diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-10-15 23:55:07 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-02-11 16:31:57 -0500 |
| commit | efbbdaa22bb78761bff8dfdde027ad04bedd47ce (patch) | |
| tree | 71624da3d658aefa36ec8b02e153e0a727cee735 /include | |
| parent | 7d5367539ae902a9208c5918e21b0f89e5feb29c (diff) | |
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 <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/trace_events.h | 4 | ||||
| -rw-r--r-- | include/trace/trace_events.h | 2 |
2 files changed, 5 insertions, 1 deletions
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; diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index 7785961d82ba..e6a8b3febc49 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -364,7 +364,7 @@ trace_raw_output_##call(struct trace_iterator *iter, int flags, \ if (ret != TRACE_TYPE_HANDLED) \ return ret; \ \ - trace_seq_printf(s, print); \ + trace_event_printf(iter, print); \ \ return trace_handle_return(s); \ } \ |