01f36a554e
trace_printk schedules work via irq_work_queue(), but doesn't
wait until it was processed. The kprobe_module.tc testcase does:
:;: "Load module again, which means the event1 should be recorded";:
modprobe trace-printk
grep "event1:" trace
so the grep which checks the trace file might run before the irq work
was processed. Fix this by adding a irq_work_sync().
Link: http://lore.kernel.org/linux-trace-devel/20191218074427.96184-3-svens@linux.ibm.com
Cc: stable@vger.kernel.org
Fixes: af2a0750f3 ("selftests/ftrace: Improve kprobe on module testcase to load/unload module")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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#include <linux/kthread.h>
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#include <linux/irq_work.h>
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/* Must not be static to force gcc to consider these non constant */
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char *trace_printk_test_global_str =
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"This is a dynamic string that will use trace_puts\n";
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char *trace_printk_test_global_str_irq =
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"(irq) This is a dynamic string that will use trace_puts\n";
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char *trace_printk_test_global_str_fmt =
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"%sThis is a %s that will use trace_printk\n";
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static struct irq_work irqwork;
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static void trace_printk_irq_work(struct irq_work *work)
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{
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trace_printk("(irq) This is a static string that will use trace_bputs\n");
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trace_printk(trace_printk_test_global_str_irq);
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trace_printk("(irq) This is a %s that will use trace_bprintk()\n",
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"static string");
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trace_printk(trace_printk_test_global_str_fmt,
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"(irq) ", "dynamic string");
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}
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static int __init trace_printk_init(void)
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{
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init_irq_work(&irqwork, trace_printk_irq_work);
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trace_printk("This is a static string that will use trace_bputs\n");
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trace_printk(trace_printk_test_global_str);
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/* Kick off printing in irq context */
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irq_work_queue(&irqwork);
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irq_work_sync(&irqwork);
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trace_printk("This is a %s that will use trace_bprintk()\n",
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"static string");
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trace_printk(trace_printk_test_global_str_fmt, "", "dynamic string");
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return 0;
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}
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static void __exit trace_printk_exit(void)
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{
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}
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module_init(trace_printk_init);
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module_exit(trace_printk_exit);
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MODULE_AUTHOR("Steven Rostedt");
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MODULE_DESCRIPTION("trace-printk");
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MODULE_LICENSE("GPL");
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