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) --- include/linux/trace_events.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/trace_events.h') diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 5d1eeac4bfbe..7077fec653bb 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -55,6 +55,8 @@ struct trace_event; int trace_raw_output_prep(struct trace_iterator *iter, struct trace_event *event); +extern __printf(2, 3) +void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...); /* * The trace entry - the most basic unit of tracing. This is what @@ -87,6 +89,8 @@ struct trace_iterator { unsigned long iter_flags; void *temp; /* temp holder */ unsigned int temp_size; + char *fmt; /* modified format holder */ + unsigned int fmt_size; /* trace_seq for __print_flags() and __print_symbolic() etc. */ struct trace_seq tmp_seq; -- cgit v1.2.3