From 22c36b18263426bdd97ef5e04c0e92224c612ee1 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Sun, 12 Jul 2020 09:10:36 +0800 Subject: tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer Current tracing_init_dentry() return a d_entry pointer, while is not necessary. This function returns NULL on success or error on failure, which means there is no valid d_entry pointer return. Let's return 0 on success and negative value for error. Link: https://lkml.kernel.org/r/20200712011036.70948-5-richard.weiyang@linux.alibaba.com Signed-off-by: Wei Yang Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 36 ++++++++++++++++++------------------ kernel/trace/trace.h | 2 +- kernel/trace/trace_dynevent.c | 8 ++++---- kernel/trace/trace_events_synth.c | 9 +++------ kernel/trace/trace_functions_graph.c | 8 ++++---- kernel/trace/trace_hwlat.c | 8 ++++---- kernel/trace/trace_kprobe.c | 10 +++++----- kernel/trace/trace_printk.c | 8 ++++---- kernel/trace/trace_stack.c | 12 ++++++------ kernel/trace/trace_stat.c | 8 ++++---- kernel/trace/trace_uprobe.c | 9 ++++----- 11 files changed, 57 insertions(+), 61 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2a7c26345e83..29a9034b38d0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8971,21 +8971,21 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) * directory. It is called via fs_initcall() by any of the boot up code * and expects to return the dentry of the top level tracing directory. */ -struct dentry *tracing_init_dentry(void) +int tracing_init_dentry(void) { struct trace_array *tr = &global_trace; if (security_locked_down(LOCKDOWN_TRACEFS)) { pr_warn("Tracing disabled due to lockdown\n"); - return ERR_PTR(-EPERM); + return -EPERM; } /* The top level trace array uses NULL as parent */ if (tr->dir) - return NULL; + return 0; if (WARN_ON(!tracefs_initialized())) - return ERR_PTR(-ENODEV); + return -ENODEV; /* * As there may still be users that expect the tracing @@ -8996,7 +8996,7 @@ struct dentry *tracing_init_dentry(void) tr->dir = debugfs_create_automount("tracing", NULL, trace_automount, NULL); - return NULL; + return 0; } extern struct trace_eval_map *__start_ftrace_eval_maps[]; @@ -9083,48 +9083,48 @@ static struct notifier_block trace_module_nb = { static __init int tracer_init_tracefs(void) { - struct dentry *d_tracer; + int ret; trace_access_lock_init(); - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; event_trace_init(); - init_tracer_tracefs(&global_trace, d_tracer); - ftrace_init_tracefs_toplevel(&global_trace, d_tracer); + init_tracer_tracefs(&global_trace, NULL); + ftrace_init_tracefs_toplevel(&global_trace, NULL); - trace_create_file("tracing_thresh", 0644, d_tracer, + trace_create_file("tracing_thresh", 0644, NULL, &global_trace, &tracing_thresh_fops); - trace_create_file("README", 0444, d_tracer, + trace_create_file("README", 0444, NULL, NULL, &tracing_readme_fops); - trace_create_file("saved_cmdlines", 0444, d_tracer, + trace_create_file("saved_cmdlines", 0444, NULL, NULL, &tracing_saved_cmdlines_fops); - trace_create_file("saved_cmdlines_size", 0644, d_tracer, + trace_create_file("saved_cmdlines_size", 0644, NULL, NULL, &tracing_saved_cmdlines_size_fops); - trace_create_file("saved_tgids", 0444, d_tracer, + trace_create_file("saved_tgids", 0444, NULL, NULL, &tracing_saved_tgids_fops); trace_eval_init(); - trace_create_eval_file(d_tracer); + trace_create_eval_file(NULL); #ifdef CONFIG_MODULES register_module_notifier(&trace_module_nb); #endif #ifdef CONFIG_DYNAMIC_FTRACE - trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, + trace_create_file("dyn_ftrace_total_info", 0444, NULL, NULL, &tracing_dyn_info_fops); #endif - create_trace_instances(d_tracer); + create_trace_instances(NULL); update_tracer_options(&global_trace); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 610d21355526..0d3a405fe446 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -737,7 +737,7 @@ struct dentry *trace_create_file(const char *name, void *data, const struct file_operations *fops); -struct dentry *tracing_init_dentry(void); +int tracing_init_dentry(void); struct ring_buffer_event; diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 9f2e8520b748..9442a9bb080e 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -206,14 +206,14 @@ static const struct file_operations dynamic_events_ops = { /* Make a tracefs interface for controlling dynamic events */ static __init int init_dynamic_event(void) { - struct dentry *d_tracer; struct dentry *entry; + int ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - entry = tracefs_create_file("dynamic_events", 0644, d_tracer, + entry = tracefs_create_file("dynamic_events", 0644, NULL, NULL, &dynamic_events_ops); /* Event list interface */ diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index c6cca0d1d584..f86a2aa0bccd 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1757,7 +1757,6 @@ static const struct file_operations synth_events_fops = { static __init int trace_events_synth_init(void) { struct dentry *entry = NULL; - struct dentry *d_tracer; int err = 0; err = dyn_event_register(&synth_event_ops); @@ -1766,13 +1765,11 @@ static __init int trace_events_synth_init(void) return err; } - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) { - err = PTR_ERR(d_tracer); + err = tracing_init_dentry(); + if (err) goto err; - } - entry = tracefs_create_file("synthetic_events", 0644, d_tracer, + entry = tracefs_create_file("synthetic_events", 0644, NULL, NULL, &synth_events_fops); if (!entry) { err = -ENODEV; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 4a9c49c08ec9..60d66278aa0d 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -1336,13 +1336,13 @@ static const struct file_operations graph_depth_fops = { static __init int init_graph_tracefs(void) { - struct dentry *d_tracer; + int ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - trace_create_file("max_graph_depth", 0644, d_tracer, + trace_create_file("max_graph_depth", 0644, NULL, NULL, &graph_depth_fops); return 0; diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index 17873e5d0353..c9ad5c6fbaad 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -538,14 +538,14 @@ static const struct file_operations window_fops = { */ static int init_tracefs(void) { - struct dentry *d_tracer; + int ret; struct dentry *top_dir; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return -ENOMEM; - top_dir = tracefs_create_dir("hwlat_detector", d_tracer); + top_dir = tracefs_create_dir("hwlat_detector", NULL); if (!top_dir) return -ENOMEM; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index aefb6065b508..feca9b19cd74 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1901,14 +1901,14 @@ subsys_initcall(init_kprobe_trace_early); /* Make a tracefs interface for controlling probe points */ static __init int init_kprobe_trace(void) { - struct dentry *d_tracer; + int ret; struct dentry *entry; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - entry = tracefs_create_file("kprobe_events", 0644, d_tracer, + entry = tracefs_create_file("kprobe_events", 0644, NULL, NULL, &kprobe_events_ops); /* Event list interface */ @@ -1916,7 +1916,7 @@ static __init int init_kprobe_trace(void) pr_warn("Could not create tracefs 'kprobe_events' entry\n"); /* Profile interface */ - entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, + entry = tracefs_create_file("kprobe_profile", 0444, NULL, NULL, &kprobe_profile_ops); if (!entry) diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index d4e31e969206..71b2e0fdc3e0 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -367,13 +367,13 @@ static const struct file_operations ftrace_formats_fops = { static __init int init_trace_printk_function_export(void) { - struct dentry *d_tracer; + int ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - trace_create_file("printk_formats", 0444, d_tracer, + trace_create_file("printk_formats", 0444, NULL, NULL, &ftrace_formats_fops); return 0; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 98bba4764c52..c408423e5d65 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -554,20 +554,20 @@ __setup("stacktrace", enable_stacktrace); static __init int stack_trace_init(void) { - struct dentry *d_tracer; + int ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - trace_create_file("stack_max_size", 0644, d_tracer, + trace_create_file("stack_max_size", 0644, NULL, &stack_trace_max_size, &stack_max_size_fops); - trace_create_file("stack_trace", 0444, d_tracer, + trace_create_file("stack_trace", 0444, NULL, NULL, &stack_trace_fops); #ifdef CONFIG_DYNAMIC_FTRACE - trace_create_file("stack_trace_filter", 0644, d_tracer, + trace_create_file("stack_trace_filter", 0644, NULL, &trace_ops, &stack_trace_filter_fops); #endif diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index d1fa19773cc8..8d141c3825a9 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -276,13 +276,13 @@ static const struct file_operations tracing_stat_fops = { static int tracing_stat_init(void) { - struct dentry *d_tracing; + int ret; - d_tracing = tracing_init_dentry(); - if (IS_ERR(d_tracing)) + ret = tracing_init_dentry(); + if (ret) return -ENODEV; - stat_dir = tracefs_create_dir("trace_stat", d_tracing); + stat_dir = tracefs_create_dir("trace_stat", NULL); if (!stat_dir) { pr_warn("Could not create tracefs 'trace_stat' entry\n"); return -ENOMEM; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index f4286c9bdeb4..56729c6b6614 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1625,21 +1625,20 @@ void destroy_local_trace_uprobe(struct trace_event_call *event_call) /* Make a trace interface for controling probe points */ static __init int init_uprobe_trace(void) { - struct dentry *d_tracer; int ret; ret = dyn_event_register(&trace_uprobe_ops); if (ret) return ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - trace_create_file("uprobe_events", 0644, d_tracer, + trace_create_file("uprobe_events", 0644, NULL, NULL, &uprobe_events_ops); /* Profile interface */ - trace_create_file("uprobe_profile", 0444, d_tracer, + trace_create_file("uprobe_profile", 0444, NULL, NULL, &uprobe_profile_ops); return 0; } -- cgit v1.2.3