[PATCH 05/11] tracing: add func and symfunc to tag format

Steven Rostedt
2009-06-10T17:01:31Z

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From: Steven Rostedt <srostedt@redhat.com>

This adds a way to print out a function name from a pointer the same way
that the Linux printf "%pF" does. Well the symfunc tag does.

If we change kmalloc and kfree formats to:

TP_FORMAT("call_site=<symfunc:call_site> ptr=<ptr:ptr> bytes_req=<int:bytes_req> "

and

TP_FORMAT("call_site=<func:call_site> ptr=<ptr:ptr>")

respectively, we would get something like:

kmalloc: call_site=__alloc_skb+0x70/0x160 ptr=ffff88003d830800 bytes_req=680
kfree: call_site=skb_release_data ptr=ffff88003d830800

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_output.c | 2 +-
kernel/trace/trace_output.h | 4 ++++
kernel/trace/trace_read_binary.c | 25 ++++++++++++++++++++++++-
3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 7938f3a..39d5eeb 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -326,7 +326,7 @@ static inline const char *kretprobed(const char *name)
}
#endif /* CONFIG_KRETPROBES */

-static int
+int
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index d38bec4..412eee8 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -47,5 +47,9 @@ do { \
return TRACE_TYPE_PARTIAL_LINE; \
} while (0)

+/* until we have a way with sprintf to do this */
+int seq_print_sym_short(struct trace_seq *s, const char *fmt,
+ unsigned long address);
+
#endif

diff --git a/kernel/trace/trace_read_binary.c b/kernel/trace/trace_read_binary.c
index 4378350..bfa8fc3 100644
--- a/kernel/trace/trace_read_binary.c
+++ b/kernel/trace/trace_read_binary.c
@@ -23,7 +23,8 @@ static struct trace_seq buffer;
* COMMAND := <TYPE:FIELD> | <mask:FIELD:DELIM:MASKS> | <sym:FIELD:SYMBOLS> |
* <if:FIELD:TRUE:FALSE> | <ifmask:FIELD:MASK:TRUE:FALSE> |
* <nsec2sec:PRECISION:FIELD> | <nsec2usec:PRECISION:FIELD> |
- * <nsec2msec:PRECISION:FIELD> | <major:FIELD> | <minor:FIELD>
+ * <nsec2msec:PRECISION:FIELD> | <major:FIELD> | <minor:FIELD> |
+ * <func:FIELD> | <symfunc:FIELD>
* TYPE := int | uint | hex | ptr | string | strarray
* FIELD := defined by the event structure
* MASKS := MASK=NAME,MASKS | MASK=NAME
@@ -43,6 +44,8 @@ static struct trace_seq buffer;
* uint : Same as int, but for unsigned.
* hex : Print the field as a hex (ie. 0x4ab)
* ptr : Print the field as a hex but without the '0x'.
+ * symfunc : Print a ptr like the "%pF" does.
+ * func : Like symfunc but without the address.
* string : Used with dynamic sized strings (__string)
* strarray : Used with static sized arrays (__array ( char , item, len)).
* if : If the field is non zero, print the TRUE text,
@@ -80,6 +83,8 @@ enum field_types {
FIELD_IS_HEX,
FIELD_IS_MINOR,
FIELD_IS_MAJOR,
+ FIELD_IS_FUNC,
+ FIELD_IS_SYMFUNC,
FIELD_IS_NSEC2SEC,
FIELD_IS_NSEC2USEC,
FIELD_IS_NSEC2MSEC,
@@ -413,6 +418,8 @@ handle_field(struct ftrace_event_call *event,
case FIELD_IS_HEX:
case FIELD_IS_MINOR:
case FIELD_IS_MAJOR:
+ case FIELD_IS_FUNC:
+ case FIELD_IS_SYMFUNC:
case FIELD_IS_STRING:
case FIELD_IS_STRARRAY:
field = find_field(event, fmt, end - fmt);
@@ -595,6 +602,12 @@ ftrace_initialize_print(struct ftrace_event_call *event, const char *fmt, ...)
else if (strncmp(fmt, "ifmask:", 7) == 0)
field_type = FIELD_IS_IFMASK;

+ else if (strncmp(fmt, "func:", 5) == 0)
+ field_type = FIELD_IS_FUNC;
+
+ else if (strncmp(fmt, "symfunc:", 8) == 0)
+ field_type = FIELD_IS_SYMFUNC;
+
else if (strncmp(fmt, "nsec2sec:", 9) == 0)
field_type = FIELD_IS_NSEC2SEC;

@@ -786,6 +799,8 @@ ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
case FIELD_IS_UINT:
case FIELD_IS_HEX:
case FIELD_IS_PTR:
+ case FIELD_IS_FUNC:
+ case FIELD_IS_SYMFUNC:
case FIELD_IS_MAJOR:
case FIELD_IS_MINOR:
field = info->data.field;
@@ -839,6 +854,14 @@ ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
trace_seq_printf(s, "%u", MINOR(val));
break;

+ case FIELD_IS_SYMFUNC:
+ trace_seq_printf(s, "%pF", (void *)val);
+ break;
+
+ case FIELD_IS_FUNC:
+ seq_print_sym_short(s, "%s", val);
+ break;
+
default:
/* hex should only print the size specified */
if (mask)
--
1.6.3.1

--