* [PATCH] ftrace/arm: add save_stack_trace_regs() implementation
@ 2014-04-23 12:52 Lin Yongting
2014-04-23 13:03 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Lin Yongting @ 2014-04-23 12:52 UTC (permalink / raw)
To: linux, rostedt, k.khlebnikov
Cc: linyongting, linux-arm-kernel, linux-kernel, linyongting
When configure kprobe events of ftrace with "stacktrace" option enabled
in arm, there is no stacktrace was recorded after the kprobe event was
triggered. The root cause is no save_stack_trace_regs() function implemented.
Implement the save_stack_trace_regs() function in arm, then ftrace will
call this architecture-related function to record the stacktrace into
ring buffer.
After this fix, stacktrace can be recorded, for example:
# mount -t debugfs nodev /sys/kernel/debug
# echo "p:netrx net_rx_action" >> /sys/kernel/debug/tracing/kprobe_events
# echo 1 > /sys/kernel/debug/tracing/events/kprobes/netrx/enable
# echo 1 > /sys/kernel/debug/tracing/options/stacktrace
# echo 1 > /sys/kernel/debug/tracing/tracing_on
# ping 127.0.0.1 -c 1
# echo 0 > /sys/kernel/debug/tracing/tracing_on
# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
# entries-in-buffer/entries-written: 12/12 #P:1
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
<------ missing some entries ---------------->
ping-1200 [000] dNs1 667.603250: netrx: (net_rx_action+0x0/0x1f8)
ping-1200 [000] dNs1 667.604738: <stack trace>
=> net_rx_action
=> do_softirq
=> local_bh_enable
=> ip_finish_output
=> ip_output
=> ip_local_out
=> ip_send_skb
=> ip_push_pending_frames
=> raw_sendmsg
=> inet_sendmsg
=> sock_sendmsg
=> SyS_sendto
=> ret_fast_syscall
Signed-off-by: Lin Yongting <linyongting@gmail.com>
---
arch/arm/kernel/stacktrace.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index af4e8c8..c558db6 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -123,6 +123,25 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
+void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+ struct stack_trace_data data;
+ struct stackframe frame;
+
+ data.trace = trace;
+ data.skip = trace->skip;
+ data.no_sched_functions = 0;
+
+ frame.fp = regs->ARM_fp;
+ frame.sp = regs->ARM_sp;
+ frame.lr = regs->ARM_lr;
+ frame.pc = regs->ARM_pc;
+
+ walk_stackframe(&frame, save_trace, &data);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
void save_stack_trace(struct stack_trace *trace)
{
save_stack_trace_tsk(current, trace);
--
1.7.9.5
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] ftrace/arm: add save_stack_trace_regs() implementation
2014-04-23 12:52 [PATCH] ftrace/arm: add save_stack_trace_regs() implementation Lin Yongting
@ 2014-04-23 13:03 ` Steven Rostedt
2014-04-27 4:15 ` ivan lin
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2014-04-23 13:03 UTC (permalink / raw)
To: Lin Yongting
Cc: linux, k.khlebnikov, linux-arm-kernel, linux-kernel, linyongting
On Wed, 23 Apr 2014 20:52:21 +0800
Lin Yongting <linyongting@gmail.com> wrote:
> When configure kprobe events of ftrace with "stacktrace" option enabled
> in arm, there is no stacktrace was recorded after the kprobe event was
> triggered. The root cause is no save_stack_trace_regs() function implemented.
>
> Implement the save_stack_trace_regs() function in arm, then ftrace will
> call this architecture-related function to record the stacktrace into
> ring buffer.
>
> After this fix, stacktrace can be recorded, for example:
>
> # mount -t debugfs nodev /sys/kernel/debug
> # echo "p:netrx net_rx_action" >> /sys/kernel/debug/tracing/kprobe_events
> # echo 1 > /sys/kernel/debug/tracing/events/kprobes/netrx/enable
> # echo 1 > /sys/kernel/debug/tracing/options/stacktrace
> # echo 1 > /sys/kernel/debug/tracing/tracing_on
> # ping 127.0.0.1 -c 1
> # echo 0 > /sys/kernel/debug/tracing/tracing_on
>
> # cat /sys/kernel/debug/tracing/trace
> # tracer: nop
> #
> # entries-in-buffer/entries-written: 12/12 #P:1
> #
> # _-----=> irqs-off
> # / _----=> need-resched
> # | / _---=> hardirq/softirq
> # || / _--=> preempt-depth
> # ||| / delay
> # TASK-PID CPU# |||| TIMESTAMP FUNCTION
> # | | | |||| | |
> <------ missing some entries ---------------->
> ping-1200 [000] dNs1 667.603250: netrx: (net_rx_action+0x0/0x1f8)
> ping-1200 [000] dNs1 667.604738: <stack trace>
> => net_rx_action
> => do_softirq
> => local_bh_enable
> => ip_finish_output
> => ip_output
> => ip_local_out
> => ip_send_skb
> => ip_push_pending_frames
> => raw_sendmsg
> => inet_sendmsg
> => sock_sendmsg
> => SyS_sendto
> => ret_fast_syscall
>
> Signed-off-by: Lin Yongting <linyongting@gmail.com>
> ---
As this affects ftrace for ARM...
Acked-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> arch/arm/kernel/stacktrace.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
> index af4e8c8..c558db6 100644
> --- a/arch/arm/kernel/stacktrace.c
> +++ b/arch/arm/kernel/stacktrace.c
> @@ -123,6 +123,25 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
> trace->entries[trace->nr_entries++] = ULONG_MAX;
> }
>
> +void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
> +{
> + struct stack_trace_data data;
> + struct stackframe frame;
> +
> + data.trace = trace;
> + data.skip = trace->skip;
> + data.no_sched_functions = 0;
> +
> + frame.fp = regs->ARM_fp;
> + frame.sp = regs->ARM_sp;
> + frame.lr = regs->ARM_lr;
> + frame.pc = regs->ARM_pc;
> +
> + walk_stackframe(&frame, save_trace, &data);
> + if (trace->nr_entries < trace->max_entries)
> + trace->entries[trace->nr_entries++] = ULONG_MAX;
> +}
> +
> void save_stack_trace(struct stack_trace *trace)
> {
> save_stack_trace_tsk(current, trace);
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] ftrace/arm: add save_stack_trace_regs() implementation
2014-04-23 13:03 ` Steven Rostedt
@ 2014-04-27 4:15 ` ivan lin
0 siblings, 0 replies; 3+ messages in thread
From: ivan lin @ 2014-04-27 4:15 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: k.khlebnikov, linux-arm-kernel, linux-kernel, Linyongting,
Steven Rostedt
2014-04-23 21:03 GMT+08:00 Steven Rostedt <rostedt@goodmis.org>:
> On Wed, 23 Apr 2014 20:52:21 +0800
> Lin Yongting <linyongting@gmail.com> wrote:
>
>> When configure kprobe events of ftrace with "stacktrace" option enabled
>> in arm, there is no stacktrace was recorded after the kprobe event was
>> triggered. The root cause is no save_stack_trace_regs() function implemented.
>>
>> Implement the save_stack_trace_regs() function in arm, then ftrace will
>> call this architecture-related function to record the stacktrace into
>> ring buffer.
>>
>> After this fix, stacktrace can be recorded, for example:
>>
>> # mount -t debugfs nodev /sys/kernel/debug
>> # echo "p:netrx net_rx_action" >> /sys/kernel/debug/tracing/kprobe_events
>> # echo 1 > /sys/kernel/debug/tracing/events/kprobes/netrx/enable
>> # echo 1 > /sys/kernel/debug/tracing/options/stacktrace
>> # echo 1 > /sys/kernel/debug/tracing/tracing_on
>> # ping 127.0.0.1 -c 1
>> # echo 0 > /sys/kernel/debug/tracing/tracing_on
>>
>> # cat /sys/kernel/debug/tracing/trace
>> # tracer: nop
>> #
>> # entries-in-buffer/entries-written: 12/12 #P:1
>> #
>> # _-----=> irqs-off
>> # / _----=> need-resched
>> # | / _---=> hardirq/softirq
>> # || / _--=> preempt-depth
>> # ||| / delay
>> # TASK-PID CPU# |||| TIMESTAMP FUNCTION
>> # | | | |||| | |
>> <------ missing some entries ---------------->
>> ping-1200 [000] dNs1 667.603250: netrx: (net_rx_action+0x0/0x1f8)
>> ping-1200 [000] dNs1 667.604738: <stack trace>
>> => net_rx_action
>> => do_softirq
>> => local_bh_enable
>> => ip_finish_output
>> => ip_output
>> => ip_local_out
>> => ip_send_skb
>> => ip_push_pending_frames
>> => raw_sendmsg
>> => inet_sendmsg
>> => sock_sendmsg
>> => SyS_sendto
>> => ret_fast_syscall
>>
>> Signed-off-by: Lin Yongting <linyongting@gmail.com>
>> ---
>
> As this affects ftrace for ARM...
>
> Acked-by: Steven Rostedt <rostedt@goodmis.org>
>
> -- Steve
>
Hi Russell
How about my Patch? any advice is appreciate。
Best Regards!
-- Yongting.
>> arch/arm/kernel/stacktrace.c | 19 +++++++++++++++++++
>> 1 file changed, 19 insertions(+)
>>
>> diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
>> index af4e8c8..c558db6 100644
>> --- a/arch/arm/kernel/stacktrace.c
>> +++ b/arch/arm/kernel/stacktrace.c
>> @@ -123,6 +123,25 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
>> trace->entries[trace->nr_entries++] = ULONG_MAX;
>> }
>>
>> +void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
>> +{
>> + struct stack_trace_data data;
>> + struct stackframe frame;
>> +
>> + data.trace = trace;
>> + data.skip = trace->skip;
>> + data.no_sched_functions = 0;
>> +
>> + frame.fp = regs->ARM_fp;
>> + frame.sp = regs->ARM_sp;
>> + frame.lr = regs->ARM_lr;
>> + frame.pc = regs->ARM_pc;
>> +
>> + walk_stackframe(&frame, save_trace, &data);
>> + if (trace->nr_entries < trace->max_entries)
>> + trace->entries[trace->nr_entries++] = ULONG_MAX;
>> +}
>> +
>> void save_stack_trace(struct stack_trace *trace)
>> {
>> save_stack_trace_tsk(current, trace);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-04-27 4:15 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2014-04-23 12:52 [PATCH] ftrace/arm: add save_stack_trace_regs() implementation Lin Yongting
2014-04-23 13:03 ` Steven Rostedt
2014-04-27 4:15 ` ivan lin
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