diff options
| author | Shengming Hu <hu.shengming@zte.com.cn> | 2026-02-21 11:33:14 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:15:18 +0100 |
| commit | 259dc5b4f8d88d25ef601bce0d3c1ad30921e030 (patch) | |
| tree | c7bf3f95e0d72bda9fd79c21e0dd739b0565d408 | |
| parent | 080b0e210088296dd50d6637c06c1db14246adfe (diff) | |
fgraph: Fix thresh_return nosleeptime double-adjust
commit b96d0c59cdbb2a22b2545f6f3d5c6276b05761dd upstream.
trace_graph_thresh_return() called handle_nosleeptime() and then delegated
to trace_graph_return(), which calls handle_nosleeptime() again. When
sleep-time accounting is disabled this double-adjusts calltime and can
produce bogus durations (including underflow).
Fix this by computing rettime once, applying handle_nosleeptime() only
once, using the adjusted calltime for threshold comparison, and writing
the return event directly via __trace_graph_return() when the threshold is
met.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260221113314048jE4VRwIyZEALiYByGK0My@zte.com.cn
Fixes: 3c9880f3ab52b ("ftrace: Use a running sleeptime instead of saving on shadow stack")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index cbe43680c9d4..b9c81fbd98dc 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -403,8 +403,12 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, unsigned long *task_var = fgraph_get_task_var(gops); struct fgraph_times *ftimes; struct trace_array *tr; + unsigned int trace_ctx; + u64 calltime, rettime; int size; + rettime = trace_clock_local(); + ftrace_graph_addr_finish(gops, trace); if (*task_var & TRACE_GRAPH_NOTRACE) { @@ -419,11 +423,13 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, tr = gops->private; handle_nosleeptime(tr, trace, ftimes, size); - if (tracing_thresh && - (trace_clock_local() - ftimes->calltime < tracing_thresh)) + calltime = ftimes->calltime; + + if (tracing_thresh && (rettime - calltime < tracing_thresh)) return; - else - trace_graph_return(trace, gops, fregs); + + trace_ctx = tracing_gen_ctx(); + __trace_graph_return(tr, trace, trace_ctx, calltime, rettime); } static struct fgraph_ops funcgraph_ops = { |