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authorQian Cai <cai@lca.pw>2020-03-05 15:00:46 -0500
committerJoerg Roedel <jroedel@suse.de>2020-03-10 10:30:33 +0100
commit2d48ea0efb8887ebba3e3720bb5b738aced4e574 (patch)
tree7f2a45433c9fe2e38224efa9a6620c428361627b /drivers/iommu/intel-iommu.c
parent65ac74f1de3334852fb7d9b1b430fa5a06524276 (diff)
iommu/vt-d: Fix RCU-list bugs in intel_iommu_init()
There are several places traverse RCU-list without holding any lock in intel_iommu_init(). Fix them by acquiring dmar_global_lock. WARNING: suspicious RCU usage ----------------------------- drivers/iommu/intel-iommu.c:5216 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by swapper/0/1. Call Trace: dump_stack+0xa0/0xea lockdep_rcu_suspicious+0x102/0x10b intel_iommu_init+0x947/0xb13 pci_iommu_init+0x26/0x62 do_one_initcall+0xfe/0x500 kernel_init_freeable+0x45a/0x4f8 kernel_init+0x11/0x139 ret_from_fork+0x3a/0x50 DMAR: Intel(R) Virtualization Technology for Directed I/O Fixes: d8190dc63886 ("iommu/vt-d: Enable DMA remapping after rmrr mapped") Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
-rw-r--r--drivers/iommu/intel-iommu.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 33593fea0250..693380355dea 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5193,6 +5193,7 @@ int __init intel_iommu_init(void)
init_iommu_pm_ops();
+ down_read(&dmar_global_lock);
for_each_active_iommu(iommu, drhd) {
iommu_device_sysfs_add(&iommu->iommu, NULL,
intel_iommu_groups,
@@ -5200,6 +5201,7 @@ int __init intel_iommu_init(void)
iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops);
iommu_device_register(&iommu->iommu);
}
+ up_read(&dmar_global_lock);
bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
if (si_domain && !hw_pass_through)
@@ -5210,7 +5212,6 @@ int __init intel_iommu_init(void)
down_read(&dmar_global_lock);
if (probe_acpi_namespace_devices())
pr_warn("ACPI name space devices didn't probe correctly\n");
- up_read(&dmar_global_lock);
/* Finally, we enable the DMA remapping hardware. */
for_each_iommu(iommu, drhd) {
@@ -5219,6 +5220,8 @@ int __init intel_iommu_init(void)
iommu_disable_protect_mem_regions(iommu);
}
+ up_read(&dmar_global_lock);
+
pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
intel_iommu_enabled = 1;