| Message ID | 20220626025604.277413-3-xiehuan09@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | trace: Introduce objtrace trigger to trace the kernel object | expand |
On Sun, 26 Jun 2022 10:56:02 +0800 Jeff Xie <xiehuan09@gmail.com> wrote: > Using objtrace trigger to get the value of the object which from the kernel > function parameter. > > Syntax: > objtrace:add:obj[,offset][:type][:count][if <filter>] > > Usage: > # echo 'p bio_add_page arg1=$arg1' > ./kprobe_events > # gdb vmlinux > (gdb) p &(((struct bio *)0)->bi_iter.bi_size) > $1 = (unsigned int *) 0x28 > # echo 'objtrace:add:arg1,0x28:u32:1 if comm == "cat"' > ./events/kprobes/ \ > p_bio_add_page_0/trigger > # cat /test.txt > Thanks for update! This looks good to me. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> > Signed-off-by: Jeff Xie <xiehuan09@gmail.com> > --- > kernel/trace/trace.c | 2 +- > kernel/trace/trace_entries.h | 5 +- > kernel/trace/trace_object.c | 187 ++++++++++++++++++++++++++++++++--- > kernel/trace/trace_output.c | 6 +- > 4 files changed, 181 insertions(+), 19 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 7074ad8bc1a0..37f5cbfa5347 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5628,7 +5628,7 @@ static const char readme_msg[] = > "\t disable_hist:<system>:<event>\n" > #endif > #ifdef CONFIG_TRACE_OBJECT > - "\t objtrace:add:obj[:count][if <filter>]\n" > + "\t objtrace:add:obj[,offset][:type][:count][if <filter>]\n" > #endif > #ifdef CONFIG_STACKTRACE > "\t\t stacktrace\n" > diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h > index bb120d9498a9..2407c45a568c 100644 > --- a/kernel/trace/trace_entries.h > +++ b/kernel/trace/trace_entries.h > @@ -413,8 +413,9 @@ FTRACE_ENTRY(object, trace_object_entry, > __field( unsigned long, ip ) > __field( unsigned long, parent_ip ) > __field( unsigned long, object ) > + __field( unsigned long, value ) > ), > > - F_printk(" %ps <-- %ps object:%lx\n", > - (void *)__entry->ip, (void *)__entry->parent_ip, __entry->object) > + F_printk(" %ps <-- %ps object:%lx value:%lx\n", (void *)__entry->ip, > + (void *)__entry->parent_ip, __entry->object, __entry->value) > ); > diff --git a/kernel/trace/trace_object.c b/kernel/trace/trace_object.c > index 19ec4b1c0186..611341abeb7c 100644 > --- a/kernel/trace/trace_object.c > +++ b/kernel/trace/trace_object.c > @@ -16,8 +16,14 @@ 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); > > +/* > + * get the offset from the special object and > + * the type size of the value > + */ > struct object_instance { > void *obj; > + int obj_offset; > + int obj_value_type_size; > struct trace_array *tr; > }; > > @@ -25,9 +31,23 @@ struct object_instance { > struct objtrace_trigger_data { > struct ftrace_event_field *field; > char objtrace_cmd[OBJTRACE_CMD_LEN]; > + int obj_offset; > + int obj_value_type_size; > struct trace_array *tr; > }; > > +/* get the type size for the special object */ > +struct objtrace_fetch_type { > + char *name; > + int type_size; > +}; > + > +enum objattr { > + OBJ_OFFSET, > + OBJ_VAL_TYPE_SIZE, > + MAX_OBJ_ATTR > +}; > + > /* objtrace data with fops and objtrace_instances */ > struct objtrace_data { > struct list_head head; > @@ -67,6 +87,35 @@ static bool object_exist(void *obj, struct trace_array *tr) > return false; > } > > +static int get_object_attr(void *obj, int objattr, > + struct trace_array *tr, int *result) > +{ > + int i, max; > + struct objtrace_data *obj_data; > + > + obj_data = get_obj_data(tr); > + if (!obj_data) > + return -EINVAL; > + > + max = READ_ONCE(obj_data->num_traced_obj); > + smp_rmb(); > + for (i = 0; i < max; i++) { > + if (obj_data->traced_obj[i].obj == obj) { > + switch (objattr) { > + case OBJ_OFFSET: > + *result = obj_data->traced_obj[i].obj_offset; > + return 0; > + case OBJ_VAL_TYPE_SIZE: > + *result = obj_data->traced_obj[i].obj_value_type_size; > + return 0; > + default: > + return -EINVAL; > + } > + } > + } > + return -EINVAL; > +} > + > static bool object_empty(struct trace_array *tr) > { > struct objtrace_data *obj_data; > @@ -78,7 +127,8 @@ static bool object_empty(struct trace_array *tr) > return !READ_ONCE(obj_data->num_traced_obj); > } > > -static void set_trace_object(void *obj, struct trace_array *tr) > +static void set_trace_object(void *obj, int obj_offset, > + int obj_value_type_size, struct trace_array *tr) > { > unsigned long flags; > struct object_instance *obj_ins; > @@ -103,6 +153,8 @@ static void set_trace_object(void *obj, struct trace_array *tr) > } > obj_ins = &obj_data->traced_obj[READ_ONCE(obj_data->num_traced_obj)]; > obj_ins->obj = obj; > + obj_ins->obj_value_type_size = obj_value_type_size; > + obj_ins->obj_offset = obj_offset; > obj_ins->tr = tr; > /* make sure the num_traced_obj update always appears after traced_obj update */ > smp_wmb(); > @@ -112,7 +164,7 @@ static void set_trace_object(void *obj, struct trace_array *tr) > } > > static void submit_trace_object(unsigned long ip, unsigned long parent_ip, > - unsigned long object, struct trace_array *tr) > + unsigned long object, unsigned long value, struct trace_array *tr) > { > > struct trace_buffer *buffer = tr->array_buffer.buffer; > @@ -129,10 +181,43 @@ static void submit_trace_object(unsigned long ip, unsigned long parent_ip, > entry->ip = ip; > entry->parent_ip = parent_ip; > entry->object = object; > + entry->value = value; > > trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); > } > > +static inline long get_object_value(unsigned long *val, void *obj, int type_size) > +{ > + char tmp[sizeof(u64)]; > + long ret = 0; > + > + ret = copy_from_kernel_nofault(tmp, obj, sizeof(tmp)); > + if (ret) > + return ret; > + switch (type_size) { > + case 1: { > + *val = (unsigned long)*(u8 *)tmp; > + break; > + } > + case 2: { > + *val = (unsigned long)*(u16 *)tmp; > + break; > + } > + case 4: { > + *val = (unsigned long)*(u32 *)tmp; > + break; > + } > + case 8: { > + *val = (unsigned long)*(u64 *)tmp; > + break; > + } > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > static void > trace_object_events_call(unsigned long ip, unsigned long parent_ip, > struct ftrace_ops *op, struct ftrace_regs *fregs) > @@ -140,7 +225,8 @@ trace_object_events_call(unsigned long ip, unsigned long parent_ip, > struct pt_regs *pt_regs = ftrace_get_regs(fregs); > struct trace_array *tr = op->private; > struct trace_array_cpu *data; > - unsigned long obj; > + int ret, val_type_size, obj_offset; > + unsigned long obj, val; > long disabled; > int cpu, n; > > @@ -154,8 +240,21 @@ trace_object_events_call(unsigned long ip, unsigned long parent_ip, > 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); > + if (object_exist((void *)obj, tr)) { > + ret = get_object_attr((void *)obj, OBJ_OFFSET, > + tr, &obj_offset); > + if (unlikely(ret) < 0) > + goto out; > + ret = get_object_attr((void *)obj, OBJ_VAL_TYPE_SIZE, > + tr, &val_type_size); > + if (unlikely(ret) < 0) > + goto out; > + if (get_object_value(&val, (void *)(obj + obj_offset), > + val_type_size)) > + continue; > + > + submit_trace_object(ip, parent_ip, obj, val, tr); > + } > /* The parameters of a function may match multiple objects */ > } > } > @@ -176,9 +275,23 @@ trace_object_trigger(struct event_trigger_data *data, > > field = obj_data->field; > memcpy(&obj, rec + field->offset, sizeof(obj)); > - set_trace_object(obj, tr); > + /* set the offset from the special object and the type size of the value*/ > + set_trace_object(obj, obj_data->obj_offset, > + obj_data->obj_value_type_size, tr); > } > > +static const struct objtrace_fetch_type objtrace_fetch_types[] = { > + {"u8", 1}, > + {"x8", 1}, > + {"u16", 2}, > + {"x16", 2}, > + {"u32", 4}, > + {"x32", 4}, > + {"u64", 8}, > + {"x64", 8}, > + {NULL, 0}, > +}; > + > static void > trace_object_trigger_free(struct event_trigger_data *data) > { > @@ -213,14 +326,25 @@ static int > event_trigger_print(const char *name, struct seq_file *m, > void *data, char *filter_str, void *objtrace_data) > { > + int i; > long count = (long)data; > struct objtrace_trigger_data *obj_data = objtrace_data; > + const char *value_type_name; > > seq_puts(m, name); > > seq_printf(m, ":%s", obj_data->objtrace_cmd); > seq_printf(m, ":%s", obj_data->field->name); > + if (obj_data->obj_offset) > + seq_printf(m, ",0x%x", obj_data->obj_offset); > > + for (i = 0; objtrace_fetch_types[i].name; i++) { > + if (objtrace_fetch_types[i].type_size == obj_data->obj_value_type_size) { > + value_type_name = objtrace_fetch_types[i].name; > + break; > + } > + } > + seq_printf(m, ":%s", value_type_name); > if (count == -1) > seq_puts(m, ":unlimited"); > else > @@ -303,16 +427,18 @@ event_object_trigger_parse(struct event_command *cmd_ops, > 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; > + char *objtrace_cmd, *obj; > + char *param, *filter, *str, *type; > + int ret, i, def_type_size, obj_value_type_size = 0; > + char *tmp_saved_param; > + long offset = 0; > bool remove; > > remove = event_trigger_check_remove(glob); > > /* > * separate the param and the filter: > - * objtrace:add:OBJ[:COUNT] [if filter] > + * objtrace:add:OBJ[,OFFS][:TYPE][:COUNT] [if filter] > */ > ret = event_trigger_separate_filter(param_and_filter, ¶m, &filter, true); > if (ret) > @@ -324,11 +450,44 @@ event_object_trigger_parse(struct event_command *cmd_ops, > return -EINVAL; > } > > - arg = strsep(¶m, ":"); > - if (!arg) > + obj = strsep(¶m, ":"); > + if (!obj) > return -EINVAL; > > - field = trace_find_event_field(file->event_call, arg); > + str = strchr(obj, ','); > + if (!str) > + offset = 0; > + else { > + *str++ = '\0'; > + ret = kstrtol(str, 0, &offset); > + if (ret) > + return -EINVAL; > + } > + def_type_size = sizeof(void *); > + if (!param) { > + obj_value_type_size = def_type_size; > + goto skip_get_type; > + } > + tmp_saved_param = param; > + type = strsep(¶m, ":"); > + if (!type) > + obj_value_type_size = def_type_size; > + /* if this is the trigger count */ > + else if (isdigit(type[0])) { > + obj_value_type_size = def_type_size; > + param = tmp_saved_param; > + } else { > + for (i = 0; objtrace_fetch_types[i].name; i++) { > + if (strcmp(objtrace_fetch_types[i].name, type) == 0) { > + obj_value_type_size = objtrace_fetch_types[i].type_size; > + break; > + } > + } > + } > + if (!obj_value_type_size) > + return -EINVAL; > +skip_get_type: > + field = trace_find_event_field(file->event_call, obj); > if (!field) > return -EINVAL; > > @@ -345,6 +504,8 @@ event_object_trigger_parse(struct event_command *cmd_ops, > return -ENOMEM; > > obj_data->field = field; > + obj_data->obj_offset = offset; > + obj_data->obj_value_type_size = obj_value_type_size; > obj_data->tr = file->tr; > snprintf(obj_data->objtrace_cmd, OBJTRACE_CMD_LEN, objtrace_cmd); > > diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c > index 34ff7b4dc521..a45871b52dcc 100644 > --- a/kernel/trace/trace_output.c > +++ b/kernel/trace/trace_output.c > @@ -1561,6 +1561,7 @@ static enum print_line_t trace_object_print(struct trace_iterator *iter, int fla > 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_printf(s, " value:0x%lx", field->value); > trace_seq_putc(s, '\n'); > > return trace_handle_return(s); > @@ -1573,9 +1574,8 @@ static enum print_line_t trace_object_raw(struct trace_iterator *iter, int flags > > trace_assign_type(field, iter->ent); > > - trace_seq_printf(&iter->seq, "%lx %lx\n", > - field->ip, > - field->parent_ip); > + trace_seq_printf(&iter->seq, "%lx %lx %lx %lx\n", field->ip, > + field->parent_ip, field->object, field->value); > > return trace_handle_return(&iter->seq); > } > -- > 2.25.1 >
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7074ad8bc1a0..37f5cbfa5347 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5628,7 +5628,7 @@ static const char readme_msg[] = "\t disable_hist:<system>:<event>\n" #endif #ifdef CONFIG_TRACE_OBJECT - "\t objtrace:add:obj[:count][if <filter>]\n" + "\t objtrace:add:obj[,offset][:type][:count][if <filter>]\n" #endif #ifdef CONFIG_STACKTRACE "\t\t stacktrace\n" diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index bb120d9498a9..2407c45a568c 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -413,8 +413,9 @@ FTRACE_ENTRY(object, trace_object_entry, __field( unsigned long, ip ) __field( unsigned long, parent_ip ) __field( unsigned long, object ) + __field( unsigned long, value ) ), - F_printk(" %ps <-- %ps object:%lx\n", - (void *)__entry->ip, (void *)__entry->parent_ip, __entry->object) + F_printk(" %ps <-- %ps object:%lx value:%lx\n", (void *)__entry->ip, + (void *)__entry->parent_ip, __entry->object, __entry->value) ); diff --git a/kernel/trace/trace_object.c b/kernel/trace/trace_object.c index 19ec4b1c0186..611341abeb7c 100644 --- a/kernel/trace/trace_object.c +++ b/kernel/trace/trace_object.c @@ -16,8 +16,14 @@ 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); +/* + * get the offset from the special object and + * the type size of the value + */ struct object_instance { void *obj; + int obj_offset; + int obj_value_type_size; struct trace_array *tr; }; @@ -25,9 +31,23 @@ struct object_instance { struct objtrace_trigger_data { struct ftrace_event_field *field; char objtrace_cmd[OBJTRACE_CMD_LEN]; + int obj_offset; + int obj_value_type_size; struct trace_array *tr; }; +/* get the type size for the special object */ +struct objtrace_fetch_type { + char *name; + int type_size; +}; + +enum objattr { + OBJ_OFFSET, + OBJ_VAL_TYPE_SIZE, + MAX_OBJ_ATTR +}; + /* objtrace data with fops and objtrace_instances */ struct objtrace_data { struct list_head head; @@ -67,6 +87,35 @@ static bool object_exist(void *obj, struct trace_array *tr) return false; } +static int get_object_attr(void *obj, int objattr, + struct trace_array *tr, int *result) +{ + int i, max; + struct objtrace_data *obj_data; + + obj_data = get_obj_data(tr); + if (!obj_data) + return -EINVAL; + + max = READ_ONCE(obj_data->num_traced_obj); + smp_rmb(); + for (i = 0; i < max; i++) { + if (obj_data->traced_obj[i].obj == obj) { + switch (objattr) { + case OBJ_OFFSET: + *result = obj_data->traced_obj[i].obj_offset; + return 0; + case OBJ_VAL_TYPE_SIZE: + *result = obj_data->traced_obj[i].obj_value_type_size; + return 0; + default: + return -EINVAL; + } + } + } + return -EINVAL; +} + static bool object_empty(struct trace_array *tr) { struct objtrace_data *obj_data; @@ -78,7 +127,8 @@ static bool object_empty(struct trace_array *tr) return !READ_ONCE(obj_data->num_traced_obj); } -static void set_trace_object(void *obj, struct trace_array *tr) +static void set_trace_object(void *obj, int obj_offset, + int obj_value_type_size, struct trace_array *tr) { unsigned long flags; struct object_instance *obj_ins; @@ -103,6 +153,8 @@ static void set_trace_object(void *obj, struct trace_array *tr) } obj_ins = &obj_data->traced_obj[READ_ONCE(obj_data->num_traced_obj)]; obj_ins->obj = obj; + obj_ins->obj_value_type_size = obj_value_type_size; + obj_ins->obj_offset = obj_offset; obj_ins->tr = tr; /* make sure the num_traced_obj update always appears after traced_obj update */ smp_wmb(); @@ -112,7 +164,7 @@ static void set_trace_object(void *obj, struct trace_array *tr) } static void submit_trace_object(unsigned long ip, unsigned long parent_ip, - unsigned long object, struct trace_array *tr) + unsigned long object, unsigned long value, struct trace_array *tr) { struct trace_buffer *buffer = tr->array_buffer.buffer; @@ -129,10 +181,43 @@ static void submit_trace_object(unsigned long ip, unsigned long parent_ip, entry->ip = ip; entry->parent_ip = parent_ip; entry->object = object; + entry->value = value; trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); } +static inline long get_object_value(unsigned long *val, void *obj, int type_size) +{ + char tmp[sizeof(u64)]; + long ret = 0; + + ret = copy_from_kernel_nofault(tmp, obj, sizeof(tmp)); + if (ret) + return ret; + switch (type_size) { + case 1: { + *val = (unsigned long)*(u8 *)tmp; + break; + } + case 2: { + *val = (unsigned long)*(u16 *)tmp; + break; + } + case 4: { + *val = (unsigned long)*(u32 *)tmp; + break; + } + case 8: { + *val = (unsigned long)*(u64 *)tmp; + break; + } + default: + return -EINVAL; + } + + return 0; +} + static void trace_object_events_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) @@ -140,7 +225,8 @@ trace_object_events_call(unsigned long ip, unsigned long parent_ip, struct pt_regs *pt_regs = ftrace_get_regs(fregs); struct trace_array *tr = op->private; struct trace_array_cpu *data; - unsigned long obj; + int ret, val_type_size, obj_offset; + unsigned long obj, val; long disabled; int cpu, n; @@ -154,8 +240,21 @@ trace_object_events_call(unsigned long ip, unsigned long parent_ip, 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); + if (object_exist((void *)obj, tr)) { + ret = get_object_attr((void *)obj, OBJ_OFFSET, + tr, &obj_offset); + if (unlikely(ret) < 0) + goto out; + ret = get_object_attr((void *)obj, OBJ_VAL_TYPE_SIZE, + tr, &val_type_size); + if (unlikely(ret) < 0) + goto out; + if (get_object_value(&val, (void *)(obj + obj_offset), + val_type_size)) + continue; + + submit_trace_object(ip, parent_ip, obj, val, tr); + } /* The parameters of a function may match multiple objects */ } } @@ -176,9 +275,23 @@ trace_object_trigger(struct event_trigger_data *data, field = obj_data->field; memcpy(&obj, rec + field->offset, sizeof(obj)); - set_trace_object(obj, tr); + /* set the offset from the special object and the type size of the value*/ + set_trace_object(obj, obj_data->obj_offset, + obj_data->obj_value_type_size, tr); } +static const struct objtrace_fetch_type objtrace_fetch_types[] = { + {"u8", 1}, + {"x8", 1}, + {"u16", 2}, + {"x16", 2}, + {"u32", 4}, + {"x32", 4}, + {"u64", 8}, + {"x64", 8}, + {NULL, 0}, +}; + static void trace_object_trigger_free(struct event_trigger_data *data) { @@ -213,14 +326,25 @@ static int event_trigger_print(const char *name, struct seq_file *m, void *data, char *filter_str, void *objtrace_data) { + int i; long count = (long)data; struct objtrace_trigger_data *obj_data = objtrace_data; + const char *value_type_name; seq_puts(m, name); seq_printf(m, ":%s", obj_data->objtrace_cmd); seq_printf(m, ":%s", obj_data->field->name); + if (obj_data->obj_offset) + seq_printf(m, ",0x%x", obj_data->obj_offset); + for (i = 0; objtrace_fetch_types[i].name; i++) { + if (objtrace_fetch_types[i].type_size == obj_data->obj_value_type_size) { + value_type_name = objtrace_fetch_types[i].name; + break; + } + } + seq_printf(m, ":%s", value_type_name); if (count == -1) seq_puts(m, ":unlimited"); else @@ -303,16 +427,18 @@ event_object_trigger_parse(struct event_command *cmd_ops, 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; + char *objtrace_cmd, *obj; + char *param, *filter, *str, *type; + int ret, i, def_type_size, obj_value_type_size = 0; + char *tmp_saved_param; + long offset = 0; bool remove; remove = event_trigger_check_remove(glob); /* * separate the param and the filter: - * objtrace:add:OBJ[:COUNT] [if filter] + * objtrace:add:OBJ[,OFFS][:TYPE][:COUNT] [if filter] */ ret = event_trigger_separate_filter(param_and_filter, ¶m, &filter, true); if (ret) @@ -324,11 +450,44 @@ event_object_trigger_parse(struct event_command *cmd_ops, return -EINVAL; } - arg = strsep(¶m, ":"); - if (!arg) + obj = strsep(¶m, ":"); + if (!obj) return -EINVAL; - field = trace_find_event_field(file->event_call, arg); + str = strchr(obj, ','); + if (!str) + offset = 0; + else { + *str++ = '\0'; + ret = kstrtol(str, 0, &offset); + if (ret) + return -EINVAL; + } + def_type_size = sizeof(void *); + if (!param) { + obj_value_type_size = def_type_size; + goto skip_get_type; + } + tmp_saved_param = param; + type = strsep(¶m, ":"); + if (!type) + obj_value_type_size = def_type_size; + /* if this is the trigger count */ + else if (isdigit(type[0])) { + obj_value_type_size = def_type_size; + param = tmp_saved_param; + } else { + for (i = 0; objtrace_fetch_types[i].name; i++) { + if (strcmp(objtrace_fetch_types[i].name, type) == 0) { + obj_value_type_size = objtrace_fetch_types[i].type_size; + break; + } + } + } + if (!obj_value_type_size) + return -EINVAL; +skip_get_type: + field = trace_find_event_field(file->event_call, obj); if (!field) return -EINVAL; @@ -345,6 +504,8 @@ event_object_trigger_parse(struct event_command *cmd_ops, return -ENOMEM; obj_data->field = field; + obj_data->obj_offset = offset; + obj_data->obj_value_type_size = obj_value_type_size; obj_data->tr = file->tr; snprintf(obj_data->objtrace_cmd, OBJTRACE_CMD_LEN, objtrace_cmd); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 34ff7b4dc521..a45871b52dcc 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1561,6 +1561,7 @@ static enum print_line_t trace_object_print(struct trace_iterator *iter, int fla 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_printf(s, " value:0x%lx", field->value); trace_seq_putc(s, '\n'); return trace_handle_return(s); @@ -1573,9 +1574,8 @@ static enum print_line_t trace_object_raw(struct trace_iterator *iter, int flags trace_assign_type(field, iter->ent); - trace_seq_printf(&iter->seq, "%lx %lx\n", - field->ip, - field->parent_ip); + trace_seq_printf(&iter->seq, "%lx %lx %lx %lx\n", field->ip, + field->parent_ip, field->object, field->value); return trace_handle_return(&iter->seq); }
Using objtrace trigger to get the value of the object which from the kernel function parameter. Syntax: objtrace:add:obj[,offset][:type][:count][if <filter>] Usage: # echo 'p bio_add_page arg1=$arg1' > ./kprobe_events # gdb vmlinux (gdb) p &(((struct bio *)0)->bi_iter.bi_size) $1 = (unsigned int *) 0x28 # echo 'objtrace:add:arg1,0x28:u32:1 if comm == "cat"' > ./events/kprobes/ \ p_bio_add_page_0/trigger # cat /test.txt Signed-off-by: Jeff Xie <xiehuan09@gmail.com> --- kernel/trace/trace.c | 2 +- kernel/trace/trace_entries.h | 5 +- kernel/trace/trace_object.c | 187 ++++++++++++++++++++++++++++++++--- kernel/trace/trace_output.c | 6 +- 4 files changed, 181 insertions(+), 19 deletions(-)