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From: Pratyush Anand <panand@redhat.com>
To: schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com
Cc: rostedt@goodmis.org, linux-s390@vger.kernel.org,
	Pratyush Anand <panand@redhat.com>, Chunyu Hu <chuhu@redhat.com>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] s390:ftrace: add save_stack_trace_regs()
Date: Fri, 29 Jan 2016 10:50:28 +0530	[thread overview]
Message-ID: <86d380d172bba0416aef64448b0e1b6a50fad326.1454044645.git.panand@redhat.com> (raw)

Implement save_stack_trace_regs, so that stacktrace of a kprobe events 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>
---
 arch/s390/kernel/stacktrace.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 1785cd82253c..586da400f931 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -94,3 +94,16 @@ 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, low, high;
+
+	sp = kernel_stack_pointer(regs);
+	low = (unsigned long) task_stack_page(current);
+	high = (unsigned long) task_pt_regs(current);
+	save_context_stack(trace, sp, low, high, 0);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);
-- 
2.5.0

             reply	other threads:[~2016-01-29  5:20 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-29  5:20 Pratyush Anand [this message]
2016-01-29  8:54 ` [PATCH] s390:ftrace: add save_stack_trace_regs() Heiko Carstens
2016-01-29 12:57   ` Heiko Carstens
2016-01-29 13:59     ` Steven Rostedt
2016-01-29 14:45       ` Heiko Carstens
2016-01-29 15:22         ` Steven Rostedt
2016-01-29 16:49           ` Heiko Carstens
2016-01-29 16:56             ` Steven Rostedt
2016-01-29 17:12               ` Heiko Carstens
2016-02-01  9:00 ` Heiko Carstens

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