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	Commitcac5cefbad("sched/smp: Make SMP unconditional") migrate_disable() even on UP builds. Commit06ddd17521("sched/smp: Always define is_percpu_thread() and scheduler_ipi()") made is_percpu_thread() check the affinity mask instead replying always true for UP mask. As a consequence smp_processor_id() now complains if invoked within a migrate_disable() section because is_percpu_thread() checks its mask and the migration check is left out. Make migration check unconditional of SMP. Fixes:cac5cefbad("sched/smp: Make SMP unconditional") Closes: https://lore.kernel.org/oe-lkp/202507100448.6b88d6f1-lkp@intel.com Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chen Yu <yu.c.chen@intel.com> Link: https://lore.kernel.org/r/20250710082748.-DPO1rjO@linutronix.de
		
			
				
	
	
		
			66 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			66 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * lib/smp_processor_id.c
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 *
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 * DEBUG_PREEMPT variant of smp_processor_id().
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 */
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#include <linux/export.h>
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#include <linux/kprobes.h>
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#include <linux/sched.h>
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noinstr static
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unsigned int check_preemption_disabled(const char *what1, const char *what2)
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{
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	int this_cpu = raw_smp_processor_id();
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	if (likely(preempt_count()))
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		goto out;
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	if (irqs_disabled())
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		goto out;
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	if (is_percpu_thread())
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		goto out;
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	if (current->migration_disabled)
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		goto out;
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	/*
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	 * It is valid to assume CPU-locality during early bootup:
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	 */
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	if (system_state < SYSTEM_SCHEDULING)
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		goto out;
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	/*
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	 * Avoid recursion:
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	 */
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	preempt_disable_notrace();
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	instrumentation_begin();
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	if (!printk_ratelimit())
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		goto out_enable;
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	printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
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		what1, what2, preempt_count() - 1, current->comm, current->pid);
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	printk("caller is %pS\n", __builtin_return_address(0));
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	dump_stack();
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out_enable:
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	instrumentation_end();
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	preempt_enable_no_resched_notrace();
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out:
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	return this_cpu;
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}
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noinstr unsigned int debug_smp_processor_id(void)
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{
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	return check_preemption_disabled("smp_processor_id", "");
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}
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EXPORT_SYMBOL(debug_smp_processor_id);
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noinstr void __this_cpu_preempt_check(const char *op)
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{
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	check_preemption_disabled("__this_cpu_", op);
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}
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EXPORT_SYMBOL(__this_cpu_preempt_check);
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