Use RCU to ensure the consistent state of the control PF global
pointer contained in struct ice_adapter. Enforce RCU usage on
the callers.
Fix a potential invalid pointer return due a TOCTOU issue
Fixes: e2193f9f9ec9 ("ice: enable timesync operation on 2xNAC E825 devices")
Signed-off-by: Sergey Temerkhanov <[email protected]>
Reviewed-by: Arkadiusz Kubalewski <[email protected]>
Tested-by: Frederick Lawler <[email protected]>
---
drivers/net/ethernet/intel/ice/ice.h | 10 +++-
drivers/net/ethernet/intel/ice/ice_adapter.h | 2 +-
drivers/net/ethernet/intel/ice/ice_ptp.c | 49 ++++++++++++++++----
drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 9 ++++
4 files changed, 59 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h
b/drivers/net/ethernet/intel/ice/ice.h
index 804f5aa8e9f5..2b2787d16c33 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -40,6 +40,7 @@
#include <linux/cpu_rmap.h>
#include <linux/dim.h>
#include <linux/gnss.h>
+#include <linux/rcupdate.h>
#include <net/pkt_cls.h>
#include <net/pkt_sched.h>
#include <net/tc_act/tc_mirred.h>
@@ -1145,14 +1146,19 @@ static inline bool ice_pf_src_tmr_owned(struct ice_pf
*pf)
* ice_get_primary_hw - Get pointer to primary ice_hw structure
* @pf: pointer to PF structure
*
+ * The function must be called from an RCU read-side critical section.
+ * hw is embedded in struct ice_pf, so it is protected by the RCU.
+ *
* Return: A pointer to ice_hw structure with access to timesync
* register space.
*/
static inline struct ice_hw *ice_get_primary_hw(struct ice_pf *pf)
{
- if (!pf->adapter->ctrl_pf)
+ struct ice_pf *ctrl_pf = rcu_dereference(pf->adapter->ctrl_pf);
+
+ if (!ctrl_pf)
return &pf->hw;
else
- return &pf->adapter->ctrl_pf->hw;
+ return &ctrl_pf->hw;
}
#endif /* _ICE_H_ */
diff --git a/drivers/net/ethernet/intel/ice/ice_adapter.h
b/drivers/net/ethernet/intel/ice/ice_adapter.h
index e95266c7f20b..349d49d57f11 100644
--- a/drivers/net/ethernet/intel/ice/ice_adapter.h
+++ b/drivers/net/ethernet/intel/ice/ice_adapter.h
@@ -42,7 +42,7 @@ struct ice_adapter {
/* For access to GLCOMM_QTX_CNTX_CTL register */
spinlock_t txq_ctx_lock;
- struct ice_pf *ctrl_pf;
+ struct ice_pf __rcu *ctrl_pf;
struct ice_port_list ports;
u64 index;
};
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c
b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 691f05c62d4e..23d9a826f88b 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -4,6 +4,7 @@
#include "ice.h"
#include "ice_lib.h"
#include "ice_trace.h"
+#include <linux/rcupdate.h>
static const char ice_pin_names[][64] = {
"SDP0",
@@ -54,11 +55,35 @@ static const struct ice_ptp_pin_desc ice_pin_desc_dpll[] = {
{ SDP3, { 3, -1 }, { 0, 0 }},
};
+/**
+ * ice_get_ctrl_pf - Get the control PF for a given PF
+ * @pf: The PF pointer to look up at
+ *
+ * The control PF is the PF which owns the PTP clock for the adapter.
+ * Only the control PF is allowed to perform certain operations on the
+ * PTP clock such as adjusting the time or configuring the pins.
+ *
+ * This function must be called from an RCU read-side critical section.
+ *
+ * Return: Pointer to the control PF, or NULL if not found
+ */
static struct ice_pf *ice_get_ctrl_pf(struct ice_pf *pf)
{
- return !pf->adapter ? NULL : pf->adapter->ctrl_pf;
+ return !pf->adapter ? NULL : rcu_dereference(pf->adapter->ctrl_pf);
}
+/**
+ * ice_get_ctrl_ptp - Get the PTP structure for the control PF
+ * @pf: The PF pointer to look up at
+ *
+ * The control PF is the PF which owns the PTP clock for the adapter.
+ * Only the control PF is allowed to perform certain operations on the
+ * PTP clock such as adjusting the time or configuring the pins.
+ *
+ * This function must be called from an RCU read-side critical section.
+ *
+ * Return: Pointer to the PTP structure of the control PF, or NULL if not found
+ */
static struct ice_ptp *ice_get_ctrl_ptp(struct ice_pf *pf)
{
struct ice_pf *ctrl_pf = ice_get_ctrl_pf(pf);
@@ -207,6 +232,8 @@ u64 ice_ptp_read_src_clk_reg(struct ice_pf *pf,
u32 hi, lo, lo2;
u8 tmr_idx;
+ guard(rcu)();
+
if (!ice_is_primary(hw))
hw = ice_get_primary_hw(pf);
@@ -3074,18 +3101,19 @@ void ice_ptp_rebuild(struct ice_pf *pf, enum
ice_reset_req reset_type)
static void ice_ptp_setup_adapter(struct ice_pf *pf)
{
- pf->adapter->ctrl_pf = pf;
+ rcu_assign_pointer(pf->adapter->ctrl_pf, pf);
}
static int ice_ptp_setup_pf(struct ice_pf *pf)
{
- struct ice_ptp *ctrl_ptp = ice_get_ctrl_ptp(pf);
struct ice_ptp *ptp = &pf->ptp;
- if (!ctrl_ptp) {
- dev_info(ice_pf_to_dev(pf),
- "PTP unavailable: no controlling PF\n");
- return -EOPNOTSUPP;
+ scoped_guard(rcu) {
+ if (!ice_get_ctrl_ptp(pf)) {
+ dev_info(ice_pf_to_dev(pf),
+ "PTP unavailable: no controlling PF\n");
+ return -EOPNOTSUPP;
+ }
}
if (pf->hw.mac_type == ICE_MAC_UNKNOWN)
@@ -3121,11 +3149,16 @@ static void ice_ptp_cleanup_pf(struct ice_pf *pf)
*/
int ice_ptp_clock_index(struct ice_pf *pf)
{
- struct ice_ptp *ctrl_ptp = ice_get_ctrl_ptp(pf);
+ struct ice_ptp *ctrl_ptp;
struct ptp_clock *clock;
+ guard(rcu)();
+
+ ctrl_ptp = ice_get_ctrl_ptp(pf);
+
if (!ctrl_ptp)
return -1;
+
clock = ctrl_ptp->clock;
return clock ? ptp_clock_index(clock) : -1;
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index f0b76660a012..30a7096854c2 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2021, Intel Corporation. */
+#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include "ice_common.h"
@@ -351,6 +352,8 @@ void ice_ptp_src_cmd(struct ice_hw *hw, enum
ice_ptp_tmr_cmd cmd)
struct ice_pf *pf = container_of(hw, struct ice_pf, hw);
u32 cmd_val = ice_ptp_tmr_cmd_to_src_reg(hw, cmd);
+ guard(rcu)();
+
if (!ice_is_primary(hw))
hw = ice_get_primary_hw(pf);
@@ -379,6 +382,8 @@ static void ice_ptp_exec_tmr_cmd(struct ice_hw *hw)
if (err)
dev_warn(ice_hw_to_dev(hw), "Failed to flush SBQ: %d\n", err);
+ guard(rcu)();
+
if (!ice_is_primary(hw))
hw = ice_get_primary_hw(pf);
@@ -1948,6 +1953,8 @@ static int ice_read_phy_and_phc_time_eth56g(struct ice_hw
*hw, u8 port,
zo = rd32(hw, GLTSYN_SHTIME_0(tmr_idx));
lo = rd32(hw, GLTSYN_SHTIME_L(tmr_idx));
} else {
+ guard(rcu)();
+
zo = rd32(ice_get_primary_hw(pf), GLTSYN_SHTIME_0(tmr_idx));
lo = rd32(ice_get_primary_hw(pf), GLTSYN_SHTIME_L(tmr_idx));
}
@@ -2117,6 +2124,8 @@ int ice_start_phy_timer_eth56g(struct ice_hw *hw, u8 port)
lo = rd32(hw, GLTSYN_INCVAL_L(tmr_idx));
hi = rd32(hw, GLTSYN_INCVAL_H(tmr_idx));
} else {
+ guard(rcu)();
+
lo = rd32(ice_get_primary_hw(pf), GLTSYN_INCVAL_L(tmr_idx));
hi = rd32(ice_get_primary_hw(pf), GLTSYN_INCVAL_H(tmr_idx));
}
--
2.53.0
