[PATCH v15 05/19] function_graph: Pass ftrace_regs to retfunc
From: Masami Hiramatsu (Google)
Date: Sun Sep 15 2024 - 05:11:16 EST
From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
Changes in v8:
- Pass ftrace_regs to retfunc, instead of adding retregfunc.
Changes in v6:
- update to use ftrace_regs_get_return_value() because of reordering
patches.
Changes in v3:
- Update for new multiple fgraph.
- Save the return address to instruction pointer in ftrace_regs.
---
include/linux/ftrace.h | 3 ++-
kernel/trace/fgraph.c | 16 +++++++++++-----
kernel/trace/ftrace.c | 3 ++-
kernel/trace/trace.h | 3 ++-
kernel/trace/trace_functions_graph.c | 7 ++++---
kernel/trace/trace_irqsoff.c | 3 ++-
kernel/trace/trace_sched_wakeup.c | 3 ++-
kernel/trace/trace_selftest.c | 3 ++-
8 files changed, 27 insertions(+), 14 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 3a3e758df931..7cd773ec4cc3 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -1069,7 +1069,8 @@ struct fgraph_ops;
/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *,
- struct fgraph_ops *); /* return */
+ struct fgraph_ops *,
+ struct ftrace_regs *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
struct fgraph_ops *,
struct ftrace_regs *); /* entry */
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 60084c2b1459..849d3353e62e 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -297,7 +297,8 @@ static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops,
}
/* ftrace_graph_return set to this to tell some archs to run function graph */
-static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops)
+static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops,
+ struct ftrace_regs *fregs)
{
}
@@ -525,7 +526,8 @@ int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
}
static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
}
@@ -816,6 +818,9 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
}
trace.rettime = trace_clock_local();
+ if (fregs)
+ ftrace_regs_set_instruction_pointer(fregs, ret);
+
#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
trace.retval = ftrace_regs_get_return_value(fregs);
#endif
@@ -825,7 +830,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
#ifdef CONFIG_HAVE_STATIC_CALL
if (static_branch_likely(&fgraph_do_direct)) {
if (test_bit(fgraph_direct_gops->idx, &bitmap))
- static_call(fgraph_retfunc)(&trace, fgraph_direct_gops);
+ static_call(fgraph_retfunc)(&trace, fgraph_direct_gops, fregs);
} else
#endif
{
@@ -835,7 +840,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
if (gops == &fgraph_stub)
continue;
- gops->retfunc(&trace, gops);
+ gops->retfunc(&trace, gops, fregs);
}
}
@@ -985,7 +990,8 @@ 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
*/
-void ftrace_stub_graph(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
+void ftrace_stub_graph(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
+ struct ftrace_regs *fregs);
/* The callbacks that hook a function */
trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3ab1bfaaafa1..66aea1baf8a2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -850,7 +850,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace,
}
static void profile_graph_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct profile_fgraph_data *profile_data;
struct ftrace_profile_stat *stat;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index c5588cdd2222..1d56d8152dc3 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -682,7 +682,8 @@ 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, struct fgraph_ops *gops);
+void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
+ struct ftrace_regs *fregs);
int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
struct ftrace_regs *fregs);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 9a8355cc4e02..0f1544336e1c 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -269,7 +269,7 @@ static void handle_nosleeptime(struct ftrace_graph_ret *trace,
}
void trace_graph_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops, struct ftrace_regs *fregs)
{
unsigned long *task_var = fgraph_get_task_var(gops);
struct trace_array *tr = gops->private;
@@ -309,7 +309,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
}
static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct fgraph_times *ftimes;
int size;
@@ -333,7 +334,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
(trace->rettime - ftimes->calltime < tracing_thresh))
return;
else
- trace_graph_return(trace, gops);
+ trace_graph_return(trace, gops, fregs);
}
static struct fgraph_ops funcgraph_ops = {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index ad739d76fc86..504de7a05498 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -208,7 +208,8 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
}
static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 23360a2700de..9ffbd9326898 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -144,7 +144,8 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
}
static void wakeup_graph_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 89067f02094a..1ebd0899238f 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -807,7 +807,8 @@ static __init int store_entry(struct ftrace_graph_ent *trace,
}
static __init void store_return(struct ftrace_graph_ret *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);
const char *type = fixture->store_type_name;