diff options
Diffstat (limited to 'kernel/trace/fgraph.c')
| -rw-r--r-- | kernel/trace/fgraph.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c5b207992fb4..484ad7a18463 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -815,6 +815,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe unsigned long bitmap; unsigned long ret; int offset; + int bit; int i; ret_stack = ftrace_pop_return_trace(&trace, &ret, frame_pointer, &offset); @@ -829,6 +830,15 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe if (fregs) ftrace_regs_set_instruction_pointer(fregs, ret); + bit = ftrace_test_recursion_trylock(trace.func, ret); + /* + * This can fail because ftrace_test_recursion_trylock() allows one nest + * call. If we are already in a nested call, then we don't probe this and + * just return the original return address. + */ + if (unlikely(bit < 0)) + goto out; + #ifdef CONFIG_FUNCTION_GRAPH_RETVAL trace.retval = ftrace_regs_get_return_value(fregs); #endif @@ -852,6 +862,8 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe } } + ftrace_test_recursion_unlock(bit); +out: /* * The ftrace_graph_return() may still access the current * ret_stack structure, we need to make sure the update of @@ -1325,6 +1337,10 @@ int register_ftrace_graph(struct fgraph_ops *gops) int ret = 0; int i = -1; + if (WARN_ONCE(gops->ops.flags & FTRACE_OPS_FL_GRAPH, + "function graph ops registered again")) + return -EBUSY; + guard(mutex)(&ftrace_lock); if (!fgraph_stack_cachep) { @@ -1393,6 +1409,8 @@ error: ftrace_graph_active--; gops->saved_func = NULL; fgraph_lru_release_index(i); + if (!ftrace_graph_active) + unregister_pm_notifier(&ftrace_suspend_notifier); } return ret; } @@ -1401,17 +1419,21 @@ void unregister_ftrace_graph(struct fgraph_ops *gops) { int command = 0; + if (WARN_ONCE(!(gops->ops.flags & FTRACE_OPS_FL_GRAPH), + "function graph ops unregistered without registering")) + return; + guard(mutex)(&ftrace_lock); if (unlikely(!ftrace_graph_active)) - return; + goto out; if (unlikely(gops->idx < 0 || gops->idx >= FGRAPH_ARRAY_SIZE || fgraph_array[gops->idx] != gops)) - return; + goto out; if (fgraph_lru_release_index(gops->idx) < 0) - return; + goto out; fgraph_array[gops->idx] = &fgraph_stub; @@ -1434,4 +1456,6 @@ void unregister_ftrace_graph(struct fgraph_ops *gops) unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); } gops->saved_func = NULL; + out: + gops->ops.flags &= ~FTRACE_OPS_FL_GRAPH; } |