Implement trace_uprobe_filter_func() and change probe_event_enable()
to setup uprobe_consumer->filter() if necessary.
Also change uprobe_dispatcher() to skip the tasks we do not want to
probe and return UPROBE_HANDLER_REMOVE to indicate that this "int3"
should be removed unless there is another consumer which wants to
trace this task.
Signed-off-by: Oleg Nesterov <o...@redhat.com>
---
kernel/trace/trace_uprobe.c | 48 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f7a2dcb..78e918f 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -112,6 +112,50 @@ static void probes_seq_show_filter(struct
trace_uprobe_filter *filter,
seq_printf(m, " pid=%d", pid_vnr(filter->tgid));
}
+static bool trace_uprobe_filter_current(struct trace_uprobe_filter *filter)
+{
+ return !filter->tgid || filter->tgid == task_tgid(current);
+}
+
+static bool trace_uprobe_filter_func(struct uprobe_consumer *uc,
+ enum uprobe_filter_ctx ctx,
+ struct mm_struct *mm)
+{
+ struct uprobe_trace_consumer *utc;
+ struct trace_uprobe_filter *filter;
+ struct task_struct *p, *t;
+ bool ret;
+
+ utc = container_of(uc, struct uprobe_trace_consumer, cons);
+ filter = &utc->tu->filter;
+
+ if (ctx == UPROBE_FILTER_MMAP)
+ return trace_uprobe_filter_current(filter);
+
+ ret = false;
+ rcu_read_lock();
+ p = pid_task(filter->tgid, PIDTYPE_PID);
+ if (p) {
+ t = p;
+ do {
+ if (t->mm) {
+ ret = (t->mm == mm);
+ break;
+ }
+ } while_each_thread(p, t);
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static inline void set_trace_uprobe_filter_func(struct uprobe_consumer *uc,
+ struct trace_uprobe_filter *filter)
+{
+ if (filter->tgid)
+ uc->filter = trace_uprobe_filter_func;
+}
+
/*
* Allocate new trace_uprobe and initialize it (including uprobes).
*/
@@ -613,6 +657,7 @@ static int probe_event_enable(struct trace_uprobe *tu, int
flag)
if (!utc)
return -EINTR;
+ set_trace_uprobe_filter_func(&utc->cons, &tu->filter);
utc->cons.handler = uprobe_dispatcher;
utc->tu = tu;
tu->consumer = utc;
@@ -784,6 +829,9 @@ static int uprobe_dispatcher(struct uprobe_consumer *con,
struct pt_regs *regs)
if (!tu || tu->consumer != utc)
return 0;
+ if (!trace_uprobe_filter_current(&tu->filter))
+ return UPROBE_HANDLER_REMOVE;
+
if (tu->flags & TP_FLAG_TRACE)
uprobe_trace_func(tu, regs);
--
1.5.5.1
--
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