From e625e50ceee18bc1e3fb1a6375e089405a797a4d Mon Sep 17 00:00:00 2001
From: Marcel Holtmann <marcel@holtmann.org>
Date: Wed, 6 May 2020 09:57:52 +0200
Subject: [PATCH] Bluetooth: Introduce debug feature when dynamic debug is disabled
Git-commit: e625e50ceee18bc1e3fb1a6375e089405a797a4d
Patch-mainline: v5.8-rc1
References: jsc#SLE-13430
In case dynamic debug is disabled, this feature allows a vendor platform
to provide debug statement printing.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
include/net/bluetooth/bluetooth.h | 11 +++++
net/bluetooth/Kconfig | 7 ++++
net/bluetooth/lib.c | 33 +++++++++++++++
net/bluetooth/mgmt.c | 87 +++++++++++++++++++++++++++++++++++++++
4 files changed, 138 insertions(+)
diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 3fa7b1e3c5d9..18190055374c 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -153,6 +153,12 @@ __printf(1, 2)
void bt_warn(const char *fmt, ...);
__printf(1, 2)
void bt_err(const char *fmt, ...);
+#if IS_ENABLED(CONFIG_BT_FEATURE_DEBUG)
+void bt_dbg_set(bool enable);
+bool bt_dbg_get(void);
+__printf(1, 2)
+void bt_dbg(const char *fmt, ...);
+#endif
__printf(1, 2)
void bt_warn_ratelimited(const char *fmt, ...);
__printf(1, 2)
@@ -161,7 +167,12 @@ void bt_err_ratelimited(const char *fmt, ...);
#define BT_INFO(fmt, ...) bt_info(fmt "\n", ##__VA_ARGS__)
#define BT_WARN(fmt, ...) bt_warn(fmt "\n", ##__VA_ARGS__)
#define BT_ERR(fmt, ...) bt_err(fmt "\n", ##__VA_ARGS__)
+
+#if IS_ENABLED(CONFIG_BT_FEATURE_DEBUG)
+#define BT_DBG(fmt, ...) bt_dbg(fmt "\n", ##__VA_ARGS__)
+#else
#define BT_DBG(fmt, ...) pr_debug(fmt "\n", ##__VA_ARGS__)
+#endif
#define bt_dev_info(hdev, fmt, ...) \
BT_INFO("%s: " fmt, (hdev)->name, ##__VA_ARGS__)
diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
index 9e25c6570170..1d6d243cdde9 100644
--- a/net/bluetooth/Kconfig
+++ b/net/bluetooth/Kconfig
@@ -135,4 +135,11 @@ config BT_SELFTEST_SMP
Run test cases for SMP cryptographic functionality, including both
legacy SMP as well as the Secure Connections features.
+config BT_FEATURE_DEBUG
+ bool "Enable runtime option for debugging statements"
+ depends on BT && !DYNAMIC_DEBUG
+ help
+ This provides an option to enable/disable debugging statements
+ at runtime via the experimental features interface.
+
source "drivers/bluetooth/Kconfig"
diff --git a/net/bluetooth/lib.c b/net/bluetooth/lib.c
index c09e0a3a0ed9..5326f41a58b7 100644
--- a/net/bluetooth/lib.c
+++ b/net/bluetooth/lib.c
@@ -183,6 +183,39 @@ void bt_err(const char *format, ...)
}
EXPORT_SYMBOL(bt_err);
+#ifdef CONFIG_BT_FEATURE_DEBUG
+static bool debug_enable;
+
+void bt_dbg_set(bool enable)
+{
+ debug_enable = enable;
+}
+
+bool bt_dbg_get(void)
+{
+ return debug_enable;
+}
+
+void bt_dbg(const char *format, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ if (likely(!debug_enable))
+ return;
+
+ va_start(args, format);
+
+ vaf.fmt = format;
+ vaf.va = &args;
+
+ printk(KERN_DEBUG pr_fmt("%pV"), &vaf);
+
+ va_end(args);
+}
+EXPORT_SYMBOL(bt_dbg);
+#endif
+
void bt_warn_ratelimited(const char *format, ...)
{
struct va_format vaf;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 3c6be70d98ef..9e8a3cccc6ca 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -3715,6 +3715,14 @@ static int read_security_info(struct sock *sk, struct hci_dev *hdev,
rp, sizeof(*rp) + sec_len);
}
+#ifdef CONFIG_BT_FEATURE_DEBUG
+/* d4992530-b9ec-469f-ab01-6c481c47da1c */
+static const u8 debug_uuid[16] = {
+ 0x1c, 0xda, 0x47, 0x1c, 0x48, 0x6c, 0x01, 0xab,
+ 0x9f, 0x46, 0xec, 0xb9, 0x30, 0x25, 0x99, 0xd4,
+};
+#endif
+
static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
void *data, u16 data_len)
{
@@ -3726,6 +3734,16 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
memset(&buf, 0, sizeof(buf));
+#ifdef CONFIG_BT_FEATURE_DEBUG
+ if (!hdev) {
+ u32 flags = bt_dbg_get() ? BIT(0) : 0;
+
+ memcpy(rp->features[idx].uuid, debug_uuid, 16);
+ rp->features[idx].flags = cpu_to_le32(flags);
+ idx++;
+ }
+#endif
+
rp->feature_count = cpu_to_le16(idx);
/* After reading the experimental features information, enable
@@ -3738,6 +3756,21 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
0, rp, sizeof(*rp) + (20 * idx));
}
+#ifdef CONFIG_BT_FEATURE_DEBUG
+static int exp_debug_feature_changed(bool enabled, struct sock *skip)
+{
+ struct mgmt_ev_exp_feature_changed ev;
+
+ memset(&ev, 0, sizeof(ev));
+ memcpy(ev.uuid, debug_uuid, 16);
+ ev.flags = cpu_to_le32(enabled ? BIT(0) : 0);
+
+ return mgmt_limited_event(MGMT_EV_EXP_FEATURE_CHANGED, NULL,
+ &ev, sizeof(ev),
+ HCI_MGMT_EXP_FEATURE_EVENTS, skip);
+}
+#endif
+
static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
void *data, u16 data_len)
{
@@ -3750,6 +3783,17 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
memset(rp.uuid, 0, 16);
rp.flags = cpu_to_le32(0);
+#ifdef CONFIG_BT_FEATURE_DEBUG
+ if (!hdev) {
+ bool changed = bt_dbg_get();
+
+ bt_dbg_set(false);
+
+ if (changed)
+ exp_debug_feature_changed(false, sk);
+ }
+#endif
+
hci_sock_set_flag(sk, HCI_MGMT_EXP_FEATURE_EVENTS);
return mgmt_cmd_complete(sk, hdev ? hdev->id : MGMT_INDEX_NONE,
@@ -3757,6 +3801,49 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
&rp, sizeof(rp));
}
+#ifdef CONFIG_BT_FEATURE_DEBUG
+ if (!memcmp(cp->uuid, debug_uuid, 16)) {
+ bool val, changed;
+ int err;
+
+ /* Command requires to use the non-controller index */
+ if (hdev)
+ return mgmt_cmd_status(sk, hdev->id,
+ MGMT_OP_SET_EXP_FEATURE,
+ MGMT_STATUS_INVALID_INDEX);
+
+ /* Parameters are limited to a single octet */
+ if (data_len != MGMT_SET_EXP_FEATURE_SIZE + 1)
+ return mgmt_cmd_status(sk, MGMT_INDEX_NONE,
+ MGMT_OP_SET_EXP_FEATURE,
+ MGMT_STATUS_INVALID_PARAMS);
+
+ /* Only boolean on/off is supported */
+ if (cp->param[0] != 0x00 && cp->param[0] != 0x01)
+ return mgmt_cmd_status(sk, MGMT_INDEX_NONE,
+ MGMT_OP_SET_EXP_FEATURE,
+ MGMT_STATUS_INVALID_PARAMS);
+
+ val = !!cp->param[0];
+ changed = val ? !bt_dbg_get() : bt_dbg_get();
+ bt_dbg_set(val);
+
+ memcpy(rp.uuid, debug_uuid, 16);
+ rp.flags = cpu_to_le32(val ? BIT(0) : 0);
+
+ hci_sock_set_flag(sk, HCI_MGMT_EXP_FEATURE_EVENTS);
+
+ err = mgmt_cmd_complete(sk, MGMT_INDEX_NONE,
+ MGMT_OP_SET_EXP_FEATURE, 0,
+ &rp, sizeof(rp));
+
+ if (changed)
+ exp_debug_feature_changed(val, sk);
+
+ return err;
+ }
+#endif
+
return mgmt_cmd_status(sk, hdev ? hdev->id : MGMT_INDEX_NONE,
MGMT_OP_SET_EXP_FEATURE,
MGMT_STATUS_NOT_SUPPORTED);
--
2.16.4