Re: [PATCH v12 1/4] trace: Add trace any kernel object

From: Google
Date: Sat Jun 25 2022 - 11:59:36 EST

On Tue, 7 Jun 2022 00:09:40 +0800
Jeff Xie <xiehuan09@xxxxxxxxx> wrote:

> Introduce objtrace trigger to get the call flow by tracing any kernel
> object in the function parameter.
>
> The objtrace trigger makes a list of the target object address from
> the given event parameter, and records all kernel function calls
> which has the object address in its parameter.
>
> Syntax:
> objtrace:add:obj[:count][if <filter>]
>
> Usage:
> # echo 'p bio_add_page arg1=$arg1' > kprobe_events
> # cd events/kprobes/p_bio_add_page_0
> # echo 'objtrace:add:arg1:1 if comm == "cat"' > ./trigger
> # cat /test.txt
>

This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Thank you,

> Signed-off-by: Jeff Xie <xiehuan09@xxxxxxxxx>
> ---
> include/linux/trace_events.h | 1 +
> kernel/trace/Kconfig | 10 +
> kernel/trace/Makefile | 1 +
> kernel/trace/trace.c | 11 +
> kernel/trace/trace.h | 21 ++
> kernel/trace/trace_entries.h | 17 ++
> kernel/trace/trace_events_trigger.c | 5 +-
> kernel/trace/trace_object.c | 450 ++++++++++++++++++++++++++++
> kernel/trace/trace_output.c | 40 +++
> 9 files changed, 554 insertions(+), 2 deletions(-)
> create mode 100644 kernel/trace/trace_object.c
>
> diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> index e6e95a9f07a5..f3645166b724 100644
> --- a/include/linux/trace_events.h
> +++ b/include/linux/trace_events.h
> @@ -693,6 +693,7 @@ enum event_trigger_type {
> ETT_EVENT_HIST = (1 << 4),
> ETT_HIST_ENABLE = (1 << 5),
> ETT_EVENT_EPROBE = (1 << 6),
> + ETT_TRACE_OBJECT = (1 << 7),
> };
>
> extern int filter_match_preds(struct event_filter *filter, void *rec);
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index 2c43e327a619..30c34d43dc3f 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -276,6 +276,16 @@ config FUNCTION_PROFILER
>
> If in doubt, say N.
>
> +config TRACE_OBJECT
> + bool "Trace kernel object in function parameter"
> + depends on FUNCTION_TRACER
> + depends on HAVE_FUNCTION_ARG_ACCESS_API
> + select TRACING
> + default y
> + help
> + You can trace the kernel object in the kernel function parameter.
> + The kernel object is dynamically specified via event trigger.
> +
> config STACK_TRACER
> bool "Trace max stack"
> depends on HAVE_FUNCTION_TRACER
> diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
> index 0d261774d6f3..90ecc3c6c9d5 100644
> --- a/kernel/trace/Makefile
> +++ b/kernel/trace/Makefile
> @@ -71,6 +71,7 @@ obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
> obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
> obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
> obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += fgraph.o
> +obj-$(CONFIG_TRACE_OBJECT) += trace_object.o
> ifeq ($(CONFIG_BLOCK),y)
> obj-$(CONFIG_EVENT_TRACING) += blktrace.o
> endif
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index f400800bc910..7074ad8bc1a0 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5627,6 +5627,9 @@ static const char readme_msg[] =
> "\t enable_hist:<system>:<event>\n"
> "\t disable_hist:<system>:<event>\n"
> #endif
> +#ifdef CONFIG_TRACE_OBJECT
> + "\t objtrace:add:obj[:count][if <filter>]\n"
> +#endif
> #ifdef CONFIG_STACKTRACE
> "\t\t stacktrace\n"
> #endif
> @@ -9272,6 +9275,9 @@ static struct trace_array *trace_array_create(const char *name)
> if (ftrace_allocate_ftrace_ops(tr) < 0)
> goto out_free_tr;
>
> + if (allocate_objtrace_data(tr) < 0)
> + goto out_free_tr;
> +
> ftrace_init_trace_array(tr);
>
> init_trace_flags_index(tr);
> @@ -9291,6 +9297,7 @@ static struct trace_array *trace_array_create(const char *name)
>
> out_free_tr:
> ftrace_free_ftrace_ops(tr);
> + free_objtrace_data(tr);
> free_trace_buffers(tr);
> free_cpumask_var(tr->tracing_cpumask);
> kfree(tr->name);
> @@ -9384,6 +9391,7 @@ static int __remove_instance(struct trace_array *tr)
> event_trace_del_tracer(tr);
> ftrace_clear_pids(tr);
> ftrace_destroy_function_files(tr);
> + free_objtrace_data(tr);
> tracefs_remove(tr->dir);
> free_percpu(tr->last_func_repeats);
> free_trace_buffers(tr);
> @@ -10118,6 +10126,9 @@ __init static int tracer_alloc_buffers(void)
> goto out_free_savedcmd;
> }
>
> + if (allocate_objtrace_data(&global_trace))
> + goto out_free_savedcmd;
> +
> if (global_trace.buffer_disabled)
> tracing_off();
>
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index ff816fb41e48..18220b659555 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -54,6 +54,7 @@ enum trace_type {
> TRACE_TIMERLAT,
> TRACE_RAW_DATA,
> TRACE_FUNC_REPEATS,
> + TRACE_OBJECT,
>
> __TRACE_LAST_TYPE,
> };
> @@ -363,6 +364,9 @@ struct trace_array {
> cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
> int ref;
> int trace_ref;
> +#ifdef CONFIG_TRACE_OBJECT
> + struct objtrace_data *obj_data;
> +#endif
> #ifdef CONFIG_FUNCTION_TRACER
> struct ftrace_ops *ops;
> struct trace_pid_list __rcu *function_pids;
> @@ -471,6 +475,7 @@ extern void __ftrace_bad_type(void);
> TRACE_GRAPH_RET); \
> IF_ASSIGN(var, ent, struct func_repeats_entry, \
> TRACE_FUNC_REPEATS); \
> + IF_ASSIGN(var, ent, struct trace_object_entry, TRACE_OBJECT);\
> __ftrace_bad_type(); \
> } while (0)
>
> @@ -1536,6 +1541,16 @@ static inline int register_trigger_hist_cmd(void) { return 0; }
> static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
> #endif
>
> +#ifdef CONFIG_TRACE_OBJECT
> +extern int register_trigger_object_cmd(void);
> +extern int allocate_objtrace_data(struct trace_array *tr);
> +extern void free_objtrace_data(struct trace_array *tr);
> +#else
> +static inline int register_trigger_object_cmd(void) { return 0; }
> +static inline int allocate_objtrace_data(struct trace_array *tr) { return 0; }
> +static inline void free_objtrace_data(struct trace_array *tr) { };
> +#endif
> +
> extern int register_trigger_cmds(void);
> extern void clear_event_triggers(struct trace_array *tr);
>
> @@ -1611,6 +1626,12 @@ extern bool event_trigger_check_remove(const char *glob);
> extern bool event_trigger_empty_param(const char *param);
> extern int event_trigger_separate_filter(char *param_and_filter, char **param,
> char **filter, bool param_required);
> +extern int register_trigger(char *glob,
> + struct event_trigger_data *data,
> + struct trace_event_file *file);
> +extern void unregister_trigger(char *glob,
> + struct event_trigger_data *test,
> + struct trace_event_file *file);
> extern struct event_trigger_data *
> event_trigger_alloc(struct event_command *cmd_ops,
> char *cmd,
> diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
> index cd41e863b51c..bb120d9498a9 100644
> --- a/kernel/trace/trace_entries.h
> +++ b/kernel/trace/trace_entries.h
> @@ -401,3 +401,20 @@ FTRACE_ENTRY(timerlat, timerlat_entry,
> __entry->context,
> __entry->timer_latency)
> );
> +
> +/*
> + * trace object entry:
> + */
> +FTRACE_ENTRY(object, trace_object_entry,
> +
> + TRACE_OBJECT,
> +
> + F_STRUCT(
> + __field( unsigned long, ip )
> + __field( unsigned long, parent_ip )
> + __field( unsigned long, object )
> + ),
> +
> + F_printk(" %ps <-- %ps object:%lx\n",
> + (void *)__entry->ip, (void *)__entry->parent_ip, __entry->object)
> +);
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index cb866c3141af..8bad4eb3b997 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -560,7 +560,7 @@ void update_cond_flag(struct trace_event_file *file)
> *
> * Return: 0 on success, errno otherwise
> */
> -static int register_trigger(char *glob,
> +int register_trigger(char *glob,
> struct event_trigger_data *data,
> struct trace_event_file *file)
> {
> @@ -605,7 +605,7 @@ static int register_trigger(char *glob,
> * Usually used directly as the @unreg method in event command
> * implementations.
> */
> -static void unregister_trigger(char *glob,
> +void unregister_trigger(char *glob,
> struct event_trigger_data *test,
> struct trace_event_file *file)
> {
> @@ -1976,6 +1976,7 @@ __init int register_trigger_cmds(void)
> register_trigger_enable_disable_cmds();
> register_trigger_hist_enable_disable_cmds();
> register_trigger_hist_cmd();
> + register_trigger_object_cmd();
>
> return 0;
> }
> diff --git a/kernel/trace/trace_object.c b/kernel/trace/trace_object.c
> new file mode 100644
> index 000000000000..19ec4b1c0186
> --- /dev/null
> +++ b/kernel/trace/trace_object.c
> @@ -0,0 +1,450 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * trace the kernel object in the kernel function parameter
> + * Copyright (C) 2021 Jeff Xie <xiehuan09@xxxxxxxxx>
> + */
> +
> +#define pr_fmt(fmt) "trace_object: " fmt
> +
> +#include "trace_output.h"
> +
> +#define MAX_TRACED_OBJECT 5
> +#define OBJTRACE_CMD_LEN 16
> +#define OBJTRACE_CMD_ADD "add"
> +static LIST_HEAD(obj_data_head);
> +static const int max_args_num = 6;
> +static void exit_trace_object(struct trace_array *tr);
> +static int init_trace_object(struct trace_array *tr);
> +
> +struct object_instance {
> + void *obj;
> + struct trace_array *tr;
> +};
> +
> +/* objtrace private data */
> +struct objtrace_trigger_data {
> + struct ftrace_event_field *field;
> + char objtrace_cmd[OBJTRACE_CMD_LEN];
> + struct trace_array *tr;
> +};
> +
> +/* objtrace data with fops and objtrace_instances */
> +struct objtrace_data {
> + struct list_head head;
> + struct trace_array *tr;
> + struct ftrace_ops fops;
> + int num_traced_obj;
> + struct object_instance traced_obj[MAX_TRACED_OBJECT];
> + raw_spinlock_t obj_data_lock;
> +};
> +
> +static struct objtrace_data *get_obj_data(struct trace_array *tr)
> +{
> + struct objtrace_data *obj_data = NULL;
> +
> + list_for_each_entry(obj_data, &obj_data_head, head) {
> + if (obj_data->tr == tr)
> + break;
> + }
> + return obj_data;
> +}
> +
> +static bool object_exist(void *obj, struct trace_array *tr)
> +{
> + int i, max;
> + struct objtrace_data *obj_data;
> +
> + obj_data = get_obj_data(tr);
> + if (!obj_data)
> + return false;
> +
> + max = READ_ONCE(obj_data->num_traced_obj);
> + smp_rmb();
> + for (i = 0; i < max; i++) {
> + if (obj_data->traced_obj[i].obj == obj)
> + return true;
> + }
> + return false;
> +}
> +
> +static bool object_empty(struct trace_array *tr)
> +{
> + struct objtrace_data *obj_data;
> +
> + obj_data = get_obj_data(tr);
> + if (!obj_data)
> + return false;
> +
> + return !READ_ONCE(obj_data->num_traced_obj);
> +}
> +
> +static void set_trace_object(void *obj, struct trace_array *tr)
> +{
> + unsigned long flags;
> + struct object_instance *obj_ins;
> + struct objtrace_data *obj_data;
> +
> + if (in_nmi())
> + return;
> +
> + if (!obj && object_exist(obj, tr))
> + return;
> +
> + obj_data = get_obj_data(tr);
> + if (!obj_data)
> + return;
> +
> + /* only this place has write operations */
> + raw_spin_lock_irqsave(&obj_data->obj_data_lock, flags);
> + if (READ_ONCE(obj_data->num_traced_obj) == MAX_TRACED_OBJECT) {
> + trace_array_printk_buf(tr->array_buffer.buffer, _THIS_IP_,
> + "object_pool is full, can't trace object:0x%px\n", obj);
> + goto out;
> + }
> + obj_ins = &obj_data->traced_obj[READ_ONCE(obj_data->num_traced_obj)];
> + obj_ins->obj = obj;
> + obj_ins->tr = tr;
> + /* make sure the num_traced_obj update always appears after traced_obj update */
> + smp_wmb();
> + obj_data->num_traced_obj++;
> +out:
> + raw_spin_unlock_irqrestore(&obj_data->obj_data_lock, flags);
> +}
> +
> +static void submit_trace_object(unsigned long ip, unsigned long parent_ip,
> + unsigned long object, struct trace_array *tr)
> +{
> +
> + struct trace_buffer *buffer = tr->array_buffer.buffer;
> + struct ring_buffer_event *event;
> + struct trace_object_entry *entry;
> + unsigned int trace_ctx = 0;
> +
> + trace_ctx = tracing_gen_ctx();
> + event = trace_buffer_lock_reserve(buffer, TRACE_OBJECT,
> + sizeof(*entry), trace_ctx);
> + if (!event)
> + return;
> + entry = ring_buffer_event_data(event);
> + entry->ip = ip;
> + entry->parent_ip = parent_ip;
> + entry->object = object;
> +
> + trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
> +}
> +
> +static void
> +trace_object_events_call(unsigned long ip, unsigned long parent_ip,
> + struct ftrace_ops *op, struct ftrace_regs *fregs)
> +{
> + struct pt_regs *pt_regs = ftrace_get_regs(fregs);
> + struct trace_array *tr = op->private;
> + struct trace_array_cpu *data;
> + unsigned long obj;
> + long disabled;
> + int cpu, n;
> +
> + preempt_disable_notrace();
> +
> + cpu = raw_smp_processor_id();
> + data = per_cpu_ptr(tr->array_buffer.data, cpu);
> + disabled = atomic_inc_return(&data->disabled);
> + if (likely(disabled == 1)) {
> + if (object_empty(tr))
> + goto out;
> + for (n = 0; n < max_args_num; n++) {
> + obj = regs_get_kernel_argument(pt_regs, n);
> + if (object_exist((void *)obj, tr))
> + submit_trace_object(ip, parent_ip, obj, tr);
> + /* The parameters of a function may match multiple objects */
> + }
> + }
> +out:
> + atomic_dec(&data->disabled);
> + preempt_enable_notrace();
> +}
> +
> +static void
> +trace_object_trigger(struct event_trigger_data *data,
> + struct trace_buffer *buffer, void *rec,
> + struct ring_buffer_event *event)
> +{
> + struct objtrace_trigger_data *obj_data = data->private_data;
> + struct trace_array *tr = obj_data->tr;
> + struct ftrace_event_field *field;
> + void *obj = NULL;
> +
> + field = obj_data->field;
> + memcpy(&obj, rec + field->offset, sizeof(obj));
> + set_trace_object(obj, tr);
> +}
> +
> +static void
> +trace_object_trigger_free(struct event_trigger_data *data)
> +{
> + struct objtrace_trigger_data *obj_data = data->private_data;
> +
> + if (WARN_ON_ONCE(data->ref <= 0))
> + return;
> +
> + data->ref--;
> + if (!data->ref) {
> + exit_trace_object(obj_data->tr);
> + kfree(data->private_data);
> + trigger_data_free(data);
> + }
> +}
> +
> +static void
> +trace_object_count_trigger(struct event_trigger_data *data,
> + struct trace_buffer *buffer, void *rec,
> + struct ring_buffer_event *event)
> +{
> + if (!data->count)
> + return;
> +
> + if (data->count != -1)
> + (data->count)--;
> +
> + trace_object_trigger(data, buffer, rec, event);
> +}
> +
> +static int
> +event_trigger_print(const char *name, struct seq_file *m,
> + void *data, char *filter_str, void *objtrace_data)
> +{
> + long count = (long)data;
> + struct objtrace_trigger_data *obj_data = objtrace_data;
> +
> + seq_puts(m, name);
> +
> + seq_printf(m, ":%s", obj_data->objtrace_cmd);
> + seq_printf(m, ":%s", obj_data->field->name);
> +
> + if (count == -1)
> + seq_puts(m, ":unlimited");
> + else
> + seq_printf(m, ":count=%ld", count);
> +
> + if (filter_str)
> + seq_printf(m, " if %s\n", filter_str);
> + else
> + seq_putc(m, '\n');
> +
> + return 0;
> +}
> +
> +static int event_object_trigger_init(struct event_trigger_data *data)
> +{
> + struct objtrace_trigger_data *obj_data = data->private_data;
> + int ret;
> +
> + if (!data->ref) {
> + ret = init_trace_object(obj_data->tr);
> + if (ret)
> + return ret;
> + }
> + data->ref++;
> + return 0;
> +}
> +
> +static int
> +trace_object_trigger_print(struct seq_file *m, struct event_trigger_data *data)
> +{
> + return event_trigger_print("objtrace", m, (void *)data->count,
> + data->filter_str, data->private_data);
> +}
> +
> +static struct event_trigger_ops objecttrace_trigger_ops = {
> + .trigger = trace_object_trigger,
> + .print = trace_object_trigger_print,
> + .init = event_object_trigger_init,
> + .free = trace_object_trigger_free,
> +};
> +
> +static struct event_trigger_ops objecttrace_count_trigger_ops = {
> + .trigger = trace_object_count_trigger,
> + .print = trace_object_trigger_print,
> + .init = event_object_trigger_init,
> + .free = trace_object_trigger_free,
> +};
> +
> +static struct event_trigger_ops *
> +objecttrace_get_trigger_ops(char *cmd, char *param)
> +{
> + return param ? &objecttrace_count_trigger_ops : &objecttrace_trigger_ops;
> +}
> +
> +static bool field_exist(struct trace_event_file *file,
> + struct event_command *cmd_ops,
> + const char *field_name)
> +{
> + struct event_trigger_data *data;
> + struct objtrace_trigger_data *obj_data;
> +
> + lockdep_assert_held(&event_mutex);
> +
> + list_for_each_entry(data, &file->triggers, list) {
> + if (data->cmd_ops->trigger_type == cmd_ops->trigger_type) {
> + obj_data = data->private_data;
> + if (!strcmp(obj_data->field->name, field_name))
> + return true;
> + }
> + }
> +
> + return false;
> +}
> +
> +static int
> +event_object_trigger_parse(struct event_command *cmd_ops,
> + struct trace_event_file *file,
> + char *glob, char *cmd, char *param_and_filter)
> +{
> + struct event_trigger_data *trigger_data;
> + struct objtrace_trigger_data *obj_data;
> + struct ftrace_event_field *field;
> + char *objtrace_cmd, *arg;
> + char *param, *filter;
> + int ret;
> + bool remove;
> +
> + remove = event_trigger_check_remove(glob);
> +
> + /*
> + * separate the param and the filter:
> + * objtrace:add:OBJ[:COUNT] [if filter]
> + */
> + ret = event_trigger_separate_filter(param_and_filter, &param, &filter, true);
> + if (ret)
> + return ret;
> +
> + objtrace_cmd = strsep(&param, ":");
> + if (!objtrace_cmd || strcmp(objtrace_cmd, OBJTRACE_CMD_ADD)) {
> + pr_err("error objtrace command\n");
> + return -EINVAL;
> + }
> +
> + arg = strsep(&param, ":");
> + if (!arg)
> + return -EINVAL;
> +
> + field = trace_find_event_field(file->event_call, arg);
> + if (!field)
> + return -EINVAL;
> +
> + if (field->size != sizeof(void *)) {
> + pr_err("the size of the %s should be:%zu\n", field->name, sizeof(void *));
> + return -EINVAL;
> + }
> +
> + if (remove && !field_exist(file, cmd_ops, field->name))
> + return -ENOENT;
> +
> + obj_data = kzalloc(sizeof(*obj_data), GFP_KERNEL);
> + if (!obj_data)
> + return -ENOMEM;
> +
> + obj_data->field = field;
> + obj_data->tr = file->tr;
> + snprintf(obj_data->objtrace_cmd, OBJTRACE_CMD_LEN, objtrace_cmd);
> +
> + trigger_data = event_trigger_alloc(cmd_ops, cmd, param, obj_data);
> + if (!trigger_data) {
> + kfree(obj_data);
> + return -ENOMEM;
> + }
> + if (remove) {
> + event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
> + kfree(obj_data);
> + kfree(trigger_data);
> + return 0;
> + }
> +
> + ret = event_trigger_parse_num(param, trigger_data);
> + if (ret)
> + goto out_free;
> +
> + ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
> + if (ret < 0)
> + goto out_free;
> +
> + ret = event_trigger_register(cmd_ops, file, glob, trigger_data);
> + if (ret)
> + goto out_free;
> +
> + return ret;
> +
> + out_free:
> + event_trigger_reset_filter(cmd_ops, trigger_data);
> + kfree(obj_data);
> + kfree(trigger_data);
> + return ret;
> +}
> +
> +static struct event_command trigger_object_cmd = {
> + .name = "objtrace",
> + .trigger_type = ETT_TRACE_OBJECT,
> + .flags = EVENT_CMD_FL_NEEDS_REC,
> + .parse = event_object_trigger_parse,
> + .reg = register_trigger,
> + .unreg = unregister_trigger,
> + .get_trigger_ops = objecttrace_get_trigger_ops,
> + .set_filter = set_trigger_filter,
> +};
> +
> +__init int register_trigger_object_cmd(void)
> +{
> + int ret;
> +
> + ret = register_event_command(&trigger_object_cmd);
> + WARN_ON(ret < 0);
> +
> + return ret;
> +}
> +
> +int allocate_objtrace_data(struct trace_array *tr)
> +{
> + struct objtrace_data *obj_data;
> + struct ftrace_ops *fops;
> +
> + obj_data = kzalloc(sizeof(*obj_data), GFP_KERNEL);
> + if (!obj_data)
> + return -ENOMEM;
> +
> + raw_spin_lock_init(&obj_data->obj_data_lock);
> + obj_data->tr = tr;
> + fops = &obj_data->fops;
> + fops->func = trace_object_events_call;
> + fops->flags = FTRACE_OPS_FL_SAVE_REGS;
> + fops->private = tr;
> + list_add(&obj_data->head, &obj_data_head);
> +
> + tr->obj_data = obj_data;
> +
> + return 0;
> +}
> +
> +static int init_trace_object(struct trace_array *tr)
> +{
> + int ret;
> +
> + ret = register_ftrace_function(&tr->obj_data->fops);
> + WARN_ON(ret < 0);
> +
> + return ret;
> +}
> +
> +void free_objtrace_data(struct trace_array *tr)
> +{
> + kfree(tr->obj_data);
> + tr->obj_data = NULL;
> +}
> +
> +static void exit_trace_object(struct trace_array *tr)
> +{
> + struct objtrace_data *obj_data = tr->obj_data;
> +
> + obj_data->num_traced_obj = 0;
> + WARN_ONCE(unregister_ftrace_function(&obj_data->fops),
> + "can't unregister ftrace for trace object\n");
> +}
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index 67f47ea27921..34ff7b4dc521 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -1551,6 +1551,45 @@ static struct trace_event trace_func_repeats_event = {
> .funcs = &trace_func_repeats_funcs,
> };
>
> +/* TRACE_OBJECT */
> +static enum print_line_t trace_object_print(struct trace_iterator *iter, int flags,
> + struct trace_event *event)
> +{
> + struct trace_object_entry *field;
> + struct trace_seq *s = &iter->seq;
> +
> + trace_assign_type(field, iter->ent);
> + print_fn_trace(s, field->ip, field->parent_ip, flags);
> + trace_seq_printf(s, " object:0x%lx", field->object);
> + trace_seq_putc(s, '\n');
> +
> + return trace_handle_return(s);
> +}
> +
> +static enum print_line_t trace_object_raw(struct trace_iterator *iter, int flags,
> + struct trace_event *event)
> +{
> + struct trace_object_entry *field;
> +
> + trace_assign_type(field, iter->ent);
> +
> + trace_seq_printf(&iter->seq, "%lx %lx\n",
> + field->ip,
> + field->parent_ip);
> +
> + return trace_handle_return(&iter->seq);
> +}
> +
> +static struct trace_event_functions trace_object_funcs = {
> + .trace = trace_object_print,
> + .raw = trace_object_raw,
> +};
> +
> +static struct trace_event trace_object_event = {
> + .type = TRACE_OBJECT,
> + .funcs = &trace_object_funcs,
> +};
> +
> static struct trace_event *events[] __initdata = {
> &trace_fn_event,
> &trace_ctx_event,
> @@ -1565,6 +1604,7 @@ static struct trace_event *events[] __initdata = {
> &trace_timerlat_event,
> &trace_raw_data_event,
> &trace_func_repeats_event,
> + &trace_object_event,
> NULL
> };
>
> --
> 2.25.1
>


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>