xtensa/cpu: Make sure cpu_die() doesn't return

cpu_die() doesn't return.  Make that more explicit with a BUG().

BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.

Link: https://lore.kernel.org/r/cca346b5c87693499e630291d78fb0bf12c24290.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 4dc109dd6214e27c47241ac1fcc081b3923dcfbd..7bad78495536954c6caf8f3028499f2afcc1bff9 100644 (file)
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -341,6 +341,8 @@ void __ref cpu_die(void)
        __asm__ __volatile__(
                        "       movi    a2, cpu_restart\n"
                        "       jx      a2\n");
+
+       BUG();
 }
 
 #endif /* CONFIG_HOTPLUG_CPU */