Commit 2103f6cba61a8b8bea3fc1b63661d830a2125e76 added a hotplug checking in
machine_kexec_prepare(), but it will lead a failure when loading the
crash-kernel in some cases.
Kexec utility can load the crash kernel by two ways:
1. kexec -l kernel-image
2. kexec -p kernel-image
In case #1, for rapid reboot, it's correct to do the hotplug checking things,
for it will shut down cpus in _cpu_down() later when command "kexec -e" be
sent, this routine needs the support of cpu hotplug.
In case #2, for use on panic, it's unnecessary to do the same thing, the whole
routing has no business with cpu shutting down. Check for cpu hot plug will
lead a failure to load the kernel.
Prior to this patch, if the first kernel is not support the CPU hotplug, when
a crash come, the kexec utility will not work.
Signed-off-by: Hu Keping <hukep...@huawei.com>
---
arch/arm/kernel/machine_kexec.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index 8cf0996..7706c67 100644
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -41,11 +41,16 @@ int machine_kexec_prepare(struct kimage *image)
int i, err;
/*
+ * For rapid reboot:
* Validate that if the current HW supports SMP, then the SW supports
* and implements CPU hotplug for the current HW. If not, we won't be
* able to kexec reliably, so fail the prepare operation.
+ *
+ * For use on panic:
+ * It is unnecessary to check the cpu hot plug.
*/
- if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug())
+ if (image->type != KEXEC_TYPE_CRASH &&
+ (num_possible_cpus() > 1 && !platform_can_cpu_hotplug()))
return -EINVAL;
/*
--
1.8.5.5
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