From f11b3f4e2932bfdcfc458ab8d1ece62724ceabfc Mon Sep 17 00:00:00 2001 From: walimis Date: Wed, 3 Jun 2009 16:01:29 +0800 Subject: [PATCH] tracing/events: fix output format of kernel stack According to "events/ftrace/kernel_stack/format", output format of kernel stack should use "=>" instead of "<=". The second problem is that we shouldn't skip the first entry in the stack, although it seems to be duplicated when used in the "function" tracer, but events also use it. If we skip the first one, we will drop the topmost entry of the stack. The last problem is that if the last entry is ULONG_MAX(0xffffffff), we should drop it, otherwise it will print a NULL name line. before fix: sh-1072 [000] 26.957239: sched_process_fork: parent sh:1072 child sh:1073 sh-1072 [000] 26.957262: <= syscall_call <= sh-1072 [000] 26.957744: sched_switch: task sh:1072 [120] (R) ==> sh:1073 [120] sh-1072 [000] 26.957752: <= preempt_schedule <= wake_up_new_task <= do_fork <= sys_clone <= syscall_call <= After fix: sh-1075 [000] 39.791848: sched_process_fork: parent sh:1075 child sh:1076 sh-1075 [000] 39.791871: => sys_clone => syscall_call sh-1075 [000] 39.792713: sched_switch: task sh:1075 [120] (R) ==> sh:1076 [120] sh-1075 [000] 39.792722: => schedule => preempt_schedule => wake_up_new_task => do_fork => sys_clone => syscall_call Signed-off-by: walimis LKML-Reference: <1244016090-7814-2-git-send-email-walimisdev@gmail.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_output.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 0fe3b223f7ed..64596a571609 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -975,16 +975,16 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter, trace_assign_type(field, iter->ent); + if (!trace_seq_puts(s, "\n")) + goto partial; for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { - if (!field->caller[i]) + if (!field->caller[i] || (field->caller[i] == ULONG_MAX)) break; - if (i) { - if (!trace_seq_puts(s, " <= ")) - goto partial; + if (!trace_seq_puts(s, " => ")) + goto partial; - if (!seq_print_ip_sym(s, field->caller[i], flags)) - goto partial; - } + if (!seq_print_ip_sym(s, field->caller[i], flags)) + goto partial; if (!trace_seq_puts(s, "\n")) goto partial; } -- 2.39.2