[tip: objtool/core] xtensa/cpu: Make sure cpu_die() doesn't return

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/core branch of tip:

Commit-ID:     d08e12e8126ec88d6cb1a7eb160d8d7b52c8699f
Gitweb:        https://git.kernel.org/tip/d08e12e8126ec88d6cb1a7eb160d8d7b52c8699f
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Mon, 13 Feb 2023 23:05:53 -08:00
Committer:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Wed, 08 Mar 2023 08:44:27 -08:00

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@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 arch/xtensa/kernel/smp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 4dc109d..7bad784 100644
--- 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 */