From d74b4e4f1a6dbe27acce723e071c86a6ed154bf2 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 22 Jun 2016 10:06:13 +0100 Subject: [PATCH] arm64: hibernate: Don't hibernate on systems with stuck CPUs Hibernate relies on cpu hotplug to prevent secondary cores executing the kernel text while it is being restored. Add a call to cpus_are_stuck_in_kernel() to determine if there are CPUs not counted by 'num_online_cpus()', and prevent hibernate in this case. Fixes: 82869ac57b5 ("arm64: kernel: Add support for hibernate/suspend-to-disk") Acked-by: Mark Rutland Signed-off-by: James Morse Signed-off-by: Will Deacon --- arch/arm64/kernel/hibernate.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index f8df75d740f4..21ab5df9fa76 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -236,6 +237,11 @@ int swsusp_arch_suspend(void) unsigned long flags; struct sleep_stack_data state; + if (cpus_are_stuck_in_kernel()) { + pr_err("Can't hibernate: no mechanism to offline secondary CPUs.\n"); + return -EBUSY; + } + local_dbg_save(flags); if (__cpu_suspend_enter(&state)) { -- 2.39.2