linux/net/bluetooth/coredump.c
Ziyang Xuan 3cd43dd15f Bluetooth: Remove unnecessary NULL check before vfree()
Remove unnecessary NULL check which causes coccinelle warning:

net/bluetooth/coredump.c:104:2-7: WARNING: NULL check before some
freeing functions is not needed.

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-08-11 11:56:54 -07:00

536 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Google Corporation
*/
#include <linux/devcoredump.h>
#include <asm/unaligned.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 DBG_UNEXPECTED_STATE() \
bt_dev_dbg(hdev, \
"Unexpected packet (%d) for state (%d). ", \
hci_dmp_cb(skb)->pkt_type, hdev->dump.state)
#define MAX_DEVCOREDUMP_HDR_SIZE 512 /* bytes */
static int hci_devcd_update_hdr_state(char *buf, size_t size, int state)
{
int len = 0;
if (!buf)
return 0;
len = scnprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);
return len + 1; /* scnprintf adds \0 at the end upon state rewrite */
}
/* Call with hci_dev_lock only. */
static int hci_devcd_update_state(struct hci_dev *hdev, int state)
{
bt_dev_dbg(hdev, "Updating devcoredump state from %d to %d.",
hdev->dump.state, state);
hdev->dump.state = state;
return hci_devcd_update_hdr_state(hdev->dump.head,
hdev->dump.alloc_size, state);
}
static int hci_devcd_mkheader(struct hci_dev *hdev, struct sk_buff *skb)
{
char dump_start[] = "--- Start dump ---\n";
char hdr[80];
int hdr_len;
hdr_len = hci_devcd_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_devcd_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_devcd_reset(struct hci_dev *hdev)
{
hdev->dump.head = NULL;
hdev->dump.tail = NULL;
hdev->dump.alloc_size = 0;
hci_devcd_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_devcd_free(struct hci_dev *hdev)
{
vfree(hdev->dump.head);
hci_devcd_reset(hdev);
}
/* Call with hci_dev_lock only. */
static int hci_devcd_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_devcd_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
return 0;
}
/* Call with hci_dev_lock only. */
static bool hci_devcd_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_devcd_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_devcd_prepare(struct hci_dev *hdev, u32 dump_size)
{
struct sk_buff *skb;
int dump_hdr_size;
int err = 0;
skb = alloc_skb(MAX_DEVCOREDUMP_HDR_SIZE, GFP_ATOMIC);
if (!skb)
return -ENOMEM;
dump_hdr_size = hci_devcd_mkheader(hdev, skb);
if (hci_devcd_alloc(hdev, dump_hdr_size + dump_size)) {
err = -ENOMEM;
goto hdr_free;
}
/* Insert the device header */
if (!hci_devcd_copy(hdev, skb->data, skb->len)) {
bt_dev_err(hdev, "Failed to insert header");
hci_devcd_free(hdev);
err = -ENOMEM;
goto hdr_free;
}
hdr_free:
kfree_skb(skb);
return err;
}
static void hci_devcd_handle_pkt_init(struct hci_dev *hdev, struct sk_buff *skb)
{
u32 dump_size;
if (hdev->dump.state != HCI_DEVCOREDUMP_IDLE) {
DBG_UNEXPECTED_STATE();
return;
}
if (skb->len != sizeof(dump_size)) {
bt_dev_dbg(hdev, "Invalid dump init pkt");
return;
}
dump_size = get_unaligned_le32(skb_pull_data(skb, 4));
if (!dump_size) {
bt_dev_err(hdev, "Zero size dump init pkt");
return;
}
if (hci_devcd_prepare(hdev, dump_size)) {
bt_dev_err(hdev, "Failed to prepare for dump");
return;
}
hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_ACTIVE);
queue_delayed_work(hdev->workqueue, &hdev->dump.dump_timeout,
hdev->dump.timeout);
}
static void hci_devcd_handle_pkt_skb(struct hci_dev *hdev, struct sk_buff *skb)
{
if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
DBG_UNEXPECTED_STATE();
return;
}
if (!hci_devcd_copy(hdev, skb->data, skb->len))
bt_dev_dbg(hdev, "Failed to insert skb");
}
static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev,
struct sk_buff *skb)
{
struct hci_devcoredump_skb_pattern *pattern;
if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
DBG_UNEXPECTED_STATE();
return;
}
if (skb->len != sizeof(*pattern)) {
bt_dev_dbg(hdev, "Invalid pattern skb");
return;
}
pattern = skb_pull_data(skb, sizeof(*pattern));
if (!hci_devcd_memset(hdev, pattern->pattern, pattern->len))
bt_dev_dbg(hdev, "Failed to set pattern");
}
static void hci_devcd_handle_pkt_complete(struct hci_dev *hdev,
struct sk_buff *skb)
{
u32 dump_size;
if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
DBG_UNEXPECTED_STATE();
return;
}
hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_DONE);
dump_size = hdev->dump.tail - hdev->dump.head;
bt_dev_dbg(hdev, "complete with size %u (expect %zu)", dump_size,
hdev->dump.alloc_size);
dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
}
static void hci_devcd_handle_pkt_abort(struct hci_dev *hdev,
struct sk_buff *skb)
{
u32 dump_size;
if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
DBG_UNEXPECTED_STATE();
return;
}
hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_ABORT);
dump_size = hdev->dump.tail - hdev->dump.head;
bt_dev_dbg(hdev, "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);
}
/* 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_devcd_init(). Once active, the driver
* can append data using hci_devcd_append() or insert a pattern
* using hci_devcd_append_pattern().
*
* HCI_DEVCOREDUMP_DONE: Once the dump collection is complete, the drive
* can signal the completion using hci_devcd_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_devcd_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_devcd_register() before using the hci
* devcoredump APIs.
*/
void hci_devcd_rx(struct work_struct *work)
{
struct hci_dev *hdev = container_of(work, struct hci_dev, dump.dump_rx);
struct sk_buff *skb;
int start_state;
while ((skb = skb_dequeue(&hdev->dump.dump_q))) {
/* Return if timeout occurs. The timeout handler function
* hci_devcd_timeout() will report the available dump data.
*/
if (hdev->dump.state == HCI_DEVCOREDUMP_TIMEOUT) {
kfree_skb(skb);
return;
}
hci_dev_lock(hdev);
start_state = hdev->dump.state;
switch (hci_dmp_cb(skb)->pkt_type) {
case HCI_DEVCOREDUMP_PKT_INIT:
hci_devcd_handle_pkt_init(hdev, skb);
break;
case HCI_DEVCOREDUMP_PKT_SKB:
hci_devcd_handle_pkt_skb(hdev, skb);
break;
case HCI_DEVCOREDUMP_PKT_PATTERN:
hci_devcd_handle_pkt_pattern(hdev, skb);
break;
case HCI_DEVCOREDUMP_PKT_COMPLETE:
hci_devcd_handle_pkt_complete(hdev, skb);
break;
case HCI_DEVCOREDUMP_PKT_ABORT:
hci_devcd_handle_pkt_abort(hdev, skb);
break;
default:
bt_dev_dbg(hdev, "Unknown packet (%d) for state (%d). ",
hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
break;
}
hci_dev_unlock(hdev);
kfree_skb(skb);
/* Notify the driver about any state changes before resetting
* the state machine
*/
if (start_state != hdev->dump.state)
hci_devcd_notify(hdev, hdev->dump.state);
/* Reset the state machine if the devcoredump is complete */
hci_dev_lock(hdev);
if (hdev->dump.state == HCI_DEVCOREDUMP_DONE ||
hdev->dump.state == HCI_DEVCOREDUMP_ABORT)
hci_devcd_reset(hdev);
hci_dev_unlock(hdev);
}
}
EXPORT_SYMBOL(hci_devcd_rx);
void hci_devcd_timeout(struct work_struct *work)
{
struct hci_dev *hdev = container_of(work, struct hci_dev,
dump.dump_timeout.work);
u32 dump_size;
hci_devcd_notify(hdev, HCI_DEVCOREDUMP_TIMEOUT);
hci_dev_lock(hdev);
cancel_work(&hdev->dump.dump_rx);
hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_TIMEOUT);
dump_size = hdev->dump.tail - hdev->dump.head;
bt_dev_dbg(hdev, "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_devcd_reset(hdev);
hci_dev_unlock(hdev);
}
EXPORT_SYMBOL(hci_devcd_timeout);
int hci_devcd_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;
hdev->dump.timeout = DEVCOREDUMP_TIMEOUT;
hci_dev_unlock(hdev);
return 0;
}
EXPORT_SYMBOL(hci_devcd_register);
static inline bool hci_devcd_enabled(struct hci_dev *hdev)
{
return hdev->dump.supported;
}
int hci_devcd_init(struct hci_dev *hdev, u32 dump_size)
{
struct sk_buff *skb;
if (!hci_devcd_enabled(hdev))
return -EOPNOTSUPP;
skb = alloc_skb(sizeof(dump_size), GFP_ATOMIC);
if (!skb)
return -ENOMEM;
hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT;
put_unaligned_le32(dump_size, skb_put(skb, 4));
skb_queue_tail(&hdev->dump.dump_q, skb);
queue_work(hdev->workqueue, &hdev->dump.dump_rx);
return 0;
}
EXPORT_SYMBOL(hci_devcd_init);
int hci_devcd_append(struct hci_dev *hdev, struct sk_buff *skb)
{
if (!skb)
return -ENOMEM;
if (!hci_devcd_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_devcd_append);
int hci_devcd_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len)
{
struct hci_devcoredump_skb_pattern p;
struct sk_buff *skb;
if (!hci_devcd_enabled(hdev))
return -EOPNOTSUPP;
skb = alloc_skb(sizeof(p), GFP_ATOMIC);
if (!skb)
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_devcd_append_pattern);
int hci_devcd_complete(struct hci_dev *hdev)
{
struct sk_buff *skb;
if (!hci_devcd_enabled(hdev))
return -EOPNOTSUPP;
skb = alloc_skb(0, GFP_ATOMIC);
if (!skb)
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_devcd_complete);
int hci_devcd_abort(struct hci_dev *hdev)
{
struct sk_buff *skb;
if (!hci_devcd_enabled(hdev))
return -EOPNOTSUPP;
skb = alloc_skb(0, GFP_ATOMIC);
if (!skb)
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_devcd_abort);