@@ -306,9 +306,8 @@ the objtool maintainers.
3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation
The call from foo() to bar() doesn't return, but bar() is missing the
- __noreturn annotation. NOTE: In addition to adding the __noreturn
- annotation, the function name also needs to be added to
- 'global_noreturns' in tools/objtool/check.c.
+ __noreturn annotation. NOTE: In addition to annotating the function
+ with __noreturn, please also add it to tools/objtool/noreturns.h.
4. file.o: warning: objtool: func(): can't find starting instruction
or
@@ -192,49 +192,11 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
struct instruction *insn;
bool empty = true;
- /*
- * Unfortunately these have to be hard coded because the noreturn
- * attribute isn't provided in ELF data. Keep 'em sorted.
- */
+#define NORETURN(func) __stringify(func),
static const char * const global_noreturns[] = {
- "__invalid_creds",
- "__module_put_and_kthread_exit",
- "__reiserfs_panic",
- "__stack_chk_fail",
- "__ubsan_handle_builtin_unreachable",
- "arch_call_rest_init",
- "arch_cpu_idle_dead",
- "btrfs_assertfail",
- "cpu_bringup_and_idle",
- "cpu_startup_entry",
- "do_exit",
- "do_group_exit",
- "do_task_dead",
- "ex_handler_msr_mce",
- "fortify_panic",
- "hlt_play_dead",
- "hv_ghcb_terminate",
- "kthread_complete_and_exit",
- "kthread_exit",
- "kunit_try_catch_throw",
- "machine_real_restart",
- "make_task_dead",
- "mpt_halt_firmware",
- "nmi_panic_self_stop",
- "panic",
- "panic_smp_self_stop",
- "rest_init",
- "rewind_stack_and_make_dead",
- "sev_es_terminate",
- "snp_abort",
- "start_kernel",
- "stop_this_cpu",
- "usercopy_abort",
- "x86_64_start_kernel",
- "x86_64_start_reservations",
- "xen_cpu_bringup_again",
- "xen_start_kernel",
+#include "noreturns.h"
};
+#undef NORETURN
if (!func)
return false;
new file mode 100644
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * This is a (sorted!) list of all known __noreturn functions in the kernel.
+ * It's needed for objtool to properly reverse-engineer the control flow graph.
+ *
+ * Yes, this is unfortunate. A better solution is in the works.
+ */
+NORETURN(__invalid_creds)
+NORETURN(__module_put_and_kthread_exit)
+NORETURN(__reiserfs_panic)
+NORETURN(__stack_chk_fail)
+NORETURN(__ubsan_handle_builtin_unreachable)
+NORETURN(arch_call_rest_init)
+NORETURN(arch_cpu_idle_dead)
+NORETURN(btrfs_assertfail)
+NORETURN(cpu_bringup_and_idle)
+NORETURN(cpu_startup_entry)
+NORETURN(do_exit)
+NORETURN(do_group_exit)
+NORETURN(do_task_dead)
+NORETURN(ex_handler_msr_mce)
+NORETURN(fortify_panic)
+NORETURN(hlt_play_dead)
+NORETURN(hv_ghcb_terminate)
+NORETURN(kthread_complete_and_exit)
+NORETURN(kthread_exit)
+NORETURN(kunit_try_catch_throw)
+NORETURN(machine_real_restart)
+NORETURN(make_task_dead)
+NORETURN(mpt_halt_firmware)
+NORETURN(nmi_panic_self_stop)
+NORETURN(panic)
+NORETURN(panic_smp_self_stop)
+NORETURN(rest_init)
+NORETURN(rewind_stack_and_make_dead)
+NORETURN(sev_es_terminate)
+NORETURN(snp_abort)
+NORETURN(start_kernel)
+NORETURN(stop_this_cpu)
+NORETURN(usercopy_abort)
+NORETURN(x86_64_start_kernel)
+NORETURN(x86_64_start_reservations)
+NORETURN(xen_cpu_bringup_again)
+NORETURN(xen_start_kernel)