uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()

Create the new functions we need to support uretprobes, and change
alloc_trace_uprobe() to initialize consumer.ret_handler if the new
"is_ret" argument is true. Curently this argument is always false,
so the new code is never called and is_ret_probe(tu) is false too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
This commit is contained in:
Oleg Nesterov 2013-03-30 18:25:23 +01:00
parent a51cc60417
commit c1ae5c75e1

View File

@ -76,6 +76,8 @@ static DEFINE_MUTEX(uprobe_lock);
static LIST_HEAD(uprobe_list);
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs);
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
{
@ -89,11 +91,16 @@ static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
return !filter->nr_systemwide && list_empty(&filter->perf_events);
}
static inline bool is_ret_probe(struct trace_uprobe *tu)
{
return tu->consumer.ret_handler != NULL;
}
/*
* Allocate new trace_uprobe and initialize it (including uprobes).
*/
static struct trace_uprobe *
alloc_trace_uprobe(const char *group, const char *event, int nargs)
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
{
struct trace_uprobe *tu;
@ -118,6 +125,8 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs)
INIT_LIST_HEAD(&tu->list);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
init_trace_uprobe_filter(&tu->filter);
return tu;
@ -315,7 +324,7 @@ static int create_trace_uprobe(int argc, char **argv)
kfree(tail);
}
tu = alloc_trace_uprobe(group, event, argc);
tu = alloc_trace_uprobe(group, event, argc, false);
if (IS_ERR(tu)) {
pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
ret = PTR_ERR(tu);
@ -530,6 +539,12 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
return 0;
}
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
uprobe_trace_print(tu, func, regs);
}
/* Event entry printers */
static enum print_line_t
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
@ -800,6 +815,12 @@ static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
uprobe_perf_print(tu, 0, regs);
return 0;
}
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
uprobe_perf_print(tu, func, regs);
}
#endif /* CONFIG_PERF_EVENTS */
static
@ -854,6 +875,23 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
return ret;
}
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs)
{
struct trace_uprobe *tu;
tu = container_of(con, struct trace_uprobe, consumer);
if (tu->flags & TP_FLAG_TRACE)
uretprobe_trace_func(tu, func, regs);
#ifdef CONFIG_PERF_EVENTS
if (tu->flags & TP_FLAG_PROFILE)
uretprobe_perf_func(tu, func, regs);
#endif
return 0;
}
static struct trace_event_functions uprobe_funcs = {
.trace = print_uprobe_event
};