Commit f5152416 authored Mar 05, 2020 by Qian Cai Committed by Joerg Roedel Mar 10, 2020

iommu/vt-d: Silence RCU-list debugging warnings



Similar to the commit 02d715b4 ("iommu/vt-d: Fix RCU list debugging
warnings"), there are several other places that call
list_for_each_entry_rcu() outside of an RCU read side critical section
but with dmar_global_lock held. Silence those false positives as well.

 drivers/iommu/intel-iommu.c:4288 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffff935892c8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x1ad/0xb97

 drivers/iommu/dmar.c:366 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffff935892c8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x125/0xb97

 drivers/iommu/intel-iommu.c:5057 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffffa71892c8 (dmar_global_lock){++++}, at: intel_iommu_init+0x61a/0xb13

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>

parent 2d48ea0e

drivers/iommu/dmar.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -363,7 +363,8 @@ dmar_find_dmaru(struct acpi_dmar_hardware_unit *drhd)
		{
		struct dmar_drhd_unit *dmaru;

		list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list)
		list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list,
		dmar_rcu_check())
		if (dmaru->segment == drhd->segment &&
		dmaru->reg_base_addr == drhd->address)
		return dmaru;

include/linux/dmar.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -74,11 +74,13 @@ extern struct list_head dmar_drhd_units;
		dmar_rcu_check())

		#define for_each_active_drhd_unit(drhd) \
		list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
		list_for_each_entry_rcu(drhd, &dmar_drhd_units, list, \
		dmar_rcu_check()) \
		if (drhd->ignored) {} else

		#define for_each_active_iommu(i, drhd) \
		list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
		list_for_each_entry_rcu(drhd, &dmar_drhd_units, list, \
		dmar_rcu_check()) \
		if (i=drhd->iommu, drhd->ignored) {} else

		#define for_each_iommu(i, drhd) \

Admin message