thunderbolt: Fix NULL dereference in tb_remove_work()grafted

There is a slight race between tb_remove_work() and tb_domain_remove()
which leads to dereferencing a NULL tb->root_switch pointer inside
tb_free_unplugged_xdomains():

        Thread A                            Thread B

  tb_remove_work()
                                    tb_domain_remove()
                                      mutex_lock(&tb->lock)
                                      tb_stop()
                                        /* doesn't cancel a running callback */
                                        cancel_delayed_work(&tcm->remove_work)
                                        ...
                                        tb_switch_remove(tb->root_switch)
                                        tb->root_switch = NULL
                                      mutex_unlock(&tb->lock)
    mutex_lock(&tb->lock)
    ...
    /* without checking ->root_switch */
    tb_free_unplugged_xdomains(tb->root_switch)
    mutex_unlock(&tb->lock)

Commit a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without
holding tb->lock") doesn't seem right to move tb_free_unplugged_xdomains()
out of the &tb->lock section and the check for tb->root_switch, in
particular.  It states:

  For this reason separate removing the XDomain from the topology data
  structures (where we need the lock) from unregistering the device from
  the bus (where remove callbacks of the drivers are being called).

tb_free_unplugged_xdomains() belongs to the former group of functions
requiring the lock.  And it also calls tb_xdomain_remove() which should
only be called with &tb->lock held.

Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.

Fixes: a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without holding tb->lock")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 135 insertions, 0 deletions

diff --git a/include/sound/sof/dai.h b/include/sound/sof/dai.h
new file mode 100644
index 000000000..e3fe492e7
--- /dev/null
+++ b/include/sound/sof/dai.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#ifndef __INCLUDE_SOUND_SOF_DAI_H__
+#define __INCLUDE_SOUND_SOF_DAI_H__
+
+#include <sound/sof/header.h>
+#include <sound/sof/dai-intel.h>
+#include <sound/sof/dai-imx.h>
+#include <sound/sof/dai-amd.h>
+#include <sound/sof/dai-mediatek.h>
+
+/*
+ * DAI Configuration.
+ *
+ * Each different DAI type will have it's own structure and IPC cmd.
+ */
+
+#define SOF_DAI_FMT_I2S		1 /**< I2S mode */
+#define SOF_DAI_FMT_RIGHT_J	2 /**< Right Justified mode */
+#define SOF_DAI_FMT_LEFT_J	3 /**< Left Justified mode */
+#define SOF_DAI_FMT_DSP_A	4 /**< L data MSB after FRM LRC */
+#define SOF_DAI_FMT_DSP_B	5 /**< L data MSB during FRM LRC */
+#define SOF_DAI_FMT_PDM		6 /**< Pulse density modulation */
+
+#define SOF_DAI_FMT_CONT	(1 << 4) /**< continuous clock */
+#define SOF_DAI_FMT_GATED	(0 << 4) /**< clock is gated */
+
+#define SOF_DAI_FMT_NB_NF	(0 << 8) /**< normal bit clock + frame */
+#define SOF_DAI_FMT_NB_IF	(2 << 8) /**< normal BCLK + inv FRM */
+#define SOF_DAI_FMT_IB_NF	(3 << 8) /**< invert BCLK + nor FRM */
+#define SOF_DAI_FMT_IB_IF	(4 << 8) /**< invert BCLK + FRM */
+
+#define SOF_DAI_FMT_CBP_CFP	(0 << 12) /**< codec bclk provider & frame provider */
+#define SOF_DAI_FMT_CBC_CFP	(2 << 12) /**< codec bclk consumer & frame provider */
+#define SOF_DAI_FMT_CBP_CFC	(3 << 12) /**< codec bclk provider & frame consumer */
+#define SOF_DAI_FMT_CBC_CFC	(4 << 12) /**< codec bclk consumer & frame consumer */
+
+/* keep old definitions for backwards compatibility */
+#define SOF_DAI_FMT_CBM_CFM	SOF_DAI_FMT_CBP_CFP
+#define SOF_DAI_FMT_CBS_CFM	SOF_DAI_FMT_CBC_CFP
+#define SOF_DAI_FMT_CBM_CFS	SOF_DAI_FMT_CBP_CFC
+#define SOF_DAI_FMT_CBS_CFS	SOF_DAI_FMT_CBC_CFC
+
+#define SOF_DAI_FMT_FORMAT_MASK		0x000f
+#define SOF_DAI_FMT_CLOCK_MASK		0x00f0
+#define SOF_DAI_FMT_INV_MASK		0x0f00
+#define SOF_DAI_FMT_CLOCK_PROVIDER_MASK	0xf000
+
+/*
+ * DAI_CONFIG flags. The 4 LSB bits are used for the commands, HW_PARAMS, HW_FREE and PAUSE
+ * representing when the IPC is sent. The 4 MSB bits are used to add quirks along with the above
+ * commands.
+ */
+#define SOF_DAI_CONFIG_FLAGS_CMD_MASK	0xF
+#define SOF_DAI_CONFIG_FLAGS_NONE	0 /**< DAI_CONFIG sent without stage information */
+#define SOF_DAI_CONFIG_FLAGS_HW_PARAMS	BIT(0) /**< DAI_CONFIG sent during hw_params stage */
+#define SOF_DAI_CONFIG_FLAGS_HW_FREE	BIT(1) /**< DAI_CONFIG sent during hw_free stage */
+/**< DAI_CONFIG sent during pause trigger. Only available ABI 3.20 onwards */
+#define SOF_DAI_CONFIG_FLAGS_PAUSE	BIT(2)
+#define SOF_DAI_CONFIG_FLAGS_QUIRK_SHIFT 4
+#define SOF_DAI_CONFIG_FLAGS_QUIRK_MASK  (0xF << SOF_DAI_CONFIG_FLAGS_QUIRK_SHIFT)
+/*
+ * This should be used along with the SOF_DAI_CONFIG_FLAGS_HW_PARAMS to indicate that pipeline
+ * stop/pause and DAI DMA stop/pause should happen in two steps. This change is only available
+ * ABI 3.20 onwards.
+ */
+#define SOF_DAI_CONFIG_FLAGS_2_STEP_STOP BIT(0)
+
+/** \brief Types of DAI */
+enum sof_ipc_dai_type {
+	SOF_DAI_INTEL_NONE = 0,		/**< None */
+	SOF_DAI_INTEL_SSP,		/**< Intel SSP */
+	SOF_DAI_INTEL_DMIC,		/**< Intel DMIC */
+	SOF_DAI_INTEL_HDA,		/**< Intel HD/A */
+	SOF_DAI_INTEL_ALH,		/**< Intel ALH  */
+	SOF_DAI_IMX_SAI,		/**< i.MX SAI */
+	SOF_DAI_IMX_ESAI,		/**< i.MX ESAI */
+	SOF_DAI_AMD_BT,			/**< AMD ACP BT*/
+	SOF_DAI_AMD_SP,			/**< AMD ACP SP */
+	SOF_DAI_AMD_DMIC,		/**< AMD ACP DMIC */
+	SOF_DAI_MEDIATEK_AFE,		/**< Mediatek AFE */
+	SOF_DAI_AMD_HS,			/**< Amd HS */
+	SOF_DAI_AMD_SP_VIRTUAL,		/**< AMD ACP SP VIRTUAL */
+	SOF_DAI_AMD_HS_VIRTUAL,		/**< AMD ACP HS VIRTUAL */
+	SOF_DAI_IMX_MICFIL,		/** < i.MX MICFIL PDM */
+	SOF_DAI_AMD_SDW,		/**< AMD ACP SDW */
+	SOF_DAI_INTEL_UAOL,		/**< Intel UAOL */
+	SOF_DAI_AMD_I2S,		/**< AMD ACP I2S */
+};
+
+/* general purpose DAI configuration */
+struct sof_ipc_dai_config {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t type;		/**< DAI type - enum sof_ipc_dai_type */
+	uint32_t dai_index;	/**< index of this type dai */
+
+	/* physical protocol and clocking */
+	uint16_t format;	/**< SOF_DAI_FMT_ */
+	uint8_t group_id;	/**< group ID, 0 means no group (ABI 3.17) */
+	uint8_t flags;		/**< SOF_DAI_CONFIG_FLAGS_ (ABI 3.19) */
+
+	/* reserved for future use */
+	uint32_t reserved[8];
+
+	/* HW specific data */
+	union {
+		struct sof_ipc_dai_ssp_params ssp;
+		struct sof_ipc_dai_dmic_params dmic;
+		struct sof_ipc_dai_hda_params hda;
+		struct sof_ipc_dai_alh_params alh;
+		struct sof_ipc_dai_esai_params esai;
+		struct sof_ipc_dai_sai_params sai;
+		struct sof_ipc_dai_acp_params acpbt;
+		struct sof_ipc_dai_acp_params acpsp;
+		struct sof_ipc_dai_acpdmic_params acpdmic;
+		struct sof_ipc_dai_acp_params acphs;
+		struct sof_ipc_dai_mtk_afe_params afe;
+		struct sof_ipc_dai_micfil_params micfil;
+		struct sof_ipc_dai_acp_sdw_params acp_sdw;
+		struct sof_ipc_dai_acp_params acp_i2s;
+	};
+} __packed;
+
+struct sof_dai_private_data {
+	struct sof_ipc_comp_dai *comp_dai;
+	struct sof_ipc_dai_config *dai_config;
+};
+
+#endif