[PATCH net v6 0/4] dpll: fix unordered unbind/bind registerer issues

[PATCH net v6 0/4] dpll: fix unordered unbind/bind registerer issues

[Arkadiusz Kubalewski]

Fix issues when performing unordered unbind/bind of a kernel modules
which are using a dpll device with DPLL_PIN_TYPE_MUX pins.
Currently only serialized bind/unbind of such use case works, fix
the issues and allow for unserialized kernel module bind order.

The issues are observed on the ice driver, i.e.,

$ echo 0000:af:00.0 > /sys/bus/pci/drivers/ice/unbind
$ echo 0000:af:00.1 > /sys/bus/pci/drivers/ice/unbind

results in:

ice 0000:af:00.0: Removed PTP clock
BUG: kernel NULL pointer dereference, address: 0000000000000010
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 71848 Comm: bash Kdump: loaded Not tainted 6.6.0-rc5_next-queue_19th-Oct-2023-01625-g039e5d15e451 #1
Hardware name: Intel Corporation S2600STB/S2600STB, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
RIP: 0010:ice_dpll_rclk_state_on_pin_get+0x2f/0x90 [ice]
Code: 41 57 4d 89 cf 41 56 41 55 4d 89 c5 41 54 55 48 89 f5 53 4c 8b 66 08 48 89 cb 4d 8d b4 24 f0 49 00 00 4c 89 f7 e8 71 ec 1f c5 <0f> b6 5b 10 41 0f b6 84 24 30 4b 00 00 29 c3 41 0f b6 84 24 28 4b
RSP: 0018:ffffc902b179fb60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8882c1398000 RSI: ffff888c7435cc60 RDI: ffff888c7435cb90
RBP: ffff888c7435cc60 R08: ffffc902b179fbb0 R09: 0000000000000000
R10: ffff888ef1fc8050 R11: fffffffffff82700 R12: ffff888c743581a0
R13: ffffc902b179fbb0 R14: ffff888c7435cb90 R15: 0000000000000000
FS:  00007fdc7dae0740(0000) GS:ffff888c105c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000132c24002 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 ? __die+0x20/0x70
 ? page_fault_oops+0x76/0x170
 ? exc_page_fault+0x65/0x150
 ? asm_exc_page_fault+0x22/0x30
 ? ice_dpll_rclk_state_on_pin_get+0x2f/0x90 [ice]
 ? __pfx_ice_dpll_rclk_state_on_pin_get+0x10/0x10 [ice]
 dpll_msg_add_pin_parents+0x142/0x1d0
 dpll_pin_event_send+0x7d/0x150
 dpll_pin_on_pin_unregister+0x3f/0x100
 ice_dpll_deinit_pins+0xa1/0x230 [ice]
 ice_dpll_deinit+0x29/0xe0 [ice]
 ice_remove+0xcd/0x200 [ice]
 pci_device_remove+0x33/0xa0
 device_release_driver_internal+0x193/0x200
 unbind_store+0x9d/0xb0
 kernfs_fop_write_iter+0x128/0x1c0
 vfs_write+0x2bb/0x3e0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x59/0x90
 ? filp_close+0x1b/0x30
 ? do_dup2+0x7d/0xd0
 ? syscall_exit_work+0x103/0x130
 ? syscall_exit_to_user_mode+0x22/0x40
 ? do_syscall_64+0x69/0x90
 ? syscall_exit_work+0x103/0x130
 ? syscall_exit_to_user_mode+0x22/0x40
 ? do_syscall_64+0x69/0x90
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7fdc7d93eb97
Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff2aa91028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007fdc7d93eb97
RDX: 000000000000000d RSI: 00005644814ec9b0 RDI: 0000000000000001
RBP: 00005644814ec9b0 R08: 0000000000000000 R09: 00007fdc7d9b14e0
R10: 00007fdc7d9b13e0 R11: 0000000000000246 R12: 000000000000000d
R13: 00007fdc7d9fb780 R14: 000000000000000d R15: 00007fdc7d9f69e0
 </TASK>
Modules linked in: uinput vfio_pci vfio_pci_core vfio_iommu_type1 vfio irqbypass ixgbevf snd_seq_dummy snd_hrtimer snd_seq snd_timer snd_seq_device snd soundcore overlay qrtr rfkill vfat fat xfs libcrc32c rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common isst_if_common skx_edac nfit libnvdimm ipmi_ssif x86_pkg_temp_thermal intel_powerclamp coretemp irdma rapl intel_cstate ib_uverbs iTCO_wdt iTCO_vendor_support acpi_ipmi intel_uncore mei_me ipmi_si pcspkr i2c_i801 ib_core mei ipmi_devintf intel_pch_thermal ioatdma i2c_smbus ipmi_msghandler lpc_ich joydev acpi_power_meter acpi_pad ext4 mbcache jbd2 sd_mod t10_pi sg ast i2c_algo_bit drm_shmem_helper drm_kms_helper ice crct10dif_pclmul ixgbe crc32_pclmul drm crc32c_intel ahci i40e libahci ghash_clmulni_intel libata mdio dca gnss wmi fuse [last unloaded: iavf]
CR2: 0000000000000010

v6:
- fix memory corruption on error path in patch [v5 2/4]

Arkadiusz Kubalewski (4):
  dpll: fix broken error path in dpll_pin_alloc(..)
  dpll: fix pin dump crash for rebound module
  dpll: fix userspace availability of pins
  dpll: fix register pin with unregistered parent pin

 drivers/dpll/dpll_core.c    | 68 +++++++++++++++++++++++++++++++------
 drivers/dpll/dpll_core.h    |  4 +--
 drivers/dpll/dpll_netlink.c | 57 ++++++++++++++++++++++---------
 3 files changed, 100 insertions(+), 29 deletions(-)


base-commit: dbc153fd3c142909e564bb256da087e13fbf239c
-- 
2.38.1

[PATCH net v6 1/4] dpll: fix broken error path in dpll_pin_alloc(..)

[Arkadiusz Kubalewski]

If pin type is not expected, or pin properities failed to allocate
memory, the unwind error path shall not destroy pin's xarrays, which
were not yet initialized.
Add new goto label and use it to fix broken error path.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
---
v6:
- no changes, bump the series version

 drivers/dpll/dpll_core.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index 1eca8cc271f8..c08772ee9fd6 100644
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -441,7 +441,7 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
 		    prop->type > DPLL_PIN_TYPE_MAX)) {
 		ret = -EINVAL;
-		goto err;
+		goto err_pin_prop;
 	}
 	pin->prop = prop;
 	refcount_set(&pin->refcount, 1);
@@ -450,11 +450,12 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
 			      &dpll_pin_xa_id, GFP_KERNEL);
 	if (ret)
-		goto err;
+		goto err_xa_alloc;
 	return pin;
-err:
+err_xa_alloc:
 	xa_destroy(&pin->dpll_refs);
 	xa_destroy(&pin->parent_refs);
+err_pin_prop:
 	kfree(pin);
 	return ERR_PTR(ret);
 }
-- 
2.38.1

[PATCH net v6 2/4] dpll: fix pin dump crash for rebound module

[Arkadiusz Kubalewski]

When a kernel module is unbound but the pin resources were not entirely
freed (other kernel module instance of the same PCI device have had kept
the reference to that pin), and kernel module is again bound, the pin
properties would not be updated (the properties are only assigned when
memory for the pin is allocated), prop pointer still points to the
kernel module memory of the kernel module which was deallocated on the
unbind.

If the pin dump is invoked in this state, the result is a kernel crash.
Prevent the crash by storing persistent pin properties in dpll subsystem,
copy the content from the kernel module when pin is allocated, instead of
using memory of the kernel module.

Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Reviewed-by: Jan Glaza <jan.glaza@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
---
v6:
- add missing call to dpll_pin_prop_free(..) on failed XA alloc path in
  dpll_pin_alloc(..)

 drivers/dpll/dpll_core.c    | 55 +++++++++++++++++++++++++++++++++++--
 drivers/dpll/dpll_core.h    |  4 +--
 drivers/dpll/dpll_netlink.c | 28 +++++++++----------
 3 files changed, 69 insertions(+), 18 deletions(-)

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index c08772ee9fd6..cb62696467d1 100644
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -425,6 +425,53 @@ void dpll_device_unregister(struct dpll_device *dpll,
 }
 EXPORT_SYMBOL_GPL(dpll_device_unregister);
 
+static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
+{
+	kfree(prop->package_label);
+	kfree(prop->panel_label);
+	kfree(prop->board_label);
+	kfree(prop->freq_supported);
+}
+
+static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
+			     struct dpll_pin_properties *dst)
+{
+	memcpy(dst, src, sizeof(*dst));
+	if (src->freq_supported && src->freq_supported_num) {
+		size_t freq_size = src->freq_supported_num *
+				   sizeof(*src->freq_supported);
+		dst->freq_supported = kmemdup(src->freq_supported,
+					      freq_size, GFP_KERNEL);
+		if (!src->freq_supported)
+			return -ENOMEM;
+	}
+	if (src->board_label) {
+		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
+		if (!dst->board_label)
+			goto err_board_label;
+	}
+	if (src->panel_label) {
+		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
+		if (!dst->panel_label)
+			goto err_panel_label;
+	}
+	if (src->package_label) {
+		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
+		if (!dst->package_label)
+			goto err_package_label;
+	}
+
+	return 0;
+
+err_package_label:
+	kfree(dst->panel_label);
+err_panel_label:
+	kfree(dst->board_label);
+err_board_label:
+	kfree(dst->freq_supported);
+	return -ENOMEM;
+}
+
 static struct dpll_pin *
 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
 	       const struct dpll_pin_properties *prop)
@@ -443,7 +490,9 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
 		ret = -EINVAL;
 		goto err_pin_prop;
 	}
-	pin->prop = prop;
+	ret = dpll_pin_prop_dup(prop, &pin->prop);
+	if (ret)
+		goto err_pin_prop;
 	refcount_set(&pin->refcount, 1);
 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
@@ -455,6 +504,7 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
 err_xa_alloc:
 	xa_destroy(&pin->dpll_refs);
 	xa_destroy(&pin->parent_refs);
+	dpll_pin_prop_free(&pin->prop);
 err_pin_prop:
 	kfree(pin);
 	return ERR_PTR(ret);
@@ -515,6 +565,7 @@ void dpll_pin_put(struct dpll_pin *pin)
 		xa_destroy(&pin->dpll_refs);
 		xa_destroy(&pin->parent_refs);
 		xa_erase(&dpll_pin_xa, pin->id);
+		dpll_pin_prop_free(&pin->prop);
 		kfree(pin);
 	}
 	mutex_unlock(&dpll_lock);
@@ -637,7 +688,7 @@ int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
 	unsigned long i, stop;
 	int ret;
 
-	if (WARN_ON(parent->prop->type != DPLL_PIN_TYPE_MUX))
+	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
 		return -EINVAL;
 
 	if (WARN_ON(!ops) ||
diff --git a/drivers/dpll/dpll_core.h b/drivers/dpll/dpll_core.h
index 5585873c5c1b..717f715015c7 100644
--- a/drivers/dpll/dpll_core.h
+++ b/drivers/dpll/dpll_core.h
@@ -44,7 +44,7 @@ struct dpll_device {
  * @module:		module of creator
  * @dpll_refs:		hold referencees to dplls pin was registered with
  * @parent_refs:	hold references to parent pins pin was registered with
- * @prop:		pointer to pin properties given by registerer
+ * @prop:		pin properties copied from the registerer
  * @rclk_dev_name:	holds name of device when pin can recover clock from it
  * @refcount:		refcount
  **/
@@ -55,7 +55,7 @@ struct dpll_pin {
 	struct module *module;
 	struct xarray dpll_refs;
 	struct xarray parent_refs;
-	const struct dpll_pin_properties *prop;
+	struct dpll_pin_properties prop;
 	refcount_t refcount;
 };
 
diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 3370dbddb86b..30f5be020862 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -303,17 +303,17 @@ dpll_msg_add_pin_freq(struct sk_buff *msg, struct dpll_pin *pin,
 	if (nla_put_64bit(msg, DPLL_A_PIN_FREQUENCY, sizeof(freq), &freq,
 			  DPLL_A_PIN_PAD))
 		return -EMSGSIZE;
-	for (fs = 0; fs < pin->prop->freq_supported_num; fs++) {
+	for (fs = 0; fs < pin->prop.freq_supported_num; fs++) {
 		nest = nla_nest_start(msg, DPLL_A_PIN_FREQUENCY_SUPPORTED);
 		if (!nest)
 			return -EMSGSIZE;
-		freq = pin->prop->freq_supported[fs].min;
+		freq = pin->prop.freq_supported[fs].min;
 		if (nla_put_64bit(msg, DPLL_A_PIN_FREQUENCY_MIN, sizeof(freq),
 				  &freq, DPLL_A_PIN_PAD)) {
 			nla_nest_cancel(msg, nest);
 			return -EMSGSIZE;
 		}
-		freq = pin->prop->freq_supported[fs].max;
+		freq = pin->prop.freq_supported[fs].max;
 		if (nla_put_64bit(msg, DPLL_A_PIN_FREQUENCY_MAX, sizeof(freq),
 				  &freq, DPLL_A_PIN_PAD)) {
 			nla_nest_cancel(msg, nest);
@@ -329,9 +329,9 @@ static bool dpll_pin_is_freq_supported(struct dpll_pin *pin, u32 freq)
 {
 	int fs;
 
-	for (fs = 0; fs < pin->prop->freq_supported_num; fs++)
-		if (freq >= pin->prop->freq_supported[fs].min &&
-		    freq <= pin->prop->freq_supported[fs].max)
+	for (fs = 0; fs < pin->prop.freq_supported_num; fs++)
+		if (freq >= pin->prop.freq_supported[fs].min &&
+		    freq <= pin->prop.freq_supported[fs].max)
 			return true;
 	return false;
 }
@@ -421,7 +421,7 @@ static int
 dpll_cmd_pin_get_one(struct sk_buff *msg, struct dpll_pin *pin,
 		     struct netlink_ext_ack *extack)
 {
-	const struct dpll_pin_properties *prop = pin->prop;
+	const struct dpll_pin_properties *prop = &pin->prop;
 	struct dpll_pin_ref *ref;
 	int ret;
 
@@ -717,7 +717,7 @@ dpll_pin_on_pin_state_set(struct dpll_pin *pin, u32 parent_idx,
 	int ret;
 
 	if (!(DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE &
-	      pin->prop->capabilities)) {
+	      pin->prop.capabilities)) {
 		NL_SET_ERR_MSG(extack, "state changing is not allowed");
 		return -EOPNOTSUPP;
 	}
@@ -753,7 +753,7 @@ dpll_pin_state_set(struct dpll_device *dpll, struct dpll_pin *pin,
 	int ret;
 
 	if (!(DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE &
-	      pin->prop->capabilities)) {
+	      pin->prop.capabilities)) {
 		NL_SET_ERR_MSG(extack, "state changing is not allowed");
 		return -EOPNOTSUPP;
 	}
@@ -780,7 +780,7 @@ dpll_pin_prio_set(struct dpll_device *dpll, struct dpll_pin *pin,
 	int ret;
 
 	if (!(DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE &
-	      pin->prop->capabilities)) {
+	      pin->prop.capabilities)) {
 		NL_SET_ERR_MSG(extack, "prio changing is not allowed");
 		return -EOPNOTSUPP;
 	}
@@ -808,7 +808,7 @@ dpll_pin_direction_set(struct dpll_pin *pin, struct dpll_device *dpll,
 	int ret;
 
 	if (!(DPLL_PIN_CAPABILITIES_DIRECTION_CAN_CHANGE &
-	      pin->prop->capabilities)) {
+	      pin->prop.capabilities)) {
 		NL_SET_ERR_MSG(extack, "direction changing is not allowed");
 		return -EOPNOTSUPP;
 	}
@@ -838,8 +838,8 @@ dpll_pin_phase_adj_set(struct dpll_pin *pin, struct nlattr *phase_adj_attr,
 	int ret;
 
 	phase_adj = nla_get_s32(phase_adj_attr);
-	if (phase_adj > pin->prop->phase_range.max ||
-	    phase_adj < pin->prop->phase_range.min) {
+	if (phase_adj > pin->prop.phase_range.max ||
+	    phase_adj < pin->prop.phase_range.min) {
 		NL_SET_ERR_MSG_ATTR(extack, phase_adj_attr,
 				    "phase adjust value not supported");
 		return -EINVAL;
@@ -1023,7 +1023,7 @@ dpll_pin_find(u64 clock_id, struct nlattr *mod_name_attr,
 	unsigned long i;
 
 	xa_for_each_marked(&dpll_pin_xa, i, pin, DPLL_REGISTERED) {
-		prop = pin->prop;
+		prop = &pin->prop;
 		cid_match = clock_id ? pin->clock_id == clock_id : true;
 		mod_match = mod_name_attr && module_name(pin->module) ?
 			!nla_strcmp(mod_name_attr,
-- 
2.38.1

[PATCH net v6 3/4] dpll: fix userspace availability of pins

[Arkadiusz Kubalewski]

If parent pin was unregistered but child pin was not, the userspace
would see the "zombie" pins - the ones that were registered with
a parent pin (dpll_pin_on_pin_register(..)).
Technically those are not available - as there is no dpll device in the
system. Do not dump those pins and prevent userspace from any
interaction with them. Provide a unified function to determine if the
pin is available and use it before acting/responding for user requests.

Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Reviewed-by: Jan Glaza <jan.glaza@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
---
v6:
- no changes, bump the series version

 drivers/dpll/dpll_netlink.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 30f5be020862..314bb3775465 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -553,6 +553,24 @@ __dpll_device_change_ntf(struct dpll_device *dpll)
 	return dpll_device_event_send(DPLL_CMD_DEVICE_CHANGE_NTF, dpll);
 }
 
+static bool dpll_pin_available(struct dpll_pin *pin)
+{
+	struct dpll_pin_ref *par_ref;
+	unsigned long i;
+
+	if (!xa_get_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED))
+		return false;
+	xa_for_each(&pin->parent_refs, i, par_ref)
+		if (xa_get_mark(&dpll_pin_xa, par_ref->pin->id,
+				DPLL_REGISTERED))
+			return true;
+	xa_for_each(&pin->dpll_refs, i, par_ref)
+		if (xa_get_mark(&dpll_device_xa, par_ref->dpll->id,
+				DPLL_REGISTERED))
+			return true;
+	return false;
+}
+
 /**
  * dpll_device_change_ntf - notify that the dpll device has been changed
  * @dpll: registered dpll pointer
@@ -579,7 +597,7 @@ dpll_pin_event_send(enum dpll_cmd event, struct dpll_pin *pin)
 	int ret = -ENOMEM;
 	void *hdr;
 
-	if (WARN_ON(!xa_get_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED)))
+	if (!dpll_pin_available(pin))
 		return -ENODEV;
 
 	msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
@@ -1130,6 +1148,10 @@ int dpll_nl_pin_id_get_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 	pin = dpll_pin_find_from_nlattr(info);
 	if (!IS_ERR(pin)) {
+		if (!dpll_pin_available(pin)) {
+			nlmsg_free(msg);
+			return -ENODEV;
+		}
 		ret = dpll_msg_add_pin_handle(msg, pin);
 		if (ret) {
 			nlmsg_free(msg);
@@ -1179,6 +1201,8 @@ int dpll_nl_pin_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 
 	xa_for_each_marked_start(&dpll_pin_xa, i, pin, DPLL_REGISTERED,
 				 ctx->idx) {
+		if (!dpll_pin_available(pin))
+			continue;
 		hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 				  cb->nlh->nlmsg_seq,
 				  &dpll_nl_family, NLM_F_MULTI,
@@ -1441,7 +1465,8 @@ int dpll_pin_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 	}
 	info->user_ptr[0] = xa_load(&dpll_pin_xa,
 				    nla_get_u32(info->attrs[DPLL_A_PIN_ID]));
-	if (!info->user_ptr[0]) {
+	if (!info->user_ptr[0] ||
+	    !dpll_pin_available(info->user_ptr[0])) {
 		NL_SET_ERR_MSG(info->extack, "pin not found");
 		ret = -ENODEV;
 		goto unlock_dev;
-- 
2.38.1

[PATCH net v6 4/4] dpll: fix register pin with unregistered parent pin

[Arkadiusz Kubalewski]

In case of multiple kernel module instances using the same dpll device:
if only one registers dpll device, then only that one can register
directly connected pins with a dpll device. When unregistered parent is
responsible for determining if the muxed pin can be registered with it
or not, the drivers need to be loaded in serialized order to work
correctly - first the driver instance which registers the direct pins
needs to be loaded, then the other instances could register muxed type
pins.

Allow registration of a pin with a parent even if the parent was not
yet registered, thus allow ability for unserialized driver instance
load order.
Do not WARN_ON notification for unregistered pin, which can be invoked
for described case, instead just return error.

Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Reviewed-by: Jan Glaza <jan.glaza@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
---
v6:
- no changes, bump the series version

 drivers/dpll/dpll_core.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index cb62696467d1..5152bd1b0daf 100644
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -29,8 +29,6 @@ static u32 dpll_pin_xa_id;
 	WARN_ON_ONCE(!xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
 #define ASSERT_DPLL_NOT_REGISTERED(d)	\
 	WARN_ON_ONCE(xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
-#define ASSERT_PIN_REGISTERED(p)	\
-	WARN_ON_ONCE(!xa_get_mark(&dpll_pin_xa, (p)->id, DPLL_REGISTERED))
 
 struct dpll_device_registration {
 	struct list_head list;
@@ -616,8 +614,6 @@ dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
 	    WARN_ON(!ops->state_on_dpll_get) ||
 	    WARN_ON(!ops->direction_get))
 		return -EINVAL;
-	if (ASSERT_DPLL_REGISTERED(dpll))
-		return -EINVAL;
 
 	mutex_lock(&dpll_lock);
 	if (WARN_ON(!(dpll->module == pin->module &&
@@ -695,8 +691,6 @@ int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
 	    WARN_ON(!ops->state_on_pin_get) ||
 	    WARN_ON(!ops->direction_get))
 		return -EINVAL;
-	if (ASSERT_PIN_REGISTERED(parent))
-		return -EINVAL;
 
 	mutex_lock(&dpll_lock);
 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
-- 
2.38.1

Re: [PATCH net v6 2/4] dpll: fix pin dump crash for rebound module

[Jiri Pirko]

Fri, Jan 19, 2024 at 02:43:02PM CET, arkadiusz.kubalewski@intel.com wrote:
>When a kernel module is unbound but the pin resources were not entirely
>freed (other kernel module instance of the same PCI device have had kept
>the reference to that pin), and kernel module is again bound, the pin
>properties would not be updated (the properties are only assigned when
>memory for the pin is allocated), prop pointer still points to the
>kernel module memory of the kernel module which was deallocated on the
>unbind.
>
>If the pin dump is invoked in this state, the result is a kernel crash.
>Prevent the crash by storing persistent pin properties in dpll subsystem,
>copy the content from the kernel module when pin is allocated, instead of
>using memory of the kernel module.
>
>Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
>Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
>Reviewed-by: Jan Glaza <jan.glaza@intel.com>
>Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
>Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH net v6 0/4] dpll: fix unordered unbind/bind registerer issues

[Vadim Fedorenko]

On 19/01/2024 13:43, Arkadiusz Kubalewski wrote:
> Fix issues when performing unordered unbind/bind of a kernel modules
> which are using a dpll device with DPLL_PIN_TYPE_MUX pins.
> Currently only serialized bind/unbind of such use case works, fix
> the issues and allow for unserialized kernel module bind order.
> 
> The issues are observed on the ice driver, i.e.,
> 
> $ echo 0000:af:00.0 > /sys/bus/pci/drivers/ice/unbind
> $ echo 0000:af:00.1 > /sys/bus/pci/drivers/ice/unbind
> 
> results in:
> 
> ice 0000:af:00.0: Removed PTP clock
> BUG: kernel NULL pointer dereference, address: 0000000000000010
> PF: supervisor read access in kernel mode
> PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0
> Oops: 0000 [#1] PREEMPT SMP PTI
> CPU: 7 PID: 71848 Comm: bash Kdump: loaded Not tainted 6.6.0-rc5_next-queue_19th-Oct-2023-01625-g039e5d15e451 #1
> Hardware name: Intel Corporation S2600STB/S2600STB, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
> RIP: 0010:ice_dpll_rclk_state_on_pin_get+0x2f/0x90 [ice]
> Code: 41 57 4d 89 cf 41 56 41 55 4d 89 c5 41 54 55 48 89 f5 53 4c 8b 66 08 48 89 cb 4d 8d b4 24 f0 49 00 00 4c 89 f7 e8 71 ec 1f c5 <0f> b6 5b 10 41 0f b6 84 24 30 4b 00 00 29 c3 41 0f b6 84 24 28 4b
> RSP: 0018:ffffc902b179fb60 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff8882c1398000 RSI: ffff888c7435cc60 RDI: ffff888c7435cb90
> RBP: ffff888c7435cc60 R08: ffffc902b179fbb0 R09: 0000000000000000
> R10: ffff888ef1fc8050 R11: fffffffffff82700 R12: ffff888c743581a0
> R13: ffffc902b179fbb0 R14: ffff888c7435cb90 R15: 0000000000000000
> FS:  00007fdc7dae0740(0000) GS:ffff888c105c0000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000010 CR3: 0000000132c24002 CR4: 00000000007706e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
>   <TASK>
>   ? __die+0x20/0x70
>   ? page_fault_oops+0x76/0x170
>   ? exc_page_fault+0x65/0x150
>   ? asm_exc_page_fault+0x22/0x30
>   ? ice_dpll_rclk_state_on_pin_get+0x2f/0x90 [ice]
>   ? __pfx_ice_dpll_rclk_state_on_pin_get+0x10/0x10 [ice]
>   dpll_msg_add_pin_parents+0x142/0x1d0
>   dpll_pin_event_send+0x7d/0x150
>   dpll_pin_on_pin_unregister+0x3f/0x100
>   ice_dpll_deinit_pins+0xa1/0x230 [ice]
>   ice_dpll_deinit+0x29/0xe0 [ice]
>   ice_remove+0xcd/0x200 [ice]
>   pci_device_remove+0x33/0xa0
>   device_release_driver_internal+0x193/0x200
>   unbind_store+0x9d/0xb0
>   kernfs_fop_write_iter+0x128/0x1c0
>   vfs_write+0x2bb/0x3e0
>   ksys_write+0x5f/0xe0
>   do_syscall_64+0x59/0x90
>   ? filp_close+0x1b/0x30
>   ? do_dup2+0x7d/0xd0
>   ? syscall_exit_work+0x103/0x130
>   ? syscall_exit_to_user_mode+0x22/0x40
>   ? do_syscall_64+0x69/0x90
>   ? syscall_exit_work+0x103/0x130
>   ? syscall_exit_to_user_mode+0x22/0x40
>   ? do_syscall_64+0x69/0x90
>   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> RIP: 0033:0x7fdc7d93eb97
> Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
> RSP: 002b:00007fff2aa91028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007fdc7d93eb97
> RDX: 000000000000000d RSI: 00005644814ec9b0 RDI: 0000000000000001
> RBP: 00005644814ec9b0 R08: 0000000000000000 R09: 00007fdc7d9b14e0
> R10: 00007fdc7d9b13e0 R11: 0000000000000246 R12: 000000000000000d
> R13: 00007fdc7d9fb780 R14: 000000000000000d R15: 00007fdc7d9f69e0
>   </TASK>
> Modules linked in: uinput vfio_pci vfio_pci_core vfio_iommu_type1 vfio irqbypass ixgbevf snd_seq_dummy snd_hrtimer snd_seq snd_timer snd_seq_device snd soundcore overlay qrtr rfkill vfat fat xfs libcrc32c rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common isst_if_common skx_edac nfit libnvdimm ipmi_ssif x86_pkg_temp_thermal intel_powerclamp coretemp irdma rapl intel_cstate ib_uverbs iTCO_wdt iTCO_vendor_support acpi_ipmi intel_uncore mei_me ipmi_si pcspkr i2c_i801 ib_core mei ipmi_devintf intel_pch_thermal ioatdma i2c_smbus ipmi_msghandler lpc_ich joydev acpi_power_meter acpi_pad ext4 mbcache jbd2 sd_mod t10_pi sg ast i2c_algo_bit drm_shmem_helper drm_kms_helper ice crct10dif_pclmul ixgbe crc32_pclmul drm crc32c_intel ahci i40e libahci ghash_clmulni_intel libata mdio dca gnss wmi fuse [last unloaded: iavf]
> CR2: 0000000000000010
> 

For the series:

Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

Thanks


> v6:
> - fix memory corruption on error path in patch [v5 2/4]
> 
> Arkadiusz Kubalewski (4):
>    dpll: fix broken error path in dpll_pin_alloc(..)
>    dpll: fix pin dump crash for rebound module
>    dpll: fix userspace availability of pins
>    dpll: fix register pin with unregistered parent pin
> 
>   drivers/dpll/dpll_core.c    | 68 +++++++++++++++++++++++++++++++------
>   drivers/dpll/dpll_core.h    |  4 +--
>   drivers/dpll/dpll_netlink.c | 57 ++++++++++++++++++++++---------
>   3 files changed, 100 insertions(+), 29 deletions(-)
> 
> 
> base-commit: dbc153fd3c142909e564bb256da087e13fbf239c

Re: [PATCH net v6 0/4] dpll: fix unordered unbind/bind registerer issues

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Fri, 19 Jan 2024 14:43:00 +0100 you wrote:
> Fix issues when performing unordered unbind/bind of a kernel modules
> which are using a dpll device with DPLL_PIN_TYPE_MUX pins.
> Currently only serialized bind/unbind of such use case works, fix
> the issues and allow for unserialized kernel module bind order.
> 
> The issues are observed on the ice driver, i.e.,
> 
> [...]

Here is the summary with links:
  - [net,v6,1/4] dpll: fix broken error path in dpll_pin_alloc(..)
    https://git.kernel.org/netdev/net/c/b6a11a7fc4d6
  - [net,v6,2/4] dpll: fix pin dump crash for rebound module
    https://git.kernel.org/netdev/net/c/830ead5fb0c5
  - [net,v6,3/4] dpll: fix userspace availability of pins
    https://git.kernel.org/netdev/net/c/db2ec3c94667
  - [net,v6,4/4] dpll: fix register pin with unregistered parent pin
    https://git.kernel.org/netdev/net/c/7dc5b18ff71b

You are awesome, thank you!
-- 
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