Commit e0115875 authored Jan 29, 2016 by Pratyush Anand Committed by Martin Schwidefsky Feb 10, 2016

s390/stacktrace: add save_stack_trace_regs()



Implement save_stack_trace_regs, so that a stack trace of a kprobe
event can be obtained.

Without this we see following warning:
"save_stack_trace_regs() not implemented yet."
when we execute:
echo stacktrace > /sys/kernel/debug/tracing/trace_options
echo "p kfree" >> /sys/kernel/debug/tracing/kprobe_events
echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable

Reported-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Pratyush Anand <panand@redhat.com>
[heiko.carstens@de.ibm.com]: changed patch to use __save_stack_trace()
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 66adce8f

arch/s390/kernel/stacktrace.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -103,3 +103,14 @@ void save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
		trace->entries[trace->nr_entries++] = ULONG_MAX;
		}
		EXPORT_SYMBOL_GPL(save_stack_trace_tsk);

		void save_stack_trace_regs(struct pt_regs regs, struct stack_trace trace)
		{
		unsigned long sp;

		sp = kernel_stack_pointer(regs);
		__save_stack_trace(trace, sp);
		if (trace->nr_entries < trace->max_entries)
		trace->entries[trace->nr_entries++] = ULONG_MAX;
		}
		EXPORT_SYMBOL_GPL(save_stack_trace_regs);

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