From: ivan lam <ivan.lam2...@gmail.com> Date: Mon, 4 Nov 2013 23:35:55 +0800 Subject: [PATCH] arm: add save_stack_trace_regs() support
When configure kprobe events of ftrace with stacktrace option enabled in arm, not stacktrace was recorded after the kprobe was triggered. Implement the save_stack_trace_regs() function in arm. 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 # | | | |||| | | 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: ivan lam <ivan.lam2...@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 00f79e5..2b52fac0 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 = 1; + + 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/