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fgraph: Simplify return address printing in function graph tracer

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Simplify return address printing in the function graph tracer by removing
fgraph_extras. Since this feature is only used by the function graph
tracer and the feature flags can directly accessible from the function
graph tracer, fgraph_extras can be removed from the fgraph callback.

Cc: Donglin Peng <dolinux.peng@gmail.com>
Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu (Google) 2024-10-10 23:59:09 +09:00 committed by Steven Rostedt (Google)
parent 474ec3e849
commit 0a6c61bc9c
8 changed files with 48 additions and 51 deletions
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16
include/linux/ftrace.h
View File

@ -1068,29 +1068,20 @@ struct ftrace_graph_ret {
unsigned long long rettime;
} __packed;
struct fgraph_extras;
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 */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
struct fgraph_ops *,
struct fgraph_extras *); /* entry */
struct fgraph_ops *); /* entry */
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops,
struct fgraph_extras *extras);
struct fgraph_ops *gops);
bool ftrace_pids_enabled(struct ftrace_ops *ops);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* Used to convey some extra datas when creating a graph entry */
struct fgraph_extras {
u32 flags;
unsigned long retaddr;
};
struct fgraph_ops {
trace_func_graph_ent_t entryfunc;
trace_func_graph_ret_t retfunc;
@ -1131,13 +1122,12 @@ function_graph_enter(unsigned long ret, unsigned long func,
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int skip);
unsigned long ftrace_graph_top_ret_addr(struct task_struct *task);
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp);
unsigned long *fgraph_get_task_var(struct fgraph_ops *gops);
u32 graph_tracer_flags_get(u32 flags);
/*
* Sometimes we don't want to trace a function with the function
* graph tracer but we want them to keep traced by the usual function

45
kernel/trace/fgraph.c
View File

@ -290,8 +290,7 @@ 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,
struct fgraph_extras *extras)
static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops)
{
return 0;
}
@ -519,8 +518,7 @@ 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_extras *extras)
struct fgraph_ops *gops)
{
return 0;
}
@ -648,20 +646,13 @@ int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
struct ftrace_graph_ent trace;
struct fgraph_extras extras;
unsigned long bitmap = 0;
int offset;
int i;
int idx = 0;
trace.func = func;
trace.depth = ++current->curr_ret_depth;
extras.flags = graph_tracer_flags_get(TRACE_GRAPH_PRINT_RETADDR);
if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR)
&& extras.flags & TRACE_GRAPH_PRINT_RETADDR)
extras.retaddr = ftrace_graph_ret_addr(current, &idx, ret, retp);
offset = ftrace_push_return_trace(ret, func, frame_pointer, retp, 0);
if (offset < 0)
goto out;
@ -670,7 +661,7 @@ 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, &extras))
if (static_call(fgraph_func)(&trace, fgraph_direct_gops))
bitmap |= BIT(fgraph_direct_gops->idx);
else
/* Clear out any saved storage */
@ -688,7 +679,7 @@ 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, &extras))
gops->entryfunc(&trace, gops))
bitmap |= BIT(i);
else
/* Clear out any saved storage */
@ -905,6 +896,29 @@ ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
return ret_stack;
}
/**
* ftrace_graph_top_ret_addr - return the top return address in the shadow stack
* @task: The task to read the shadow stack from.
*
* Return the first return address on the shadow stack of the @task, which is
* not the fgraph's return_to_handler.
*/
unsigned long ftrace_graph_top_ret_addr(struct task_struct *task)
{
unsigned long return_handler = (unsigned long)dereference_kernel_function_descriptor(return_to_handler);
struct ftrace_ret_stack *ret_stack = NULL;
int offset = task->curr_ret_stack;
if (offset < 0)
return 0;
do {
ret_stack = get_ret_stack(task, offset, &offset);
} while (ret_stack && ret_stack->ret == return_handler);
return ret_stack ? ret_stack->ret : 0;
}
/**
* ftrace_graph_ret_addr - return the original value of the return address
* @task: The task the unwinder is being executed on
@ -1145,8 +1159,7 @@ 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_extras *extras)
struct fgraph_ops *gops)
{
struct trace_array *tr = gops->ops.private;
int pid;
@ -1160,7 +1173,7 @@ static int fgraph_pid_func(struct ftrace_graph_ent *trace,
return 0;
}
return gops->saved_func(trace, gops, NULL);
return gops->saved_func(trace, gops);
}
void fgraph_update_pid_func(void)

3
kernel/trace/ftrace.c
View File

@ -827,8 +827,7 @@ struct profile_fgraph_data {
};
static int profile_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops,
struct fgraph_extras *extras)
struct fgraph_ops *gops)
{
struct profile_fgraph_data *profile_data;

3
kernel/trace/trace.h
View File

@ -695,8 +695,7 @@ 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,
struct fgraph_extras *extras);
int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);

18
kernel/trace/trace_functions_graph.c
View File

@ -90,9 +90,9 @@ static struct tracer_flags tracer_flags = {
.opts = trace_opts
};
u32 graph_tracer_flags_get(u32 flags)
static bool tracer_flags_is_set(u32 flags)
{
return tracer_flags.val & flags;
return (tracer_flags.val & flags) == flags;
}
/*
@ -179,8 +179,7 @@ struct fgraph_times {
};
int trace_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops,
struct fgraph_extras *extras)
struct fgraph_ops *gops)
{
unsigned long *task_var = fgraph_get_task_var(gops);
struct trace_array *tr = gops->private;
@ -246,11 +245,12 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1)) {
trace_ctx = tracing_gen_ctx_flags(flags);
if (unlikely(IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) && extras
&& (extras->flags & TRACE_GRAPH_PRINT_RETADDR)))
ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx,
extras->retaddr);
else
if (unlikely(IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR))) {
unsigned long retaddr = ftrace_graph_top_ret_addr(current);
ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx, retaddr);
} else
ret = __trace_graph_entry(tr, trace, trace_ctx);
} else {
ret = 0;

3
kernel/trace/trace_irqsoff.c
View File

@ -176,8 +176,7 @@ 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_extras *extras)
struct fgraph_ops *gops)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;

3
kernel/trace/trace_sched_wakeup.c
View File

@ -113,8 +113,7 @@ 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_extras *extras)
struct fgraph_ops *gops)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;

8
kernel/trace/trace_selftest.c
View File

@ -774,8 +774,7 @@ struct fgraph_fixture {
};
static __init int store_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops,
struct fgraph_extras *extras)
struct fgraph_ops *gops)
{
struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);
const char *type = fixture->store_type_name;
@ -1026,8 +1025,7 @@ 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_extras *extras)
struct fgraph_ops *gops)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
@ -1041,7 +1039,7 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace,
return 0;
}
return trace_graph_entry(trace, gops, NULL);
return trace_graph_entry(trace, gops);
}
static struct fgraph_ops fgraph_ops __initdata = {