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| author | Steven Rostedt <rostedt@goodmis.org> | 2025-02-08 00:15:11 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-17 10:05:40 +0100 |
| commit | 39603bb38cf1d427c78cb218376c61d3112a658d (patch) | |
| tree | 915b44105bbe4726af6dc70f323d042f5fe299e4 /kernel/trace | |
| parent | 2ae4bade5a64d126bd18eb66bd419005c5550218 (diff) | |
| download | linux-39603bb38cf1d427c78cb218376c61d3112a658d.tar.gz linux-39603bb38cf1d427c78cb218376c61d3112a658d.tar.bz2 linux-39603bb38cf1d427c78cb218376c61d3112a658d.zip | |
fgraph: Fix set_graph_notrace with setting TRACE_GRAPH_NOTRACE_BIT
commit c8c9b1d2d5b4377c72a979f5a26e842a869aefc9 upstream.
The code was restructured where the function graph notrace code, that
would not trace a function and all its children is done by setting a
NOTRACE flag when the function that is not to be traced is hit.
There's a TRACE_GRAPH_NOTRACE_BIT which defines the bit in the flags and a
TRACE_GRAPH_NOTRACE which is the mask with that bit set. But the
restructuring used TRACE_GRAPH_NOTRACE_BIT when it should have used
TRACE_GRAPH_NOTRACE.
For example:
# cd /sys/kernel/tracing
# echo set_track_prepare stack_trace_save > set_graph_notrace
# echo function_graph > current_tracer
# cat trace
[..]
0) | __slab_free() {
0) | free_to_partial_list() {
0) | arch_stack_walk() {
0) | __unwind_start() {
0) 0.501 us | get_stack_info();
Where a non filter trace looks like:
# echo > set_graph_notrace
# cat trace
0) | free_to_partial_list() {
0) | set_track_prepare() {
0) | stack_trace_save() {
0) | arch_stack_walk() {
0) | __unwind_start() {
Where the filter should look like:
# cat trace
0) | free_to_partial_list() {
0) | _raw_spin_lock_irqsave() {
0) 0.350 us | preempt_count_add();
0) 0.351 us | do_raw_spin_lock();
0) 2.440 us | }
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250208001511.535be150@batman.local.home
Fixes: b84214890a9bc ("function_graph: Move graph notrace bit to shadow stack global var")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index a569daaac4c4..ebb61ddca749 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -150,7 +150,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace, * returning from the function. */ if (ftrace_graph_notrace_addr(trace->func)) { - *task_var |= TRACE_GRAPH_NOTRACE_BIT; + *task_var |= TRACE_GRAPH_NOTRACE; /* * Need to return 1 to have the return called * that will clear the NOTRACE bit. |