Re: [PATCH] powerpc: fix unbalanced node refcount in check_kvm_guest()
From: Srikar Dronamraju <hidden>
Date: 2021-09-29 07:30:24
* Nathan Lynch [off-list ref] [2021-09-28 07:45:50]:
When check_kvm_guest() succeeds in looking up a /hypervisor OF node, it returns without performing a matching put for the lookup, leaving the node's reference count elevated. Add the necessary call to of_node_put(), rearranging the code slightly to avoid repetition or goto.
Looks good to me. I do see few other cases where we call of_find_node calls without of_node_put(). Some of them that I saw were in find_legacy_serial_ports() in arch/powerpc/kernel/legacy_serial.c proc_ppc64_create in arch/powerpc/proc/powerpc.c update_events_in_group in arch/powerpc/perf/imc-pmu.c cell_iommu_init_disabled in arch/powerpc/platforms/cell/iommu.c cell_publish_devices in arch/powerpc/platforms/cell/setup.c spufs_init_isolated_loader in arch/powerpc/platforms/cell/spufs/inode.c holly_init_pci / holly_restart and holly_init_IRQ in arch/powerpc/platforms/embedded6xx/holly.c Reviewed-by: Srikar Dronamraju <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Nathan Lynch <redacted> Fixes: 107c55005fbd ("powerpc/pseries: Add KVM guest doorbell restrictions") --- arch/powerpc/kernel/firmware.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)diff --git a/arch/powerpc/kernel/firmware.c b/arch/powerpc/kernel/firmware.c index c7022c41cc31..20328f72f9f2 100644 --- a/arch/powerpc/kernel/firmware.c +++ b/arch/powerpc/kernel/firmware.c@@ -31,11 +31,10 @@ int __init check_kvm_guest(void) if (!hyper_node) return 0; - if (!of_device_is_compatible(hyper_node, "linux,kvm")) - return 0; - - static_branch_enable(&kvm_guest); + if (of_device_is_compatible(hyper_node, "linux,kvm")) + static_branch_enable(&kvm_guest); + of_node_put(hyper_node); return 0; } core_initcall(check_kvm_guest); // before kvm_guest_init()-- 2.31.1
-- Thanks and Regards Srikar Dronamraju