ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 527 insertions, 0 deletions

diff --git a/sound/virtio/virtio_kctl.c b/sound/virtio/virtio_kctl.c
new file mode 100644
index 000000000..45f7b6a5b
--- /dev/null
+++ b/sound/virtio/virtio_kctl.c
@@ -0,0 +1,527 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2022 OpenSynergy GmbH
+ */
+#include <sound/control.h>
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/* Map for converting VirtIO types to ALSA types. */
+static const snd_ctl_elem_type_t g_v2a_type_map[] = {
+	[VIRTIO_SND_CTL_TYPE_BOOLEAN] = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
+	[VIRTIO_SND_CTL_TYPE_INTEGER] = SNDRV_CTL_ELEM_TYPE_INTEGER,
+	[VIRTIO_SND_CTL_TYPE_INTEGER64] = SNDRV_CTL_ELEM_TYPE_INTEGER64,
+	[VIRTIO_SND_CTL_TYPE_ENUMERATED] = SNDRV_CTL_ELEM_TYPE_ENUMERATED,
+	[VIRTIO_SND_CTL_TYPE_BYTES] = SNDRV_CTL_ELEM_TYPE_BYTES,
+	[VIRTIO_SND_CTL_TYPE_IEC958] = SNDRV_CTL_ELEM_TYPE_IEC958
+};
+
+/* Map for converting VirtIO types to maximum value counts. */
+static const unsigned int g_v2a_count_map[] = {
+	[VIRTIO_SND_CTL_TYPE_BOOLEAN] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer),
+	[VIRTIO_SND_CTL_TYPE_INTEGER] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer),
+	[VIRTIO_SND_CTL_TYPE_INTEGER64] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer64),
+	[VIRTIO_SND_CTL_TYPE_ENUMERATED] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.enumerated),
+	[VIRTIO_SND_CTL_TYPE_BYTES] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.bytes),
+	[VIRTIO_SND_CTL_TYPE_IEC958] = 1
+};
+
+/* Map for converting VirtIO access rights to ALSA access rights. */
+static const unsigned int g_v2a_access_map[] = {
+	[VIRTIO_SND_CTL_ACCESS_READ] = SNDRV_CTL_ELEM_ACCESS_READ,
+	[VIRTIO_SND_CTL_ACCESS_WRITE] = SNDRV_CTL_ELEM_ACCESS_WRITE,
+	[VIRTIO_SND_CTL_ACCESS_VOLATILE] = SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+	[VIRTIO_SND_CTL_ACCESS_INACTIVE] = SNDRV_CTL_ELEM_ACCESS_INACTIVE,
+	[VIRTIO_SND_CTL_ACCESS_TLV_READ] = SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	[VIRTIO_SND_CTL_ACCESS_TLV_WRITE] = SNDRV_CTL_ELEM_ACCESS_TLV_WRITE,
+	[VIRTIO_SND_CTL_ACCESS_TLV_COMMAND] = SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND
+};
+
+/* Map for converting VirtIO event masks to ALSA event masks. */
+static const unsigned int g_v2a_mask_map[] = {
+	[VIRTIO_SND_CTL_EVT_MASK_VALUE] = SNDRV_CTL_EVENT_MASK_VALUE,
+	[VIRTIO_SND_CTL_EVT_MASK_INFO] = SNDRV_CTL_EVENT_MASK_INFO,
+	[VIRTIO_SND_CTL_EVT_MASK_TLV] = SNDRV_CTL_EVENT_MASK_TLV
+};
+
+static int virtsnd_kctl_validate_info(struct virtio_snd *snd, u32 cid,
+				      struct virtio_snd_ctl_info *kinfo)
+{
+	struct virtio_device *vdev = snd->vdev;
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+
+	if (type >= ARRAY_SIZE(g_v2a_type_map)) {
+		dev_err(&vdev->dev, "control #%u: unknown type %u\n",
+			cid, type);
+		return -EINVAL;
+	}
+
+	if (count > g_v2a_count_map[type] ||
+	    (type == VIRTIO_SND_CTL_TYPE_IEC958 && count != 1)) {
+		dev_err(&vdev->dev, "control #%u: invalid count %u for type %u\n",
+			cid, count, type);
+		return -EINVAL;
+	}
+
+	if (type == VIRTIO_SND_CTL_TYPE_ENUMERATED &&
+	    !le32_to_cpu(kinfo->value.enumerated.items)) {
+		dev_err(&vdev->dev,
+			"control #%u: no items for enumerated control\n",
+			cid);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_info() - Returns information about the control.
+ * @kcontrol: ALSA control element.
+ * @uinfo: Element information.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_info(struct snd_kcontrol *kcontrol,
+			     struct snd_ctl_elem_info *uinfo)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_kctl *kctl = &snd->kctls[kcontrol->private_value];
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int i;
+
+	uinfo->type = g_v2a_type_map[le32_to_cpu(kinfo->type)];
+	uinfo->count = le32_to_cpu(kinfo->count);
+
+	switch (uinfo->type) {
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		uinfo->value.integer.min =
+			le32_to_cpu(kinfo->value.integer.min);
+		uinfo->value.integer.max =
+			le32_to_cpu(kinfo->value.integer.max);
+		uinfo->value.integer.step =
+			le32_to_cpu(kinfo->value.integer.step);
+
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		uinfo->value.integer64.min =
+			le64_to_cpu(kinfo->value.integer64.min);
+		uinfo->value.integer64.max =
+			le64_to_cpu(kinfo->value.integer64.max);
+		uinfo->value.integer64.step =
+			le64_to_cpu(kinfo->value.integer64.step);
+
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		uinfo->value.enumerated.items =
+			le32_to_cpu(kinfo->value.enumerated.items);
+		i = uinfo->value.enumerated.item;
+		if (i >= uinfo->value.enumerated.items)
+			return -EINVAL;
+
+		strscpy(uinfo->value.enumerated.name, kctl->items[i].item,
+			sizeof(uinfo->value.enumerated.name));
+
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_get() - Read the value from the control.
+ * @kcontrol: ALSA control element.
+ * @uvalue: Element value.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_get(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *uvalue)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	struct virtio_snd_ctl_value *kvalue;
+	size_t request_size = sizeof(*hdr);
+	size_t response_size = sizeof(struct virtio_snd_hdr) + sizeof(*kvalue);
+	unsigned int i;
+	int rc;
+
+	msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	virtsnd_ctl_msg_ref(msg);
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_READ);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	rc = virtsnd_ctl_msg_send_sync(snd, msg);
+	if (rc)
+		goto on_failure;
+
+	kvalue = (void *)((u8 *)virtsnd_ctl_msg_response(msg) +
+			  sizeof(struct virtio_snd_hdr));
+
+	switch (type) {
+	case VIRTIO_SND_CTL_TYPE_BOOLEAN:
+	case VIRTIO_SND_CTL_TYPE_INTEGER:
+		for (i = 0; i < count; ++i)
+			uvalue->value.integer.value[i] =
+				le32_to_cpu(kvalue->value.integer[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_INTEGER64:
+		for (i = 0; i < count; ++i)
+			uvalue->value.integer64.value[i] =
+				le64_to_cpu(kvalue->value.integer64[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_ENUMERATED:
+		for (i = 0; i < count; ++i)
+			uvalue->value.enumerated.item[i] =
+				le32_to_cpu(kvalue->value.enumerated[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_BYTES:
+		memcpy(uvalue->value.bytes.data, kvalue->value.bytes, count);
+		break;
+	case VIRTIO_SND_CTL_TYPE_IEC958:
+		memcpy(&uvalue->value.iec958, &kvalue->value.iec958,
+		       sizeof(uvalue->value.iec958));
+		break;
+	}
+
+on_failure:
+	virtsnd_ctl_msg_unref(msg);
+
+	return rc;
+}
+
+/**
+ * virtsnd_kctl_put() - Write the value to the control.
+ * @kcontrol: ALSA control element.
+ * @uvalue: Element value.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_put(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *uvalue)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	struct virtio_snd_ctl_value *kvalue;
+	size_t request_size = sizeof(*hdr) + sizeof(*kvalue);
+	size_t response_size = sizeof(struct virtio_snd_hdr);
+	unsigned int i;
+
+	msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_WRITE);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	kvalue = (void *)((u8 *)hdr + sizeof(*hdr));
+
+	switch (type) {
+	case VIRTIO_SND_CTL_TYPE_BOOLEAN:
+	case VIRTIO_SND_CTL_TYPE_INTEGER:
+		for (i = 0; i < count; ++i)
+			kvalue->value.integer[i] =
+				cpu_to_le32(uvalue->value.integer.value[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_INTEGER64:
+		for (i = 0; i < count; ++i)
+			kvalue->value.integer64[i] =
+				cpu_to_le64(uvalue->value.integer64.value[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_ENUMERATED:
+		for (i = 0; i < count; ++i)
+			kvalue->value.enumerated[i] =
+				cpu_to_le32(uvalue->value.enumerated.item[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_BYTES:
+		memcpy(kvalue->value.bytes, uvalue->value.bytes.data, count);
+		break;
+	case VIRTIO_SND_CTL_TYPE_IEC958:
+		memcpy(&kvalue->value.iec958, &uvalue->value.iec958,
+		       sizeof(kvalue->value.iec958));
+		break;
+	}
+
+	return virtsnd_ctl_msg_send_sync(snd, msg);
+}
+
+/**
+ * virtsnd_kctl_tlv_op() - Perform an operation on the control's metadata.
+ * @kcontrol: ALSA control element.
+ * @op_flag: Operation code (SNDRV_CTL_TLV_OP_XXX).
+ * @size: Size of the TLV data in bytes.
+ * @utlv: TLV data.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_tlv_op(struct snd_kcontrol *kcontrol, int op_flag,
+			       unsigned int size, unsigned int __user *utlv)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	unsigned int *tlv;
+	struct scatterlist sg;
+	int rc;
+
+	msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), sizeof(struct virtio_snd_hdr),
+				    GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	tlv = kzalloc(size, GFP_KERNEL);
+	if (!tlv) {
+		rc = -ENOMEM;
+		goto on_msg_unref;
+	}
+
+	sg_init_one(&sg, tlv, size);
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	switch (op_flag) {
+	case SNDRV_CTL_TLV_OP_READ:
+		hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_READ);
+
+		rc = virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
+		if (!rc) {
+			if (copy_to_user(utlv, tlv, size))
+				rc = -EFAULT;
+		}
+
+		break;
+	case SNDRV_CTL_TLV_OP_WRITE:
+	case SNDRV_CTL_TLV_OP_CMD:
+		if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
+			hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_WRITE);
+		else
+			hdr->hdr.code =
+				cpu_to_le32(VIRTIO_SND_R_CTL_TLV_COMMAND);
+
+		if (copy_from_user(tlv, utlv, size)) {
+			rc = -EFAULT;
+			goto on_msg_unref;
+		} else {
+			rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
+		}
+
+		break;
+	default:
+		rc = -EINVAL;
+		/* We never get here - we listed all values for op_flag */
+		WARN_ON(1);
+		goto on_msg_unref;
+	}
+	kfree(tlv);
+	return rc;
+
+on_msg_unref:
+	virtsnd_ctl_msg_unref(msg);
+	kfree(tlv);
+
+	return rc;
+}
+
+/**
+ * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
+ * @snd: VirtIO sound device.
+ * @cid: Control element ID.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_get_enum_items(struct virtio_snd *snd, unsigned int cid)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
+	struct virtio_kctl *kctl = &snd->kctls[cid];
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	unsigned int n = le32_to_cpu(kinfo->value.enumerated.items);
+	struct scatterlist sg;
+
+	msg = virtsnd_ctl_msg_alloc(sizeof(*hdr),
+				    sizeof(struct virtio_snd_hdr), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	kctl->items = devm_kcalloc(&vdev->dev, n, sizeof(*kctl->items),
+				   GFP_KERNEL);
+	if (!kctl->items) {
+		virtsnd_ctl_msg_unref(msg);
+		return -ENOMEM;
+	}
+
+	sg_init_one(&sg, kctl->items, n * sizeof(*kctl->items));
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_ENUM_ITEMS);
+	hdr->control_id = cpu_to_le32(cid);
+
+	return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
+}
+
+/**
+ * virtsnd_kctl_parse_cfg() - Parse the control element configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_kctl_parse_cfg(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	u32 i;
+	int rc;
+
+	virtio_cread_le(vdev, struct virtio_snd_config, controls,
+			&snd->nkctls);
+	if (!snd->nkctls)
+		return 0;
+
+	snd->kctl_infos = devm_kcalloc(&vdev->dev, snd->nkctls,
+				       sizeof(*snd->kctl_infos), GFP_KERNEL);
+	if (!snd->kctl_infos)
+		return -ENOMEM;
+
+	snd->kctls = devm_kcalloc(&vdev->dev, snd->nkctls, sizeof(*snd->kctls),
+				  GFP_KERNEL);
+	if (!snd->kctls)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CTL_INFO, 0, snd->nkctls,
+				    sizeof(*snd->kctl_infos), snd->kctl_infos);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < snd->nkctls; ++i) {
+		struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[i];
+		unsigned int type = le32_to_cpu(kinfo->type);
+
+		rc = virtsnd_kctl_validate_info(snd, i, kinfo);
+		if (rc)
+			return rc;
+
+		if (type == VIRTIO_SND_CTL_TYPE_ENUMERATED) {
+			rc = virtsnd_kctl_get_enum_items(snd, i);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_build_devs() - Build ALSA control elements.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_kctl_build_devs(struct virtio_snd *snd)
+{
+	unsigned int cid;
+
+	for (cid = 0; cid < snd->nkctls; ++cid) {
+		struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
+		struct virtio_kctl *kctl = &snd->kctls[cid];
+		struct snd_kcontrol_new kctl_new;
+		unsigned int i;
+		int rc;
+
+		memset(&kctl_new, 0, sizeof(kctl_new));
+
+		kctl_new.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+		kctl_new.name = kinfo->name;
+		kctl_new.index = le32_to_cpu(kinfo->index);
+
+		for (i = 0; i < ARRAY_SIZE(g_v2a_access_map); ++i)
+			if (le32_to_cpu(kinfo->access) & (1 << i))
+				kctl_new.access |= g_v2a_access_map[i];
+
+		if (kctl_new.access & (SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+				       SNDRV_CTL_ELEM_ACCESS_TLV_WRITE |
+				       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND)) {
+			kctl_new.access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
+			kctl_new.tlv.c = virtsnd_kctl_tlv_op;
+		}
+
+		kctl_new.info = virtsnd_kctl_info;
+		kctl_new.get = virtsnd_kctl_get;
+		kctl_new.put = virtsnd_kctl_put;
+		kctl_new.private_value = cid;
+
+		kctl->kctl = snd_ctl_new1(&kctl_new, snd);
+		if (!kctl->kctl)
+			return -ENOMEM;
+
+		rc = snd_ctl_add(snd->card, kctl->kctl);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_event() - Handle the control element event notification.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event)
+{
+	struct virtio_snd_ctl_event *kevent =
+		(struct virtio_snd_ctl_event *)event;
+	struct virtio_kctl *kctl;
+	unsigned int cid = le16_to_cpu(kevent->control_id);
+	unsigned int mask = 0;
+	unsigned int i;
+
+	if (cid >= snd->nkctls)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(g_v2a_mask_map); ++i)
+		if (le16_to_cpu(kevent->mask) & (1 << i))
+			mask |= g_v2a_mask_map[i];
+
+
+	kctl = &snd->kctls[cid];
+
+	snd_ctl_notify(snd->card, mask, &kctl->kctl->id);
+}