On 9/20/21 10:55, Nathan Lynch wrote:
If, due to bugs elsewhere, we get into unregister_cpu_online() with a CPU
that isn't marked hotpluggable, we can emit a warning and return an
appropriate error instead of crashing.
Signed-off-by: Nathan Lynch <nath...@linux.ibm.com>
---
As mentioned by Christophe this will not solve the crash for kernels with
panic_on_warn, but at least it will panic with a clearer message on those
and will not panic for everyone else.
Reviewed-by: Daniel Henrique Barboza <danielhb...@gmail.com>
arch/powerpc/kernel/sysfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index defecb3b1b15..08d8072d6e7a 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -928,7 +928,8 @@ static int unregister_cpu_online(unsigned int cpu)
struct device_attribute *attrs, *pmc_attrs;
int i, nattrs;
- BUG_ON(!c->hotpluggable);
+ if (WARN_RATELIMIT(!c->hotpluggable, "cpu %d can't be offlined\n", cpu))
+ return -EBUSY;
#ifdef CONFIG_PPC64
if (cpu_has_feature(CPU_FTR_SMT))
