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, 387 insertions, 0 deletions

diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
new file mode 100644
index 000000000..fdb785fa4
--- /dev/null
+++ b/include/ras/ras_event.h
@@ -0,0 +1,387 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM ras
+#define TRACE_INCLUDE_FILE ras_event
+
+#if !defined(_TRACE_HW_EVENT_MC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HW_EVENT_MC_H
+
+#include <linux/tracepoint.h>
+#include <linux/edac.h>
+#include <linux/ktime.h>
+#include <linux/pci.h>
+#include <linux/aer.h>
+#include <linux/cper.h>
+
+/*
+ * MCE Extended Error Log trace event
+ *
+ * These events are generated when hardware detects a corrected or
+ * uncorrected event.
+ */
+
+/* memory trace event */
+
+#if defined(CONFIG_ACPI_EXTLOG) || defined(CONFIG_ACPI_EXTLOG_MODULE)
+TRACE_EVENT(extlog_mem_event,
+	TP_PROTO(struct cper_sec_mem_err *mem,
+		 u32 err_seq,
+		 const guid_t *fru_id,
+		 const char *fru_text,
+		 u8 sev),
+
+	TP_ARGS(mem, err_seq, fru_id, fru_text, sev),
+
+	TP_STRUCT__entry(
+		__field(u32, err_seq)
+		__field(u8, etype)
+		__field(u8, sev)
+		__field(u64, pa)
+		__field(u8, pa_mask_lsb)
+		__field_struct(guid_t, fru_id)
+		__string(fru_text, fru_text)
+		__field_struct(struct cper_mem_err_compact, data)
+	),
+
+	TP_fast_assign(
+		__entry->err_seq = err_seq;
+		if (mem->validation_bits & CPER_MEM_VALID_ERROR_TYPE)
+			__entry->etype = mem->error_type;
+		else
+			__entry->etype = ~0;
+		__entry->sev = sev;
+		if (mem->validation_bits & CPER_MEM_VALID_PA)
+			__entry->pa = mem->physical_addr;
+		else
+			__entry->pa = ~0ull;
+
+		if (mem->validation_bits & CPER_MEM_VALID_PA_MASK)
+			__entry->pa_mask_lsb = (u8)__ffs64(mem->physical_addr_mask);
+		else
+			__entry->pa_mask_lsb = ~0;
+		__entry->fru_id = *fru_id;
+		__assign_str(fru_text);
+		cper_mem_err_pack(mem, &__entry->data);
+	),
+
+	TP_printk("{%d} %s error: %s physical addr: %016llx (mask lsb: %x) %sFRU: %pUl %.20s",
+		  __entry->err_seq,
+		  cper_severity_str(__entry->sev),
+		  cper_mem_err_type_str(__entry->etype),
+		  __entry->pa,
+		  __entry->pa_mask_lsb,
+		  cper_mem_err_unpack(p, &__entry->data),
+		  &__entry->fru_id,
+		  __get_str(fru_text))
+);
+#endif
+
+/*
+ * Hardware Events Report
+ *
+ * Those events are generated when hardware detected a corrected or
+ * uncorrected event, and are meant to replace the current API to report
+ * errors defined on both EDAC and MCE subsystems.
+ *
+ * FIXME: Add events for handling memory errors originated from the
+ *        MCE subsystem.
+ */
+
+/*
+ * Hardware-independent Memory Controller specific events
+ */
+
+/*
+ * Default error mechanisms for Memory Controller errors (CE and UE)
+ */
+TRACE_EVENT(mc_event,
+
+	TP_PROTO(const unsigned int err_type,
+		 const char *error_msg,
+		 const char *label,
+		 const int error_count,
+		 const u8 mc_index,
+		 const s8 top_layer,
+		 const s8 mid_layer,
+		 const s8 low_layer,
+		 unsigned long address,
+		 const u8 grain_bits,
+		 unsigned long syndrome,
+		 const char *driver_detail),
+
+	TP_ARGS(err_type, error_msg, label, error_count, mc_index,
+		top_layer, mid_layer, low_layer, address, grain_bits,
+		syndrome, driver_detail),
+
+	TP_STRUCT__entry(
+		__field(	unsigned int,	error_type		)
+		__string(	msg,		error_msg		)
+		__string(	label,		label			)
+		__field(	u16,		error_count		)
+		__field(	u8,		mc_index		)
+		__field(	s8,		top_layer		)
+		__field(	s8,		middle_layer		)
+		__field(	s8,		lower_layer		)
+		__field(	long,		address			)
+		__field(	u8,		grain_bits		)
+		__field(	long,		syndrome		)
+		__string(	driver_detail,	driver_detail		)
+	),
+
+	TP_fast_assign(
+		__entry->error_type		= err_type;
+		__assign_str(msg);
+		__assign_str(label);
+		__entry->error_count		= error_count;
+		__entry->mc_index		= mc_index;
+		__entry->top_layer		= top_layer;
+		__entry->middle_layer		= mid_layer;
+		__entry->lower_layer		= low_layer;
+		__entry->address		= address;
+		__entry->grain_bits		= grain_bits;
+		__entry->syndrome		= syndrome;
+		__assign_str(driver_detail);
+	),
+
+	TP_printk("%d %s error%s:%s%s on %s (mc:%d location:%d:%d:%d address:0x%08lx grain:%d syndrome:0x%08lx%s%s)",
+		  __entry->error_count,
+		  mc_event_error_type(__entry->error_type),
+		  __entry->error_count > 1 ? "s" : "",
+		  __get_str(msg)[0] ? " " : "",
+		  __get_str(msg),
+		  __get_str(label),
+		  __entry->mc_index,
+		  __entry->top_layer,
+		  __entry->middle_layer,
+		  __entry->lower_layer,
+		  __entry->address,
+		  1 << __entry->grain_bits,
+		  __entry->syndrome,
+		  __get_str(driver_detail)[0] ? " " : "",
+		  __get_str(driver_detail))
+);
+
+/*
+ * ARM Processor Events Report
+ *
+ * This event is generated when hardware detects an ARM processor error
+ * has occurred. UEFI 2.6 spec section N.2.4.4.
+ */
+#define APEIL "ARM Processor Err Info data len"
+#define APEID "ARM Processor Err Info raw data"
+#define APECIL "ARM Processor Err Context Info data len"
+#define APECID "ARM Processor Err Context Info raw data"
+#define VSEIL "Vendor Specific Err Info data len"
+#define VSEID "Vendor Specific Err Info raw data"
+TRACE_EVENT(arm_event,
+
+	TP_PROTO(const struct cper_sec_proc_arm *proc,
+		 const u8 *pei_err,
+		 const u32 pei_len,
+		 const u8 *ctx_err,
+		 const u32 ctx_len,
+		 const u8 *oem,
+		 const u32 oem_len,
+		 u8 sev,
+		 int cpu),
+
+	TP_ARGS(proc, pei_err, pei_len, ctx_err, ctx_len, oem, oem_len, sev, cpu),
+
+	TP_STRUCT__entry(
+		__field(u64, mpidr)
+		__field(u64, midr)
+		__field(u32, running_state)
+		__field(u32, psci_state)
+		__field(u8, affinity)
+		__field(u32, pei_len)
+		__dynamic_array(u8, pei_buf, pei_len)
+		__field(u32, ctx_len)
+		__dynamic_array(u8, ctx_buf, ctx_len)
+		__field(u32, oem_len)
+		__dynamic_array(u8, oem_buf, oem_len)
+		__field(u8, sev)
+		__field(int, cpu)
+	),
+
+	TP_fast_assign(
+		if (proc->validation_bits & CPER_ARM_VALID_AFFINITY_LEVEL)
+			__entry->affinity = proc->affinity_level;
+		else
+			__entry->affinity = ~0;
+		if (proc->validation_bits & CPER_ARM_VALID_MPIDR)
+			__entry->mpidr = proc->mpidr;
+		else
+			__entry->mpidr = 0ULL;
+		__entry->midr = proc->midr;
+		if (proc->validation_bits & CPER_ARM_VALID_RUNNING_STATE) {
+			__entry->running_state = proc->running_state;
+			__entry->psci_state = proc->psci_state;
+		} else {
+			__entry->running_state = ~0;
+			__entry->psci_state = ~0;
+		}
+		__entry->pei_len = pei_len;
+		memcpy(__get_dynamic_array(pei_buf), pei_err, pei_len);
+		__entry->ctx_len = ctx_len;
+		memcpy(__get_dynamic_array(ctx_buf), ctx_err, ctx_len);
+		__entry->oem_len = oem_len;
+		memcpy(__get_dynamic_array(oem_buf), oem, oem_len);
+		__entry->sev = sev;
+		__entry->cpu = cpu;
+	),
+
+	TP_printk("cpu: %d; error: %d; affinity level: %d; MPIDR: %016llx; MIDR: %016llx; "
+		  "running state: %d; PSCI state: %d; "
+		  "%s: %d; %s: %s; %s: %d; %s: %s; %s: %d; %s: %s",
+		  __entry->cpu,
+		  __entry->sev,
+		  __entry->affinity, __entry->mpidr, __entry->midr,
+		  __entry->running_state, __entry->psci_state,
+		  APEIL, __entry->pei_len, APEID,
+		  __print_hex(__get_dynamic_array(pei_buf), __entry->pei_len),
+		  APECIL, __entry->ctx_len, APECID,
+		  __print_hex(__get_dynamic_array(ctx_buf), __entry->ctx_len),
+		  VSEIL, __entry->oem_len, VSEID,
+		  __print_hex(__get_dynamic_array(oem_buf), __entry->oem_len))
+);
+
+/*
+ * Non-Standard Section Report
+ *
+ * This event is generated when hardware detected a hardware
+ * error event, which may be of non-standard section as defined
+ * in UEFI spec appendix "Common Platform Error Record", or may
+ * be of sections for which TRACE_EVENT is not defined.
+ *
+ */
+TRACE_EVENT(non_standard_event,
+
+	TP_PROTO(const guid_t *sec_type,
+		 const guid_t *fru_id,
+		 const char *fru_text,
+		 const u8 sev,
+		 const u8 *err,
+		 const u32 len),
+
+	TP_ARGS(sec_type, fru_id, fru_text, sev, err, len),
+
+	TP_STRUCT__entry(
+		__array(char, sec_type, UUID_SIZE)
+		__array(char, fru_id, UUID_SIZE)
+		__string(fru_text, fru_text)
+		__field(u8, sev)
+		__field(u32, len)
+		__dynamic_array(u8, buf, len)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->sec_type, sec_type, UUID_SIZE);
+		memcpy(__entry->fru_id, fru_id, UUID_SIZE);
+		__assign_str(fru_text);
+		__entry->sev = sev;
+		__entry->len = len;
+		memcpy(__get_dynamic_array(buf), err, len);
+	),
+
+	TP_printk("severity: %d; sec type:%pU; FRU: %pU %s; data len:%d; raw data:%s",
+		  __entry->sev, __entry->sec_type,
+		  __entry->fru_id, __get_str(fru_text),
+		  __entry->len,
+		  __print_hex(__get_dynamic_array(buf), __entry->len))
+);
+
+#ifdef CONFIG_PCIEAER
+/*
+ * PCIe AER Trace event
+ *
+ * These events are generated when hardware detects a corrected or
+ * uncorrected event on a PCIe device. The event report has
+ * the following structure:
+ *
+ * char * dev_name -	The name of the slot where the device resides
+ *			([domain:]bus:device.function).
+ * u32 status -		Either the correctable or uncorrectable register
+ *			indicating what error or errors have been seen
+ * u8 severity -	error severity 0:NONFATAL 1:FATAL 2:CORRECTED
+ */
+
+#define aer_correctable_errors					\
+	{PCI_ERR_COR_RCVR,	"Receiver Error"},		\
+	{PCI_ERR_COR_BAD_TLP,	"Bad TLP"},			\
+	{PCI_ERR_COR_BAD_DLLP,	"Bad DLLP"},			\
+	{PCI_ERR_COR_REP_ROLL,	"RELAY_NUM Rollover"},		\
+	{PCI_ERR_COR_REP_TIMER,	"Replay Timer Timeout"},	\
+	{PCI_ERR_COR_ADV_NFAT,	"Advisory Non-Fatal Error"},	\
+	{PCI_ERR_COR_INTERNAL,	"Corrected Internal Error"},	\
+	{PCI_ERR_COR_LOG_OVER,	"Header Log Overflow"}
+
+#define aer_uncorrectable_errors				\
+	{PCI_ERR_UNC_UND,	"Undefined"},			\
+	{PCI_ERR_UNC_DLP,	"Data Link Protocol Error"},	\
+	{PCI_ERR_UNC_SURPDN,	"Surprise Down Error"},		\
+	{PCI_ERR_UNC_POISON_TLP,"Poisoned TLP"},		\
+	{PCI_ERR_UNC_FCP,	"Flow Control Protocol Error"},	\
+	{PCI_ERR_UNC_COMP_TIME,	"Completion Timeout"},		\
+	{PCI_ERR_UNC_COMP_ABORT,"Completer Abort"},		\
+	{PCI_ERR_UNC_UNX_COMP,	"Unexpected Completion"},	\
+	{PCI_ERR_UNC_RX_OVER,	"Receiver Overflow"},		\
+	{PCI_ERR_UNC_MALF_TLP,	"Malformed TLP"},		\
+	{PCI_ERR_UNC_ECRC,	"ECRC Error"},			\
+	{PCI_ERR_UNC_UNSUP,	"Unsupported Request Error"},	\
+	{PCI_ERR_UNC_ACSV,	"ACS Violation"},		\
+	{PCI_ERR_UNC_INTN,	"Uncorrectable Internal Error"},\
+	{PCI_ERR_UNC_MCBTLP,	"MC Blocked TLP"},		\
+	{PCI_ERR_UNC_ATOMEG,	"AtomicOp Egress Blocked"},	\
+	{PCI_ERR_UNC_TLPPRE,	"TLP Prefix Blocked Error"}
+
+TRACE_EVENT(aer_event,
+	TP_PROTO(const char *dev_name,
+		 const u32 status,
+		 const u8 severity,
+		 const u8 tlp_header_valid,
+		 struct pcie_tlp_log *tlp,
+		 const char *bus_type),
+
+
+	TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp, bus_type),
+
+	TP_STRUCT__entry(
+		__string(	dev_name,	dev_name	)
+		__field(	u32,		status		)
+		__field(	u8,		severity	)
+		__field(	u8, 		tlp_header_valid)
+		__array(	u32, 		tlp_header, PCIE_STD_MAX_TLP_HEADERLOG)
+		__string(	bus_type,	bus_type	)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__assign_str(bus_type);
+		__entry->status		= status;
+		__entry->severity	= severity;
+		__entry->tlp_header_valid = tlp_header_valid;
+		if (tlp_header_valid) {
+			int i;
+
+			for (i = 0; i < PCIE_STD_MAX_TLP_HEADERLOG; i++)
+				__entry->tlp_header[i] = tlp->dw[i];
+		}
+	),
+
+	TP_printk("%s %s Bus Error: severity=%s, %s, TLP Header=%s\n",
+		__get_str(dev_name), __get_str(bus_type),
+		__entry->severity == AER_CORRECTABLE ? "Corrected" :
+			__entry->severity == AER_FATAL ?
+			"Fatal" : "Uncorrected, non-fatal",
+		__entry->severity == AER_CORRECTABLE ?
+		__print_flags(__entry->status, "|", aer_correctable_errors) :
+		__print_flags(__entry->status, "|", aer_uncorrectable_errors),
+		__entry->tlp_header_valid ?
+			__print_array(__entry->tlp_header, PCIE_STD_MAX_TLP_HEADERLOG, 4) :
+			"Not available")
+);
+#endif /* CONFIG_PCIEAER */
+#endif /* _TRACE_HW_EVENT_MC_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>