From: Jianxin Xiong <jianxin.xiong@xxxxxxxxx>
This fixes the following warnings with PROVE_LOCKING and PROVE_RCU
enabled in the kernel:
case (1):
[ INFO: suspicious RCU usage. ]
drivers/infiniband/hw/hfi1/init.c:532
suspicious rcu_dereference_check() usage!
case (2):
[ INFO: suspicious RCU usage. ]
drivers/infiniband/hw/hfi1/hfi.h:1624
suspicious rcu_dereference_check() usage!
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Jianxin Xiong <jianxin.xiong@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/hfi.h | 13 +++++++++++--
drivers/infiniband/hw/hfi1/init.c | 11 ++++++-----
drivers/infiniband/hw/hfi1/mad.c | 2 +-
3 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index 7df4cb2..d22876d 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -1616,8 +1616,7 @@ static inline u16 hfi1_get_pkey(struct hfi1_ibport *ibp, unsigned index)
}
/*
- * Readers of cc_state must call get_cc_state() under rcu_read_lock().
- * Writers of cc_state must call get_cc_state() under cc_state_lock.
+ * Called by readers of cc_state only, must call under rcu_read_lock().
*/
static inline struct cc_state *get_cc_state(struct hfi1_pportdata *ppd)
{
@@ -1625,6 +1624,16 @@ static inline struct cc_state *get_cc_state(struct hfi1_pportdata *ppd)
}
/*
+ * Called by writers of cc_state only, must call under cc_state_lock.
+ */
+static inline
+struct cc_state *get_cc_state_protected(struct hfi1_pportdata *ppd)
+{
+ return rcu_dereference_protected(ppd->cc_state,
+ lockdep_is_held(&ppd->cc_state_lock));
+}
+
+/*
* values for dd->flags (_device_ related flags)
*/
#define HFI1_INITTED 0x1 /* chip and driver up and initted */
diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index ec77c7e..44ec3a8 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -475,8 +475,9 @@ static enum hrtimer_restart cca_timer_fn(struct hrtimer *t)
void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd,
struct hfi1_devdata *dd, u8 hw_pidx, u8 port)
{
- int i, size;
+ int i;
uint default_pkey_idx;
+ struct cc_state *cc_state;
ppd->dd = dd;
ppd->hw_pidx = hw_pidx;
@@ -527,9 +528,9 @@ void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd,
spin_lock_init(&ppd->cc_state_lock);
spin_lock_init(&ppd->cc_log_lock);
- size = sizeof(struct cc_state);
- RCU_INIT_POINTER(ppd->cc_state, kzalloc(size, GFP_KERNEL));
- if (!rcu_dereference(ppd->cc_state))
+ cc_state = kzalloc(sizeof(*cc_state), GFP_KERNEL);
+ RCU_INIT_POINTER(ppd->cc_state, cc_state);
+ if (!cc_state)
goto bail;
return;
@@ -1327,7 +1328,7 @@ static void cleanup_device_data(struct hfi1_devdata *dd)
hrtimer_cancel(&ppd->cca_timer[i].hrtimer);
spin_lock(&ppd->cc_state_lock);
- cc_state = get_cc_state(ppd);
+ cc_state = get_cc_state_protected(ppd);
RCU_INIT_POINTER(ppd->cc_state, NULL);
spin_unlock(&ppd->cc_state_lock);
diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c
index 5590a4c..1263abe 100644
--- a/drivers/infiniband/hw/hfi1/mad.c
+++ b/drivers/infiniband/hw/hfi1/mad.c
@@ -3375,7 +3375,7 @@ static void apply_cc_state(struct hfi1_pportdata *ppd)
*/
spin_lock(&ppd->cc_state_lock);
- old_cc_state = get_cc_state(ppd);
+ old_cc_state = get_cc_state_protected(ppd);
if (!old_cc_state) {
/* never active, or shutting down */
spin_unlock(&ppd->cc_state_lock);
--
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