On 6/13/2024 3:42 PM, Hongchen Zhang wrote:
Call work_on_cpu(cpu, fn, arg) in pci_call_probe() while the argument @cpu is a offline cpu would cause system stuck forever.
This can be happen if a node is online while all its CPUs are offline (We can use "maxcpus=1" without "nr_cpus=1" to reproduce it).
So, in the above case, let pci_call_probe() call local_pci_probe() instead of work_on_cpu() when the best selected cpu is offline.
Fixes: 69a18b18699b ("PCI: Restrict probe functions to housekeeping CPUs") Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Hongchen Zhang zhanghongchen@loongson.cn
v2 -> v3: Modify commit message according to Markus's suggestion v1 -> v2: Add a method to reproduce the problem
drivers/pci/pci-driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index af2996d0d17f..32a99828e6a3 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -386,7 +386,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, free_cpumask_var(wq_domain_mask); }
- if (cpu < nr_cpu_ids)
Why not choose the right cpu to callwork_on_cpu() ? the one that is online. Thanks, Ethan
- if ((cpu < nr_cpu_ids) && cpu_online(cpu)) error = work_on_cpu(cpu, local_pci_probe, &ddi); else error = local_pci_probe(&ddi);