@@ -481,7 +481,20 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- prepare_ftrace_return(ip, &arch_ftrace_regs(fregs)->lr, arch_ftrace_regs(fregs)->fp);
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long frame_pointer = arch_ftrace_regs(fregs)->fp;
+ unsigned long *parent = &arch_ftrace_regs(fregs)->lr;
+ unsigned long old;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ old = *parent;
+
+ if (!function_graph_enter_regs(old, ip, frame_pointer,
+ (void *)frame_pointer, fregs)) {
+ *parent = return_hooker;
+ }
}
#else
/*
@@ -243,8 +243,16 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
{
struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
unsigned long *parent = (unsigned long *)®s->regs[1];
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long old;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ old = *parent;
- prepare_ftrace_return(ip, (unsigned long *)parent);
+ if (!function_graph_enter_regs(old, ip, 0, parent, fregs))
+ *parent = return_hooker;
}
#else
static int ftrace_modify_graph_caller(bool enable)
@@ -665,7 +665,7 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
goto out;
- if (!function_graph_enter(parent_ip, ip, 0, (unsigned long *)sp))
+ if (!function_graph_enter_regs(parent_ip, ip, 0, (unsigned long *)sp, fregs))
parent_ip = ppc_function_entry(return_to_handler);
out:
@@ -787,7 +787,8 @@ int ftrace_disable_ftrace_graph_caller(void)
* in current thread info. Return the address we want to divert to.
*/
static unsigned long
-__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp)
+__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp,
+ struct ftrace_regs *fregs)
{
unsigned long return_hooker;
@@ -799,7 +800,7 @@ __prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp
return_hooker = ppc_function_entry(return_to_handler);
- if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp))
+ if (!function_graph_enter_regs(parent, ip, 0, (unsigned long *)sp, fregs))
parent = return_hooker;
out:
@@ -810,13 +811,14 @@ __prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- arch_ftrace_regs(fregs)->regs.link = __prepare_ftrace_return(parent_ip, ip, arch_ftrace_regs(fregs)->regs.gpr[1]);
+ arch_ftrace_regs(fregs)->regs.link = __prepare_ftrace_return(parent_ip, ip,
+ arch_ftrace_regs(fregs)->regs.gpr[1], fregs);
}
#else
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
unsigned long sp)
{
- return __prepare_ftrace_return(parent, ip, sp);
+ return __prepare_ftrace_return(parent, ip, sp, NULL);
}
#endif
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
@@ -214,7 +214,22 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- prepare_ftrace_return(&arch_ftrace_regs(fregs)->ra, ip, arch_ftrace_regs(fregs)->s0);
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long frame_pointer = arch_ftrace_regs(fregs)->s0;
+ unsigned long *parent = &arch_ftrace_regs(fregs)->ra;
+ unsigned long old;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ /*
+ * We don't suffer access faults, so no extra fault-recovery assembly
+ * is needed here.
+ */
+ old = *parent;
+
+ if (!function_graph_enter_regs(old, ip, frame_pointer, parent, fregs))
+ *parent = return_hooker;
}
#else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
extern void ftrace_graph_call(void);
@@ -607,15 +607,8 @@ int ftrace_disable_ftrace_graph_caller(void)
}
#endif /* CONFIG_DYNAMIC_FTRACE && !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
-/*
- * Hook the return address and push it in the stack of return addrs
- * in current thread info.
- */
-void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
- unsigned long frame_pointer)
+static inline bool skip_ftrace_return(void)
{
- unsigned long return_hooker = (unsigned long)&return_to_handler;
-
/*
* When resuming from suspend-to-ram, this function can be indirectly
* called from early CPU startup code while the CPU is in real mode,
@@ -625,13 +618,27 @@ void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
* This check isn't as accurate as virt_addr_valid(), but it should be
* good enough for this purpose, and it's fast.
*/
- if (unlikely((long)__builtin_frame_address(0) >= 0))
- return;
+ if ((long)__builtin_frame_address(0) >= 0)
+ return true;
- if (unlikely(ftrace_graph_is_dead()))
- return;
+ if (ftrace_graph_is_dead())
+ return true;
+
+ if (atomic_read(¤t->tracing_graph_pause))
+ return true;
+ return false;
+}
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
+ unsigned long frame_pointer)
+{
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
- if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ if (unlikely(skip_ftrace_return()))
return;
if (!function_graph_enter(*parent, ip, frame_pointer, parent))
@@ -644,8 +651,15 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
{
struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
unsigned long *stack = (unsigned long *)kernel_stack_pointer(regs);
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long *parent = (unsigned long *)stack;
+
+ if (unlikely(skip_ftrace_return()))
+ return;
+
- prepare_ftrace_return(ip, (unsigned long *)stack, 0);
+ if (!function_graph_enter_regs(*parent, ip, 0, parent, fregs))
+ *parent = return_hooker;
}
#endif
@@ -1071,10 +1071,12 @@ struct fgraph_ops;
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 */
+ struct fgraph_ops *,
+ struct ftrace_regs *); /* entry */
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops);
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs);
bool ftrace_pids_enabled(struct ftrace_ops *ops);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -1114,8 +1116,15 @@ struct ftrace_ret_stack {
extern void return_to_handler(void);
extern int
-function_graph_enter(unsigned long ret, unsigned long func,
- unsigned long frame_pointer, unsigned long *retp);
+function_graph_enter_regs(unsigned long ret, unsigned long func,
+ unsigned long frame_pointer, unsigned long *retp,
+ struct ftrace_regs *fregs);
+
+static inline int function_graph_enter(unsigned long ret, unsigned long func,
+ unsigned long fp, unsigned long *retp)
+{
+ return function_graph_enter_regs(ret, func, fp, retp, NULL);
+}
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int skip);
@@ -292,7 +292,8 @@ static inline unsigned long make_data_type_val(int idx, int size, int offset)
}
/* ftrace_graph_entry set to this to tell some archs to run function graph */
-static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops)
+static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops,
+ struct ftrace_regs *fregs)
{
return 0;
}
@@ -520,7 +521,8 @@ int __weak ftrace_disable_ftrace_graph_caller(void)
#endif
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
return 0;
}
@@ -644,8 +646,9 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
#endif
/* If the caller does not use ftrace, call this function. */
-int function_graph_enter(unsigned long ret, unsigned long func,
- unsigned long frame_pointer, unsigned long *retp)
+int function_graph_enter_regs(unsigned long ret, unsigned long func,
+ unsigned long frame_pointer, unsigned long *retp,
+ struct ftrace_regs *fregs)
{
struct ftrace_graph_ent trace;
unsigned long bitmap = 0;
@@ -668,7 +671,7 @@ int function_graph_enter(unsigned long ret, unsigned long func,
if (static_branch_likely(&fgraph_do_direct)) {
int save_curr_ret_stack = current->curr_ret_stack;
- if (static_call(fgraph_func)(&trace, fgraph_direct_gops))
+ if (static_call(fgraph_func)(&trace, fgraph_direct_gops, fregs))
bitmap |= BIT(fgraph_direct_gops->idx);
else
/* Clear out any saved storage */
@@ -686,7 +689,7 @@ int function_graph_enter(unsigned long ret, unsigned long func,
save_curr_ret_stack = current->curr_ret_stack;
if (ftrace_ops_test(&gops->ops, func, NULL) &&
- gops->entryfunc(&trace, gops))
+ gops->entryfunc(&trace, gops, fregs))
bitmap |= BIT(i);
else
/* Clear out any saved storage */
@@ -1180,7 +1183,8 @@ void ftrace_graph_exit_task(struct task_struct *t)
#ifdef CONFIG_DYNAMIC_FTRACE
static int fgraph_pid_func(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct trace_array *tr = gops->ops.private;
int pid;
@@ -1194,7 +1198,7 @@ static int fgraph_pid_func(struct ftrace_graph_ent *trace,
return 0;
}
- return gops->saved_func(trace, gops);
+ return gops->saved_func(trace, gops, fregs);
}
void fgraph_update_pid_func(void)
@@ -819,7 +819,8 @@ struct profile_fgraph_data {
};
static int profile_graph_entry(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct profile_fgraph_data *profile_data;
@@ -694,7 +694,8 @@ 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);
-int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
+int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
+ struct ftrace_regs *fregs);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
@@ -175,7 +175,8 @@ struct fgraph_times {
};
int trace_graph_entry(struct ftrace_graph_ent *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;
@@ -176,7 +176,8 @@ static int irqsoff_display_graph(struct trace_array *tr, int set)
}
static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
@@ -113,7 +113,8 @@ static int wakeup_display_graph(struct trace_array *tr, int set)
}
static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
@@ -774,7 +774,8 @@ struct fgraph_fixture {
};
static __init int store_entry(struct ftrace_graph_ent *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;
@@ -1025,7 +1026,8 @@ 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,
- struct fgraph_ops *gops)
+ struct fgraph_ops *gops,
+ struct ftrace_regs *fregs)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
@@ -1039,7 +1041,7 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace,
return 0;
}
- return trace_graph_entry(trace, gops);
+ return trace_graph_entry(trace, gops, fregs);
}
static struct fgraph_ops fgraph_ops __initdata = {