b24413180f
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
414 lines
9.5 KiB
C
414 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Watchdog support on powerpc systems.
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*
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* Copyright 2017, IBM Corporation.
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*
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* This uses code from arch/sparc/kernel/nmi.c and kernel/watchdog.c
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*/
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/init.h>
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#include <linux/percpu.h>
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#include <linux/cpu.h>
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#include <linux/nmi.h>
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#include <linux/module.h>
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#include <linux/export.h>
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#include <linux/kprobes.h>
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#include <linux/hardirq.h>
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#include <linux/reboot.h>
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#include <linux/slab.h>
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#include <linux/kdebug.h>
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#include <linux/sched/debug.h>
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#include <linux/delay.h>
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#include <linux/smp.h>
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#include <asm/paca.h>
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/*
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* The watchdog has a simple timer that runs on each CPU, once per timer
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* period. This is the heartbeat.
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*
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* Then there are checks to see if the heartbeat has not triggered on a CPU
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* for the panic timeout period. Currently the watchdog only supports an
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* SMP check, so the heartbeat only turns on when we have 2 or more CPUs.
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*
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* This is not an NMI watchdog, but Linux uses that name for a generic
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* watchdog in some cases, so NMI gets used in some places.
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*/
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static cpumask_t wd_cpus_enabled __read_mostly;
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static u64 wd_panic_timeout_tb __read_mostly; /* timebase ticks until panic */
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static u64 wd_smp_panic_timeout_tb __read_mostly; /* panic other CPUs */
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static u64 wd_timer_period_ms __read_mostly; /* interval between heartbeat */
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static DEFINE_PER_CPU(struct timer_list, wd_timer);
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static DEFINE_PER_CPU(u64, wd_timer_tb);
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/*
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* These are for the SMP checker. CPUs clear their pending bit in their
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* heartbeat. If the bitmask becomes empty, the time is noted and the
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* bitmask is refilled.
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*
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* All CPUs clear their bit in the pending mask every timer period.
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* Once all have cleared, the time is noted and the bits are reset.
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* If the time since all clear was greater than the panic timeout,
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* we can panic with the list of stuck CPUs.
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*
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* This will work best with NMI IPIs for crash code so the stuck CPUs
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* can be pulled out to get their backtraces.
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*/
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static unsigned long __wd_smp_lock;
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static cpumask_t wd_smp_cpus_pending;
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static cpumask_t wd_smp_cpus_stuck;
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static u64 wd_smp_last_reset_tb;
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static inline void wd_smp_lock(unsigned long *flags)
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{
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/*
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* Avoid locking layers if possible.
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* This may be called from low level interrupt handlers at some
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* point in future.
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*/
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raw_local_irq_save(*flags);
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hard_irq_disable(); /* Make it soft-NMI safe */
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while (unlikely(test_and_set_bit_lock(0, &__wd_smp_lock))) {
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raw_local_irq_restore(*flags);
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spin_until_cond(!test_bit(0, &__wd_smp_lock));
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raw_local_irq_save(*flags);
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hard_irq_disable();
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}
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}
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static inline void wd_smp_unlock(unsigned long *flags)
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{
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clear_bit_unlock(0, &__wd_smp_lock);
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raw_local_irq_restore(*flags);
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}
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static void wd_lockup_ipi(struct pt_regs *regs)
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{
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pr_emerg("Watchdog CPU:%d Hard LOCKUP\n", raw_smp_processor_id());
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print_modules();
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print_irqtrace_events(current);
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if (regs)
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show_regs(regs);
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else
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dump_stack();
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if (hardlockup_panic)
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nmi_panic(regs, "Hard LOCKUP");
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}
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static void set_cpumask_stuck(const struct cpumask *cpumask, u64 tb)
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{
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cpumask_or(&wd_smp_cpus_stuck, &wd_smp_cpus_stuck, cpumask);
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cpumask_andnot(&wd_smp_cpus_pending, &wd_smp_cpus_pending, cpumask);
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if (cpumask_empty(&wd_smp_cpus_pending)) {
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wd_smp_last_reset_tb = tb;
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cpumask_andnot(&wd_smp_cpus_pending,
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&wd_cpus_enabled,
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&wd_smp_cpus_stuck);
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}
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}
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static void set_cpu_stuck(int cpu, u64 tb)
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{
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set_cpumask_stuck(cpumask_of(cpu), tb);
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}
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static void watchdog_smp_panic(int cpu, u64 tb)
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{
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unsigned long flags;
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int c;
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wd_smp_lock(&flags);
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/* Double check some things under lock */
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if ((s64)(tb - wd_smp_last_reset_tb) < (s64)wd_smp_panic_timeout_tb)
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goto out;
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if (cpumask_test_cpu(cpu, &wd_smp_cpus_pending))
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goto out;
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if (cpumask_weight(&wd_smp_cpus_pending) == 0)
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goto out;
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pr_emerg("Watchdog CPU:%d detected Hard LOCKUP other CPUS:%*pbl\n",
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cpu, cpumask_pr_args(&wd_smp_cpus_pending));
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/*
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* Try to trigger the stuck CPUs.
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*/
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for_each_cpu(c, &wd_smp_cpus_pending) {
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if (c == cpu)
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continue;
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smp_send_nmi_ipi(c, wd_lockup_ipi, 1000000);
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}
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smp_flush_nmi_ipi(1000000);
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/* Take the stuck CPUs out of the watch group */
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set_cpumask_stuck(&wd_smp_cpus_pending, tb);
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wd_smp_unlock(&flags);
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printk_safe_flush();
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/*
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* printk_safe_flush() seems to require another print
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* before anything actually goes out to console.
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*/
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if (sysctl_hardlockup_all_cpu_backtrace)
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trigger_allbutself_cpu_backtrace();
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if (hardlockup_panic)
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nmi_panic(NULL, "Hard LOCKUP");
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return;
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out:
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wd_smp_unlock(&flags);
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}
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static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
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{
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if (!cpumask_test_cpu(cpu, &wd_smp_cpus_pending)) {
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if (unlikely(cpumask_test_cpu(cpu, &wd_smp_cpus_stuck))) {
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unsigned long flags;
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pr_emerg("Watchdog CPU:%d became unstuck\n", cpu);
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wd_smp_lock(&flags);
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cpumask_clear_cpu(cpu, &wd_smp_cpus_stuck);
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wd_smp_unlock(&flags);
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}
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return;
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}
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cpumask_clear_cpu(cpu, &wd_smp_cpus_pending);
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if (cpumask_empty(&wd_smp_cpus_pending)) {
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unsigned long flags;
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wd_smp_lock(&flags);
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if (cpumask_empty(&wd_smp_cpus_pending)) {
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wd_smp_last_reset_tb = tb;
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cpumask_andnot(&wd_smp_cpus_pending,
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&wd_cpus_enabled,
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&wd_smp_cpus_stuck);
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}
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wd_smp_unlock(&flags);
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}
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}
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static void watchdog_timer_interrupt(int cpu)
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{
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u64 tb = get_tb();
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per_cpu(wd_timer_tb, cpu) = tb;
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wd_smp_clear_cpu_pending(cpu, tb);
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if ((s64)(tb - wd_smp_last_reset_tb) >= (s64)wd_smp_panic_timeout_tb)
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watchdog_smp_panic(cpu, tb);
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}
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void soft_nmi_interrupt(struct pt_regs *regs)
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{
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unsigned long flags;
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int cpu = raw_smp_processor_id();
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u64 tb;
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if (!cpumask_test_cpu(cpu, &wd_cpus_enabled))
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return;
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nmi_enter();
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__this_cpu_inc(irq_stat.soft_nmi_irqs);
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tb = get_tb();
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if (tb - per_cpu(wd_timer_tb, cpu) >= wd_panic_timeout_tb) {
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per_cpu(wd_timer_tb, cpu) = tb;
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wd_smp_lock(&flags);
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if (cpumask_test_cpu(cpu, &wd_smp_cpus_stuck)) {
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wd_smp_unlock(&flags);
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goto out;
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}
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set_cpu_stuck(cpu, tb);
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pr_emerg("Watchdog CPU:%d Hard LOCKUP\n", cpu);
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print_modules();
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print_irqtrace_events(current);
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if (regs)
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show_regs(regs);
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else
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dump_stack();
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wd_smp_unlock(&flags);
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if (sysctl_hardlockup_all_cpu_backtrace)
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trigger_allbutself_cpu_backtrace();
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if (hardlockup_panic)
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nmi_panic(regs, "Hard LOCKUP");
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}
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if (wd_panic_timeout_tb < 0x7fffffff)
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mtspr(SPRN_DEC, wd_panic_timeout_tb);
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out:
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nmi_exit();
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}
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static void wd_timer_reset(unsigned int cpu, struct timer_list *t)
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{
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t->expires = jiffies + msecs_to_jiffies(wd_timer_period_ms);
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if (wd_timer_period_ms > 1000)
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t->expires = __round_jiffies_up(t->expires, cpu);
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add_timer_on(t, cpu);
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}
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static void wd_timer_fn(unsigned long data)
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{
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struct timer_list *t = this_cpu_ptr(&wd_timer);
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int cpu = smp_processor_id();
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watchdog_timer_interrupt(cpu);
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wd_timer_reset(cpu, t);
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}
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void arch_touch_nmi_watchdog(void)
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{
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unsigned long ticks = tb_ticks_per_usec * wd_timer_period_ms * 1000;
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int cpu = smp_processor_id();
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if (get_tb() - per_cpu(wd_timer_tb, cpu) >= ticks)
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watchdog_timer_interrupt(cpu);
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}
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EXPORT_SYMBOL(arch_touch_nmi_watchdog);
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static void start_watchdog_timer_on(unsigned int cpu)
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{
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struct timer_list *t = per_cpu_ptr(&wd_timer, cpu);
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per_cpu(wd_timer_tb, cpu) = get_tb();
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setup_pinned_timer(t, wd_timer_fn, 0);
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wd_timer_reset(cpu, t);
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}
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static void stop_watchdog_timer_on(unsigned int cpu)
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{
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struct timer_list *t = per_cpu_ptr(&wd_timer, cpu);
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del_timer_sync(t);
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}
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static int start_wd_on_cpu(unsigned int cpu)
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{
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unsigned long flags;
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if (cpumask_test_cpu(cpu, &wd_cpus_enabled)) {
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WARN_ON(1);
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return 0;
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}
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if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
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return 0;
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if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
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return 0;
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wd_smp_lock(&flags);
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cpumask_set_cpu(cpu, &wd_cpus_enabled);
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if (cpumask_weight(&wd_cpus_enabled) == 1) {
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cpumask_set_cpu(cpu, &wd_smp_cpus_pending);
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wd_smp_last_reset_tb = get_tb();
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}
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wd_smp_unlock(&flags);
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start_watchdog_timer_on(cpu);
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return 0;
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}
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static int stop_wd_on_cpu(unsigned int cpu)
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{
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unsigned long flags;
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if (!cpumask_test_cpu(cpu, &wd_cpus_enabled))
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return 0; /* Can happen in CPU unplug case */
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stop_watchdog_timer_on(cpu);
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wd_smp_lock(&flags);
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cpumask_clear_cpu(cpu, &wd_cpus_enabled);
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wd_smp_unlock(&flags);
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wd_smp_clear_cpu_pending(cpu, get_tb());
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return 0;
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}
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static void watchdog_calc_timeouts(void)
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{
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wd_panic_timeout_tb = watchdog_thresh * ppc_tb_freq;
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/* Have the SMP detector trigger a bit later */
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wd_smp_panic_timeout_tb = wd_panic_timeout_tb * 3 / 2;
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/* 2/5 is the factor that the perf based detector uses */
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wd_timer_period_ms = watchdog_thresh * 1000 * 2 / 5;
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}
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void watchdog_nmi_stop(void)
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{
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int cpu;
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for_each_cpu(cpu, &wd_cpus_enabled)
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stop_wd_on_cpu(cpu);
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}
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void watchdog_nmi_start(void)
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{
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int cpu;
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watchdog_calc_timeouts();
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for_each_cpu_and(cpu, cpu_online_mask, &watchdog_cpumask)
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start_wd_on_cpu(cpu);
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}
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/*
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* Invoked from core watchdog init.
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*/
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int __init watchdog_nmi_probe(void)
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{
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int err;
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err = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
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"powerpc/watchdog:online",
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start_wd_on_cpu, stop_wd_on_cpu);
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if (err < 0) {
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pr_warn("Watchdog could not be initialized");
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return err;
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}
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return 0;
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}
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static void handle_backtrace_ipi(struct pt_regs *regs)
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{
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nmi_cpu_backtrace(regs);
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}
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static void raise_backtrace_ipi(cpumask_t *mask)
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{
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unsigned int cpu;
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for_each_cpu(cpu, mask) {
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if (cpu == smp_processor_id())
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handle_backtrace_ipi(NULL);
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else
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smp_send_nmi_ipi(cpu, handle_backtrace_ipi, 1000000);
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}
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}
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void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
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{
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nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
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}
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