- /*
- * Protect against fault, even if it shouldn't
- * happen. This tool is too much intrusive to
- * ignore such a protection.
- */
- asm volatile(
- "1: " PPC_LL "%[old], 0(%[parent])\n"
- "2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
- " li %[faulted], 0\n"
- "3:\n"
-
- ".section .fixup, \"ax\"\n"
- "4: li %[faulted], 1\n"
- " b 3b\n"
- ".previous\n"
-
- ".section __ex_table,\"a\"\n"
- PPC_LONG_ALIGN "\n"
- PPC_LONG "1b,4b\n"
- PPC_LONG "2b,4b\n"
- ".previous"
-
- : [old] "=&r" (old), [faulted] "=r" (faulted)
- : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
- : "memory"
- );
-
- if (unlikely(faulted)) {
- ftrace_graph_stop();
- WARN_ON(1);
- return;
- }
-
- trace.func = self_addr;