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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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bd27acaac2
Currently instrumentation_end() won't be called if printk_ratelimit()
returned false.
Link: https://lkml.kernel.org/r/a636d8e0-ad32-5888-acac-671f7f553bb3@I-love.SAKURA.ne.jp
Fixes: 126f21f0e8 ("lib/smp_processor_id: Move it into noinstr section")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
69 lines
1.4 KiB
C
69 lines
1.4 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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#ifdef CONFIG_SMP
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if (current->migration_disabled)
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goto out;
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#endif
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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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