2023-03-23 21:19:49

by Manish Mandlik

[permalink] [raw]
Subject: [PATCH v8 1/4] Bluetooth: Add support for hci devcoredump

From: Abhishek Pandit-Subedi <[email protected]>

Add devcoredump APIs to hci core so that drivers only have to provide
the dump skbs instead of managing the synchronization and timeouts.

The devcoredump APIs should be used in the following manner:
- hci_devcoredump_init is called to allocate the dump.
- hci_devcoredump_append is called to append any skbs with dump data
OR hci_devcoredump_append_pattern is called to insert a pattern.
- hci_devcoredump_complete is called when all dump packets have been
sent OR hci_devcoredump_abort is called to indicate an error and
cancel an ongoing dump collection.

The high level APIs just prepare some skbs with the appropriate data and
queue it for the dump to process. Packets part of the crashdump can be
intercepted in the driver in interrupt context and forwarded directly to
the devcoredump APIs.

Internally, there are 5 states for the dump: idle, active, complete,
abort and timeout. A devcoredump will only be in active state after it
has been initialized. Once active, it accepts data to be appended,
patterns to be inserted (i.e. memset) and a completion event or an abort
event to generate a devcoredump. The timeout is initialized at the same
time the dump is initialized (defaulting to 10s) and will be cleared
either when the timeout occurs or the dump is complete or aborted.

Signed-off-by: Abhishek Pandit-Subedi <[email protected]>
Signed-off-by: Manish Mandlik <[email protected]>
Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
---

Changes in v8:
- Update hci_devcoredump_mkheader() and .dmp_hdr() to use skb

Changes in v6:
- Remove #ifdef from .c and move to function in .h as per suggestion
- Remove coredump_enabled from hci_devcoredump struct since the sysfs
flag related change has been abandoned

Changes in v4:
- Add .enabled() and .coredump() to hci_devcoredump struct

Changes in v3:
- Add attribute to enable/disable and set default state to disabled

Changes in v2:
- Move hci devcoredump implementation to new files
- Move dump queue and dump work to hci_devcoredump struct
- Add CONFIG_DEV_COREDUMP conditional compile

include/net/bluetooth/coredump.h | 114 +++++++
include/net/bluetooth/hci_core.h | 14 +
net/bluetooth/Makefile | 2 +
net/bluetooth/coredump.c | 508 +++++++++++++++++++++++++++++++
net/bluetooth/hci_core.c | 1 +
net/bluetooth/hci_sync.c | 2 +
6 files changed, 641 insertions(+)
create mode 100644 include/net/bluetooth/coredump.h
create mode 100644 net/bluetooth/coredump.c

diff --git a/include/net/bluetooth/coredump.h b/include/net/bluetooth/coredump.h
new file mode 100644
index 000000000000..168b1afb5c33
--- /dev/null
+++ b/include/net/bluetooth/coredump.h
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022 Google Corporation
+ */
+
+#ifndef __COREDUMP_H
+#define __COREDUMP_H
+
+#define DEVCOREDUMP_TIMEOUT msecs_to_jiffies(10000) /* 10 sec */
+
+typedef void (*coredump_t)(struct hci_dev *hdev);
+typedef void (*dmp_hdr_t)(struct hci_dev *hdev, struct sk_buff *skb);
+typedef void (*notify_change_t)(struct hci_dev *hdev, int state);
+
+/* struct hci_devcoredump - Devcoredump state
+ *
+ * @supported: Indicates if FW dump collection is supported by driver
+ * @state: Current state of dump collection
+ * @alloc_size: Total size of the dump
+ * @head: Start of the dump
+ * @tail: Pointer to current end of dump
+ * @end: head + alloc_size for easy comparisons
+ *
+ * @dump_q: Dump queue for state machine to process
+ * @dump_rx: Devcoredump state machine work
+ * @dump_timeout: Devcoredump timeout work
+ *
+ * @coredump: Called from the driver's .coredump() function.
+ * @dmp_hdr: Create a dump header to identify controller/fw/driver info
+ * @notify_change: Notify driver when devcoredump state has changed
+ */
+struct hci_devcoredump {
+ bool supported;
+
+ enum devcoredump_state {
+ HCI_DEVCOREDUMP_IDLE,
+ HCI_DEVCOREDUMP_ACTIVE,
+ HCI_DEVCOREDUMP_DONE,
+ HCI_DEVCOREDUMP_ABORT,
+ HCI_DEVCOREDUMP_TIMEOUT
+ } state;
+
+ size_t alloc_size;
+ char *head;
+ char *tail;
+ char *end;
+
+ struct sk_buff_head dump_q;
+ struct work_struct dump_rx;
+ struct delayed_work dump_timeout;
+
+ coredump_t coredump;
+ dmp_hdr_t dmp_hdr;
+ notify_change_t notify_change;
+};
+
+#ifdef CONFIG_DEV_COREDUMP
+
+void hci_devcoredump_reset(struct hci_dev *hdev);
+void hci_devcoredump_rx(struct work_struct *work);
+void hci_devcoredump_timeout(struct work_struct *work);
+
+int hci_devcoredump_register(struct hci_dev *hdev, coredump_t coredump,
+ dmp_hdr_t dmp_hdr, notify_change_t notify_change);
+int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size);
+int hci_devcoredump_append(struct hci_dev *hdev, struct sk_buff *skb);
+int hci_devcoredump_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len);
+int hci_devcoredump_complete(struct hci_dev *hdev);
+int hci_devcoredump_abort(struct hci_dev *hdev);
+
+#else
+
+static inline void hci_devcoredump_reset(struct hci_dev *hdev) {}
+static inline void hci_devcoredump_rx(struct work_struct *work) {}
+static inline void hci_devcoredump_timeout(struct work_struct *work) {}
+
+static inline int hci_devcoredump_register(struct hci_dev *hdev,
+ coredump_t coredump,
+ dmp_hdr_t dmp_hdr,
+ notify_change_t notify_change)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_append(struct hci_dev *hdev,
+ struct sk_buff *skb)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_append_pattern(struct hci_dev *hdev,
+ u8 pattern, u32 len)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_complete(struct hci_dev *hdev)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_abort(struct hci_dev *hdev)
+{
+ return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_DEV_COREDUMP */
+
+#endif /* __COREDUMP_H */
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 9488671c1219..e405fd4d25db 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -32,6 +32,7 @@
#include <net/bluetooth/hci.h>
#include <net/bluetooth/hci_sync.h>
#include <net/bluetooth/hci_sock.h>
+#include <net/bluetooth/coredump.h>

/* HCI priority */
#define HCI_PRIO_MAX 7
@@ -590,6 +591,10 @@ struct hci_dev {
const char *fw_info;
struct dentry *debugfs;

+#ifdef CONFIG_DEV_COREDUMP
+ struct hci_devcoredump dump;
+#endif
+
struct device dev;

struct rfkill *rfkill;
@@ -1496,6 +1501,15 @@ static inline void hci_set_aosp_capable(struct hci_dev *hdev)
#endif
}

+static inline void hci_devcoredump_setup(struct hci_dev *hdev)
+{
+#ifdef CONFIG_DEV_COREDUMP
+ INIT_WORK(&hdev->dump.dump_rx, hci_devcoredump_rx);
+ INIT_DELAYED_WORK(&hdev->dump.dump_timeout, hci_devcoredump_timeout);
+ skb_queue_head_init(&hdev->dump.dump_q);
+#endif
+}
+
int hci_dev_open(__u16 dev);
int hci_dev_close(__u16 dev);
int hci_dev_do_close(struct hci_dev *hdev);
diff --git a/net/bluetooth/Makefile b/net/bluetooth/Makefile
index 0e7b7db42750..141ac1fda0bf 100644
--- a/net/bluetooth/Makefile
+++ b/net/bluetooth/Makefile
@@ -17,6 +17,8 @@ bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o hci_codec.o \
eir.o hci_sync.o

+bluetooth-$(CONFIG_DEV_COREDUMP) += coredump.o
+
bluetooth-$(CONFIG_BT_BREDR) += sco.o
bluetooth-$(CONFIG_BT_LE) += iso.o
bluetooth-$(CONFIG_BT_HS) += a2mp.o amp.o
diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
new file mode 100644
index 000000000000..c4bf408baef6
--- /dev/null
+++ b/net/bluetooth/coredump.c
@@ -0,0 +1,508 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Google Corporation
+ */
+
+#include <linux/devcoredump.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+enum hci_devcoredump_pkt_type {
+ HCI_DEVCOREDUMP_PKT_INIT,
+ HCI_DEVCOREDUMP_PKT_SKB,
+ HCI_DEVCOREDUMP_PKT_PATTERN,
+ HCI_DEVCOREDUMP_PKT_COMPLETE,
+ HCI_DEVCOREDUMP_PKT_ABORT,
+};
+
+struct hci_devcoredump_skb_cb {
+ u16 pkt_type;
+};
+
+struct hci_devcoredump_skb_pattern {
+ u8 pattern;
+ u32 len;
+} __packed;
+
+#define hci_dmp_cb(skb) ((struct hci_devcoredump_skb_cb *)((skb)->cb))
+
+#define MAX_DEVCOREDUMP_HDR_SIZE 512 /* bytes */
+
+static int hci_devcoredump_update_hdr_state(char *buf, size_t size, int state)
+{
+ int len = 0;
+
+ if (!buf)
+ return 0;
+
+ len = snprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);
+
+ return len + 1; /* snprintf adds \0 at the end upon state rewrite */
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_update_state(struct hci_dev *hdev, int state)
+{
+ hdev->dump.state = state;
+
+ return hci_devcoredump_update_hdr_state(hdev->dump.head,
+ hdev->dump.alloc_size, state);
+}
+
+static int hci_devcoredump_mkheader(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ char dump_start[] = "--- Start dump ---\n";
+ char hdr[80];
+ int hdr_len;
+
+ hdr_len = hci_devcoredump_update_hdr_state(hdr, sizeof(hdr),
+ HCI_DEVCOREDUMP_IDLE);
+ skb_put_data(skb, hdr, hdr_len);
+
+ if (hdev->dump.dmp_hdr)
+ hdev->dump.dmp_hdr(hdev, skb);
+
+ skb_put_data(skb, dump_start, strlen(dump_start));
+
+ return skb->len;
+}
+
+/* Do not call with hci_dev_lock since this calls driver code. */
+static void hci_devcoredump_notify(struct hci_dev *hdev, int state)
+{
+ if (hdev->dump.notify_change)
+ hdev->dump.notify_change(hdev, state);
+}
+
+/* Call with hci_dev_lock only. */
+void hci_devcoredump_reset(struct hci_dev *hdev)
+{
+ hdev->dump.head = NULL;
+ hdev->dump.tail = NULL;
+ hdev->dump.alloc_size = 0;
+
+ hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
+
+ cancel_delayed_work(&hdev->dump.dump_timeout);
+ skb_queue_purge(&hdev->dump.dump_q);
+}
+
+/* Call with hci_dev_lock only. */
+static void hci_devcoredump_free(struct hci_dev *hdev)
+{
+ if (hdev->dump.head)
+ vfree(hdev->dump.head);
+
+ hci_devcoredump_reset(hdev);
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_alloc(struct hci_dev *hdev, u32 size)
+{
+ hdev->dump.head = vmalloc(size);
+ if (!hdev->dump.head)
+ return -ENOMEM;
+
+ hdev->dump.alloc_size = size;
+ hdev->dump.tail = hdev->dump.head;
+ hdev->dump.end = hdev->dump.head + size;
+
+ hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
+
+ return 0;
+}
+
+/* Call with hci_dev_lock only. */
+static bool hci_devcoredump_copy(struct hci_dev *hdev, char *buf, u32 size)
+{
+ if (hdev->dump.tail + size > hdev->dump.end)
+ return false;
+
+ memcpy(hdev->dump.tail, buf, size);
+ hdev->dump.tail += size;
+
+ return true;
+}
+
+/* Call with hci_dev_lock only. */
+static bool hci_devcoredump_memset(struct hci_dev *hdev, u8 pattern, u32 len)
+{
+ if (hdev->dump.tail + len > hdev->dump.end)
+ return false;
+
+ memset(hdev->dump.tail, pattern, len);
+ hdev->dump.tail += len;
+
+ return true;
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_prepare(struct hci_dev *hdev, u32 dump_size)
+{
+ struct sk_buff *skb = NULL;
+ int dump_hdr_size;
+ int err = 0;
+
+ skb = alloc_skb(MAX_DEVCOREDUMP_HDR_SIZE, GFP_ATOMIC);
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump prepare");
+ return -ENOMEM;
+ }
+
+ dump_hdr_size = hci_devcoredump_mkheader(hdev, skb);
+
+ if (hci_devcoredump_alloc(hdev, dump_hdr_size + dump_size)) {
+ err = -ENOMEM;
+ goto hdr_free;
+ }
+
+ /* Insert the device header */
+ if (!hci_devcoredump_copy(hdev, skb->data, skb->len)) {
+ bt_dev_err(hdev, "Failed to insert header");
+ hci_devcoredump_free(hdev);
+
+ err = -ENOMEM;
+ goto hdr_free;
+ }
+
+hdr_free:
+ if (skb)
+ kfree_skb(skb);
+
+ return err;
+}
+
+/* Bluetooth devcoredump state machine.
+ *
+ * Devcoredump states:
+ *
+ * HCI_DEVCOREDUMP_IDLE: The default state.
+ *
+ * HCI_DEVCOREDUMP_ACTIVE: A devcoredump will be in this state once it has
+ * been initialized using hci_devcoredump_init(). Once active, the
+ * driver can append data using hci_devcoredump_append() or insert
+ * a pattern using hci_devcoredump_append_pattern().
+ *
+ * HCI_DEVCOREDUMP_DONE: Once the dump collection is complete, the drive
+ * can signal the completion using hci_devcoredump_complete(). A
+ * devcoredump is generated indicating the completion event and
+ * then the state machine is reset to the default state.
+ *
+ * HCI_DEVCOREDUMP_ABORT: The driver can cancel ongoing dump collection in
+ * case of any error using hci_devcoredump_abort(). A devcoredump
+ * is still generated with the available data indicating the abort
+ * event and then the state machine is reset to the default state.
+ *
+ * HCI_DEVCOREDUMP_TIMEOUT: A timeout timer for HCI_DEVCOREDUMP_TIMEOUT sec
+ * is started during devcoredump initialization. Once the timeout
+ * occurs, the driver is notified, a devcoredump is generated with
+ * the available data indicating the timeout event and then the
+ * state machine is reset to the default state.
+ *
+ * The driver must register using hci_devcoredump_register() before using the
+ * hci devcoredump APIs.
+ */
+void hci_devcoredump_rx(struct work_struct *work)
+{
+ struct hci_dev *hdev = container_of(work, struct hci_dev, dump.dump_rx);
+ struct sk_buff *skb;
+ struct hci_devcoredump_skb_pattern *pattern;
+ u32 dump_size;
+ int start_state;
+
+#define DBG_UNEXPECTED_STATE() \
+ bt_dev_dbg(hdev, \
+ "Unexpected packet (%d) for state (%d). ", \
+ hci_dmp_cb(skb)->pkt_type, hdev->dump.state)
+
+ while ((skb = skb_dequeue(&hdev->dump.dump_q))) {
+ hci_dev_lock(hdev);
+ start_state = hdev->dump.state;
+
+ switch (hci_dmp_cb(skb)->pkt_type) {
+ case HCI_DEVCOREDUMP_PKT_INIT:
+ if (hdev->dump.state != HCI_DEVCOREDUMP_IDLE) {
+ DBG_UNEXPECTED_STATE();
+ goto loop_continue;
+ }
+
+ if (skb->len != sizeof(dump_size)) {
+ bt_dev_dbg(hdev, "Invalid dump init pkt");
+ goto loop_continue;
+ }
+
+ dump_size = *((u32 *)skb->data);
+ if (!dump_size) {
+ bt_dev_err(hdev, "Zero size dump init pkt");
+ goto loop_continue;
+ }
+
+ if (hci_devcoredump_prepare(hdev, dump_size)) {
+ bt_dev_err(hdev, "Failed to prepare for dump");
+ goto loop_continue;
+ }
+
+ hci_devcoredump_update_state(hdev,
+ HCI_DEVCOREDUMP_ACTIVE);
+ queue_delayed_work(hdev->workqueue,
+ &hdev->dump.dump_timeout,
+ DEVCOREDUMP_TIMEOUT);
+ break;
+
+ case HCI_DEVCOREDUMP_PKT_SKB:
+ if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+ DBG_UNEXPECTED_STATE();
+ goto loop_continue;
+ }
+
+ if (!hci_devcoredump_copy(hdev, skb->data, skb->len))
+ bt_dev_dbg(hdev, "Failed to insert skb");
+ break;
+
+ case HCI_DEVCOREDUMP_PKT_PATTERN:
+ if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+ DBG_UNEXPECTED_STATE();
+ goto loop_continue;
+ }
+
+ if (skb->len != sizeof(*pattern)) {
+ bt_dev_dbg(hdev, "Invalid pattern skb");
+ goto loop_continue;
+ }
+
+ pattern = (void *)skb->data;
+
+ if (!hci_devcoredump_memset(hdev, pattern->pattern,
+ pattern->len))
+ bt_dev_dbg(hdev, "Failed to set pattern");
+ break;
+
+ case HCI_DEVCOREDUMP_PKT_COMPLETE:
+ if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+ DBG_UNEXPECTED_STATE();
+ goto loop_continue;
+ }
+
+ hci_devcoredump_update_state(hdev,
+ HCI_DEVCOREDUMP_DONE);
+ dump_size = hdev->dump.tail - hdev->dump.head;
+
+ bt_dev_info(hdev,
+ "Devcoredump complete with size %u "
+ "(expect %zu)",
+ dump_size, hdev->dump.alloc_size);
+
+ dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
+ GFP_KERNEL);
+ break;
+
+ case HCI_DEVCOREDUMP_PKT_ABORT:
+ if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+ DBG_UNEXPECTED_STATE();
+ goto loop_continue;
+ }
+
+ hci_devcoredump_update_state(hdev,
+ HCI_DEVCOREDUMP_ABORT);
+ dump_size = hdev->dump.tail - hdev->dump.head;
+
+ bt_dev_info(hdev,
+ "Devcoredump aborted with size %u "
+ "(expect %zu)",
+ dump_size, hdev->dump.alloc_size);
+
+ /* Emit a devcoredump with the available data */
+ dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
+ GFP_KERNEL);
+ break;
+
+ default:
+ bt_dev_dbg(hdev,
+ "Unknown packet (%d) for state (%d). ",
+ hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
+ break;
+ }
+
+loop_continue:
+ kfree_skb(skb);
+ hci_dev_unlock(hdev);
+
+ if (start_state != hdev->dump.state)
+ hci_devcoredump_notify(hdev, hdev->dump.state);
+
+ hci_dev_lock(hdev);
+ if (hdev->dump.state == HCI_DEVCOREDUMP_DONE ||
+ hdev->dump.state == HCI_DEVCOREDUMP_ABORT)
+ hci_devcoredump_reset(hdev);
+ hci_dev_unlock(hdev);
+ }
+}
+EXPORT_SYMBOL(hci_devcoredump_rx);
+
+void hci_devcoredump_timeout(struct work_struct *work)
+{
+ struct hci_dev *hdev = container_of(work, struct hci_dev,
+ dump.dump_timeout.work);
+ u32 dump_size;
+
+ hci_devcoredump_notify(hdev, HCI_DEVCOREDUMP_TIMEOUT);
+
+ hci_dev_lock(hdev);
+
+ cancel_work_sync(&hdev->dump.dump_rx);
+
+ hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_TIMEOUT);
+ dump_size = hdev->dump.tail - hdev->dump.head;
+ bt_dev_info(hdev, "Devcoredump timeout with size %u (expect %zu)",
+ dump_size, hdev->dump.alloc_size);
+
+ /* Emit a devcoredump with the available data */
+ dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
+
+ hci_devcoredump_reset(hdev);
+
+ hci_dev_unlock(hdev);
+}
+EXPORT_SYMBOL(hci_devcoredump_timeout);
+
+int hci_devcoredump_register(struct hci_dev *hdev, coredump_t coredump,
+ dmp_hdr_t dmp_hdr, notify_change_t notify_change)
+{
+ /* Driver must implement coredump() and dmp_hdr() functions for
+ * bluetooth devcoredump. The coredump() should trigger a coredump
+ * event on the controller when the device's coredump sysfs entry is
+ * written to. The dmp_hdr() should create a dump header to identify
+ * the controller/fw/driver info.
+ */
+ if (!coredump || !dmp_hdr)
+ return -EINVAL;
+
+ hci_dev_lock(hdev);
+ hdev->dump.coredump = coredump;
+ hdev->dump.dmp_hdr = dmp_hdr;
+ hdev->dump.notify_change = notify_change;
+ hdev->dump.supported = true;
+ hci_dev_unlock(hdev);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_register);
+
+static inline bool hci_devcoredump_enabled(struct hci_dev *hdev)
+{
+ return hdev->dump.supported;
+}
+
+int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size)
+{
+ struct sk_buff *skb = NULL;
+
+ if (!hci_devcoredump_enabled(hdev))
+ return -EOPNOTSUPP;
+
+ skb = alloc_skb(sizeof(dmp_size), GFP_ATOMIC);
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump init");
+ return -ENOMEM;
+ }
+
+ hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT;
+ skb_put_data(skb, &dmp_size, sizeof(dmp_size));
+
+ skb_queue_tail(&hdev->dump.dump_q, skb);
+ queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_init);
+
+int hci_devcoredump_append(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ if (!skb)
+ return -ENOMEM;
+
+ if (!hci_devcoredump_enabled(hdev)) {
+ kfree_skb(skb);
+ return -EOPNOTSUPP;
+ }
+
+ hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_SKB;
+
+ skb_queue_tail(&hdev->dump.dump_q, skb);
+ queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_append);
+
+int hci_devcoredump_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len)
+{
+ struct hci_devcoredump_skb_pattern p;
+ struct sk_buff *skb = NULL;
+
+ if (!hci_devcoredump_enabled(hdev))
+ return -EOPNOTSUPP;
+
+ skb = alloc_skb(sizeof(p), GFP_ATOMIC);
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump pattern");
+ return -ENOMEM;
+ }
+
+ p.pattern = pattern;
+ p.len = len;
+
+ hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_PATTERN;
+ skb_put_data(skb, &p, sizeof(p));
+
+ skb_queue_tail(&hdev->dump.dump_q, skb);
+ queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_append_pattern);
+
+int hci_devcoredump_complete(struct hci_dev *hdev)
+{
+ struct sk_buff *skb = NULL;
+
+ if (!hci_devcoredump_enabled(hdev))
+ return -EOPNOTSUPP;
+
+ skb = alloc_skb(0, GFP_ATOMIC);
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump complete");
+ return -ENOMEM;
+ }
+
+ hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_COMPLETE;
+
+ skb_queue_tail(&hdev->dump.dump_q, skb);
+ queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_complete);
+
+int hci_devcoredump_abort(struct hci_dev *hdev)
+{
+ struct sk_buff *skb = NULL;
+
+ if (!hci_devcoredump_enabled(hdev))
+ return -EOPNOTSUPP;
+
+ skb = alloc_skb(0, GFP_ATOMIC);
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump abort");
+ return -ENOMEM;
+ }
+
+ hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_ABORT;
+
+ skb_queue_tail(&hdev->dump.dump_q, skb);
+ queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+ return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_abort);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 334e308451f5..37aa70192ccb 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2544,6 +2544,7 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);
INIT_DELAYED_WORK(&hdev->ncmd_timer, hci_ncmd_timeout);

+ hci_devcoredump_setup(hdev);
hci_request_setup(hdev);

hci_init_sysfs(hdev);
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 561a519a11bd..e0423867ff19 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4722,6 +4722,8 @@ int hci_dev_open_sync(struct hci_dev *hdev)
goto done;
}

+ hci_devcoredump_reset(hdev);
+
set_bit(HCI_RUNNING, &hdev->flags);
hci_sock_dev_event(hdev, HCI_DEV_OPEN);

--
2.40.0.348.gf938b09366-goog


2023-03-23 21:21:24

by Manish Mandlik

[permalink] [raw]
Subject: [PATCH v8 2/4] Bluetooth: Add vhci devcoredump support

Add devcoredump support for vhci that creates forcce_devcoredump debugfs
entry. This is used for mgmt-tester tests.

Signed-off-by: Manish Mandlik <[email protected]>
---

Changes in v8:
- Update vhci_coredump_hdr() to use skb

Changes in v7:
- New patch in the series

drivers/bluetooth/Kconfig | 1 +
drivers/bluetooth/hci_vhci.c | 64 ++++++++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+)

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 5a1a7bec3c42..7bc7a765ad69 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -363,6 +363,7 @@ config BT_HCIBLUECARD

config BT_HCIVHCI
tristate "HCI VHCI (Virtual HCI device) driver"
+ select WANT_DEV_COREDUMP
help
Bluetooth Virtual HCI device driver.
This driver is required if you want to use HCI Emulation software.
diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index c443c3b0a4da..1c3c27b7e9b6 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -278,6 +278,67 @@ static int vhci_setup(struct hci_dev *hdev)
return 0;
}

+static void vhci_coredump(struct hci_dev *hdev)
+{
+ /* No need to do anything */
+}
+
+static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ char buf[80];
+
+ snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n");
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n");
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Driver: vhci_drv\n");
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Vendor: vhci\n");
+ skb_put_data(skb, buf, strlen(buf));
+}
+
+static ssize_t force_devcoredump_write(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct vhci_data *data = file->private_data;
+ struct hci_dev *hdev = data->hdev;
+ struct sk_buff *skb = NULL;
+ char buf[512];
+ int ret;
+
+ ret = simple_write_to_buffer(&buf, sizeof(buf), ppos, user_buf, count);
+ if (ret < count)
+ return ret;
+
+ skb = alloc_skb(count, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+ skb_put_data(skb, &buf, count);
+
+ hci_devcoredump_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);
+
+ ret = hci_devcoredump_init(hdev, skb->len);
+ if (ret) {
+ BT_ERR("Failed to generate devcoredump");
+ kfree_skb(skb);
+ return ret;
+ }
+
+ hci_devcoredump_append(hdev, skb);
+ hci_devcoredump_complete(hdev);
+
+ return count;
+}
+
+static const struct file_operations force_devcoredump_fops = {
+ .open = simple_open,
+ .write = force_devcoredump_write,
+};
+
static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
{
struct hci_dev *hdev;
@@ -355,6 +416,9 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
&aosp_capable_fops);

+ debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
+ &force_devcoredump_fops);
+
hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;

skb_put_u8(skb, 0xff);
--
2.40.0.348.gf938b09366-goog

2023-03-23 21:21:28

by Manish Mandlik

[permalink] [raw]
Subject: [PATCH v8 3/4] Bluetooth: btusb: Add btusb devcoredump support

This patch implements the btusb driver side .coredump() callback to
trigger a devcoredump via sysfs.

Signed-off-by: Manish Mandlik <[email protected]>
Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
---

(no changes since v6)

Changes in v6:
- Remove dev->coredump_disabled check since the sysfs flag related
change has been abandoned

Changes in v4:
- New patch in the series

drivers/bluetooth/btusb.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 4ca91c033d2f..9c9f7bf1375a 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4385,6 +4385,17 @@ static int btusb_resume(struct usb_interface *intf)
}
#endif

+#ifdef CONFIG_DEV_COREDUMP
+static void btusb_coredump(struct device *dev)
+{
+ struct btusb_data *data = dev_get_drvdata(dev);
+ struct hci_dev *hdev = data->hdev;
+
+ if (hdev->dump.coredump)
+ hdev->dump.coredump(hdev);
+}
+#endif
+
static struct usb_driver btusb_driver = {
.name = "btusb",
.probe = btusb_probe,
@@ -4396,6 +4407,14 @@ static struct usb_driver btusb_driver = {
.id_table = btusb_table,
.supports_autosuspend = 1,
.disable_hub_initiated_lpm = 1,
+
+#ifdef CONFIG_DEV_COREDUMP
+ .drvwrap = {
+ .driver = {
+ .coredump = btusb_coredump,
+ },
+ },
+#endif
};

module_usb_driver(btusb_driver);
--
2.40.0.348.gf938b09366-goog

2023-03-23 21:21:41

by Manish Mandlik

[permalink] [raw]
Subject: [PATCH v8 4/4] Bluetooth: btintel: Add Intel devcoredump support

From: Abhishek Pandit-Subedi <[email protected]>

Intercept debug exception events from the controller and put them into
a devcoredump using hci devcoredump APIs. The debug exception contains
data in a TLV format and it will be parsed in userspace.

Signed-off-by: Abhishek Pandit-Subedi <[email protected]>
Signed-off-by: Manish Mandlik <[email protected]>
Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
Reviewed-by: Chethan Tumkur Narayan <[email protected]>
---

Changes in v8:
- Update btintel_dmp_hdr() to use skb
- Use driver name reference instead of copying it

Changes in v7:
- Update btintel_coredump() and btusb_intel_diagnostics()

Changes in v6:
- Implement btintel_coredump()

Changes in v4:
- Add btintel_coredump() placeholder

Changes in v2:
- Create a local struct to store coredump_info in btintel.c
- Call btintel_register_devcoredump_support() from btintel.c
- Fix strncpy() destination bound warning

drivers/bluetooth/btintel.c | 72 ++++++++++++++++++++++++++++++++++++-
drivers/bluetooth/btintel.h | 12 +++++--
drivers/bluetooth/btusb.c | 54 ++++++++++++++++++++++++----
3 files changed, 128 insertions(+), 10 deletions(-)

diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index bede8b005594..cb84524bbacd 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -36,6 +36,12 @@ struct cmd_write_boot_params {
u8 fw_build_yy;
} __packed;

+static struct {
+ const char *driver_name;
+ u8 hw_variant;
+ u32 fw_build_num;
+} coredump_info;
+
int btintel_check_bdaddr(struct hci_dev *hdev)
{
struct hci_rp_read_bd_addr *bda;
@@ -308,6 +314,9 @@ int btintel_version_info(struct hci_dev *hdev, struct intel_version *ver)
return -EINVAL;
}

+ coredump_info.hw_variant = ver->hw_variant;
+ coredump_info.fw_build_num = ver->fw_build_num;
+
bt_dev_info(hdev, "%s revision %u.%u build %u week %u %u",
variant, ver->fw_revision >> 4, ver->fw_revision & 0x0f,
ver->fw_build_num, ver->fw_build_ww,
@@ -502,6 +511,9 @@ static int btintel_version_info_tlv(struct hci_dev *hdev,
return -EINVAL;
}

+ coredump_info.hw_variant = INTEL_HW_VARIANT(version->cnvi_bt);
+ coredump_info.fw_build_num = version->build_num;
+
bt_dev_info(hdev, "%s timestamp %u.%u buildtype %u build %u", variant,
2000 + (version->timestamp >> 8), version->timestamp & 0xff,
version->build_type, version->build_num);
@@ -1453,6 +1465,59 @@ int btintel_set_quality_report(struct hci_dev *hdev, bool enable)
}
EXPORT_SYMBOL_GPL(btintel_set_quality_report);

+static void btintel_coredump(struct hci_dev *hdev)
+{
+ struct sk_buff *skb;
+
+ skb = __hci_cmd_sync(hdev, 0xfc4e, 0, NULL, HCI_CMD_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_err(hdev, "Coredump failed (%ld)", PTR_ERR(skb));
+ return;
+ }
+
+ kfree_skb(skb);
+}
+
+static void btintel_dmp_hdr(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ char buf[80];
+
+ snprintf(buf, sizeof(buf), "Controller Name: 0x%X\n",
+ coredump_info.hw_variant);
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Firmware Version: 0x%X\n",
+ coredump_info.fw_build_num);
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Driver: %s\n", coredump_info.driver_name);
+ skb_put_data(skb, buf, strlen(buf));
+
+ snprintf(buf, sizeof(buf), "Vendor: Intel\n");
+ skb_put_data(skb, buf, strlen(buf));
+}
+
+static int btintel_register_devcoredump_support(struct hci_dev *hdev)
+{
+ struct intel_debug_features features;
+ int err;
+
+ err = btintel_read_debug_features(hdev, &features);
+ if (err) {
+ bt_dev_info(hdev, "Error reading debug features");
+ return err;
+ }
+
+ if (!(features.page1[0] & 0x3f)) {
+ bt_dev_dbg(hdev, "Telemetry exception format not supported");
+ return -EOPNOTSUPP;
+ }
+
+ hci_devcoredump_register(hdev, btintel_coredump, btintel_dmp_hdr, NULL);
+
+ return err;
+}
+
static const struct firmware *btintel_legacy_rom_get_fw(struct hci_dev *hdev,
struct intel_version *ver)
{
@@ -2582,6 +2647,7 @@ static int btintel_setup_combined(struct hci_dev *hdev)
btintel_set_msft_opcode(hdev, ver.hw_variant);

err = btintel_bootloader_setup(hdev, &ver);
+ btintel_register_devcoredump_support(hdev);
break;
default:
bt_dev_err(hdev, "Unsupported Intel hw variant (%u)",
@@ -2655,6 +2721,7 @@ static int btintel_setup_combined(struct hci_dev *hdev)
btintel_set_msft_opcode(hdev, ver.hw_variant);

err = btintel_bootloader_setup(hdev, &ver);
+ btintel_register_devcoredump_support(hdev);
break;
case 0x17:
case 0x18:
@@ -2678,6 +2745,7 @@ static int btintel_setup_combined(struct hci_dev *hdev)
INTEL_HW_VARIANT(ver_tlv.cnvi_bt));

err = btintel_bootloader_setup_tlv(hdev, &ver_tlv);
+ btintel_register_devcoredump_support(hdev);
break;
default:
bt_dev_err(hdev, "Unsupported Intel hw variant (%u)",
@@ -2727,7 +2795,7 @@ static int btintel_shutdown_combined(struct hci_dev *hdev)
return 0;
}

-int btintel_configure_setup(struct hci_dev *hdev)
+int btintel_configure_setup(struct hci_dev *hdev, const char *driver_name)
{
hdev->manufacturer = 2;
hdev->setup = btintel_setup_combined;
@@ -2736,6 +2804,8 @@ int btintel_configure_setup(struct hci_dev *hdev)
hdev->set_diag = btintel_set_diag_combined;
hdev->set_bdaddr = btintel_set_bdaddr;

+ coredump_info.driver_name = driver_name;
+
return 0;
}
EXPORT_SYMBOL_GPL(btintel_configure_setup);
diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
index 8e7da877efae..c34553fef3b0 100644
--- a/drivers/bluetooth/btintel.h
+++ b/drivers/bluetooth/btintel.h
@@ -150,6 +150,13 @@ struct btintel_loc_aware_reg {
__le32 delta;
} __packed;

+#define INTEL_TLV_TYPE_ID 0x01
+
+#define INTEL_TLV_SYSTEM_EXCEPTION 0x00
+#define INTEL_TLV_FATAL_EXCEPTION 0x01
+#define INTEL_TLV_DEBUG_EXCEPTION 0x02
+#define INTEL_TLV_TEST_EXCEPTION 0xDE
+
#define INTEL_HW_PLATFORM(cnvx_bt) ((u8)(((cnvx_bt) & 0x0000ff00) >> 8))
#define INTEL_HW_VARIANT(cnvx_bt) ((u8)(((cnvx_bt) & 0x003f0000) >> 16))
#define INTEL_CNVX_TOP_TYPE(cnvx_top) ((cnvx_top) & 0x00000fff)
@@ -219,7 +226,7 @@ int btintel_read_boot_params(struct hci_dev *hdev,
struct intel_boot_params *params);
int btintel_download_firmware(struct hci_dev *dev, struct intel_version *ver,
const struct firmware *fw, u32 *boot_param);
-int btintel_configure_setup(struct hci_dev *hdev);
+int btintel_configure_setup(struct hci_dev *hdev, const char *driver_name);
void btintel_bootup(struct hci_dev *hdev, const void *ptr, unsigned int len);
void btintel_secure_send_result(struct hci_dev *hdev,
const void *ptr, unsigned int len);
@@ -300,7 +307,8 @@ static inline int btintel_download_firmware(struct hci_dev *dev,
return -EOPNOTSUPP;
}

-static inline int btintel_configure_setup(struct hci_dev *hdev)
+static inline int btintel_configure_setup(struct hci_dev *hdev,
+ const char *driver_name)
{
return -ENODEV;
}
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 9c9f7bf1375a..4f7aa32696f4 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2376,16 +2376,47 @@ static int btusb_recv_bulk_intel(struct btusb_data *data, void *buffer,
return btusb_recv_bulk(data, buffer, count);
}

+static int btusb_intel_diagnostics(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ struct intel_tlv *tlv = (void *)&skb->data[5];
+
+ /* The first event is always an event type TLV */
+ if (tlv->type != INTEL_TLV_TYPE_ID)
+ goto recv_frame;
+
+ switch (tlv->val[0]) {
+ case INTEL_TLV_SYSTEM_EXCEPTION:
+ case INTEL_TLV_FATAL_EXCEPTION:
+ case INTEL_TLV_DEBUG_EXCEPTION:
+ case INTEL_TLV_TEST_EXCEPTION:
+ /* Generate devcoredump from exception */
+ if (!hci_devcoredump_init(hdev, skb->len)) {
+ hci_devcoredump_append(hdev, skb);
+ hci_devcoredump_complete(hdev);
+ } else {
+ bt_dev_err(hdev, "Failed to generate devcoredump");
+ kfree_skb(skb);
+ }
+ return 0;
+ default:
+ bt_dev_err(hdev, "Invalid exception type %02X", tlv->val[0]);
+ }
+
+recv_frame:
+ return hci_recv_frame(hdev, skb);
+}
+
static int btusb_recv_event_intel(struct hci_dev *hdev, struct sk_buff *skb)
{
- if (btintel_test_flag(hdev, INTEL_BOOTLOADER)) {
- struct hci_event_hdr *hdr = (void *)skb->data;
+ struct hci_event_hdr *hdr = (void *)skb->data;
+ const char diagnostics_hdr[] = { 0x87, 0x80, 0x03 };

- if (skb->len > HCI_EVENT_HDR_SIZE && hdr->evt == 0xff &&
- hdr->plen > 0) {
- const void *ptr = skb->data + HCI_EVENT_HDR_SIZE + 1;
- unsigned int len = skb->len - HCI_EVENT_HDR_SIZE - 1;
+ if (skb->len > HCI_EVENT_HDR_SIZE && hdr->evt == 0xff &&
+ hdr->plen > 0) {
+ const void *ptr = skb->data + HCI_EVENT_HDR_SIZE + 1;
+ unsigned int len = skb->len - HCI_EVENT_HDR_SIZE - 1;

+ if (btintel_test_flag(hdev, INTEL_BOOTLOADER)) {
switch (skb->data[2]) {
case 0x02:
/* When switching to the operational firmware
@@ -2404,6 +2435,15 @@ static int btusb_recv_event_intel(struct hci_dev *hdev, struct sk_buff *skb)
break;
}
}
+
+ /* Handle all diagnostics events separately. May still call
+ * hci_recv_frame.
+ */
+ if (len >= sizeof(diagnostics_hdr) &&
+ memcmp(&skb->data[2], diagnostics_hdr,
+ sizeof(diagnostics_hdr)) == 0) {
+ return btusb_intel_diagnostics(hdev, skb);
+ }
}

return hci_recv_frame(hdev, skb);
@@ -4008,7 +4048,7 @@ static int btusb_probe(struct usb_interface *intf,

/* Combined Intel Device setup to support multiple setup routine */
if (id->driver_info & BTUSB_INTEL_COMBINED) {
- err = btintel_configure_setup(hdev);
+ err = btintel_configure_setup(hdev, btusb_driver.name);
if (err)
goto out_free_dev;

--
2.40.0.348.gf938b09366-goog

2023-03-23 21:59:41

by bluez.test.bot

[permalink] [raw]
Subject: RE: [v8,1/4] Bluetooth: Add support for hci devcoredump

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=733320

---Test result---

Test Summary:
CheckPatch FAIL 4.76 seconds
GitLint PASS 1.00 seconds
SubjectPrefix PASS 0.34 seconds
BuildKernel PASS 31.65 seconds
CheckAllWarning PASS 34.64 seconds
CheckSparse PASS 39.17 seconds
CheckSmatch PASS 109.35 seconds
BuildKernel32 PASS 30.47 seconds
TestRunnerSetup PASS 439.87 seconds
TestRunner_l2cap-tester PASS 16.09 seconds
TestRunner_iso-tester PASS 15.83 seconds
TestRunner_bnep-tester PASS 5.03 seconds
TestRunner_mgmt-tester PASS 102.86 seconds
TestRunner_rfcomm-tester PASS 8.13 seconds
TestRunner_sco-tester PASS 7.41 seconds
TestRunner_ioctl-tester PASS 8.62 seconds
TestRunner_mesh-tester PASS 6.37 seconds
TestRunner_smp-tester PASS 7.40 seconds
TestRunner_userchan-tester PASS 5.26 seconds
IncrementalBuild PASS 44.73 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[v8,1/4] Bluetooth: Add support for hci devcoredump
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#146:
new file mode 100644

WARNING: Possible unnecessary 'out of memory' message
#471: FILE: net/bluetooth/coredump.c:149:
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump prepare");

WARNING: quoted string split across lines
#615: FILE: net/bluetooth/coredump.c:293:
+ "Devcoredump complete with size %u "
+ "(expect %zu)",

WARNING: quoted string split across lines
#634: FILE: net/bluetooth/coredump.c:312:
+ "Devcoredump aborted with size %u "
+ "(expect %zu)",

WARNING: Possible unnecessary 'out of memory' message
#728: FILE: net/bluetooth/coredump.c:406:
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump init");

WARNING: Possible unnecessary 'out of memory' message
#771: FILE: net/bluetooth/coredump.c:449:
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump pattern");

WARNING: Possible unnecessary 'out of memory' message
#797: FILE: net/bluetooth/coredump.c:475:
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump complete");

WARNING: Possible unnecessary 'out of memory' message
#819: FILE: net/bluetooth/coredump.c:497:
+ if (!skb) {
+ bt_dev_err(hdev, "Failed to allocate devcoredump abort");

total: 0 errors, 8 warnings, 0 checks, 677 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.

/github/workspace/src/src/13186091.patch has style problems, please review.

NOTE: Ignored message types: UNKNOWN_COMMIT_ID

NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.




---
Regards,
Linux Bluetooth

2023-03-26 15:55:21

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH v8 1/4] Bluetooth: Add support for hci devcoredump

On Thu, Mar 23, 2023 at 02:10:15PM -0700, Manish Mandlik wrote:
> From: Abhishek Pandit-Subedi <[email protected]>
>
> Add devcoredump APIs to hci core so that drivers only have to provide
> the dump skbs instead of managing the synchronization and timeouts.
>
> The devcoredump APIs should be used in the following manner:
> - hci_devcoredump_init is called to allocate the dump.
> - hci_devcoredump_append is called to append any skbs with dump data
> OR hci_devcoredump_append_pattern is called to insert a pattern.
> - hci_devcoredump_complete is called when all dump packets have been
> sent OR hci_devcoredump_abort is called to indicate an error and
> cancel an ongoing dump collection.
>
> The high level APIs just prepare some skbs with the appropriate data and
> queue it for the dump to process. Packets part of the crashdump can be
> intercepted in the driver in interrupt context and forwarded directly to
> the devcoredump APIs.
>
> Internally, there are 5 states for the dump: idle, active, complete,
> abort and timeout. A devcoredump will only be in active state after it
> has been initialized. Once active, it accepts data to be appended,
> patterns to be inserted (i.e. memset) and a completion event or an abort
> event to generate a devcoredump. The timeout is initialized at the same
> time the dump is initialized (defaulting to 10s) and will be cleared
> either when the timeout occurs or the dump is complete or aborted.
>
> Signed-off-by: Abhishek Pandit-Subedi <[email protected]>
> Signed-off-by: Manish Mandlik <[email protected]>
> Reviewed-by: Abhishek Pandit-Subedi <[email protected]>

...

> +static int hci_devcoredump_update_hdr_state(char *buf, size_t size, int state)
> +{
> + int len = 0;
> +
> + if (!buf)
> + return 0;
> +
> + len = snprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);

The snprintf documentation says:

* The return value is the number of characters which would be
* generated for the given input, excluding the trailing null,
* as per ISO C99. If the return is greater than or equal to
* @size, the resulting string is truncated.

While the scnprintf documentation says:

* The return value is the number of characters written into @buf not including
* the trailing '\0'. If @size is == 0 the function returns 0.

As the return value us used to determine how many bytes to put to
an skb, you might want scnprintf(), or a check on the value of len here.

> +
> + return len + 1; /* snprintf adds \0 at the end upon state rewrite */
> +}
> +
> +/* Call with hci_dev_lock only. */
> +static int hci_devcoredump_update_state(struct hci_dev *hdev, int state)
> +{
> + hdev->dump.state = state;
> +
> + return hci_devcoredump_update_hdr_state(hdev->dump.head,
> + hdev->dump.alloc_size, state);
> +}

...

> +/* Call with hci_dev_lock only. */
> +static int hci_devcoredump_prepare(struct hci_dev *hdev, u32 dump_size)
> +{
> + struct sk_buff *skb = NULL;
> + int dump_hdr_size;
> + int err = 0;
> +
> + skb = alloc_skb(MAX_DEVCOREDUMP_HDR_SIZE, GFP_ATOMIC);
> + if (!skb) {
> + bt_dev_err(hdev, "Failed to allocate devcoredump prepare");

I don't think memory allocation errors need to be logged like this,
as they are already logged by the core.

Please run checkpatch, which flags this.

> + return -ENOMEM;
> + }
> +
> + dump_hdr_size = hci_devcoredump_mkheader(hdev, skb);
> +
> + if (hci_devcoredump_alloc(hdev, dump_hdr_size + dump_size)) {
> + err = -ENOMEM;
> + goto hdr_free;
> + }
> +
> + /* Insert the device header */
> + if (!hci_devcoredump_copy(hdev, skb->data, skb->len)) {
> + bt_dev_err(hdev, "Failed to insert header");
> + hci_devcoredump_free(hdev);
> +
> + err = -ENOMEM;
> + goto hdr_free;
> + }
> +
> +hdr_free:
> + if (skb)

It seems that this condition is always true.
And in any case, kfree_skb can handle a NULL argument.

> + kfree_skb(skb);
> +
> + return err;
> +}

...

> +void hci_devcoredump_rx(struct work_struct *work)
> +{
> + struct hci_dev *hdev = container_of(work, struct hci_dev, dump.dump_rx);
> + struct sk_buff *skb;
> + struct hci_devcoredump_skb_pattern *pattern;
> + u32 dump_size;
> + int start_state;
> +
> +#define DBG_UNEXPECTED_STATE() \
> + bt_dev_dbg(hdev, \
> + "Unexpected packet (%d) for state (%d). ", \
> + hci_dmp_cb(skb)->pkt_type, hdev->dump.state)

nit: indentation seems excessive in above 3 lines.

> +
> + while ((skb = skb_dequeue(&hdev->dump.dump_q))) {
> + hci_dev_lock(hdev);
> + start_state = hdev->dump.state;
> +
> + switch (hci_dmp_cb(skb)->pkt_type) {
> + case HCI_DEVCOREDUMP_PKT_INIT:
> + if (hdev->dump.state != HCI_DEVCOREDUMP_IDLE) {
> + DBG_UNEXPECTED_STATE();
> + goto loop_continue;

I'm probably missing something terribly obvious.
But can the need for the loop_continue label be avoided by using 'break;' ?

> + }
> +
> + if (skb->len != sizeof(dump_size)) {
> + bt_dev_dbg(hdev, "Invalid dump init pkt");
> + goto loop_continue;
> + }
> +
> + dump_size = *((u32 *)skb->data);
> + if (!dump_size) {
> + bt_dev_err(hdev, "Zero size dump init pkt");
> + goto loop_continue;
> + }
> +
> + if (hci_devcoredump_prepare(hdev, dump_size)) {
> + bt_dev_err(hdev, "Failed to prepare for dump");
> + goto loop_continue;
> + }
> +
> + hci_devcoredump_update_state(hdev,
> + HCI_DEVCOREDUMP_ACTIVE);
> + queue_delayed_work(hdev->workqueue,
> + &hdev->dump.dump_timeout,
> + DEVCOREDUMP_TIMEOUT);
> + break;
> +
> + case HCI_DEVCOREDUMP_PKT_SKB:
> + if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
> + DBG_UNEXPECTED_STATE();
> + goto loop_continue;
> + }
> +
> + if (!hci_devcoredump_copy(hdev, skb->data, skb->len))
> + bt_dev_dbg(hdev, "Failed to insert skb");
> + break;
> +
> + case HCI_DEVCOREDUMP_PKT_PATTERN:
> + if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
> + DBG_UNEXPECTED_STATE();
> + goto loop_continue;
> + }
> +
> + if (skb->len != sizeof(*pattern)) {
> + bt_dev_dbg(hdev, "Invalid pattern skb");
> + goto loop_continue;
> + }
> +
> + pattern = (void *)skb->data;
> +
> + if (!hci_devcoredump_memset(hdev, pattern->pattern,
> + pattern->len))
> + bt_dev_dbg(hdev, "Failed to set pattern");
> + break;
> +
> + case HCI_DEVCOREDUMP_PKT_COMPLETE:
> + if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
> + DBG_UNEXPECTED_STATE();
> + goto loop_continue;
> + }
> +
> + hci_devcoredump_update_state(hdev,
> + HCI_DEVCOREDUMP_DONE);
> + dump_size = hdev->dump.tail - hdev->dump.head;
> +
> + bt_dev_info(hdev,
> + "Devcoredump complete with size %u "
> + "(expect %zu)",

I think it is best practice not to split quoted strings across multiple lines.
Although it leads to long lines (which is undesirable)
keeping the string on one line aids searching the code (with grep).

checkpatch warns about this.

> + dump_size, hdev->dump.alloc_size);
> +
> + dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
> + GFP_KERNEL);
> + break;
> +
> + case HCI_DEVCOREDUMP_PKT_ABORT:
> + if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
> + DBG_UNEXPECTED_STATE();
> + goto loop_continue;
> + }
> +
> + hci_devcoredump_update_state(hdev,
> + HCI_DEVCOREDUMP_ABORT);
> + dump_size = hdev->dump.tail - hdev->dump.head;
> +
> + bt_dev_info(hdev,
> + "Devcoredump aborted with size %u "
> + "(expect %zu)",
> + dump_size, hdev->dump.alloc_size);
> +
> + /* Emit a devcoredump with the available data */
> + dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
> + GFP_KERNEL);
> + break;
> +
> + default:
> + bt_dev_dbg(hdev,
> + "Unknown packet (%d) for state (%d). ",
> + hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
> + break;
> + }
> +
> +loop_continue:
> + kfree_skb(skb);
> + hci_dev_unlock(hdev);
> +
> + if (start_state != hdev->dump.state)
> + hci_devcoredump_notify(hdev, hdev->dump.state);
> +
> + hci_dev_lock(hdev);
> + if (hdev->dump.state == HCI_DEVCOREDUMP_DONE ||
> + hdev->dump.state == HCI_DEVCOREDUMP_ABORT)
> + hci_devcoredump_reset(hdev);
> + hci_dev_unlock(hdev);
> + }
> +}
> +EXPORT_SYMBOL(hci_devcoredump_rx);

...

> +static inline bool hci_devcoredump_enabled(struct hci_dev *hdev)
> +{
> + return hdev->dump.supported;
> +}
> +
> +int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size)
> +{
> + struct sk_buff *skb = NULL;

nit: I don't think it is necessary to initialise skb here.
Likewise elsewhere in this patch.

> +
> + if (!hci_devcoredump_enabled(hdev))
> + return -EOPNOTSUPP;
> +
> + skb = alloc_skb(sizeof(dmp_size), GFP_ATOMIC);
> + if (!skb) {
> + bt_dev_err(hdev, "Failed to allocate devcoredump init");
> + return -ENOMEM;
> + }
> +
> + hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT;
> + skb_put_data(skb, &dmp_size, sizeof(dmp_size));
> +
> + skb_queue_tail(&hdev->dump.dump_q, skb);
> + queue_work(hdev->workqueue, &hdev->dump.dump_rx);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(hci_devcoredump_init);

...