From efbbdaa22bb78761bff8dfdde027ad04bedd47ce Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 15 Oct 2020 23:55:07 +0900 Subject: tracing: Show real address for trace event arguments To help debugging kernel, show real address for trace event arguments in tracefs/trace{,pipe} instead of hashed pointer value. Since ftrace human-readable format uses vsprintf(), all %p are translated to hash values instead of pointer address. However, when debugging the kernel, raw address value gives a hint when comparing with the memory mapping in the kernel. (Those are sometimes used with crash log, which is not hashed too) So converting %p with %px when calling trace_seq_printf(). Moreover, this is not improving the security because the tracefs can be used only by root user and the raw address values are readable from tracefs/percpu/cpu*/trace_pipe_raw file. Link: https://lkml.kernel.org/r/160277370703.29307.5134475491761971203.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_output.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_output.c') diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 92b1575ae0ca..61255bad7e01 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -312,13 +312,23 @@ int trace_raw_output_prep(struct trace_iterator *iter, } EXPORT_SYMBOL(trace_raw_output_prep); +void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + trace_seq_vprintf(&iter->seq, trace_event_format(iter, fmt), ap); + va_end(ap); +} +EXPORT_SYMBOL(trace_event_printf); + static int trace_output_raw(struct trace_iterator *iter, char *name, char *fmt, va_list ap) { struct trace_seq *s = &iter->seq; trace_seq_printf(s, "%s: ", name); - trace_seq_vprintf(s, fmt, ap); + trace_seq_vprintf(s, trace_event_format(iter, fmt), ap); return trace_handle_return(s); } -- cgit v1.2.3