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ftrace/function_graph: Pass fgraph_ops to function graph callbacks
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Pass the fgraph_ops structure to the function graph callbacks. This will
allow callbacks to add a descriptor to a fgraph_ops private field that wil
be added in the future and use it for the callbacks. This will be useful
when more than one callback can be registered to the function graph tracer.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509098588.162236.4787930115997357578.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.035147698@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Steven Rostedt (VMware) committed Jun 4, 2024
1 parent 2fbb549 commit 37238ab
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Showing 8 changed files with 40 additions and 24 deletions.
10 changes: 7 additions & 3 deletions include/linux/ftrace.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1027,11 +1027,15 @@ struct ftrace_graph_ret {
unsigned long long rettime;
} __packed;

struct fgraph_ops;

/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *,
struct fgraph_ops *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
struct fgraph_ops *); /* entry */

extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

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16 changes: 9 additions & 7 deletions kernel/trace/fgraph.c
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Original file line number Diff line number Diff line change
Expand Up @@ -164,13 +164,13 @@ set_bitmap(struct task_struct *t, int offset, unsigned long bitmap)
}

/* ftrace_graph_entry set to this to tell some archs to run function graph */
static int entry_run(struct ftrace_graph_ent *trace)
static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops)
{
return 0;
}

/* ftrace_graph_return set to this to tell some archs to run function graph */
static void return_run(struct ftrace_graph_ret *trace)
static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops)
{
}

Expand Down Expand Up @@ -234,12 +234,14 @@ int __weak ftrace_disable_ftrace_graph_caller(void)
}
#endif

int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
return 0;
}

static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace)
static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
}

Expand Down Expand Up @@ -379,7 +381,7 @@ int function_graph_enter(unsigned long ret, unsigned long func,
if (gops == &fgraph_stub)
continue;

if (gops->entryfunc(&trace))
if (gops->entryfunc(&trace, gops))
bitmap |= BIT(i);
}

Expand Down Expand Up @@ -527,7 +529,7 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs
if (gops == &fgraph_stub)
continue;

gops->retfunc(&trace);
gops->retfunc(&trace, gops);
}

/*
Expand Down Expand Up @@ -681,7 +683,7 @@ void ftrace_graph_sleep_time_control(bool enable)
* Simply points to ftrace_stub, but with the proper protocol.
* Defined by the linker script in linux/vmlinux.lds.h
*/
extern void ftrace_stub_graph(struct ftrace_graph_ret *);
void ftrace_stub_graph(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);

/* The callbacks that hook a function */
trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;
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6 changes: 4 additions & 2 deletions kernel/trace/ftrace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -815,7 +815,8 @@ void ftrace_graph_graph_time_control(bool enable)
fgraph_graph_time = enable;
}

static int profile_graph_entry(struct ftrace_graph_ent *trace)
static int profile_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
struct ftrace_ret_stack *ret_stack;

Expand All @@ -832,7 +833,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace)
return 1;
}

static void profile_graph_return(struct ftrace_graph_ret *trace)
static void profile_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
struct ftrace_ret_stack *ret_stack;
struct ftrace_profile_stat *stat;
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4 changes: 2 additions & 2 deletions kernel/trace/trace.h
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Original file line number Diff line number Diff line change
Expand Up @@ -679,8 +679,8 @@ void trace_latency_header(struct seq_file *m);
void trace_default_header(struct seq_file *m);
void print_trace_header(struct seq_file *m, struct trace_iterator *iter);

void trace_graph_return(struct ftrace_graph_ret *trace);
int trace_graph_entry(struct ftrace_graph_ent *trace);
void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
void set_graph_array(struct trace_array *tr);

void tracing_start_cmdline_record(void);
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11 changes: 7 additions & 4 deletions kernel/trace/trace_functions_graph.c
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Original file line number Diff line number Diff line change
Expand Up @@ -129,7 +129,8 @@ static inline int ftrace_graph_ignore_irqs(void)
return in_hardirq();
}

int trace_graph_entry(struct ftrace_graph_ent *trace)
int trace_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = graph_array;
struct trace_array_cpu *data;
Expand Down Expand Up @@ -238,7 +239,8 @@ void __trace_graph_return(struct trace_array *tr,
trace_buffer_unlock_commit_nostack(buffer, event);
}

void trace_graph_return(struct ftrace_graph_ret *trace)
void trace_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = graph_array;
struct trace_array_cpu *data;
Expand Down Expand Up @@ -275,7 +277,8 @@ void set_graph_array(struct trace_array *tr)
smp_mb();
}

static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
ftrace_graph_addr_finish(trace);

Expand All @@ -288,7 +291,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
(trace->rettime - trace->calltime < tracing_thresh))
return;
else
trace_graph_return(trace);
trace_graph_return(trace, gops);
}

static struct fgraph_ops funcgraph_thresh_ops = {
Expand Down
6 changes: 4 additions & 2 deletions kernel/trace/trace_irqsoff.c
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Original file line number Diff line number Diff line change
Expand Up @@ -175,7 +175,8 @@ static int irqsoff_display_graph(struct trace_array *tr, int set)
return start_irqsoff_tracer(irqsoff_trace, set);
}

static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
Expand Down Expand Up @@ -205,7 +206,8 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
return ret;
}

static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
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6 changes: 4 additions & 2 deletions kernel/trace/trace_sched_wakeup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -112,7 +112,8 @@ static int wakeup_display_graph(struct trace_array *tr, int set)
return start_func_tracer(tr, set);
}

static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
Expand Down Expand Up @@ -141,7 +142,8 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
return ret;
}

static void wakeup_graph_return(struct ftrace_graph_ret *trace)
static void wakeup_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
Expand Down
5 changes: 3 additions & 2 deletions kernel/trace/trace_selftest.c
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Original file line number Diff line number Diff line change
Expand Up @@ -762,7 +762,8 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
static unsigned int graph_hang_thresh;

/* Wrap the real function entry probe to avoid possible hanging */
static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
Expand All @@ -776,7 +777,7 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
return 0;
}

return trace_graph_entry(trace);
return trace_graph_entry(trace, gops);
}

static struct fgraph_ops fgraph_ops __initdata = {
Expand Down

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