linux/arch/loongarch
Josh Poimboeuf 071c44e427 sched/idle: Mark arch_cpu_idle_dead() __noreturn
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead()
return"), in Xen, when a previously offlined CPU was brought back
online, it unexpectedly resumed execution where it left off in the
middle of the idle loop.

There were some hacks to make that work, but the behavior was surprising
as do_idle() doesn't expect an offlined CPU to return from the dead (in
arch_cpu_idle_dead()).

Now that Xen has been fixed, and the arch-specific implementations of
arch_cpu_idle_dead() also don't return, give it a __noreturn attribute.

This will cause the compiler to complain if an arch-specific
implementation might return.  It also improves code generation for both
caller and callee.

Also fixes the following warning:

  vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-03-08 08:44:28 -08:00
..
boot loongarch: efi: enable generic EFI compressed boot 2022-09-20 09:50:31 +02:00
configs LoongArch: kdump: Add single kernel image implementation 2023-02-25 22:12:17 +08:00
include loongarch/cpu: Mark play_dead() __noreturn 2023-03-06 15:34:06 -08:00
kernel sched/idle: Mark arch_cpu_idle_dead() __noreturn 2023-03-08 08:44:28 -08:00
lib LoongArch: Mark some assembler symbols as non-kprobe-able 2023-02-25 22:12:17 +08:00
mm LoongArch: Add kprobes support 2023-02-25 22:12:17 +08:00
net LoongArch, bpf: Use 4 instructions for function address in JIT 2023-02-17 17:43:07 +01:00
pci LoongArch: Add FDT booting support from efi system table 2022-12-14 08:41:53 +08:00
power LoongArch: Add JUMP_VIRT_ADDR macro implementation to avoid using la.abs 2023-02-25 22:12:16 +08:00
vdso LoongArch: Fix build warnings in VDSO 2022-08-25 19:34:59 +08:00
Kbuild LoongArch: Add BPF JIT support 2022-10-12 16:36:20 +08:00
Kconfig LoongArch: Add kprobes on ftrace support 2023-02-25 22:12:17 +08:00
Kconfig.debug LoongArch: Add prologue unwinder support 2022-08-12 13:10:11 +08:00
Makefile LoongArch: kdump: Add single kernel image implementation 2023-02-25 22:12:17 +08:00