Protect iommu_add_dt_device() with dtdevs_lock to prevent concurrent access to add/remove/assign/deassign. With addition of dynamic programming feature(follow-up patches in this series), this function can be concurrently access by pci device assign/deassign and also by dynamic node add/remove using device tree overlays.
Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com> Reviewed-by: Luca Fancellu <luca.fance...@arm.com> Reviewed-by: Michal Orzel <michal.or...@amd.com> --- Changes from v7: Update commit message and fix indent. --- --- xen/drivers/passthrough/device_tree.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c index 5796ee1f93..096ef2dd68 100644 --- a/xen/drivers/passthrough/device_tree.c +++ b/xen/drivers/passthrough/device_tree.c @@ -148,6 +148,8 @@ int iommu_add_dt_device(struct dt_device_node *np) if ( dev_iommu_fwspec_get(dev) ) return 0; + spin_lock(&dtdevs_lock); + /* * According to the Documentation/devicetree/bindings/iommu/iommu.txt * from Linux. @@ -160,7 +162,10 @@ int iommu_add_dt_device(struct dt_device_node *np) * these callback implemented. */ if ( !ops->add_device || !ops->dt_xlate ) - return -EINVAL; + { + rc = -EINVAL; + goto fail; + } if ( !dt_device_is_available(iommu_spec.np) ) break; @@ -191,6 +196,8 @@ int iommu_add_dt_device(struct dt_device_node *np) if ( rc < 0 ) iommu_fwspec_free(dev); + fail: + spin_unlock(&dtdevs_lock); return rc; } -- 2.17.1