v4.19.13 snapshot.
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
new file mode 100644
index 0000000..e9de8ad
--- /dev/null
+++ b/include/linux/tracepoint.h
@@ -0,0 +1,551 @@
+#ifndef _LINUX_TRACEPOINT_H
+#define _LINUX_TRACEPOINT_H
+
+/*
+ * Kernel Tracepoint API.
+ *
+ * See Documentation/trace/tracepoints.rst.
+ *
+ * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Heavily inspired from the Linux Kernel Markers.
+ *
+ * This file is released under the GPLv2.
+ * See the file COPYING for more details.
+ */
+
+#include <linux/smp.h>
+#include <linux/srcu.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/cpumask.h>
+#include <linux/rcupdate.h>
+#include <linux/tracepoint-defs.h>
+
+struct module;
+struct tracepoint;
+struct notifier_block;
+
+struct trace_eval_map {
+ const char *system;
+ const char *eval_string;
+ unsigned long eval_value;
+};
+
+#define TRACEPOINT_DEFAULT_PRIO 10
+
+extern struct srcu_struct tracepoint_srcu;
+
+extern int
+tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
+extern int
+tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data,
+ int prio);
+extern int
+tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
+extern void
+for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
+ void *priv);
+
+#ifdef CONFIG_MODULES
+struct tp_module {
+ struct list_head list;
+ struct module *mod;
+};
+
+bool trace_module_has_bad_taint(struct module *mod);
+extern int register_tracepoint_module_notifier(struct notifier_block *nb);
+extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
+#else
+static inline bool trace_module_has_bad_taint(struct module *mod)
+{
+ return false;
+}
+static inline
+int register_tracepoint_module_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline
+int unregister_tracepoint_module_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+#endif /* CONFIG_MODULES */
+
+/*
+ * tracepoint_synchronize_unregister must be called between the last tracepoint
+ * probe unregistration and the end of module exit to make sure there is no
+ * caller executing a probe when it is freed.
+ */
+#ifdef CONFIG_TRACEPOINTS
+static inline void tracepoint_synchronize_unregister(void)
+{
+ synchronize_srcu(&tracepoint_srcu);
+ synchronize_sched();
+}
+#else
+static inline void tracepoint_synchronize_unregister(void)
+{ }
+#endif
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+extern int syscall_regfunc(void);
+extern void syscall_unregfunc(void);
+#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
+
+#define PARAMS(args...) args
+
+#define TRACE_DEFINE_ENUM(x)
+#define TRACE_DEFINE_SIZEOF(x)
+
+#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
+static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
+{
+ return offset_to_ptr(p);
+}
+
+#define __TRACEPOINT_ENTRY(name) \
+ asm(" .section \"__tracepoints_ptrs\", \"a\" \n" \
+ " .balign 4 \n" \
+ " .long __tracepoint_" #name " - . \n" \
+ " .previous \n")
+#else
+static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
+{
+ return *p;
+}
+
+#define __TRACEPOINT_ENTRY(name) \
+ static tracepoint_ptr_t __tracepoint_ptr_##name __used \
+ __attribute__((section("__tracepoints_ptrs"))) = \
+ &__tracepoint_##name
+#endif
+
+#endif /* _LINUX_TRACEPOINT_H */
+
+/*
+ * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
+ * file ifdef protection.
+ * This is due to the way trace events work. If a file includes two
+ * trace event headers under one "CREATE_TRACE_POINTS" the first include
+ * will override the TRACE_EVENT and break the second include.
+ */
+
+#ifndef DECLARE_TRACE
+
+#define TP_PROTO(args...) args
+#define TP_ARGS(args...) args
+#define TP_CONDITION(args...) args
+
+/*
+ * Individual subsystem my have a separate configuration to
+ * enable their tracepoints. By default, this file will create
+ * the tracepoints if CONFIG_TRACEPOINT is defined. If a subsystem
+ * wants to be able to disable its tracepoints from being created
+ * it can define NOTRACE before including the tracepoint headers.
+ */
+#if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
+#define TRACEPOINTS_ENABLED
+#endif
+
+#ifdef TRACEPOINTS_ENABLED
+
+/*
+ * it_func[0] is never NULL because there is at least one element in the array
+ * when the array itself is non NULL.
+ *
+ * Note, the proto and args passed in includes "__data" as the first parameter.
+ * The reason for this is to handle the "void" prototype. If a tracepoint
+ * has a "void" prototype, then it is invalid to declare a function
+ * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just
+ * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto".
+ */
+#define __DO_TRACE(tp, proto, args, cond, rcuidle) \
+ do { \
+ struct tracepoint_func *it_func_ptr; \
+ void *it_func; \
+ void *__data; \
+ int __maybe_unused __idx = 0; \
+ \
+ if (!(cond)) \
+ return; \
+ \
+ /* srcu can't be used from NMI */ \
+ WARN_ON_ONCE(rcuidle && in_nmi()); \
+ \
+ /* keep srcu and sched-rcu usage consistent */ \
+ preempt_disable_notrace(); \
+ \
+ /* \
+ * For rcuidle callers, use srcu since sched-rcu \
+ * doesn't work from the idle path. \
+ */ \
+ if (rcuidle) { \
+ __idx = srcu_read_lock_notrace(&tracepoint_srcu);\
+ rcu_irq_enter_irqson(); \
+ } \
+ \
+ it_func_ptr = rcu_dereference_raw((tp)->funcs); \
+ \
+ if (it_func_ptr) { \
+ do { \
+ it_func = (it_func_ptr)->func; \
+ __data = (it_func_ptr)->data; \
+ ((void(*)(proto))(it_func))(args); \
+ } while ((++it_func_ptr)->func); \
+ } \
+ \
+ if (rcuidle) { \
+ rcu_irq_exit_irqson(); \
+ srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
+ } \
+ \
+ preempt_enable_notrace(); \
+ } while (0)
+
+#ifndef MODULE
+#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \
+ static inline void trace_##name##_rcuidle(proto) \
+ { \
+ if (static_key_false(&__tracepoint_##name.key)) \
+ __DO_TRACE(&__tracepoint_##name, \
+ TP_PROTO(data_proto), \
+ TP_ARGS(data_args), \
+ TP_CONDITION(cond), 1); \
+ }
+#else
+#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
+#endif
+
+/*
+ * Make sure the alignment of the structure in the __tracepoints section will
+ * not add unwanted padding between the beginning of the section and the
+ * structure. Force alignment to the same alignment as the section start.
+ *
+ * When lockdep is enabled, we make sure to always do the RCU portions of
+ * the tracepoint code, regardless of whether tracing is on. However,
+ * don't check if the condition is false, due to interaction with idle
+ * instrumentation. This lets us find RCU issues triggered with tracepoints
+ * even when this tracepoint is off. This code has no purpose other than
+ * poking RCU a bit.
+ */
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
+ extern struct tracepoint __tracepoint_##name; \
+ static inline void trace_##name(proto) \
+ { \
+ if (static_key_false(&__tracepoint_##name.key)) \
+ __DO_TRACE(&__tracepoint_##name, \
+ TP_PROTO(data_proto), \
+ TP_ARGS(data_args), \
+ TP_CONDITION(cond), 0); \
+ if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
+ rcu_read_lock_sched_notrace(); \
+ rcu_dereference_sched(__tracepoint_##name.funcs);\
+ rcu_read_unlock_sched_notrace(); \
+ } \
+ } \
+ __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
+ PARAMS(cond), PARAMS(data_proto), PARAMS(data_args)) \
+ static inline int \
+ register_trace_##name(void (*probe)(data_proto), void *data) \
+ { \
+ return tracepoint_probe_register(&__tracepoint_##name, \
+ (void *)probe, data); \
+ } \
+ static inline int \
+ register_trace_prio_##name(void (*probe)(data_proto), void *data,\
+ int prio) \
+ { \
+ return tracepoint_probe_register_prio(&__tracepoint_##name, \
+ (void *)probe, data, prio); \
+ } \
+ static inline int \
+ unregister_trace_##name(void (*probe)(data_proto), void *data) \
+ { \
+ return tracepoint_probe_unregister(&__tracepoint_##name,\
+ (void *)probe, data); \
+ } \
+ static inline void \
+ check_trace_callback_type_##name(void (*cb)(data_proto)) \
+ { \
+ } \
+ static inline bool \
+ trace_##name##_enabled(void) \
+ { \
+ return static_key_false(&__tracepoint_##name.key); \
+ }
+
+/*
+ * We have no guarantee that gcc and the linker won't up-align the tracepoint
+ * structures, so we create an array of pointers that will be used for iteration
+ * on the tracepoints.
+ */
+#define DEFINE_TRACE_FN(name, reg, unreg) \
+ static const char __tpstrtab_##name[] \
+ __attribute__((section("__tracepoints_strings"))) = #name; \
+ struct tracepoint __tracepoint_##name \
+ __attribute__((section("__tracepoints"), used)) = \
+ { __tpstrtab_##name, STATIC_KEY_INIT_FALSE, reg, unreg, NULL };\
+ __TRACEPOINT_ENTRY(name);
+
+#define DEFINE_TRACE(name) \
+ DEFINE_TRACE_FN(name, NULL, NULL);
+
+#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
+ EXPORT_SYMBOL_GPL(__tracepoint_##name)
+#define EXPORT_TRACEPOINT_SYMBOL(name) \
+ EXPORT_SYMBOL(__tracepoint_##name)
+
+#else /* !TRACEPOINTS_ENABLED */
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
+ static inline void trace_##name(proto) \
+ { } \
+ static inline void trace_##name##_rcuidle(proto) \
+ { } \
+ static inline int \
+ register_trace_##name(void (*probe)(data_proto), \
+ void *data) \
+ { \
+ return -ENOSYS; \
+ } \
+ static inline int \
+ unregister_trace_##name(void (*probe)(data_proto), \
+ void *data) \
+ { \
+ return -ENOSYS; \
+ } \
+ static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
+ { \
+ } \
+ static inline bool \
+ trace_##name##_enabled(void) \
+ { \
+ return false; \
+ }
+
+#define DEFINE_TRACE_FN(name, reg, unreg)
+#define DEFINE_TRACE(name)
+#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
+#define EXPORT_TRACEPOINT_SYMBOL(name)
+
+#endif /* TRACEPOINTS_ENABLED */
+
+#ifdef CONFIG_TRACING
+/**
+ * tracepoint_string - register constant persistent string to trace system
+ * @str - a constant persistent string that will be referenced in tracepoints
+ *
+ * If constant strings are being used in tracepoints, it is faster and
+ * more efficient to just save the pointer to the string and reference
+ * that with a printf "%s" instead of saving the string in the ring buffer
+ * and wasting space and time.
+ *
+ * The problem with the above approach is that userspace tools that read
+ * the binary output of the trace buffers do not have access to the string.
+ * Instead they just show the address of the string which is not very
+ * useful to users.
+ *
+ * With tracepoint_string(), the string will be registered to the tracing
+ * system and exported to userspace via the debugfs/tracing/printk_formats
+ * file that maps the string address to the string text. This way userspace
+ * tools that read the binary buffers have a way to map the pointers to
+ * the ASCII strings they represent.
+ *
+ * The @str used must be a constant string and persistent as it would not
+ * make sense to show a string that no longer exists. But it is still fine
+ * to be used with modules, because when modules are unloaded, if they
+ * had tracepoints, the ring buffers are cleared too. As long as the string
+ * does not change during the life of the module, it is fine to use
+ * tracepoint_string() within a module.
+ */
+#define tracepoint_string(str) \
+ ({ \
+ static const char *___tp_str __tracepoint_string = str; \
+ ___tp_str; \
+ })
+#define __tracepoint_string __attribute__((section("__tracepoint_str")))
+#else
+/*
+ * tracepoint_string() is used to save the string address for userspace
+ * tracing tools. When tracing isn't configured, there's no need to save
+ * anything.
+ */
+# define tracepoint_string(str) str
+# define __tracepoint_string
+#endif
+
+/*
+ * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
+ * (void). "void" is a special value in a function prototype and can
+ * not be combined with other arguments. Since the DECLARE_TRACE()
+ * macro adds a data element at the beginning of the prototype,
+ * we need a way to differentiate "(void *data, proto)" from
+ * "(void *data, void)". The second prototype is invalid.
+ *
+ * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
+ * and "void *__data" as the callback prototype.
+ *
+ * DECLARE_TRACE() passes "proto" as the tracepoint protoype and
+ * "void *__data, proto" as the callback prototype.
+ */
+#define DECLARE_TRACE_NOARGS(name) \
+ __DECLARE_TRACE(name, void, , \
+ cpu_online(raw_smp_processor_id()), \
+ void *__data, __data)
+
+#define DECLARE_TRACE(name, proto, args) \
+ __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
+ cpu_online(raw_smp_processor_id()), \
+ PARAMS(void *__data, proto), \
+ PARAMS(__data, args))
+
+#define DECLARE_TRACE_CONDITION(name, proto, args, cond) \
+ __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
+ cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
+ PARAMS(void *__data, proto), \
+ PARAMS(__data, args))
+
+#define TRACE_EVENT_FLAGS(event, flag)
+
+#define TRACE_EVENT_PERF_PERM(event, expr...)
+
+#endif /* DECLARE_TRACE */
+
+#ifndef TRACE_EVENT
+/*
+ * For use with the TRACE_EVENT macro:
+ *
+ * We define a tracepoint, its arguments, its printk format
+ * and its 'fast binary record' layout.
+ *
+ * Firstly, name your tracepoint via TRACE_EVENT(name : the
+ * 'subsystem_event' notation is fine.
+ *
+ * Think about this whole construct as the
+ * 'trace_sched_switch() function' from now on.
+ *
+ *
+ * TRACE_EVENT(sched_switch,
+ *
+ * *
+ * * A function has a regular function arguments
+ * * prototype, declare it via TP_PROTO():
+ * *
+ *
+ * TP_PROTO(struct rq *rq, struct task_struct *prev,
+ * struct task_struct *next),
+ *
+ * *
+ * * Define the call signature of the 'function'.
+ * * (Design sidenote: we use this instead of a
+ * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
+ * *
+ *
+ * TP_ARGS(rq, prev, next),
+ *
+ * *
+ * * Fast binary tracing: define the trace record via
+ * * TP_STRUCT__entry(). You can think about it like a
+ * * regular C structure local variable definition.
+ * *
+ * * This is how the trace record is structured and will
+ * * be saved into the ring buffer. These are the fields
+ * * that will be exposed to user-space in
+ * * /sys/kernel/debug/tracing/events/<*>/format.
+ * *
+ * * The declared 'local variable' is called '__entry'
+ * *
+ * * __field(pid_t, prev_prid) is equivalent to a standard declariton:
+ * *
+ * * pid_t prev_pid;
+ * *
+ * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
+ * *
+ * * char prev_comm[TASK_COMM_LEN];
+ * *
+ *
+ * TP_STRUCT__entry(
+ * __array( char, prev_comm, TASK_COMM_LEN )
+ * __field( pid_t, prev_pid )
+ * __field( int, prev_prio )
+ * __array( char, next_comm, TASK_COMM_LEN )
+ * __field( pid_t, next_pid )
+ * __field( int, next_prio )
+ * ),
+ *
+ * *
+ * * Assign the entry into the trace record, by embedding
+ * * a full C statement block into TP_fast_assign(). You
+ * * can refer to the trace record as '__entry' -
+ * * otherwise you can put arbitrary C code in here.
+ * *
+ * * Note: this C code will execute every time a trace event
+ * * happens, on an active tracepoint.
+ * *
+ *
+ * TP_fast_assign(
+ * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
+ * __entry->prev_pid = prev->pid;
+ * __entry->prev_prio = prev->prio;
+ * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
+ * __entry->next_pid = next->pid;
+ * __entry->next_prio = next->prio;
+ * ),
+ *
+ * *
+ * * Formatted output of a trace record via TP_printk().
+ * * This is how the tracepoint will appear under ftrace
+ * * plugins that make use of this tracepoint.
+ * *
+ * * (raw-binary tracing wont actually perform this step.)
+ * *
+ *
+ * TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
+ * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
+ * __entry->next_comm, __entry->next_pid, __entry->next_prio),
+ *
+ * );
+ *
+ * This macro construct is thus used for the regular printk format
+ * tracing setup, it is used to construct a function pointer based
+ * tracepoint callback (this is used by programmatic plugins and
+ * can also by used by generic instrumentation like SystemTap), and
+ * it is also used to expose a structured trace record in
+ * /sys/kernel/debug/tracing/events/.
+ *
+ * A set of (un)registration functions can be passed to the variant
+ * TRACE_EVENT_FN to perform any (un)registration work.
+ */
+
+#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
+#define DEFINE_EVENT(template, name, proto, args) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_CONDITION(template, name, proto, \
+ args, cond) \
+ DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
+ PARAMS(args), PARAMS(cond))
+
+#define TRACE_EVENT(name, proto, args, struct, assign, print) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN(name, proto, args, struct, \
+ assign, print, reg, unreg) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN_COND(name, proto, args, cond, struct, \
+ assign, print, reg, unreg) \
+ DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
+ PARAMS(args), PARAMS(cond))
+#define TRACE_EVENT_CONDITION(name, proto, args, cond, \
+ struct, assign, print) \
+ DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
+ PARAMS(args), PARAMS(cond))
+
+#define TRACE_EVENT_FLAGS(event, flag)
+
+#define TRACE_EVENT_PERF_PERM(event, expr...)
+
+#endif /* ifdef TRACE_EVENT (see note above) */