unsigned long trampoline_size;
struct list_head list;
ftrace_ops_func_t ops_func;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ unsigned long direct_call;
+#endif
#endif
};
static void call_direct_funcs(unsigned long ip, unsigned long pip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
- unsigned long addr;
+ unsigned long addr = READ_ONCE(ops->direct_call);
- addr = ftrace_find_rec_direct(ip);
if (!addr)
return;
ops->func = call_direct_funcs;
ops->flags = MULTI_FLAGS;
ops->trampoline = FTRACE_REGS_ADDR;
+ ops->direct_call = addr;
err = register_ftrace_function_nolock(ops);
/* Enable the tmp_ops to have the same functions as the direct ops */
ftrace_ops_init(&tmp_ops);
tmp_ops.func_hash = ops->func_hash;
+ tmp_ops.direct_call = addr;
err = register_ftrace_function_nolock(&tmp_ops);
if (err)
entry->direct = addr;
}
}
+ /* Prevent store tearing if a trampoline concurrently accesses the value */
+ WRITE_ONCE(ops->direct_call, addr);
mutex_unlock(&ftrace_lock);