavior, the other half are additional objtool annotations - Update objtool to latest (known) compiler quirks and objtool bugs triggered by compiler code generation - Misc fixes" * tag 'objtool-urgent-2025-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) objtool/loongarch: Add unwind hints in prepare_frametrace() rcu-tasks: Always inline rcu_irq_work_resched() context_tracking: Always inline ct_{nmi,irq}_{enter,exit}() sched/smt: Always inline sched_smt_active() objtool: Fix verbose disassembly if CROSS_COMPILE isn't set objtool: Change "warning:" to "error: " for fatal errors objtool: Always fail on fatal errors Revert "objtool: Increase per-function WARN_FUNC() rate limit" objtool: Append "()" to function name in "unexpected end of section" warning objtool: Ignore end-of-section jumps for KCOV/GCOV objtool: Silence more KCOV warnings, part 2 objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions objtool: Fix segfault in ignore_unreachable_insn() objtool: Fix NULL printf() '%s' argument in builtin-check.c:save_argv() objtool, lkdtm: Obfuscate the do_nothing() pointer objtool, regulator: rk808: Remove potential undefined behavior in rk806_set_mode_dcdc() objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler() objtool, Input: cyapa - Remove undefined behavior in cyapa_update_fw_store() objtool, panic: Disable SMAP in __stack_chk_fail() ...
2025-03-25objtool, panic: Disable SMAP in __stack_chk_fail()Josh Poimboeuf1-0/+6
__stack_chk_fail() can be called from uaccess-enabled code. Make sure uaccess gets disabled before calling panic(). Fixes the following warning: kernel/trace/trace_branch.o: error: objtool: ftrace_likely_update+0x1ea: call to __stack_chk_fail() with UACCESS enabled Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/a3e97e0119e1b04c725a8aa05f7bc83d98e657eb.1742852847.git.jpoimboe@kernel.org
2025-03-06taint: Add TAINT_FWCTLJason Gunthorpe1-0/+1
Requesting a fwctl scope of access that includes mutating device debug data will cause the kernel to be tainted. Changing the device operation through things in the debug scope may cause the device to malfunction in undefined ways. This should be reflected in the TAINT flags to help any debuggers understand that something has been done. Link: https://patch.msgid.link/r/4-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Shannon Nelson <shannon.nelson@amd.com> Tested-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Shannon Nelson <shannon.nelson@amd.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-01-28treewide: const qualify ctl_tables where applicableJoel Granados1-1/+1
Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2024-09-19Merge tag 'drm-next-2024-09-19' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-1/+1
Pull drm updates from Dave Airlie: "This adds a couple of patches outside the drm core, all should be acked appropriately, the string and pstore ones are the main ones that come to mind. Otherwise it's the usual drivers, xe is getting enabled by default on some new hardware, we've changed the device number handling to allow more devices, and we added some optional rust code to create QR codes in the panic handler, an idea first suggested I think 10 years ago :-) string: - add mem_is_zero() core: - support more device numbers - use XArray for minor ids - add backlight constants - Split dma fence array creation into alloc and arm fbdev: - remove usage of old fbdev hooks kms: - Add might_fault() to drm_modeset_lock priming - Add dynamic per-crtc vblank configuration support dma-buf: - docs cleanup buddy: - Add start address support for trim function printk: - pass description to kmsg_dump scheduler: - Remove full_recover from drm_sched_start ttm: - Make LRU walk restartable after dropping locks - Allow direct reclaim to allocate local memory panic: - add display QR code (in rust) displayport: - mst: GUID improvements bridge: - Silence error message on -EPROBE_DEFER - analogix: Clean aup - bridge-connector: Fix double free - lt6505: Disable interrupt when powered off - tc358767: Make default DP port preemphasis configurable - lt9611uxc: require DRM_BRIDGE_ATTACH_NO_CONNECTOR - anx7625: simplify OF array handling - dw-hdmi: simplify clock handling - lontium-lt8912b: fix mode validation - nwl-dsi: fix mode vsync/hsync polarity xe: - Enable LunarLake and Battlemage support - Introducing Xe2 ccs modifiers for integrated and discrete graphics - rename xe perf to xe observation - use wb caching on DGFX for system memory - add fence timeouts - Lunar Lake graphics/media/display workarounds - Battlemage workarounds - Battlemage GSC support - GSC and HuC fw updates for LL/BM - use dma_fence_chain_free - refactor hw engine lookup and mmio access - enable priority mem read for Xe2 - Add first GuC BMG fw - fix dma-resv lock - Fix DGFX display suspend/resume - Use xe_managed for kernel BOs - Use reserved copy engine for user binds on faulting devices - Allow mixing dma-fence jobs and long-running faulting jobs - fix media TLB invalidation - fix rpm in TTM swapout path - track resources and VF state by PF i915: - Type-C programming fix for MTL+ - FBC cleanup - Calc vblank delay more accurately - On DP MST, Enable LT fallback for UHBR<->non-UHBR rates - Fix DP LTTPR detection - limit relocations to INT_MAX - fix long hangs in buddy allocator on DG2/A380 amdgpu: - Per-queue reset support - SDMA devcoredump support - DCN 4.0.1 updates - GFX12/VCN4/JPEG4 updates - Convert vbios embedded EDID to drm_edid - GFX9.3/9.4 devcoredump support - process isolation framework for GFX 9.4.3/4 - take IOMMU mappings into account for P2P DMA amdkfd: - CRIU fixes - HMM fix - Enable process isolation support for GFX 9.4.3/4 - Allow users to target recommended SDMA engines - KFD support for targetting queues on recommended SDMA engines radeon: - remove .load and drm_dev_alloc - Fix vbios embedded EDID size handling - Convert vbios embedded EDID to drm_edid - Use GEM references instead of TTM - r100 cp init cleanup - Fix potential overflows in evergreen CS offset tracking msm: - DPU: - implement DP/PHY mapping on SC8180X - Enable writeback on SM8150, SC8180X, SM6125, SM6350 - DP: - Enable widebus on all relevant chipsets - MSM8998 HDMI support - GPU: - A642L speedbin support - A615/A306/A621 support - A7xx devcoredump support ast: - astdp: Support AST2600 with VGA - Clean up HPD - Fix timeout loop for DP link training - reorganize output code by type (VGA, DP, etc) - convert to struct drm_edid - fix BMC handling for all outputs exynos: - drop stale MAINTAINERS pattern - constify struct loongson: - use GEM refcount over TTM mgag200: - Improve BMC handling - Support VBLANK intterupts - transparently support BMC outputs nouveau: - Refactor and clean up internals - Use GEM refcount over TTM's gm12u320: - convert to struct drm_edid gma500: - update i2c terms lcdif: - pixel clock fix host1x: - fix syncpoint IRQ during resume - use iommu_paging_domain_alloc() imx: - ipuv3: convert to struct drm_edid omapdrm: - improve error handling - use common helper for_each_endpoint_of_node() panel: - add support for BOE TV101WUM-LL2 plus DT bindings - novatek-nt35950: improve error handling - nv3051d: improve error handling - panel-edp: - add support for BOE NE140WUM-N6G - revert support for SDC ATNA45AF01 - visionox-vtdr6130: - improve error handling - use devm_regulator_bulk_get_const() - boe-th101mb31ig002: - Support for starry-er88577 MIPI-DSI panel plus DT - Fix porch parameter - edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1, BOE NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2, CMN N116BCP-EA2, CSW MNB601LS1-4 - himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT - ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT - jd9365da: - Support Melfas lmfbx101117480 MIPI-DSI panel plus DT - Refactor for code sharing - panel-edp: fix name for HKC MB116AN01 - jd9365da: fix "exit sleep" commands - jdi-fhd-r63452: simplify error handling with DSI multi-style helpers - mantix-mlaf057we51: simplify error handling with DSI multi-style helpers - simple: - support Innolux G070ACE-LH3 plus DT bindings - support On Tat Industrial Company KD50G21-40NT-A1 plus DT bindings - st7701: - decouple DSI and DRM code - add SPI support - support Anbernic RG28XX plus DT bindings mediatek: - support alpha blending - remove cl in struct cmdq_pkt - ovl adaptor fix - add power domain binding for mediatek DPI controller renesas: - rz-du: add support for RZ/G2UL plus DT bindings rockchip: - Improve DP sink-capability reporting - dw_hdmi: Support 4k@60Hz - vop: - Support RGB display on Rockchip RK3066 - Support 4096px width sti: - convert to struct drm_edid stm: - Avoid UAF wih managed plane and CRTC helpers - Fix module owner - Fix error handling in probe - Depend on COMMON_CLK - ltdc: - Fix transparency after disabling plane - Remove unused interrupt tegra: - gr3d: improve PM domain handling - convert to struct drm_edid - Call drm_atomic_helper_shutdown() vc4: - fix PM during detect - replace DRM_ERROR() with drm_error() - v3d: simplify clock retrieval v3d: - Clean up perfmon virtio: - add DRM capset" * tag 'drm-next-2024-09-19' of https://gitlab.freedesktop.org/drm/kernel: (1326 commits) drm/xe: Fix missing conversion to xe_display_pm_runtime_resume drm/xe/xe2hpg: Add Wa_15016589081 drm/xe: Don't keep stale pointer to bo->ggtt_node drm/xe: fix missing 'xe_vm_put' drm/xe: fix build warning with CONFIG_PM=n drm/xe: Suppress missing outer rpm protection warning drm/xe: prevent potential UAF in pf_provision_vf_ggtt() drm/amd/display: Add all planes on CRTC to state for overlay cursor drm/i915/bios: fix printk format width drm/i915/display: Fix BMG CCS modifiers drm/amdgpu: get rid of bogus includes of fdtable.h drm/amdkfd: CRIU fixes drm/amdgpu: fix a race in kfd_mem_export_dmabuf() drm: new helper: drm_gem_prime_handle_to_dmabuf() drm/amdgpu/atomfirmware: Silence UBSAN warning drm/amdgpu: Fix kdoc entry in 'amdgpu_vm_cpu_prepare' drm/amd/amdgpu: apply command submission parser for JPEG v1 drm/amd/amdgpu: apply command submission parser for JPEG v2+ drm/amd/pm: fix the pp_dpm_pcie issue on smu v14.0.2/3 drm/amd/pm: update the features set on smu v14.0.2/3 ...
2024-08-27Merge v6.11-rc5 into drm-nextDaniel Vetter1-1/+7
amdgpu pr conconflicts due to patches cherry-picked to -fixes, I might as well catch up with a backmerge and handle them all. Plus both misc and intel maintainers asked for a backmerge anyway. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2024-08-21panic: Mark emergency section in oopsJohn Ogness1-0/+2
Mark an emergency section beginning with oops_enter() until the end of oops_exit(). In this section, every printk() call will attempt to directly flush to the consoles using the EMERGENCY priority. The very end of oops_exit() performs a kmsg_dump(). This is not included in the emergency section because it is another flushing mechanism that should occur after the consoles have flushed the oops messages. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240820063001.36405-34-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21panic: Mark emergency section in warnThomas Gleixner1-0/+4
Mark the full contents of __warn() as an emergency section. In this section, every printk() call will attempt to directly flush to the consoles using the EMERGENCY priority. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240820063001.36405-33-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21printk: Coordinate direct printing in panicJohn Ogness1-0/+2
If legacy and nbcon consoles are registered and the nbcon consoles are allowed to flush (i.e. no boot consoles registered), the legacy consoles will no longer perform direct printing on the panic CPU until after the backtrace has been stored. This will give the safe nbcon consoles a chance to print the panic messages before allowing the unsafe legacy consoles to print. If no nbcon consoles are registered or they are not allowed to flush because boot consoles are registered, there is no change in behavior (i.e. legacy consoles will always attempt to print from the printk() caller context). Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240820063001.36405-30-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21printk: nbcon: Add unsafe flushing on panicJohn Ogness1-0/+1
Add nbcon_atomic_flush_unsafe() to flush all nbcon consoles using the write_atomic() callback and allowing unsafe hostile takeovers. Call this at the end of panic() as a final attempt to flush any pending messages. Note that legacy consoles use unsafe methods for flushing from the beginning of panic (see bust_spinlocks()). Therefore, systems using both legacy and nbcon consoles may still fail to see panic messages due to unsafe legacy console usage. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240820063001.36405-27-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-13printk/panic: Allow cpu backtraces to be written into ringbuffer during panicRyo Takakura1-1/+7
commit 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing to ringbuffer") disabled non-panic CPUs to further write messages to ringbuffer after panicked. Since the commit, non-panicked CPU's are not allowed to write to ring buffer after panicked and CPU backtrace which is triggered after panicked to sample non-panicked CPUs' backtrace no longer serves its function as it has nothing to print. Fix the issue by allowing non-panicked CPUs to write into ringbuffer while CPU backtrace is in flight. Fixes: 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing to ringbuffer") Signed-off-by: Ryo Takakura <takakura@valinux.co.jp> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240812072703.339690-1-takakura@valinux.co.jp Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-08Merge tag 'drm-misc-next-2024-08-01' of ↵Daniel Vetter1-1/+1
https://gitlab.freedesktop.org/drm/misc/kernel into drm-next drm-misc-next for v6.12: UAPI Changes: virtio: - Define DRM capset Cross-subsystem Changes: dma-buf: - heaps: Clean up documentation printk: - Pass description to kmsg_dump() Core Changes: CI: - Update IGT tests - Point upstream repo to GitLab instance modesetting: - Introduce Power Saving Policy property for connectors - Add might_fault() to drm_modeset_lock priming - Add dynamic per-crtc vblank configuration support panic: - Avoid build-time interference with framebuffer console docs: - Document Colorspace property scheduler: - Remove full_recover from drm_sched_start TTM: - Make LRU walk restartable after dropping locks - Allow direct reclaim to allocate local memory Driver Changes: amdgpu: - Support Power Saving Policy connector property ast: - astdp: Support AST2600 with VGA; Clean up HPD bridge: - Silence error message on -EPROBE_DEFER - analogix: Clean aup - bridge-connector: Fix double free - lt6505: Disable interrupt when powered off - tc358767: Make default DP port preemphasis configurable gma500: - Update i2c terminology ivpu: - Add MODULE_FIRMWARE() lcdif: - Fix pixel clock loongson: - Use GEM refcount over TTM's mgag200: - Improve BMC handling - Support VBLANK intterupts nouveau: - Refactor and clean up internals - Use GEM refcount over TTM's panel: - Shutdown fixes plus documentation - Refactor several drivers for better code sharing - boe-th101mb31ig002: Support for starry-er88577 MIPI-DSI panel plus DT; Fix porch parameter - edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1, BOE NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2, CMN N116BCP-EA2, CSW MNB601LS1-4 - himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT - ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT - jd9365da: Support Melfas lmfbx101117480 MIPI-DSI panel plus DT; Refactor for code sharing sti: - Fix module owner stm: - Avoid UAF wih managed plane and CRTC helpers - Fix module owner - Fix error handling in probe - Depend on COMMON_CLK - ltdc: Fix transparency after disabling plane; Remove unused interrupt tegra: - Call drm_atomic_helper_shutdown() v3d: - Clean up perfmon vkms: - Clean up Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> From: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20240801121406.GA102996@linux.fritz.box
2024-07-17printk: Add a short description string to kmsg_dump()Jocelyn Falempe1-1/+1
kmsg_dump doesn't forward the panic reason string to the kmsg_dumper callback. This patch adds a new struct kmsg_dump_detail, that will hold the reason and description, and pass it to the dump() callback. To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc() function and a macro for backward compatibility. I've written this for drm_panic, but it can be useful for other kmsg_dumper. It allows to see the panic reason, like "sysrq triggered crash" or "VFS: Unable to mount root fs on xxxx" on the drm panic screen. v2: * Use a struct kmsg_dump_detail to hold the reason and description pointer, for more flexibility if we want to add other parameters. (Kees Cook) * Fix powerpc/nvram_64 build, as I didn't update the forward declaration of oops_to_nvram() Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Kees Cook <kees@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com
2024-06-24kernel/panic: add verbose logging of kernel taints in backtracesJani Nikula1-11/+34
With nearly 20 taint flags and respective characters, it's getting a bit difficult to remember what each taint flag character means. Add verbose logging of the set taints in the format: Tainted: [P]=PROPRIETARY_MODULE, [W]=WARN in dump_stack_print_info() when there are taints. Note that the "negative flag" G is not included. Link: https://lkml.kernel.org/r/7321e306166cb2ca2807ab8639e665baa2462e9c.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24kernel/panic: initialize taint_flags[] using a macroJani Nikula1-19/+27
Make it easier to extend struct taint_flags in follow-up. Link: https://lkml.kernel.org/r/8a2498285d37953cfad9dce939ed3abef61051bd.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24kernel/panic: convert print_tainted() to use struct seq_buf internallyJani Nikula1-14/+24
Convert print_tainted() to use struct seq_buf internally in order to be more aware of the buffer constraints as well as make it easier to extend in follow-up work. Link: https://lkml.kernel.org/r/cb6006fa7c0f82a6b6885e8eea2920fcdc4fc9d0.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24kernel/panic: return early from print_tainted() when not taintedJani Nikula1-12/+13
Reduce indent to make follow-up changes slightly easier on the eyes. Link: https://lkml.kernel.org/r/01d6c03de1c9d1b52b59c652a3704a0a9886ed63.1717146197.git.jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-24kernel misc: Remove the now superfluous sentinel elements from ctl_table arrayJoel Granados1-1/+0
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove the sentinel from ctl_table arrays. Reduce by one the values used to compare the size of the adjusted arrays. Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-03-14Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of ↵Linus Torvalds1-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min heap optimizations". - Kuan-Wei Chiu has also sped up the library sorting code in the series "lib/sort: Optimize the number of swaps and comparisons". - Alexey Gladkov has added the ability for code running within an IPC namespace to alter its IPC and MQ limits. The series is "Allow to change ipc/mq sysctls inside ipc namespace". - Geert Uytterhoeven has contributed some dhrystone maintenance work in the series "lib: dhry: miscellaneous cleanups". - Ryusuke Konishi continues nilfs2 maintenance work in the series "nilfs2: eliminate kmap and kmap_atomic calls" "nilfs2: fix kernel bug at submit_bh_wbc()" - Nathan Chancellor has updated our build tools requirements in the series "Bump the minimum supported version of LLVM to 13.0.1". - Muhammad Usama Anjum continues with the selftests maintenance work in the series "selftests/mm: Improve run_vmtests.sh". - Oleg Nesterov has done some maintenance work against the signal code in the series "get_signal: minor cleanups and fix". Plus the usual shower of singleton patches in various parts of the tree. Please see the individual changelogs for details. * tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits) nilfs2: prevent kernel bug at submit_bh_wbc() nilfs2: fix failure to detect DAT corruption in btree and direct mappings ocfs2: enable ocfs2_listxattr for special files ocfs2: remove SLAB_MEM_SPREAD flag usage assoc_array: fix the return value in assoc_array_insert_mid_shortcut() buildid: use kmap_local_page() watchdog/core: remove sysctl handlers from public header nilfs2: use div64_ul() instead of do_div() mul_u64_u64_div_u64: increase precision by conditionally swapping a and b kexec: copy only happens before uchunk goes to zero get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig get_signal: don't abuse ksig->info.si_signo and ksig->sig const_structs.checkpatch: add device_type Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>" dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace() list: leverage list_is_head() for list_entry_is_head() nilfs2: MAINTAINERS: drop unreachable project mirror site smp: make __smp_processor_id() 0-argument macro fat: fix uninitialized field in nostale filehandles ...
2024-02-22panic: add option to dump blocked tasks in panic_printFeng Tang1-0/+4
For debugging kernel panics and other bugs, there is already an option of panic_print to dump all tasks' call stacks. On today's large servers running many containers, there could be thousands of tasks or more, and this will print out huge amount of call stacks, taking a lot of time (for serial console which is main target user case of panic_print). And in many cases, only those several tasks being blocked are key for the panic, so add an option to only dump blocked tasks' call stacks. [akpm@linux-foundation.org: clarify documentation a little] Link: https://lkml.kernel.org/r/20240202132042.3609657-1-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22panic: suppress gnu_printf warningBaoquan He1-0/+5
with GCC 13.2.1 and W=1, there's compiling warning like this: kernel/panic.c: In function `__warn': kernel/panic.c:676:17: warning: function `__warn' might be a candidate for `gnu_printf' format attribute [-Wsuggest-attribute=format] 676 | vprintk(args->fmt, args->args); | ^~~~~~~ The normal __printf(x,y) adding can't fix it. So add workaround which disables -Wsuggest-attribute=format to mute it. Link: https://lkml.kernel.org/r/20240107091641.579849-1-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07panic: Flush kernel log buffer at the endJohn Ogness1-0/+8
If the kernel crashes in a context where printk() calls always defer printing (such as in NMI or inside a printk_safe section) then the final panic messages will be deferred to irq_work. But if irq_work is not available, the messages will not get printed unless explicitly flushed. The result is that the final "end Kernel panic" banner does not get printed. Add one final flush after the last printk() call to make sure the final panic messages make it out as well. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2023-10-04panic: use atomic_try_cmpxchg in panic() and nmi_panic()Uros Bizjak1-9/+13
Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old in panic() and nmi_panic(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, rename cpu variable to this_cpu in nmi_panic() and try to unify logic flow between panic() and nmi_panic(). No functional change intended. [ubizjak@gmail.com: clean up if/else block] Link: https://lkml.kernel.org/r/20230906191200.68707-1-ubizjak@gmail.com Link: https://lkml.kernel.org/r/20230904152230.9227-1-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-15panic: Reenable preemption in WARN slowpathLukas Wunner1-0/+1
Commit: 5a5d7e9badd2 ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG") amended warn_slowpath_fmt() to disable preemption until the WARN splat has been emitted. However the commit neglected to reenable preemption in the !fmt codepath, i.e. when a WARN splat is emitted without additional format string. One consequence is that users may see more splats than intended. E.g. a WARN splat emitted in a work item results in at least two extra splats: BUG: workqueue leaked lock or atomic (emitted by process_one_work()) BUG: scheduling while atomic (emitted by worker_thread() -> schedule()) Ironically the point of the commit was to *avoid* extra splats. ;) Fix it. Fixes: 5a5d7e9badd2 ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/3ec48fde01e4ee6505f77908ba351bad200ae3d1.1694763684.git.lukas@wunner.de
2023-08-18mm: remove arguments of show_mem()Kefeng Wang1-1/+1
All callers of show_mem() pass 0 and NULL, so we can remove the two arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in show_mem(). Link: https://lkml.kernel.org/r/20230630062253.189440-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09panic: hide unused global functionsArnd Bergmann1-2/+1
Building with W=1 shows warnings about two functions that have no declaration or caller in certain configurations: kernel/panic.c:688:6: error: no previous prototype for 'warn_slowpath_fmt' [-Werror=missing-prototypes] kernel/panic.c:710:6: error: no previous prototype for '__warn_printk' [-Werror=missing-prototypes] Enclose the definition in the same #ifdef check as the declaration. Link: https://lkml.kernel.org/r/20230517131102.934196-8-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Paris <eparis@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-14cpu: Mark nmi_panic_self_stop() __noreturnJosh Poimboeuf1-1/+1
In preparation for improving objtool's handling of weak noreturn functions, mark nmi_panic_self_stop() __noreturn. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/316fc6dfab5a8c4e024c7185484a1ee5fb0afb79.1681342859.git.jpoimboe@kernel.org
2023-04-14cpu: Mark panic_smp_self_stop() __noreturnJosh Poimboeuf1-1/+1
In preparation for improving objtool's handling of weak noreturn functions, mark panic_smp_self_stop() __noreturn. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/92d76ab5c8bf660f04fdcd3da1084519212de248.1681342859.git.jpoimboe@kernel.org