From: Dave Martin <[email protected]>
If a trace event contains an array, there is currently no standard
way to format this for text output. Drivers are currently hacking
around this by a) local hacks that use the trace_seq functionailty
directly, or b) just not printing that information. For fixed size
arrays, formatting of the elements can be open-coded, but this gets
cumbersome for arrays of non-trivial size.
These approaches result in non-standard content of the event format
description delivered to userspace, so userland tools needs to be
taught to understand and parse each array printing method
individually.
This patch implements common __print_<type>_array() helpers that
tracepoint implementations can use instead of reinventing them. A
simple C-style syntax is used to delimit the array and its elements
{like,this}.
So that the helpers can be used with large static arrays as well as
dynamic arrays, they take a pointer and element count: they can be
used with __get_dynamic_array() for use with dynamic arrays.
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Dave Martin <[email protected]>
Signed-off-by: Javi Merino <[email protected]>
---
Changes since v1[0]
- Replaced the DEFINE_PRINT_ARRAY macros with a single
ftrace_print_array_seq() function.
[0] http://thread.gmane.org/gmane.linux.kernel/1845418/focus=54110
include/linux/ftrace_event.h | 4 ++++
include/trace/ftrace.h | 5 +++++
kernel/trace/trace_output.c | 42 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 51 insertions(+)
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 0bebb5c348b8..5aa4a9269547 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -44,6 +44,10 @@ const char *ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
const char *ftrace_print_hex_seq(struct trace_seq *p,
const unsigned char *buf, int len);
+const char *ftrace_print_array_seq(struct trace_seq *p,
+ const void *buf, int buf_len,
+ size_t el_size);
+
struct trace_iterator;
struct trace_event;
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 139b5067345b..da911289a8dd 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -263,6 +263,10 @@
#undef __print_hex
#define __print_hex(buf, buf_len) ftrace_print_hex_seq(p, buf, buf_len)
+#undef __print_array
+#define __print_array(array, count, el_size) \
+ ftrace_print_array_seq(p, array, count, el_size)
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t \
@@ -674,6 +678,7 @@ static inline void ftrace_test_probe_##call(void) \
#undef __get_dynamic_array_len
#undef __get_str
#undef __get_bitmask
+#undef __print_array
#undef TP_printk
#define TP_printk(fmt, args...) "\"" fmt "\", " __stringify(args)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index b77b9a697619..6cee7c36a669 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -177,6 +177,48 @@ ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
}
EXPORT_SYMBOL(ftrace_print_hex_seq);
+const char *
+ftrace_print_array_seq(struct trace_seq *p, const void *buf, int buf_len,
+ size_t el_size)
+{
+ const char *ret = trace_seq_buffer_ptr(p);
+ const char *prefix = "";
+ void *ptr = (void *)buf;
+
+ trace_seq_putc(p, '{');
+
+ while (ptr < buf + buf_len) {
+ switch (el_size) {
+ case 8:
+ trace_seq_printf(p, "%s0x%x", prefix,
+ *(u8 *)ptr);
+ break;
+ case 16:
+ trace_seq_printf(p, "%s0x%x", prefix,
+ *(u16 *)ptr);
+ break;
+ case 32:
+ trace_seq_printf(p, "%s0x%x", prefix,
+ *(u32 *)ptr);
+ break;
+ case 64:
+ trace_seq_printf(p, "%s0x%llx", prefix,
+ *(u64 *)ptr);
+ break;
+ default:
+ BUG();
+ }
+ prefix = ",";
+ ptr += el_size / 8;
+ }
+
+ trace_seq_putc(p, '}');
+ trace_seq_putc(p, 0);
+
+ return ret;
+}
+EXPORT_SYMBOL(ftrace_print_array_seq);
+
int ftrace_raw_output_prep(struct trace_iterator *iter,
struct trace_event *trace_event)
{
--
1.9.1
Trace can now generate traces with variable element size arrays. Add
support to parse them.
Cc: Namhyung Kim <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Jiri Olsa <[email protected]>
Signed-off-by: Javi Merino <[email protected]>
---
tools/lib/traceevent/event-parse.c | 127 +++++++++++++++++++++++++++++++++++++
tools/lib/traceevent/event-parse.h | 8 +++
2 files changed, 135 insertions(+)
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index cf3a44bf1ec3..00dd6213449c 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -757,6 +757,11 @@ static void free_arg(struct print_arg *arg)
free_arg(arg->hex.field);
free_arg(arg->hex.size);
break;
+ case PRINT_INT_ARRAY:
+ free_arg(arg->int_array.field);
+ free_arg(arg->int_array.size);
+ free_arg(arg->int_array.el_size);
+ break;
case PRINT_TYPE:
free(arg->typecast.type);
free_arg(arg->typecast.item);
@@ -2533,6 +2538,71 @@ process_hex(struct event_format *event, struct print_arg *arg, char **tok)
}
static enum event_type
+process_int_array(struct event_format *event, struct print_arg *arg, char **tok)
+{
+ struct print_arg *field;
+ enum event_type type;
+ char *token;
+
+ memset(arg, 0, sizeof(*arg));
+ arg->type = PRINT_INT_ARRAY;
+
+ field = alloc_arg();
+ if (!field) {
+ do_warning_event(event, "%s: not enough memory!", __func__);
+ goto out;
+ }
+
+ type = process_arg(event, field, &token);
+
+ if (test_type_token(type, token, EVENT_DELIM, ","))
+ goto out_free;
+
+ arg->int_array.field = field;
+
+ free_token(token);
+
+ field = alloc_arg();
+ if (!field) {
+ do_warning_event(event, "%s: not enough memory!", __func__);
+ goto out;
+ }
+
+ type = process_arg(event, field, &token);
+
+ if (test_type_token(type, token, EVENT_DELIM, ","))
+ goto out_free;
+
+ arg->int_array.size = field;
+
+ free_token(token);
+
+ field = alloc_arg();
+ if (!field) {
+ do_warning_event(event, "%s: not enough memory!", __func__);
+ goto out;
+ }
+
+ type = process_arg(event, field, &token);
+
+ if (test_type_token(type, token, EVENT_DELIM, ")"))
+ goto out_free;
+
+ arg->int_array.el_size = field;
+
+ free_token(token);
+ type = read_token_item(tok);
+ return type;
+
+ out_free:
+ free_arg(field);
+ free_token(token);
+out:
+ *tok = NULL;
+ return EVENT_ERROR;
+}
+
+static enum event_type
process_dynamic_array(struct event_format *event, struct print_arg *arg, char **tok)
{
struct format_field *field;
@@ -2827,6 +2897,10 @@ process_function(struct event_format *event, struct print_arg *arg,
free_token(token);
return process_hex(event, arg, tok);
}
+ if (strcmp(token, "__print_array") == 0) {
+ free_token(token);
+ return process_int_array(event, arg, tok);
+ }
if (strcmp(token, "__get_str") == 0) {
free_token(token);
return process_str(event, arg, tok);
@@ -3355,6 +3429,7 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg
break;
case PRINT_FLAGS:
case PRINT_SYMBOL:
+ case PRINT_INT_ARRAY:
case PRINT_HEX:
break;
case PRINT_TYPE:
@@ -3765,6 +3840,49 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
}
break;
+ case PRINT_INT_ARRAY: {
+ void *num;
+ int el_size;
+
+ if (arg->int_array.field->type == PRINT_DYNAMIC_ARRAY) {
+ unsigned long offset;
+
+ offset = pevent_read_number(pevent,
+ data + arg->int_array.field->dynarray.field->offset,
+ arg->int_array.field->dynarray.field->size);
+ num = data + (offset & 0xffff);
+ } else {
+ field = arg->int_array.field->field.field;
+ if (!field) {
+ str = arg->int_array.field->field.name;
+ field = pevent_find_any_field(event, str);
+ if (!field)
+ goto out_warning_field;
+ arg->int_array.field->field.field = field;
+ }
+ num = data + field->offset;
+ }
+ len = eval_num_arg(data, size, event, arg->int_array.size);
+ el_size = eval_num_arg(data, size, event,
+ arg->int_array.el_size);
+ el_size /= 8;
+ for (i = 0; i < len; i++) {
+ if (i)
+ trace_seq_putc(s, ' ');
+
+ if (el_size == 1)
+ trace_seq_printf(s, "%u", *(uint8_t *)num);
+ else if (el_size == 2)
+ trace_seq_printf(s, "%u", *(uint16_t *)num);
+ else if (el_size == 4)
+ trace_seq_printf(s, "%u", *(uint32_t *)num);
+ else if (el_size == 8)
+ trace_seq_printf(s, "%lu", *(uint64_t *)num);
+
+ num += el_size;
+ }
+ break;
+ }
case PRINT_TYPE:
break;
case PRINT_STRING: {
@@ -4928,6 +5046,15 @@ static void print_args(struct print_arg *args)
print_args(args->hex.size);
printf(")");
break;
+ case PRINT_INT_ARRAY:
+ printf("__print_array(");
+ print_args(args->int_array.field);
+ printf(", ");
+ print_args(args->int_array.size);
+ printf(", ");
+ print_args(args->int_array.el_size);
+ printf(")");
+ break;
case PRINT_STRING:
case PRINT_BSTRING:
printf("__get_str(%s)", args->string.string);
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 7a3873ff9a4f..5ac3e3c00389 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -245,6 +245,12 @@ struct print_arg_hex {
struct print_arg *size;
};
+struct print_arg_int_array {
+ struct print_arg *field;
+ struct print_arg *size;
+ struct print_arg *el_size;
+};
+
struct print_arg_dynarray {
struct format_field *field;
struct print_arg *index;
@@ -273,6 +279,7 @@ enum print_arg_type {
PRINT_FLAGS,
PRINT_SYMBOL,
PRINT_HEX,
+ PRINT_INT_ARRAY,
PRINT_TYPE,
PRINT_STRING,
PRINT_BSTRING,
@@ -292,6 +299,7 @@ struct print_arg {
struct print_arg_flags flags;
struct print_arg_symbol symbol;
struct print_arg_hex hex;
+ struct print_arg_int_array int_array;
struct print_arg_func func;
struct print_arg_string string;
struct print_arg_bitmask bitmask;
--
1.9.1