Commit 02d715b4 authored by Amol Grover's avatar Amol Grover Committed by Joerg Roedel

iommu/vt-d: Fix RCU list debugging warnings

dmar_drhd_units is traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section but under the
protection of dmar_global_lock. Hence add corresponding lockdep
expression to silence the following false-positive warnings:

[    1.603975] =============================
[    1.603976] WARNING: suspicious RCU usage
[    1.603977] 5.5.4-stable #17 Not tainted
[    1.603978] -----------------------------
[    1.603980] drivers/iommu/intel-iommu.c:4769 RCU-list traversed in non-reader section!!

[    1.603869] =============================
[    1.603870] WARNING: suspicious RCU usage
[    1.603872] 5.5.4-stable #17 Not tainted
[    1.603874] -----------------------------
[    1.603875] drivers/iommu/dmar.c:293 RCU-list traversed in non-reader section!!
Tested-by: default avatarMadhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: default avatarAmol Grover <frextrite@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 98d54f81
......@@ -69,8 +69,9 @@ struct dmar_pci_notify_info {
extern struct rw_semaphore dmar_global_lock;
extern struct list_head dmar_drhd_units;
#define for_each_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list)
#define for_each_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list, \
dmar_rcu_check())
#define for_each_active_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
......@@ -81,7 +82,8 @@ extern struct list_head dmar_drhd_units;
if (i=drhd->iommu, drhd->ignored) {} else
#define for_each_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, 0) {} else
static inline bool dmar_rcu_check(void)
......
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