Commit 007517a0 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

tracing/probe: Change traceprobe_set_print_fmt() to take a type 

Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.

Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org



Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 845cbf3e

kernel/trace/trace_kprobe.c

+7 −2
Original line number Diff line number Diff line
@@ -742,6 +742,7 @@ static int __trace_kprobe_create(int argc, const char *argv[]) 
	bool is_return = false;

	char *symbol = NULL, *tmp = NULL;

	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;

	enum probe_print_type ptype;

	int maxactive = 0;

	long offset = 0;

	void *addr = NULL;
@@ -875,7 +876,8 @@ static int __trace_kprobe_create(int argc, const char *argv[]) 
			goto error;	/* This can be -ENOMEM */

	}



	ret = traceprobe_set_print_fmt(&tk->tp, is_return);

	ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;

	ret = traceprobe_set_print_fmt(&tk->tp, ptype);

	if (ret < 0)

		goto error;
@@ -1799,6 +1801,7 @@ struct trace_event_call * 
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,

			  bool is_return)

{

	enum probe_print_type ptype;

	struct trace_kprobe *tk;

	int ret;

	char *event;
@@ -1822,7 +1825,9 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 


	init_trace_event_call(tk);



	if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {

	ptype = trace_kprobe_is_return(tk) ?

		PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;

	if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {

		ret = -ENOMEM;

		goto error;

	}

kernel/trace/trace_probe.c

+12 −6
Original line number Diff line number Diff line
@@ -851,19 +851,25 @@ int traceprobe_update_arg(struct probe_arg *arg) 
/* When len=0, we just calculate the needed length */

#define LEN_OR_ZERO (len ? len - pos : 0)

static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,

			   bool is_return)

			   enum probe_print_type ptype)

{

	struct probe_arg *parg;

	int i, j;

	int pos = 0;

	const char *fmt, *arg;



	if (!is_return) {

	switch (ptype) {

	case PROBE_PRINT_NORMAL:

		fmt = "(%lx)";

		arg = "REC->" FIELD_STRING_IP;

	} else {

		break;

	case PROBE_PRINT_RETURN:

		fmt = "(%lx <- %lx)";

		arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;

		break;

	default:

		WARN_ON_ONCE(1);

		return 0;

	}



	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
@@ -912,20 +918,20 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 
}

#undef LEN_OR_ZERO



int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)

int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)

{

	struct trace_event_call *call = trace_probe_event_call(tp);

	int len;

	char *print_fmt;



	/* First: called with 0 length to calculate the needed length */

	len = __set_print_fmt(tp, NULL, 0, is_return);

	len = __set_print_fmt(tp, NULL, 0, ptype);

	print_fmt = kmalloc(len + 1, GFP_KERNEL);

	if (!print_fmt)

		return -ENOMEM;



	/* Second: actually write the @print_fmt */

	__set_print_fmt(tp, print_fmt, len + 1, is_return);

	__set_print_fmt(tp, print_fmt, len + 1, ptype);

	call->print_fmt = print_fmt;



	return 0;

kernel/trace/trace_probe.h

+6 −1
Original line number Diff line number Diff line
@@ -363,7 +363,12 @@ extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,

				char *buf, int offset);



extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);

enum probe_print_type {

	PROBE_PRINT_NORMAL,

	PROBE_PRINT_RETURN,

};



extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);



#ifdef CONFIG_PERF_EVENTS

extern struct trace_event_call *

kernel/trace/trace_uprobe.c

+6 −2
Original line number Diff line number Diff line
@@ -536,6 +536,7 @@ static int __trace_uprobe_create(int argc, const char **argv) 
	const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;

	char *arg, *filename, *rctr, *rctr_end, *tmp;

	char buf[MAX_EVENT_NAME_LEN];

	enum probe_print_type ptype;

	struct path path;

	unsigned long offset, ref_ctr_offset;

	bool is_return = false;
@@ -687,7 +688,8 @@ static int __trace_uprobe_create(int argc, const char **argv) 
			goto error;

	}



	ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));

	ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;

	ret = traceprobe_set_print_fmt(&tu->tp, ptype);

	if (ret < 0)

		goto error;
@@ -1578,6 +1580,7 @@ struct trace_event_call * 
create_local_trace_uprobe(char *name, unsigned long offs,

			  unsigned long ref_ctr_offset, bool is_return)

{

	enum probe_print_type ptype;

	struct trace_uprobe *tu;

	struct path path;

	int ret;
@@ -1612,7 +1615,8 @@ create_local_trace_uprobe(char *name, unsigned long offs, 
	tu->filename = kstrdup(name, GFP_KERNEL);

	init_trace_event_call(tu);



	if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {

	ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;

	if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {

		ret = -ENOMEM;

		goto error;

	}