[PATCH 3/8] tracing/events: nicer print format for parsing

[Steven Rostedt]

From: Steven Rostedt <srostedt@xxxxxxxxxx>

The current print format that is exported to userspace is simply a
copy of the printk format used to output the data. It would take a
full C parser to parse it. But as more tools are made to read the
binary data from ftrace, the larger the need for a nice parsing
format to facilitate tools in reading the binary buffer.

For example we currently have:

irq_handler_entry:
 print fmt: "irq=%d handler=%s", REC->irq, (char *)((void *)REC + REC->__data_loc
_name)

softirq_entry:
 print fmt: "softirq=%d action=%s", REC->vec, ({ static const struct trace_print_
flags symbols[] = { { HI_SOFTIRQ, "HI" }, { TIMER_SOFTIRQ, "TIMER" }, { NET_TX_S
OFTIRQ, "NET_TX" }, { NET_RX_SOFTIRQ, "NET_RX" }, { BLOCK_SOFTIRQ, "BLOCK" }, {
TASKLET_SOFTIRQ, "TASKLET" }, { SCHED_SOFTIRQ, "SCHED" }, { HRTIMER_SOFTIRQ, "HR
TIMER" }, { RCU_SOFTIRQ, "RCU" }, { -1, ((void *)0) }}; ftrace_print_symbols_seq
(p, REC->vec, symbols); })

kmalloc:
 print fmt: "call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s", RE
C->call_site, REC->ptr, REC->bytes_req, REC->bytes_alloc, (REC->gfp_flags) ? ({
static const struct trace_print_flags flags[] = { {(unsigned long)(((gfp_t)0x10u
) | ((gfp_t)0x40u) | ((gfp_t)0x80u) | ((gfp_t)0x20000u) | ((gfp_t)0x02u) | ((gfp
_t)0x100000u)), "GFP_HIGHUSER_MOVABLE"}, {(unsigned long)(((gfp_t)0x10u) | ((gfp
_t)0x40u) | ((gfp_t)0x80u) | ((gfp_t)0x20000u) | ((gfp_t)0x02u)), "GFP_HIGHUSER"
}, {(unsigned long)(((gfp_t)0x10u) | ((gfp_t)0x40u) | ((gfp_t)0x80u) | ((gfp_t)0
x20000u)), "GFP_USER"}, {(unsigned long)(((gfp_t)0x10u) | ((gfp_t)0x40u) | ((gfp
_t)0x80u) | ((gfp_t)0x80000u)), "GFP_TEMPORARY"}, {(unsigned long)(((gfp_t)0x10u
) | ((gfp_t)0x40u) | ((gfp_t)0x80u)), "GFP_KERNEL"}, {(unsigned long)(((gfp_t)0x
10u) | ((gfp_t)0x40u)), "GFP_NOFS"}, {(unsigned long)(((gfp_t)0x20u)), "GFP_ATOM
IC"}, {(unsigned long)(((gfp_t)0x10u)), "GFP_NOIO"}, {(unsigned long)((gfp_t)0x2
0u), "GFP_HIGH"}, {(unsigned long)((gfp_t)0x10u), "GFP_WAIT"}, {(unsigned long)(
(gfp_t)0x40u), "GFP_IO"}, {(unsigned long)((gfp_t)0x100u), "GFP_COLD"}, {(unsign
ed long)((gfp_t)0x200u), "GFP_NOWARN"}, {(unsigned long)((gfp_t)0x400u), "GFP_RE
PEAT"}, {(unsigned long)((gfp_t)0x800u), "GFP_NOFAIL"}, {(unsigned long)((gfp_t)
0x1000u), "GFP_NORETRY"}, {(unsigned long)((gfp_t)0x4000u), "GFP_COMP"}, {(unsig
ned long)((gfp_t)0x8000u), "GFP_ZERO"}, {(unsigned long)((gfp_t)0x10000u), "GFP_
NOMEMALLOC"}, {(unsigned long)((gfp_t)0x20000u), "GFP_HARDWALL"}, {(unsigned lon
g)((gfp_t)0x40000u), "GFP_THISNODE"}, {(unsigned long)((gfp_t)0x80000u), "GFP_RE
CLAIMABLE"}, {(unsigned long)((gfp_t)0x100000u), "GFP_MOVABLE"}, { -1, ((void *)
0) }}; ftrace_print_flags_seq(p, "|", REC->gfp_flags, flags); }) : "GFP_NOWAIT"

The language that is added by this patch is of the following:

 * FMT :=  constant string FMT | COMMAND FMT | empty
 * COMMAND := <TYPE:FIELD> | <mask:FIELD:DELIM:MASKS> | <sym:FIELD:SYMBOLS> |
 *               <if:FIELD:TRUE:FALSE> | <ifmask:FIELD:MASK:TRUE:FALSE>
 * TYPE := int | uint | hex | ptr | string | strarray
 * FIELD := defined by the event structure
 * MASKS := MASK=NAME,MASKS | MASK=NAME
 * MASK := the bit mask to match
 * DELIM := delimiter to separate the fields. None and ':' are both allowed
 * SYMBOLS := SYM=NAME,SYMBOLS | SYM=NAME
 * SYM := the symbol value to test against
 * TRUE := print when field is non zero
 * FALSE := print when field is zero or NULL
 * NAME := the name to write when a match is found
 *
 * A '\<' would print '<'

The above examples would then look like:

irq_handler_entry:
 format: irq=<int:irq> handler=<string:name>

softirq_entry:
 format: softirq=<int:vec> action=<sym:vec:0=HI,1=TIMER,2=NET_TX,3=NET_RX,4=BLOCK,5=TASKLET,6=SCHED,7=HRTIMER,8=RCU

kmalloc:
 format: call_site=<hex:call_site> ptr=<ptr:ptr> bytes_req=<int:bytes_req> bytes_alloc=<int:bytes_alloc> gfp_flags=<mask:gfp_flags:|:0=GFP_NOWAIT,0x1200d2=GFP_HIGHUSER_MOVABLE,0x200d2=GFP_HIGHUSER,0x200d0=GFP_USER,0x800d0=GFP_TEMPORARY,0xd0=GFP_KERNEL,0x50=GFP_NOFS,0x20=GFP_ATOMIC,0x10=GFP_NOIO,0x20=GFP_HIGH,0x10=GFP_WAIT,0x40=GFP_IO,0x100=GFP_COLD,0x200=GFP_NOWARN,0x400=GFP_REPEAT,0x800=GFP_NOFAIL,0x1000=GFP_NORETRY,0x4000=GFP_COMP,0x8000=GFP_ZERO,0x10000=GFP_NOMEMALLOC,0x20000=GFP_HARDWALL,0x40000=GFP_THISNODE,0x80000=GFP_RECLAIMABLE,0x100000=GFP_MOVABLE

The above "mask" command takes '0' as a special mask that should be done only in the beginning. It will write that symbol out when the mask is zero.

Another nice thing about this change set is that it can live together with
the current print format. The old version will show "print fmt:" in
the output file, where as the new version will use "format:" as shown
in the above examples.

Both may be used, but it would be preferable to use the new language.
If the new language is not adequate for a new trace point we can always
add new types. Userspace tools should just ignore types it does not
understand.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 include/linux/ftrace_event.h     |   11 +
 include/trace/ftrace.h           |   22 +-
 kernel/trace/Makefile            |    1 +
 kernel/trace/trace_events.c      |    1 +
 kernel/trace/trace_read_binary.c |  766 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 799 insertions(+), 2 deletions(-)
 create mode 100644 kernel/trace/trace_read_binary.c

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 5c093ff..d963a78 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -119,6 +119,9 @@ struct ftrace_event_call {
 	void			*filter;
 	void			*mod;
 
+	struct list_head	print_info;
+	const char		*print_text;
+
 #ifdef CONFIG_EVENT_PROFILE
 	atomic_t	profile_count;
 	int		(*profile_enable)(struct ftrace_event_call *);
@@ -136,6 +139,14 @@ extern int filter_current_check_discard(struct ftrace_event_call *call,
 					void *rec,
 					struct ring_buffer_event *event);
 
+extern char *ftrace_read_binary(struct trace_seq *p,
+				struct ftrace_event_call *event,
+				struct trace_entry *entry);
+extern int ftrace_initialize_print(struct ftrace_event_call *event,
+				   const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
+extern void ftrace_destroy_print(struct ftrace_event_call *event);
+
 extern int trace_define_field(struct ftrace_event_call *call, char *type,
 			      char *name, int offset, int size, int is_signed);
 
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 40ede4d..e3370c5 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -124,6 +124,10 @@
 #undef TP_printk
 #define TP_printk(fmt, args...) fmt "\n", args
 
+#undef TP_FORMAT
+#define TP_FORMAT(fmt, args...) \
+	"%s\n", ftrace_read_binary(p, event_call, entry)
+
 #undef __get_dynamic_array
 #define __get_dynamic_array(field)	\
 		((void *)__entry + __entry->__data_loc_##field)
@@ -152,6 +156,7 @@
 enum print_line_t							\
 ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
 {									\
+	struct ftrace_event_call *event_call __maybe_unused = &event_##call; \
 	struct trace_seq *s = &iter->seq;				\
 	struct ftrace_raw_##call *field;				\
 	struct trace_entry *entry;					\
@@ -234,7 +239,10 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
 #define __entry REC
 
 #undef TP_printk
-#define TP_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
+#define TP_printk(fmt, args...) "print fmt: %s, %s\n", #fmt, __stringify(args)
+
+#undef TP_FORMAT
+#define TP_FORMAT(fmt, args...) "format: " fmt "\n",  ##args
 
 #undef TP_fast_assign
 #define TP_fast_assign(args...) args
@@ -249,7 +257,7 @@ ftrace_format_##call(struct trace_seq *s)				\
 									\
 	tstruct;							\
 									\
-	trace_seq_printf(s, "\nprint fmt: " print);			\
+	trace_seq_printf(s, "\n" print);				\
 									\
 	return ret;							\
 }
@@ -279,6 +287,13 @@ ftrace_format_##call(struct trace_seq *s)				\
 				offsetof(typeof(field), __data_loc_##item),    \
 				 sizeof(field.__data_loc_##item), 0);
 
+#undef TP_printk
+#define TP_printk(fmt, args...)
+
+#undef TP_FORMAT
+#define TP_FORMAT(fmt, args...) \
+	ftrace_initialize_print(event_call, fmt, ##args)
+
 #undef __string
 #define __string(item, src) __dynamic_array(char, item, -1)
 
@@ -299,6 +314,8 @@ ftrace_define_fields_##call(void)					\
 									\
 	tstruct;							\
 									\
+	print;								\
+									\
 	return ret;							\
 }
 
@@ -563,6 +580,7 @@ static int ftrace_raw_init_event_##call(void)				\
 	event_##call.id = id;						\
 	INIT_LIST_HEAD(&event_##call.fields);				\
 	init_preds(&event_##call);					\
+	INIT_LIST_HEAD(&event_##call.print_info);			\
 	return 0;							\
 }									\
 									\
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 844164d..9b112e2 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -54,5 +54,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o
 obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
 obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
+obj-$(CONFIG_EVENT_TRACING) += trace_read_binary.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index aa08be6..eb917b8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1061,6 +1061,7 @@ static void trace_module_remove_events(struct module *mod)
 			list_del(&call->list);
 			trace_destroy_fields(call);
 			destroy_preds(call);
+			ftrace_destroy_print(call);
 		}
 	}
 
diff --git a/kernel/trace/trace_read_binary.c b/kernel/trace/trace_read_binary.c
new file mode 100644
index 0000000..b47285d
--- /dev/null
+++ b/kernel/trace/trace_read_binary.c
@@ -0,0 +1,766 @@
+/*
+ * trace_read_binary.c
+ *
+ * Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@xxxxxxxxxx>
+ *
+ */
+
+#include <linux/ftrace_event.h>
+#include <linux/hardirq.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+
+#include "trace.h"
+
+static DEFINE_MUTEX(buffer_lock);
+static struct trace_seq buffer;
+
+/*
+ * Binary string parser. The print format uses a special language to explain
+ * the format to print the entry out. The language is as follows:
+ *
+ * FMT :=  constant string FMT | COMMAND FMT | empty
+ * COMMAND := <TYPE:FIELD> | <mask:FIELD:DELIM:MASKS> | <sym:FIELD:SYMBOLS> |
+ *               <if:FIELD:TRUE:FALSE> | <ifmask:FIELD:MASK:TRUE:FALSE>
+ * TYPE := int | uint | hex | ptr | string | strarray
+ * FIELD := defined by the event structure
+ * MASKS := MASK=NAME,MASKS | MASK=NAME
+ * MASK := the bit mask to match
+ * DELIM := delimiter to separate the fields. None and ':' are both allowed
+ * SYMBOLS := SYM=NAME,SYMBOLS | SYM=NAME
+ * SYM := the symbol value to test against
+ * TRUE := print when field is non zero
+ * FALSE := print when field is zero or NULL
+ * NAME := the name to write when a match is found
+ *
+ * A '\<' would print '<'
+ */
+
+#define TOK_SIZE 32
+
+enum field_types {
+	FIELD_IS_TEXT,
+	FIELD_IS_INT,
+	FIELD_IS_UINT,
+	FIELD_IS_PTR,
+	FIELD_IS_LT,
+	FIELD_IS_IF,
+	FIELD_IS_IFMASK,
+	FIELD_IS_STRING,
+	FIELD_IS_STRARRAY,
+	FIELD_IS_HEX,
+	FIELD_IS_MASK,
+	FIELD_IS_SYMBOL,
+};
+
+struct sym_mask {
+	struct list_head			list;
+	unsigned long long			val;
+	unsigned short				start;
+	unsigned short				len;
+};
+
+struct print_info {
+	struct list_head				list;
+	enum field_types				type;
+	union {
+		struct {
+			unsigned short			start;
+			unsigned short			len;
+		} text;
+		struct {
+			struct ftrace_event_field	*field;
+		} data;
+		struct {
+			struct ftrace_event_field	*field;
+			unsigned long long		mask;
+			unsigned short			true_text;
+			unsigned short			true_len;
+			unsigned short			false_text;
+			unsigned short			false_len;
+		} cond;
+		struct {
+			struct ftrace_event_field	*field;
+			struct list_head		masks;
+			unsigned short			delim;
+			unsigned short			len;
+		} sym_mask;
+	};
+};
+
+static void free_sym_masks(struct list_head *list)
+{
+	struct sym_mask *sm, *n;
+
+	list_for_each_entry_safe(sm, n, list, list) {
+		list_del(&sm->list);
+		kfree(sm);
+	}
+}
+
+void ftrace_destroy_print(struct ftrace_event_call *event)
+{
+	struct print_info *info, *n;
+
+	if (!event->print_text)
+		return;
+
+	kfree(event->print_text);
+	event->print_text = NULL;
+
+	list_for_each_entry_safe(info, n, &event->print_info, list) {
+		switch (info->type) {
+		case FIELD_IS_SYMBOL:
+		case FIELD_IS_MASK:
+			free_sym_masks(&info->sym_mask.masks);
+			break;
+		default:
+			/* nothing special for the rest */
+			break;
+		}
+		list_del(&info->list);
+		kfree(info);
+	}
+}
+
+static struct print_info *
+alloc_print_info(struct ftrace_event_call *call, enum field_types type)
+{
+	struct print_info *info;
+
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (WARN_ON(!info))
+		return NULL;
+
+	info->type = type;
+
+	list_add_tail(&info->list, &call->print_info);
+
+	return info;
+}
+
+static int
+add_text(struct ftrace_event_call *call, const char *start, const char *end)
+{
+	struct print_info *info;
+
+	info = alloc_print_info(call, FIELD_IS_TEXT);
+	if (!info)
+		return -ENOMEM;
+
+	info->text.start = start - call->print_text;
+	if (!end)
+		end = call->print_text + strlen(call->print_text);
+	info->text.len = end - start;
+
+	return 0;
+}
+
+static int
+add_less_than(struct ftrace_event_call *call,
+	      const char *start, const char *end)
+{
+	struct print_info *info;
+
+	info = alloc_print_info(call, FIELD_IS_LT);
+	if (!info)
+		return -ENOMEM;
+
+	info->text.start = start - call->print_text;
+	info->text.len = end - start;
+
+	return 0;
+}
+
+static int
+add_data(struct ftrace_event_call *call, enum field_types type,
+	 struct ftrace_event_field *field)
+{
+	struct print_info *info;
+
+	info = alloc_print_info(call, type);
+	if (!info)
+		return -ENOMEM;
+
+	info->data.field = field;
+
+	return 0;
+}
+
+static int
+add_if(struct ftrace_event_call *call, enum field_types type,
+       struct ftrace_event_field *field, unsigned long long mask,
+       const char *fmt, const char *end)
+{
+	struct print_info *info;
+	const char *tok;
+
+	info = alloc_print_info(call, type);
+	if (!info)
+		return -ENOMEM;
+
+	info->cond.field = field;
+	info->cond.mask = mask;
+
+	tok = strchr(fmt, ':');
+	if (WARN(!tok || tok > end, "error in format: %s\n", fmt))
+		return -EINVAL;
+
+	info->cond.true_text = fmt - call->print_text;
+	info->cond.true_len = tok - fmt;
+
+	fmt = tok + 1;
+
+	info->cond.false_text = fmt - call->print_text;
+	info->cond.false_len = end - fmt;
+
+	return 0;
+}
+
+static int add_sym_mask(struct ftrace_event_call *call, struct list_head *list,
+			unsigned long long val,
+			const char *start, const char *end)
+{
+	struct sym_mask *sm;
+
+	sm = kmalloc(sizeof(*sm), GFP_KERNEL);
+	if (WARN_ON(!sm))
+		return -ENOMEM;
+
+	list_add_tail(&sm->list, list);
+	sm->val = val;
+	sm->start = start - call->print_text;
+	sm->len = end - start;
+
+	return 0;
+}
+
+static const char *
+add_mask(struct ftrace_event_call *call, struct ftrace_event_field *field,
+	 const char *delim, unsigned int delim_len,
+	 const char *fmt, const char *end)
+{
+	struct print_info *info;
+	unsigned long long mask;
+	const char *tok;
+	int ret;
+
+	info = alloc_print_info(call, FIELD_IS_MASK);
+	if (!info)
+		return NULL;
+
+	info->sym_mask.field = field;
+
+	INIT_LIST_HEAD(&info->sym_mask.masks);
+	info->sym_mask.len = delim_len;
+	if (delim_len)
+		info->sym_mask.delim = delim - call->print_text;
+
+	do {
+		while (isspace(*fmt))
+			fmt++;
+
+		tok = strchr(fmt, '=');
+		if (WARN(!tok || tok > end, "error in format '%s'\n", fmt))
+			return NULL;
+
+		mask = simple_strtoull(fmt, NULL, 0);
+		fmt = tok + 1;
+
+		tok = strchr(fmt, ',');
+		if (!tok || tok > end)
+			tok = end;
+
+		ret = add_sym_mask(call, &info->sym_mask.masks, mask, fmt, tok);
+		if (ret)
+			return NULL;
+
+		fmt = tok + 1;
+	} while (fmt < end);
+
+	return end;
+}
+
+static const char *
+add_symbol(struct ftrace_event_call *call, struct ftrace_event_field *field,
+	   const char *fmt, const char *end)
+{
+	struct print_info *info;
+	unsigned long long sym;
+	const char *tok;
+	int ret;
+
+	info = alloc_print_info(call, FIELD_IS_SYMBOL);
+	if (!info)
+		return NULL;
+
+	info->sym_mask.field = field;
+
+	INIT_LIST_HEAD(&info->sym_mask.masks);
+
+	do {
+		while (isspace(*fmt))
+			fmt++;
+
+		tok = strchr(fmt, '=');
+		if (WARN(!tok || tok > end, "error in format '%s'\n", fmt))
+			return NULL;
+
+		sym = simple_strtoull(fmt, NULL, 0);
+		fmt = tok + 1;
+
+		tok = strchr(fmt, ',');
+		if (!tok || tok > end)
+			tok = end;
+
+		ret = add_sym_mask(call, &info->sym_mask.masks, sym, fmt, tok);
+		if (ret)
+			return NULL;
+
+		fmt = tok + 1;
+	} while (fmt < end);
+
+	return end;
+}
+
+static struct ftrace_event_field *
+find_field(struct ftrace_event_call *call, const char *name, int len)
+{
+	struct ftrace_event_field *field;
+
+	list_for_each_entry(field, &call->fields, link) {
+		if (!strncmp(field->name, name, len))
+			return field;
+	}
+
+	return NULL;
+}
+
+static const char *
+handle_field(struct ftrace_event_call *event,
+	     const char *fmt, enum field_types field_type)
+{
+	struct ftrace_event_field *field;
+	const char *end, *tok, *delim;
+	unsigned long long mask;
+	unsigned int delim_len;
+	int ret;
+
+	end = strchr(fmt, '>');
+	if (!end)
+		goto out_err;
+
+	switch (field_type) {
+	case FIELD_IS_INT:
+	case FIELD_IS_UINT:
+	case FIELD_IS_PTR:
+	case FIELD_IS_HEX:
+	case FIELD_IS_STRING:
+	case FIELD_IS_STRARRAY:
+		field = find_field(event, fmt, end - fmt);
+		if (!field)
+			goto out_err;
+
+		ret = add_data(event, field_type, field);
+		if (ret)
+			return NULL;
+		break;
+
+	case FIELD_IS_IF:
+	case FIELD_IS_IFMASK:
+		tok = strchr(fmt, ':');
+		if (!tok || tok > end)
+			goto out_err;
+
+		field = find_field(event, fmt, tok - fmt);
+		if (!field)
+			goto out_err;
+
+		fmt = tok + 1;
+
+		if (field_type == FIELD_IS_IFMASK) {
+			tok = strchr(fmt, ':');
+			if (!tok || tok > end)
+				goto out_err;
+			mask = simple_strtoull(fmt, NULL, 0);
+			fmt = tok + 1;
+		} else
+			mask = 0;
+
+		ret = add_if(event, field_type, field, mask, fmt, end);
+		if (ret)
+			return NULL;
+		break;
+
+	case FIELD_IS_MASK:
+	case FIELD_IS_SYMBOL:
+		tok = strchr(fmt, ':');
+		if (!tok || tok > end)
+			goto out_err;
+
+		field = find_field(event, fmt, tok - fmt);
+		if (!field)
+			goto out_err;
+
+		fmt = tok + 1;
+
+		if (field_type == FIELD_IS_MASK) {
+			tok = strchr(fmt, ':');
+			if (!tok || tok > end)
+				goto out_err;
+
+			delim = fmt;
+			delim_len = tok - fmt;
+
+			/* we allow ':' as a delimiter */
+			if (!delim_len && tok[1] == ':') {
+				tok++;
+				delim_len++;
+			}
+
+			fmt = tok+1;
+
+			end = add_mask(event, field, delim, delim_len,
+				       fmt, end);
+		} else
+			end = add_symbol(event, field, fmt, end);
+
+		if (!end)
+			return NULL;
+		break;
+	default:
+		WARN(1, "unknown field: %s\n", fmt);
+	}
+
+	end++;
+	return end;
+
+ out_err:
+	WARN(1, "error in format field: '%s'\n", fmt);
+	return NULL;
+}
+
+int
+ftrace_initialize_print(struct ftrace_event_call *event, const char *fmt, ...)
+{
+	const char *tok;
+	va_list ap;
+	int ret;
+
+	mutex_lock(&buffer_lock);
+	trace_seq_init(&buffer);
+
+	va_start(ap, fmt);
+	ret = trace_seq_vprintf(&buffer, fmt, ap);
+	va_end(ap);
+	if (!ret)
+		goto err_unlock;
+
+	ret = trace_seq_putc(&buffer, 0);
+	if (!ret)
+		goto err_unlock;
+
+	event->print_text = kstrdup(buffer.buffer, GFP_KERNEL);
+	if (!event->print_text)
+		goto err_unlock;
+
+	mutex_unlock(&buffer_lock);
+
+	fmt = event->print_text;
+
+	do {
+		enum field_types field_type;
+
+		tok = strchr(fmt, '<');
+		if (!tok) {
+			ret = add_text(event, fmt, tok);
+			if (ret)
+				goto err_free;
+			break;
+		}
+		if (*(tok - 1) == '\\') {
+			ret = add_less_than(event, fmt, tok);
+			if (ret)
+				goto err_free;
+			fmt = tok + 1;
+			continue;
+		}
+
+		ret = add_text(event, fmt, tok);
+		if (ret)
+			goto err_free;
+
+		fmt = tok + 1;
+
+		tok = strchr(fmt, ':');
+		if (!tok)
+			goto err_format;
+
+		if (strncmp(fmt, "int:", 4) == 0)
+			field_type = FIELD_IS_INT;
+
+		else if (strncmp(fmt, "uint:", 5) == 0)
+			field_type = FIELD_IS_UINT;
+
+		else if (strncmp(fmt, "ptr:", 4) == 0)
+			field_type = FIELD_IS_PTR;
+
+		else if (strncmp(fmt, "string:", 7) == 0)
+			field_type = FIELD_IS_STRING;
+
+		else if (strncmp(fmt, "hex:", 4) == 0)
+			field_type = FIELD_IS_HEX;
+
+		else if (strncmp(fmt, "if:", 3) == 0)
+			field_type = FIELD_IS_IF;
+
+		else if (strncmp(fmt, "ifmask:", 7) == 0)
+			field_type = FIELD_IS_IFMASK;
+
+		else if (strncmp(fmt, "mask:", 5) == 0)
+			field_type = FIELD_IS_MASK;
+
+		else if (strncmp(fmt, "sym:", 4) == 0)
+			field_type = FIELD_IS_SYMBOL;
+
+		else if (strncmp(fmt, "strarray:", 9) == 0)
+			field_type = FIELD_IS_STRARRAY;
+
+		else
+			goto err_format;
+
+		tok++;
+		fmt = handle_field(event, tok, field_type);
+		if (!fmt)
+			goto err_free;
+
+	} while (fmt);
+
+	return 0;
+
+ err_unlock:
+	WARN(1, "Can not allocate event print format data\n");
+	mutex_unlock(&buffer_lock);
+	return -1;
+
+ err_format:
+	WARN(1, "error in format type: '%s'\n", fmt);
+ err_free:
+	ftrace_destroy_print(event);
+	return -1;
+}
+EXPORT_SYMBOL_GPL(ftrace_initialize_print);
+
+
+static void
+trace_read_mask(struct trace_seq *s, unsigned long long val,
+		struct print_info *info, struct ftrace_event_call *event)
+{
+	unsigned long long mask;
+	struct sym_mask *sm;
+	int first = 1;
+
+	list_for_each_entry(sm, &info->sym_mask.masks, list) {
+		mask = sm->val;
+
+		if (first && !mask && !val) {
+			trace_seq_putmem(s, event->print_text + sm->start,
+					 sm->len);
+			return;
+		}
+
+		if (mask && (mask & val) == mask) {
+			if (first)
+				first = 0;
+			else if (info->sym_mask.len)
+				trace_seq_putmem(s, event->print_text +
+						 info->sym_mask.delim,
+						 info->sym_mask.len);
+			val &= ~mask;
+
+			trace_seq_putmem(s, event->print_text + sm->start,
+					 sm->len);
+		}
+	}
+
+	if (val)
+		trace_seq_printf(s, "(%llx)", val);
+
+	return;
+}
+
+static void
+trace_read_symbol(struct trace_seq *s, unsigned long long val,
+		  struct print_info *info, struct ftrace_event_call *event)
+{
+	unsigned long long sym;
+	struct sym_mask *sm;
+	int found = 0;
+
+	list_for_each_entry(sm, &info->sym_mask.masks, list) {
+		sym = sm->val;
+
+		if (sym == val) {
+			found = 1;
+			trace_seq_putmem(s, event->print_text + sm->start,
+					 sm->len);
+			break;
+		}
+	}
+
+	if (!found)
+		trace_seq_printf(s, "(%llx)", val);
+
+}
+
+char *
+ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
+		   struct trace_entry *entry)
+{
+	unsigned long long val, mask;
+	struct print_info *info;
+	char *start = s->buffer + s->len;
+	struct ftrace_event_field *field;
+	void *p;
+
+	if (!event->print_text) {
+		trace_seq_puts(s, "UNDEFINED EVENT\n");
+		return start;
+	}
+
+	list_for_each_entry(info, &event->print_info, list) {
+
+		p = entry;
+
+		switch (info->type) {
+		case FIELD_IS_LT:
+		case FIELD_IS_TEXT:
+			trace_seq_putmem(s, event->print_text +
+					 info->text.start,
+					 info->text.len);
+			if (info->type == FIELD_IS_LT)
+				trace_seq_putc(s, '<');
+			break;
+		case FIELD_IS_INT:
+		case FIELD_IS_UINT:
+		case FIELD_IS_HEX:
+		case FIELD_IS_PTR:
+			field = info->data.field;
+			goto skip_if;
+
+		case FIELD_IS_IF:
+		case FIELD_IS_IFMASK:
+			field = info->cond.field;
+ skip_if:
+			p += field->offset;
+
+			switch (field->size) {
+			case 1:
+				val = *(char *)p;
+				mask =  0xffULL;
+				break;
+			case 2:
+				val = *(short *)p;
+				mask =  0xffffULL;
+				break;
+			case 4:
+				val = *(int *)p;
+				mask =  0xffffffffULL;
+				break;
+			case 8:
+				val = *(long long *)p;
+				mask = 0;
+				break;
+
+			default:
+				trace_seq_printf(s,
+					"<error: bad field size %d?>\n",
+					field->size);
+				return start;
+			}
+
+			if (info->type == FIELD_IS_IF ||
+			    info->type == FIELD_IS_IFMASK) {
+
+				if (info->type == FIELD_IS_IFMASK)
+					val &= info->cond.mask;
+
+				if (val)
+					trace_seq_putmem(s, event->print_text +
+							 info->cond.true_text,
+							 info->cond.true_len);
+				else
+					trace_seq_putmem(s, event->print_text +
+							 info->cond.false_text,
+							 info->cond.false_len);
+			} else if (info->type == FIELD_IS_INT)
+				trace_seq_printf(s, "%lld", val);
+			else if (info->type == FIELD_IS_UINT)
+				trace_seq_printf(s, "%llu", val);
+			else {
+				/* hex should only print the size specified */
+				if (mask)
+					val &= mask;
+
+				trace_seq_printf(s, "%llx", val);
+			}
+
+			break;
+
+		case FIELD_IS_STRING:
+			p += info->data.field->offset;
+			/* indexes are expected to be unsigned short */
+			if (info->data.field->size != 2) {
+				trace_seq_puts(s, "BAD FIELD SIZE\n");
+				return start;
+			}
+			p = (void *)entry + *(unsigned short *)p;
+			trace_seq_puts(s, p);
+			break;
+
+		case FIELD_IS_STRARRAY:
+			p += info->data.field->offset;
+			trace_seq_puts(s, p);
+			break;
+
+		case FIELD_IS_MASK:
+		case FIELD_IS_SYMBOL:
+
+			p += info->sym_mask.field->offset;
+
+			switch (info->sym_mask.field->size) {
+			case 1:
+				val = *(unsigned char *)p;
+				break;
+			case 2:
+				val = *(unsigned short *)p;
+				break;
+			case 4:
+				val = *(unsigned int *)p;
+				break;
+			case 8:
+				val = *(unsigned long long *)p;
+				break;
+
+			default:
+				trace_seq_printf(s,
+					 "<error: bad field size %d?>\n",
+					 info->sym_mask.field->size);
+				return start;
+			}
+
+			if (info->type == FIELD_IS_MASK)
+				trace_read_mask(s, val, info, event);
+			else
+				trace_read_symbol(s, val, info, event);
+			break;
+		default:
+			trace_seq_printf(s, "UNKNOWN TYPE %d\n", info->type);
+		}
+	}
+
+	trace_seq_putc(s, 0);
+
+	return start;
+}
+EXPORT_SYMBOL_GPL(ftrace_read_binary);
-- 
1.6.3.1

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/