fgraph: Pass ftrace_regs to retfunc

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.

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: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173518992972.391279.14055405490327765506.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 069f270bd7aeb7b3d8d0b8fce453dfae520074c8..9a1e768e47daa074f1ab53ec1bef62fc162faff2 100644 (file)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -1075,7 +1075,8 @@ 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 51196f10d96ec0b8025b282fef3b2fb2f5f77625..c928527251e3d8be0635e71d19dbf25aad270c4c 100644 (file)
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -299,7 +299,8 @@ 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)
 {
 }
 
@@ -528,7 +529,8 @@ 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)
 {
 }
 
@@ -825,6 +827,9 @@ __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
@@ -834,7 +839,7 @@ __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
        {
@@ -844,7 +849,7 @@ __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);
                }
        }
 
@@ -1016,7 +1021,8 @@ 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 ae29e1c4177d99ffbf174a2a4d625af7a65063b8..f054343be0263c5ab570b6471cabfc639ad7dccf 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -842,7 +842,8 @@ 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 0f38f36a5a8a93bf1bdc255c4d6926e017476c96..5f3e68a8d8a0064490235a99f539e836808a1c30 100644 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -693,7 +693,8 @@ 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 676cf3e38f516edfbbdea18cc797537d01e39037..dc62eb93837abf643d29c92aa5bfdeb015cc13bb 100644 (file)
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -310,7 +310,7 @@ 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;
@@ -348,7 +348,8 @@ 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;
@@ -372,7 +373,7 @@ 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 ad739d76fc8621189cee05826fac2faf1862b224..504de7a05498e0726b1b10adea7a6a479ef09fad 100644 (file)
--- 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 0d9e1075d815f1a801ce5f995d1054a97a748273..8165382a174a8d8be6a332acafa2d163e0ec62ac 100644 (file)
--- 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 f54493f8783d2cb5ce80164cfb5ad05a0ddac712..d88c44f1dfa5537856199233b16ca2ea10988e40 100644 (file)
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -808,7 +808,8 @@ 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;