#include <side/macros.h>
#include <side/endian.h>
-/* SIDE stands for "Static Instrumentation Dynamically Enabled" */
+/*
+ * SIDE stands for "Static Instrumentation Dynamically Enabled"
+ *
+ * This is an instrumentation API for Linux user-space, which exposes an
+ * instrumentation type system and facilities allowing a kernel or
+ * user-space tracer to consume user-space instrumentation.
+ *
+ * This instrumentation API exposes 3 type systems:
+ *
+ * * Stack-copy type system: This is the core type system which can
+ * represent all supported types and into which all other type systems
+ * can be nested. This type system requires that every type is
+ * statically or dynamically declared and then registered, thus giving
+ * tracers a complete description of the events and their associated
+ * fields before the associated instrumentation is invoked. The
+ * application needs to copy each argument (side_arg_...()) onto the
+ * stack when calling the instrumentation.
+ *
+ * This is the most expressive of the 3 type systems, althrough not the
+ * fastest due to the extra copy of the arguments.
+ *
+ * * Data-gathering type system: This type system requires every type to
+ * be statically or dynamically declared and registered, but does not
+ * require the application to copy its arguments onto the stack.
+ * Instead, the type description contains all the required information
+ * to fetch the data from the application memory. The only argument
+ * required from the instrumentation is the base pointer from which
+ * the data should be fetched.
+ *
+ * This type system can be used as an event field, or nested within
+ * the stack-copy type system. Nesting of gather-vla within
+ * gather-array and gather-vla types is not allowed.
+ *
+ * This type system is has the least overhead of the 3 type systems.
+ *
+ * * Dynamic type system: This type system receives both type
+ * description and actual data onto the stack at runtime. It has more
+ * overhead that the 2 other type systems, but does not require a
+ * prior registration of event field description. This makes it useful
+ * for seldom used types which are not performance critical, but for
+ * which registering each individual events would needlessly grow the
+ * number of events to declare and register.
+ *
+ * Another use-case for this type system is for use by dynamically
+ * typed language runtimes, where the field type is only known when
+ * the instrumentation is called.
+ *
+ * Those dynamic types can be either used as arguments to a variadic
+ * field list, or as on-stack instrumentation argument for a static
+ * type SIDE_TYPE_DYNAMIC place holder in the stack-copy type system.
+ */
//TODO: as those structures will be ABI, we need to either consider them
//fixed forever, or think of a scheme that would allow their binary
struct side_events_register_handle;
enum side_type_label {
- /* Statically declared types */
+ /* Stack-copy basic types */
SIDE_TYPE_NULL,
SIDE_TYPE_BOOL,
SIDE_TYPE_U8,
SIDE_TYPE_FLOAT_BINARY128,
SIDE_TYPE_STRING,
- /* Statically declared compound types */
+ /* Stack-copy compound types */
SIDE_TYPE_STRUCT,
SIDE_TYPE_ARRAY,
SIDE_TYPE_VLA,
SIDE_TYPE_VLA_POINTER32,
SIDE_TYPE_VLA_POINTER64,
- /* Statically declared enumeration types */
+ /* Stack-copy enumeration types */
SIDE_TYPE_ENUM,
SIDE_TYPE_ENUM_BITMAP,
+ /* Stack-copy place holder for dynamic types */
SIDE_TYPE_DYNAMIC,
- /* Gather types */
+ /* Gather basic types */
+ SIDE_TYPE_GATHER_BOOL,
SIDE_TYPE_GATHER_UNSIGNED_INT,
SIDE_TYPE_GATHER_SIGNED_INT,
+ SIDE_TYPE_GATHER_BYTE,
SIDE_TYPE_GATHER_FLOAT,
+
+ /* Gather compound types */
SIDE_TYPE_GATHER_STRUCT,
SIDE_TYPE_GATHER_ARRAY,
SIDE_TYPE_GATHER_VLA,
- /* Dynamic types */
+ /* Dynamic basic types */
SIDE_TYPE_DYNAMIC_NULL,
SIDE_TYPE_DYNAMIC_BOOL,
SIDE_TYPE_DYNAMIC_U8,
# define SIDE_TYPE_FLOAT_WORD_ORDER_HOST SIDE_TYPE_BYTE_ORDER_BE
#endif
+enum side_type_gather_access_mode {
+ SIDE_TYPE_GATHER_ACCESS_DIRECT,
+ SIDE_TYPE_GATHER_ACCESS_POINTER, /* Pointer dereference */
+};
+
typedef enum side_visitor_status (*side_visitor_func)(
const struct side_tracer_visitor_ctx *tracer_ctx,
void *app_ctx);
struct side_type_bool {
const struct side_attr *attr;
uint32_t nr_attr;
+ uint16_t bool_size_bits; /* bits */
+ uint16_t len_bits; /* bits */
+ uint8_t byte_order; /* enum side_type_label_byte_order */
} SIDE_PACKED;
struct side_type_byte {
const struct side_type *elem_type;
} SIDE_PACKED;
+struct side_type_gather_bool {
+ uint64_t offset; /* bytes */
+ uint8_t access_mode; /* enum side_type_gather_access_mode */
+ struct side_type_bool type;
+ uint16_t offset_bits; /* bits */
+} SIDE_PACKED;
+
+struct side_type_gather_byte {
+ uint64_t offset; /* bytes */
+ uint8_t access_mode; /* enum side_type_gather_access_mode */
+ struct side_type_byte type;
+} SIDE_PACKED;
+
struct side_type_gather_integer {
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_vla type;
} SIDE_PACKED;
-enum side_type_gather_access_mode {
- SIDE_TYPE_GATHER_ACCESS_ADDRESS,
- SIDE_TYPE_GATHER_ACCESS_POINTER,
-};
-
struct side_type_gather {
union {
+ struct side_type_gather_bool side_bool;
+ struct side_type_gather_byte side_byte;
struct side_type_gather_integer side_integer;
struct side_type_gather_float side_float;
struct side_type_gather_array side_array;
} SIDE_PACKED u;
} SIDE_PACKED;
-/* Statically defined types. */
struct side_type {
uint32_t type; /* enum side_type_label */
union {
- /* Basic types */
+ /* Stack-copy basic types */
struct side_type_null side_null;
struct side_type_bool side_bool;
struct side_type_byte side_byte;
struct side_type_integer side_integer;
struct side_type_float side_float;
- /* Compound types */
+ /* Stack-copy compound types */
struct side_type_array side_array;
struct side_type_vla side_vla;
struct side_type_vla_visitor side_vla_visitor;
const struct side_type_struct *side_struct;
- /* Enumeration types */
+ /* Stack-copy enumeration types */
struct side_type_enum side_enum;
struct side_type_enum_bitmap side_enum_bitmap;
} SIDE_PACKED;
struct side_arg_static {
- /* Basic types */
+ /* Stack-copy basic types */
uint8_t bool_value;
uint8_t byte_value;
uint64_t string_value; /* const char * */
union side_integer_value integer_value;
union side_float_value float_value;
- /* Compound types */
+ /* Stack-copy compound types */
const struct side_arg_vec *side_struct;
const struct side_arg_vec *side_array;
const struct side_arg_vec *side_vla;
uint32_t length;
} SIDE_PACKED side_vla_fixint;
- /* Gather types */
+ /* Gather basic types */
+ void *side_bool_gather_ptr;
+ void *side_byte_gather_ptr;
void *side_integer_gather_ptr;
void *side_float_gather_ptr;
+
+ /* Gather compound types */
void *side_array_gather_ptr;
void *side_struct_gather_ptr;
struct {
} SIDE_PACKED;
struct side_arg_dynamic {
- /* Basic types */
+ /* Dynamic basic types */
struct side_type_null side_null;
struct {
struct side_type_bool type;
uint8_t value;
} SIDE_PACKED side_bool;
-
struct {
struct side_type_byte type;
uint8_t value;
} SIDE_PACKED side_byte;
-
struct {
struct side_type_string type;
uint64_t value; /* const char * */
} SIDE_PACKED side_string;
-
- /* Integer type */
struct {
struct side_type_integer type;
union side_integer_value value;
} SIDE_PACKED side_integer;
-
struct {
struct side_type_float type;
union side_float_value value;
} SIDE_PACKED side_float;
- /* Compound types */
+ /* Dynamic compound types */
const struct side_arg_dynamic_struct *side_dynamic_struct;
const struct side_arg_dynamic_vla *side_dynamic_vla;
#define side_attr_float_binary128(_val) { .type = SIDE_ATTR_TYPE_FLOAT_BINARY128, .u = { .float_value = { .side_float_binary128 = (_val) } } }
#define side_attr_string(_val) { .type = SIDE_ATTR_TYPE_STRING, .u = { .string_value = (uintptr_t) (_val) } }
-/* Static field definition */
+/* Stack-copy enumeration type definitions */
+
+#define side_define_enum(_identifier, _mappings, _attr) \
+ const struct side_enum_mappings _identifier = { \
+ .mappings = _mappings, \
+ .attr = _attr, \
+ .nr_mappings = SIDE_ARRAY_SIZE(SIDE_PARAM(_mappings)), \
+ .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ }
+
+#define side_enum_mapping_list(...) \
+ SIDE_COMPOUND_LITERAL(const struct side_enum_mapping, __VA_ARGS__)
+
+#define side_enum_mapping_range(_label, _begin, _end) \
+ { \
+ .range_begin = _begin, \
+ .range_end = _end, \
+ .label = _label, \
+ }
+
+#define side_enum_mapping_value(_label, _value) \
+ { \
+ .range_begin = _value, \
+ .range_end = _value, \
+ .label = _label, \
+ }
+
+#define side_define_enum_bitmap(_identifier, _mappings, _attr) \
+ const struct side_enum_bitmap_mappings _identifier = { \
+ .mappings = _mappings, \
+ .attr = _attr, \
+ .nr_mappings = SIDE_ARRAY_SIZE(SIDE_PARAM(_mappings)), \
+ .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ }
+
+#define side_enum_bitmap_mapping_list(...) \
+ SIDE_COMPOUND_LITERAL(const struct side_enum_bitmap_mapping, __VA_ARGS__)
+
+#define side_enum_bitmap_mapping_range(_label, _begin, _end) \
+ { \
+ .range_begin = _begin, \
+ .range_end = _end, \
+ .label = _label, \
+ }
+
+#define side_enum_bitmap_mapping_value(_label, _value) \
+ { \
+ .range_begin = _value, \
+ .range_end = _value, \
+ .label = _label, \
+ }
+
+/* Stack-copy field and type definitions */
#define side_type_null(_attr) \
{ \
.side_bool = { \
.attr = _attr, \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ .bool_size_bits = 8, \
+ .len_bits = 1, \
+ .byte_order = SIDE_TYPE_BYTE_ORDER_HOST, \
}, \
}, \
}
#define side_field_vla_visitor(_name, _elem_type, _visitor, _attr) \
_side_field(_name, side_type_vla_visitor(SIDE_PARAM(_elem_type), _visitor, SIDE_PARAM(_attr)))
-/* Gather fields */
+/* Gather field and type definitions */
+
+#define side_type_gather_byte(_offset, _access_mode, _attr) \
+ { \
+ .type = SIDE_TYPE_GATHER_BYTE, \
+ .u = { \
+ .side_gather = { \
+ .u = { \
+ .side_byte = { \
+ .offset = _offset, \
+ .access_mode = _access_mode, \
+ .type = { \
+ .attr = _attr, \
+ .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ }, \
+ }, \
+ }, \
+ }, \
+ }, \
+ }
+#define side_field_gather_byte(_name, _offset, _access_mode, _attr) \
+ _side_field(_name, side_type_gather_byte(_offset, _access_mode, SIDE_PARAM(_attr)))
+
+#define _side_type_gather_bool(_byte_order, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ { \
+ .type = SIDE_TYPE_GATHER_BOOL, \
+ .u = { \
+ .side_gather = { \
+ .u = { \
+ .side_bool = { \
+ .offset = _offset, \
+ .access_mode = _access_mode, \
+ .type = { \
+ .attr = _attr, \
+ .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ .bool_size_bits = _bool_size_bits, \
+ .len_bits = _len_bits, \
+ .byte_order = _byte_order, \
+ }, \
+ .offset_bits = _offset_bits, \
+ }, \
+ }, \
+ }, \
+ }, \
+ }
+#define side_type_gather_bool(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_type_gather_bool(SIDE_TYPE_BYTE_ORDER_HOST, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr)
+#define side_type_gather_bool_le(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_type_gather_bool(SIDE_TYPE_BYTE_ORDER_LE, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr)
+#define side_type_gather_bool_be(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_type_gather_bool(SIDE_TYPE_BYTE_ORDER_BE, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr)
+
+#define side_field_gather_bool(_name, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_field(_name, side_type_gather_bool(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, SIDE_PARAM(_attr)))
+#define side_field_gather_bool_le(_name, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_field(_name, side_type_gather_bool_le(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, SIDE_PARAM(_attr)))
+#define side_field_gather_bool_be(_name, _offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
+ _side_field(_name, side_type_gather_bool_be(_offset, _bool_size_bits, _offset_bits, _len_bits, _access_mode, SIDE_PARAM(_attr)))
#define _side_type_gather_integer(_type, _signedness, _byte_order, _offset, \
_integer_size_bits, _offset_bits, _len_bits, _access_mode, _attr) \
#define side_field_list(...) \
SIDE_COMPOUND_LITERAL(const struct side_event_field, __VA_ARGS__)
-/* Static field arguments */
+/* Stack-copy field arguments */
#define side_arg_null(_val) { .type = SIDE_TYPE_NULL }
#define side_arg_bool(_val) { .type = SIDE_TYPE_BOOL, .u = { .side_static = { .bool_value = !!(_val) } } }
#define side_arg_vla_pointer(_ptr, _length) { .type = SIDE_TYPE_VLA_POINTER_HOST, .u = { .side_static = { .side_vla_fixint = { .p = (_ptr), .length = (_length) } } } }
/* Gather field arguments */
+
+#define side_arg_gather_bool(_ptr) { .type = SIDE_TYPE_GATHER_BOOL, .u = { .side_static = { .side_bool_gather_ptr = (_ptr) } } }
+#define side_arg_gather_byte(_ptr) { .type = SIDE_TYPE_GATHER_BYTE, .u = { .side_static = { .side_byte_gather_ptr = (_ptr) } } }
#define side_arg_gather_unsigned_integer(_ptr) { .type = SIDE_TYPE_GATHER_UNSIGNED_INT, .u = { .side_static = { .side_integer_gather_ptr = (_ptr) } } }
#define side_arg_gather_signed_integer(_ptr) { .type = SIDE_TYPE_GATHER_SIGNED_INT, .u = { .side_static = { .side_integer_gather_ptr = (_ptr) } } }
#define side_arg_gather_float(_ptr) { .type = SIDE_TYPE_GATHER_FLOAT, .u = { .side_static = { .side_float_gather_ptr = (_ptr) } } }
.type = { \
.attr = _attr, \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
+ .bool_size_bits = sizeof(uint8_t) * CHAR_BIT, \
+ .len_bits = 1, \
+ .byte_order = SIDE_TYPE_BYTE_ORDER_HOST, \
}, \
.value = !!(_val), \
}, \
.elem = _elem, \
}
-#define side_arg_list(...) __VA_ARGS__
-
-#define side_define_enum(_identifier, _mappings, _attr) \
- const struct side_enum_mappings _identifier = { \
- .mappings = _mappings, \
- .attr = _attr, \
- .nr_mappings = SIDE_ARRAY_SIZE(SIDE_PARAM(_mappings)), \
- .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
- }
-
-#define side_enum_mapping_list(...) \
- SIDE_COMPOUND_LITERAL(const struct side_enum_mapping, __VA_ARGS__)
-
-#define side_enum_mapping_range(_label, _begin, _end) \
- { \
- .range_begin = _begin, \
- .range_end = _end, \
- .label = _label, \
- }
-
-#define side_enum_mapping_value(_label, _value) \
- { \
- .range_begin = _value, \
- .range_end = _value, \
- .label = _label, \
- }
-
-#define side_define_enum_bitmap(_identifier, _mappings, _attr) \
- const struct side_enum_bitmap_mappings _identifier = { \
- .mappings = _mappings, \
- .attr = _attr, \
- .nr_mappings = SIDE_ARRAY_SIZE(SIDE_PARAM(_mappings)), \
- .nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM(_attr)), \
- }
-
-#define side_enum_bitmap_mapping_list(...) \
- SIDE_COMPOUND_LITERAL(const struct side_enum_bitmap_mapping, __VA_ARGS__)
-
-#define side_enum_bitmap_mapping_range(_label, _begin, _end) \
- { \
- .range_begin = _begin, \
- .range_end = _end, \
- .label = _label, \
- }
+/*
+ * Event instrumentation description registration, runtime enabled state
+ * check, and instrumentation invocation.
+ */
-#define side_enum_bitmap_mapping_value(_label, _value) \
- { \
- .range_begin = _value, \
- .range_end = _value, \
- .label = _label, \
- }
+#define side_arg_list(...) __VA_ARGS__
#define side_event_cond(_identifier) \
if (side_unlikely(__atomic_load_n(&side_event_enable__##_identifier, \
const struct side_arg_vec *side_arg_vec,
const struct side_arg_dynamic_struct *var_struct);
+struct side_events_register_handle *side_events_register(struct side_event_description **events,
+ uint32_t nr_events);
+void side_events_unregister(struct side_events_register_handle *handle);
+
+/*
+ * Userspace tracer registration API. This allows userspace tracers to
+ * register event notification callbacks to be notified of the currently
+ * registered instrumentation, and to register their callbacks to
+ * specific events.
+ */
typedef void (*side_tracer_callback_func)(const struct side_event_description *desc,
const struct side_arg_vec *side_arg_vec,
void *priv);
side_tracer_callback_variadic_func call_variadic,
void *priv);
-struct side_events_register_handle *side_events_register(struct side_event_description **events,
- uint32_t nr_events);
-void side_events_unregister(struct side_events_register_handle *handle);
-
enum side_tracer_notification {
SIDE_TRACER_NOTIFICATION_INSERT_EVENTS,
SIDE_TRACER_NOTIFICATION_REMOVE_EVENTS,
void *priv);
void side_tracer_event_notification_unregister(struct side_tracer_handle *handle);
+/*
+ * Explicit hooks to initialize/finalize the side instrumentation
+ * library. Those are also library constructor/destructor.
+ */
void side_init(void);
void side_exit(void);
+/*
+ * The following constructors/destructors perform automatic registration
+ * of the declared side events. Those may have to be called explicitly
+ * in a statically linked library.
+ */
+
/*
* These weak symbols, the constructor, and destructor take care of
* registering only _one_ instance of the side instrumentation per
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