From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A8AE2F3C01; Mon, 1 Sep 2025 14:45:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756737925; cv=none; b=EaEbcY+VrMlKgnnbHuYfJuwMtpoBpkCGdb+MZuhQCibceahDxW3mlRkSbcw3Ao9hN/CXL4VsbKFyb6Ghjd0ZMp+NUQ97MkanbiBVTuLdcgTnY5X3WJz5jSCd9dOWEr/fCtzfQmoEV+FcYQi8VrBrVQEqzdCnK4CvUfmE/3fFZ60= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756737925; c=relaxed/simple; bh=LoJG8nz0zNgEcQHKrTjGS5ckrC3RDAUe+mWEA5UPsQM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=UIitW8+xzZ1uW4M/YfFMOmJ7G+JZib06RhJ03ltFCfaGggmW22PsPXV+7+StP33tPK0nnakJdCWSGRQCyeFnGY3QBRZGdmZRRh8CfZ0Mhfc8ZwD0vzJmPce70CCQ8rJQtaRVTDuWqkGyookI0wYTrKfGGZY4lXiRKWFBbUAJb4A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ubyeRu/B; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ubyeRu/B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE355C4CEF0; Mon, 1 Sep 2025 14:45:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756737924; bh=LoJG8nz0zNgEcQHKrTjGS5ckrC3RDAUe+mWEA5UPsQM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ubyeRu/BS9a6UGLzGGpzPoy17R+ojgvjr0bVqASObXsfF1qTysrSF3W9TYlSS2kkE zVV+umYLSdaZBIGlAihlclLGe5BO7n2sk2791MzSLnFIN4Juw6VzZD0447AxL/EzXo VtUSzoeViFLww+Co8La9YCDwQ0SOTEoUl74qUlrqDLLRs1FesT8gIvqiLRoVvVFXiq uCJZyXCtkPz4I3M4nVWhCZzRtZikLjhLHinItSTZHMLGIEslfAM52nVa/pYB7Qs4Ld O6/Q7ImYBXxEvv/1tPSB18FVgTjCiF8P4iZsnUp57hfQqiXvIct1l2QqQBC9Srp2Z4 hem0QlFIi0MVA== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Peter Zijlstra , Ingo Molnar , x86@kernel.org Cc: Mathieu Desnoyers , Masami Hiramatsu , Thomas Gleixner , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Alexander Shishkin , Ian Rogers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [RFC PATCH 4/6] tracing: wprobe: Add wprobe event trigger Date: Mon, 1 Sep 2025 23:45:19 +0900 Message-ID: <175673791934.478080.13510585438052558733.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <175673787502.478080.3342912952394010967.stgit@devnote2> References: <175673787502.478080.3342912952394010967.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) Add wprobe event trigger to set and clear the watch event dynamically. This allows us to set an watchpoint on a given local variables and a slab object instead of static objects. The trigger syntax is below; set_wprobe:WPROBE:FIELD[+offset] [if FILTER] clear_wprobe:WPROBE As you can see, this only sets the address of wprobe, not changing type and length. That should be set when a new wprobe is created. Also, the WPROBE event must be disabled when setting the new trigger and it will be busy afterwards. Recommended usage is to add a new wprobe at NULL address and keep disabled. Signed-off-by: Masami Hiramatsu (Google) --- Documentation/trace/wprobetrace.rst | 60 +++++ include/linux/trace_events.h | 1 kernel/trace/Kconfig | 10 + kernel/trace/trace_wprobe.c | 426 +++++++++++++++++++++++++++++++++++ 4 files changed, 497 insertions(+) diff --git a/Documentation/trace/wprobetrace.rst b/Documentation/trace/wprobetrace.rst index 9774f57e2947..67dbf2566289 100644 --- a/Documentation/trace/wprobetrace.rst +++ b/Documentation/trace/wprobetrace.rst @@ -67,3 +67,63 @@ Here is an example to add a wprobe event on a variable `jiffies`. -0 [000] d.Z1. 717.026373: my_jiffies: (tick_do_update_jiffies64+0xbe/0x130) You can see the code which writes to `jiffies` is `do_timer()`. + +Combination with trigger action +------------------------------- +The event trigger action can extend the utilization of this wprobe. + +- set_wprobe:WPEVENT:FIELD[+|-ADJUST] +- clear_wprobe:WPEVENT + +Set these triggers to the target event, then the WPROBE event will be +setup to trace the memory access at FIELD[+|-ADJUST] address. + +For example, trace the first 8 byte of the dentry data structure passed +to do_truncate() until it is deleted by __dentry_kill(). +(Note: all tracefs setup uses '>>' so that it does not kick do_truncate()) + + # echo 'w:watch rw@0:8 address=$addr value=+0($addr)' > dynamic_events + + # echo 'f:truncate do_truncate dentry=$arg2' >> dynamic_events + # echo 'set_wprobe:watch:dentry' >> events/fprobes/truncate/trigger + + # echo 'f:dentry_kill __dentry_kill dentry=$arg1' >> dynamic_events + # echo 'clear_wprobe:watch' >> events/fprobes/dentry_kill/trigger + + # echo 1 >> events/fprobes/truncate/enable + # echo 1 >> events/fprobes/dentry_kill/enable + + # echo aaa > /tmp/hoge + # echo bbb > /tmp/hoge + # echo ccc > /tmp/hoge + # rm /tmp/hoge + +Then, the trace data will show; + +# tracer: nop +# +# entries-in-buffer/entries-written: 16/16 #P:8 +# +# _-----=> irqs-off/BH-disabled +# / _----=> need-resched +# | / _---=> hardirq/softirq +# || / _--=> preempt-depth +# ||| / _-=> migrate-disable +# |||| / delay +# TASK-PID CPU# ||||| TIMESTAMP FUNCTION +# [ 7.026136] sh (113) used greatest stack depth: 12912 bytes left + | | | ||||| | | + sh-113 [002] ..... 7.024402: truncate: (do_truncate+0x4/0x120) dentry=0xffff8880069194b8 + sh-113 [002] ..Zff 7.024822: watch: (lookup_fast+0xaa/0x150) address=0xffff8880069194b8 value=0x200008 + sh-113 [002] ..Zff 7.024830: watch: (step_into+0x82/0x360) address=0xffff8880069194b8 value=0x200008 + sh-113 [002] ..Zff 7.024834: watch: (step_into+0x9f/0x360) address=0xffff8880069194b8 value=0x200008 + sh-113 [002] ..Zff 7.024839: watch: (path_openat+0xb3a/0xe70) address=0xffff8880069194b8 value=0x200008 + sh-113 [002] ..Zff 7.024843: watch: (path_openat+0xb9a/0xe70) address=0xffff8880069194b8 value=0x200008 + sh-113 [002] ..... 7.024847: truncate: (do_truncate+0x4/0x120) dentry=0xffff8880069194b8 + sh-113 [002] ...1. 7.025364: dentry_kill: (__dentry_kill+0x0/0x220) dentry=0xffff888006919380 + sh-113 [002] ...1. 7.025511: dentry_kill: (__dentry_kill+0x0/0x220) dentry=0xffff8880069195f0 + rm-118 [003] ...1. 7.027543: dentry_kill: (__dentry_kill+0x0/0x220) dentry=0xffff8880069194b8 + sh-113 [002] ...2. 7.027825: dentry_kill: (__dentry_kill+0x0/0x220) dentry=0xffff8880044429c0 + sh-113 [002] ...2. 7.027833: dentry_kill: (__dentry_kill+0x0/0x220) dentry=0xffff888004442270 + +You can see the watch event is correctly configured on the dentry. diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 7c65f2f73ff4..6517c5d7e03e 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -720,6 +720,7 @@ enum event_trigger_type { ETT_EVENT_HIST = (1 << 4), ETT_HIST_ENABLE = (1 << 5), ETT_EVENT_EPROBE = (1 << 6), + ETT_EVENT_WPROBE = (1 << 7), }; extern int filter_match_preds(struct event_filter *filter, void *rec); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index dd8919386425..7396191ccb4d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -821,6 +821,16 @@ config WPROBE_EVENTS Those events can be inserted wherever hardware breakpoints can be set, and record various register and memory values. +config WPROBE_TRIGGERS + bool "Enable an event trigger for wprobe" + depends on WPROBE_EVENTS + depends on HAVE_REINSTALL_HW_BREAKPOINT + default y + help + This adds an event trigger which will set the wprobe on a specific + field of an event. This allows user to trace the memory access of + an address pointed by the event field. + config BPF_EVENTS depends on BPF_SYSCALL depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS diff --git a/kernel/trace/trace_wprobe.c b/kernel/trace/trace_wprobe.c index 4b00a8e917c1..a758032429f3 100644 --- a/kernel/trace/trace_wprobe.c +++ b/kernel/trace/trace_wprobe.c @@ -6,6 +6,8 @@ */ #define pr_fmt(fmt) "trace_wprobe: " fmt +#include +#include #include #include #include @@ -14,11 +16,14 @@ #include #include #include +#include #include #include +#include #include +#include "trace.h" #include "trace_dynevent.h" #include "trace_probe.h" #include "trace_probe_kernel.h" @@ -51,6 +56,12 @@ struct trace_wprobe { struct trace_probe tp; }; +/* This must be called under cpu locked (e.g. preempt off, irq off) */ +static struct perf_event *trace_wprobe_local_perf(struct trace_wprobe *tw) +{ + return *this_cpu_ptr(tw->bp_event); +} + static bool is_trace_wprobe(struct dyn_event *ev) { return ev->ops == &trace_wprobe_ops; @@ -683,3 +694,418 @@ static __init int init_wprobe_trace(void) } fs_initcall(init_wprobe_trace); + +#ifdef CONFIG_WPROBE_TRIGGERS + +static int wprobe_trigger_global_enabled; + +#define SET_WPROBE_STR "set_wprobe" +#define CLEAR_WPROBE_STR "clear_wprobe" +#define WPROBE_DEFAULT_CLEAR_ADDRESS ((unsigned long)&wprobe_trigger_global_enabled) + +struct wprobe_trigger_data { + struct trace_event_file *file; + struct trace_wprobe *tw; + + struct perf_event_attr attr; + raw_spinlock_t lock; /* lock protects attr */ + struct work_struct work;// TBD: use work + IPI or use sched/raw_syscall event? + unsigned int offset; + long adjust; + const char *field; + // size must be unsigned long because it should be an address. + bool clear; +}; + +static int trace_wprobe_update_local(struct trace_wprobe *tw, + struct perf_event_attr *attr) +{ + struct perf_event *bp = trace_wprobe_local_perf(tw); + + return modify_wide_hw_breakpoint_local(bp, attr); +} + +static void wprobe_smp_update_func(void *data) +{ + struct wprobe_trigger_data *trigger_data = data; + unsigned long flags; + + raw_spin_lock_irqsave(&trigger_data->lock, flags); + trace_wprobe_update_local(trigger_data->tw, &trigger_data->attr); + raw_spin_unlock_irqrestore(&trigger_data->lock, flags); +} + +static void wprobe_work_func(struct work_struct *work) +{ + struct wprobe_trigger_data *data = container_of(work, struct wprobe_trigger_data, work); + + on_each_cpu(wprobe_smp_update_func, data, false); +} + +static void wprobe_trigger(struct event_trigger_data *data, + struct trace_buffer *buffer, void *rec, + struct ring_buffer_event *event) +{ + struct wprobe_trigger_data *wprobe_data = data->private_data; + struct perf_event_attr *attr = &wprobe_data->attr; + struct trace_wprobe *tw = wprobe_data->tw; + unsigned long addr, flags; + int ret = -EBUSY; + + addr = *(unsigned long *)(rec + wprobe_data->offset); + addr += wprobe_data->adjust; + + raw_spin_lock_irqsave(&wprobe_data->lock, flags); + + if (!wprobe_data->clear) { + if (tw->addr != WPROBE_DEFAULT_CLEAR_ADDRESS) + goto unlock; + + tw->addr = attr->bp_addr = addr; + ret = trace_wprobe_update_local(tw, attr); + if (WARN_ON_ONCE(ret)) + goto unlock; + clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &wprobe_data->file->flags); + } else { + if (tw->addr == WPROBE_DEFAULT_CLEAR_ADDRESS) + goto unlock; + + tw->addr = attr->bp_addr = WPROBE_DEFAULT_CLEAR_ADDRESS; + ret = trace_wprobe_update_local(tw, attr); + if (WARN_ON_ONCE(ret)) + goto unlock; + set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &wprobe_data->file->flags); + } + schedule_work(&wprobe_data->work); +unlock: + raw_spin_unlock_irqrestore(&wprobe_data->lock, flags); +} + +static void free_wprobe_trigger_data(struct wprobe_trigger_data *wprobe_data) +{ + if (wprobe_data) + kfree(wprobe_data->field); + kfree(wprobe_data); +} + +DEFINE_FREE(free_wprobe_trigger_data, struct wprobe_trigger_data *, free_wprobe_trigger_data(_T)); + +static int wprobe_trigger_print(struct seq_file *m, + struct event_trigger_data *data) +{ + struct wprobe_trigger_data *wprobe_data = data->private_data; + + if (wprobe_data->clear) + seq_printf(m, "%s:%s", CLEAR_WPROBE_STR, + trace_event_name(wprobe_data->file->event_call)); + else + seq_printf(m, "%s:%s:%s%+ld", SET_WPROBE_STR, + trace_event_name(wprobe_data->file->event_call), + wprobe_data->field, wprobe_data->adjust); + + if (data->filter_str) + seq_printf(m, " if %s\n", data->filter_str); + else + seq_putc(m, '\n'); + + return 0; +} + +static struct wprobe_trigger_data * +wprobe_trigger_alloc(struct trace_wprobe *tw, struct trace_event_file *file, + bool clear) +{ + struct wprobe_trigger_data *wprobe_data; + struct perf_event_attr *attr; + + wprobe_data = kzalloc(sizeof(*wprobe_data), GFP_KERNEL); + if (!wprobe_data) + return NULL; + + wprobe_data->tw = tw; + wprobe_data->clear = clear; + wprobe_data->file = file; + + attr = &wprobe_data->attr; + hw_breakpoint_init(attr); + attr->bp_type = tw->type; + attr->bp_addr = WPROBE_DEFAULT_CLEAR_ADDRESS; + attr->bp_len = tw->len; + + raw_spin_lock_init(&wprobe_data->lock); + INIT_WORK(&wprobe_data->work, wprobe_work_func); + + return wprobe_data; +} + +static void wprobe_trigger_free(struct event_trigger_data *data) +{ + struct wprobe_trigger_data *wprobe_data = data->private_data; + + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + data->ref--; + if (!data->ref) { + /* Remove the SOFT_MODE flag */ + trace_event_enable_disable(wprobe_data->file, 0, 1); + trace_event_put_ref(wprobe_data->file->event_call); + trigger_data_free(data); + free_wprobe_trigger_data(wprobe_data); + } +} + +static const struct event_trigger_ops set_wprobe_trigger_ops = { + .trigger = wprobe_trigger, + .print = wprobe_trigger_print, + .init = event_trigger_init, + .free = wprobe_trigger_free, +}; + +static const struct event_trigger_ops clear_wprobe_trigger_ops = { + .trigger = wprobe_trigger, + .print = wprobe_trigger_print, + .init = event_trigger_init, + .free = wprobe_trigger_free, +}; + +static int wprobe_trigger_cmd_parse(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, + char *param_and_filter) +{ + /* + * set_wp:EVENT:FIELD[+OFFS] + * clear_wp:EVENT + */ + struct wprobe_trigger_data *wprobe_data __free(free_wprobe_trigger_data) = NULL; + struct event_trigger_data *trigger_data __free(kfree) = NULL; + struct ftrace_event_field *field = NULL; + struct trace_event_file *wprobe_file; + struct trace_array *tr = file->tr; + struct trace_event_call *event; + struct perf_event_attr *attr; + char *event_str, *field_str; + bool remove, clear = false; + struct trace_wprobe *tw; + char *param, *filter; + int ret; + + remove = event_trigger_check_remove(glob); + + if (!strcmp(cmd, CLEAR_WPROBE_STR)) + clear = true; + + if (event_trigger_empty_param(param_and_filter)) + return -EINVAL; + + ret = event_trigger_separate_filter(param_and_filter, ¶m, &filter, true); + if (ret) + return ret; + + event_str = strsep(¶m, ":"); + + /* Find target wprobe */ + tw = find_trace_wprobe(event_str, WPROBE_EVENT_SYSTEM); + if (!tw) + return -ENOENT; + /* The target wprobe must not be used (unless clear) */ + if (!remove && !clear && trace_probe_is_enabled(&tw->tp)) + return -EBUSY; + + wprobe_file = find_event_file(tr, WPROBE_EVENT_SYSTEM, event_str); + if (!wprobe_file) + return -EINVAL; + + wprobe_data = wprobe_trigger_alloc(tw, wprobe_file, clear); + if (!wprobe_data) + return -ENOMEM; + attr = &wprobe_data->attr; + + if (!clear) { + char *offs; + + /* Find target field, which must be equivarent to "void *" */ + field_str = strsep(¶m, ":"); + if (!field_str) + return -EINVAL; + + offs = strpbrk(field_str, "+-"); + if (offs) { + long val; + + if (kstrtol(offs, 0, &val) < 0) + return -EINVAL; + wprobe_data->adjust = val; + *offs = '\0'; + } + + event = file->event_call; + field = trace_find_event_field(event, field_str); + if (!field) + return -ENOENT; + + if (field->size != sizeof(void *)) + return -ENOEXEC; + wprobe_data->offset = field->offset; + wprobe_data->field = kstrdup(field_str, GFP_KERNEL); + if (!wprobe_data->field) + return -ENOMEM; + } + + trigger_data = trigger_data_alloc(cmd_ops, cmd, param, wprobe_data); + if (!trigger_data) + return -ENOMEM; + + /* Up the trigger_data count to make sure nothing frees it on failure */ + event_trigger_init(trigger_data); + + if (remove) { + event_trigger_unregister(cmd_ops, file, glob+1, trigger_data); + return 0; + } + + ret = event_trigger_parse_num(param, trigger_data); + if (ret) + return ret; + + ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data); + if (ret < 0) + return ret; + + /* Soft-enable (register) wprobe event on WPROBE_DEFAULT_CLEAR_ADDRESS */ + tw->addr = attr->bp_addr = WPROBE_DEFAULT_CLEAR_ADDRESS; + ret = trace_event_enable_disable(wprobe_file, 1, 1); + if (ret < 0) { + event_trigger_reset_filter(cmd_ops, trigger_data); + return ret; + } + ret = event_trigger_register(cmd_ops, file, glob, trigger_data); + if (ret) { + event_trigger_reset_filter(cmd_ops, trigger_data); + trace_event_enable_disable(wprobe_file, 0, 1); + return ret; + } + /* Make it NULL to avoid freeing trigger_data and wprobe_data by __free() */ + trigger_data = NULL; + wprobe_data = NULL; + + return 0; +} + +/* Return true if there is a trigger which points the same wprobe */ +static bool wprobe_trigger_exist_same(struct event_trigger_data *test, + struct trace_event_file *file) +{ + struct wprobe_trigger_data *test_wprobe_data = test->private_data; + struct wprobe_trigger_data *wprobe_data; + struct event_trigger_data *iter; + + list_for_each_entry(iter, &file->triggers, list) { + wprobe_data = iter->private_data; + if (!wprobe_data || + iter->cmd_ops->trigger_type != + test->cmd_ops->trigger_type) + continue; + if (wprobe_data->tw == test_wprobe_data->tw) + return true; + } + return false; +} + +static int wprobe_register_trigger(char *glob, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + int ret = 0; + + lockdep_assert_held(&event_mutex); + + /* The same wprobe is not accept on the same file (event) */ + if (wprobe_trigger_exist_same(data, file)) + return -EEXIST; + + if (data->ops->init) { + ret = data->ops->init(data); + if (ret < 0) + return ret; + } + + list_add_rcu(&data->list, &file->triggers); + + update_cond_flag(file); + ret = trace_event_trigger_enable_disable(file, 1); + if (ret < 0) { + list_del_rcu(&data->list); + update_cond_flag(file); + } + return ret; +} + +static void wprobe_unregister_trigger(char *glob, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + lockdep_assert_held(&event_mutex); + + if (wprobe_trigger_exist_same(data, file)) { + list_del_rcu(&data->list); + trace_event_trigger_enable_disable(file, 0); + update_cond_flag(file); + } + + if (data && data->ops->free) + data->ops->free(data); +} + +static const struct event_trigger_ops * +wprobe_get_trigger_ops(char *cmd, char *param) +{ + if (!strcmp(cmd, SET_WPROBE_STR)) + return &set_wprobe_trigger_ops; + + return &clear_wprobe_trigger_ops; +} + +static struct event_command trigger_wprobe_set_cmd = { + .name = SET_WPROBE_STR, + .trigger_type = ETT_EVENT_WPROBE, + /* This triggers after when the event is recorded. */ + .flags = EVENT_CMD_FL_NEEDS_REC, + .parse = wprobe_trigger_cmd_parse, + .reg = wprobe_register_trigger, + .unreg = wprobe_unregister_trigger, + .get_trigger_ops = wprobe_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static struct event_command trigger_wprobe_clear_cmd = { + .name = CLEAR_WPROBE_STR, + .trigger_type = ETT_EVENT_WPROBE, + /* This triggers after when the event is recorded. */ + .flags = EVENT_CMD_FL_NEEDS_REC, + .parse = wprobe_trigger_cmd_parse, + .reg = wprobe_register_trigger, + .unreg = wprobe_unregister_trigger, + .get_trigger_ops = wprobe_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static __init int init_trigger_wprobe_cmds(void) +{ + int ret; + + ret = register_event_command(&trigger_wprobe_set_cmd); + if (WARN_ON(ret < 0)) + return ret; + ret = register_event_command(&trigger_wprobe_clear_cmd); + if (WARN_ON(ret < 0)) + unregister_event_command(&trigger_wprobe_set_cmd); + + if (!ret) + wprobe_trigger_global_enabled = 1; + + return ret; +} +fs_initcall(init_trigger_wprobe_cmds); +#endif /* CONFIG_WPROBE_TRIGGERS */ \ No newline at end of file