Commit 457d1772 authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

uprobes/tracing: Generalize struct uprobe_trace_entry_head 



struct uprobe_trace_entry_head has a single member for reporting,
"unsigned long ip". If we want to support uretprobes we need to
create another struct which has "func" and "ret_ip" and duplicate
a lot of functions, like trace_kprobe.c does.

To avoid this copy-and-paste horror we turn ->ip into ->vaddr[]
and add couple of trivial helpers to calculate sizeof/data. This
uglifies the code a bit, but this allows us to avoid a lot more
complications later, when we add the support for ret-probes.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: default avatarAnton Arapov <anton@redhat.com>
parent 0e3853d2

kernel/trace/trace.h

+0 −5
Original line number Diff line number Diff line
@@ -103,11 +103,6 @@ struct kretprobe_trace_entry_head { 
	unsigned long		ret_ip;

};



struct uprobe_trace_entry_head {

	struct trace_entry	ent;

	unsigned long		ip;

};



/*

 * trace_flag_type is an enumeration that holds different

 * states when a trace occurs. These are:

kernel/trace/trace_uprobe.c

+36 −26
Original line number Diff line number Diff line
@@ -28,6 +28,18 @@ 


#define UPROBE_EVENT_SYSTEM	"uprobes"



struct uprobe_trace_entry_head {

	struct trace_entry	ent;

	unsigned long		vaddr[];

};



#define SIZEOF_TRACE_ENTRY(is_return)			\

	(sizeof(struct uprobe_trace_entry_head) +	\

	 sizeof(unsigned long) * (is_return ? 2 : 1))



#define DATAOF_TRACE_ENTRY(entry, is_return)		\

	((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))



struct trace_uprobe_filter {

	rwlock_t		rwlock;

	int			nr_systemwide;
@@ -491,20 +503,19 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) 
	struct uprobe_trace_entry_head *entry;

	struct ring_buffer_event *event;

	struct ring_buffer *buffer;

	u8 *data;

	void *data;

	int size, i;

	struct ftrace_event_call *call = &tu->call;



	size = sizeof(*entry) + tu->size;



	size = SIZEOF_TRACE_ENTRY(false) + tu->size;

	event = trace_current_buffer_lock_reserve(&buffer, call->event.type,

						  size, 0, 0);

	if (!event)

		return 0;



	entry = ring_buffer_event_data(event);

	entry->ip = instruction_pointer(regs);

	data = (u8 *)&entry[1];

	entry->vaddr[0] = instruction_pointer(regs);

	data = DATAOF_TRACE_ENTRY(entry, false);

	for (i = 0; i < tu->nr_args; i++)

		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
@@ -518,22 +529,22 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) 
static enum print_line_t

print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)

{

	struct uprobe_trace_entry_head *field;

	struct uprobe_trace_entry_head *entry;

	struct trace_seq *s = &iter->seq;

	struct trace_uprobe *tu;

	u8 *data;

	int i;



	field = (struct uprobe_trace_entry_head *)iter->ent;

	entry = (struct uprobe_trace_entry_head *)iter->ent;

	tu = container_of(event, struct trace_uprobe, call.event);



	if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name, field->ip))

	if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name, entry->vaddr[0]))

		goto partial;



	data = (u8 *)&field[1];

	data = DATAOF_TRACE_ENTRY(entry, false);

	for (i = 0; i < tu->nr_args; i++) {

		if (!tu->args[i].type->print(s, tu->args[i].name,

					     data + tu->args[i].offset, field))

					     data + tu->args[i].offset, entry))

			goto partial;

	}
@@ -585,16 +596,17 @@ static void probe_event_disable(struct trace_uprobe *tu, int flag) 


static int uprobe_event_define_fields(struct ftrace_event_call *event_call)

{

	int ret, i;

	int ret, i, size;

	struct uprobe_trace_entry_head field;

	struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data;

	struct trace_uprobe *tu = event_call->data;



	DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);

	DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);

	size = SIZEOF_TRACE_ENTRY(false);

	/* Set argument names as fields */

	for (i = 0; i < tu->nr_args; i++) {

		ret = trace_define_field(event_call, tu->args[i].type->fmttype,

					 tu->args[i].name,

					 sizeof(field) + tu->args[i].offset,

					 size + tu->args[i].offset,

					 tu->args[i].type->size,

					 tu->args[i].type->is_signed,

					 FILTER_OTHER);
@@ -748,33 +760,31 @@ static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) 
	struct ftrace_event_call *call = &tu->call;

	struct uprobe_trace_entry_head *entry;

	struct hlist_head *head;

	u8 *data;

	int size, __size, i;

	int rctx;

	unsigned long ip;

	void *data;

	int size, rctx, i;



	if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))

		return UPROBE_HANDLER_REMOVE;



	__size = sizeof(*entry) + tu->size;

	size = ALIGN(__size + sizeof(u32), sizeof(u64));

	size -= sizeof(u32);

	size = SIZEOF_TRACE_ENTRY(false);

	size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32);

	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))

		return 0;



	preempt_disable();



	entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);

	if (!entry)

		goto out;



	entry->ip = instruction_pointer(regs);

	data = (u8 *)&entry[1];

	ip = instruction_pointer(regs);

	entry->vaddr[0] = ip;

	data = DATAOF_TRACE_ENTRY(entry, false);

	for (i = 0; i < tu->nr_args; i++)

		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);



	head = this_cpu_ptr(call->perf_events);

	perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL);



	perf_trace_buf_submit(entry, size, rctx, ip, 1, regs, head, NULL);

 out:

	preempt_enable();

	return 0;
@@ -784,7 +794,7 @@ static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) 
static

int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)

{

	struct trace_uprobe *tu = (struct trace_uprobe *)event->data;

	struct trace_uprobe *tu = event->data;



	switch (type) {

	case TRACE_REG_REGISTER:

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