| 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 2 | * |
| 3 | * lttng-event-notifier-notification.c |
| 4 | * |
| 5 | * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com> |
| 6 | */ |
| 7 | |
| 8 | #include <linux/bug.h> |
| 9 | |
| 10 | #include <lttng/lttng-bytecode.h> |
| 11 | #include <lttng/events.h> |
| 12 | #include <lttng/msgpack.h> |
| 13 | #include <lttng/event-notifier-notification.h> |
| 14 | |
| 15 | static |
| 16 | int capture_enum(struct lttng_msgpack_writer *writer, |
| 17 | struct lttng_interpreter_output *output) __attribute__ ((unused)); |
| 18 | static |
| 19 | int capture_enum(struct lttng_msgpack_writer *writer, |
| 20 | struct lttng_interpreter_output *output) |
| 21 | { |
| 22 | int ret; |
| 23 | |
| 24 | /* |
| 25 | * Enums are captured as a map containing 2 key-value pairs. Such as: |
| 26 | * - type: enum |
| 27 | * value: 177 |
| 28 | */ |
| 29 | ret = lttng_msgpack_begin_map(writer, 2); |
| 30 | if (ret) { |
| 31 | WARN_ON_ONCE(1); |
| 32 | goto end; |
| 33 | } |
| 34 | |
| 35 | ret = lttng_msgpack_write_str(writer, "type"); |
| 36 | if (ret) { |
| 37 | WARN_ON_ONCE(1); |
| 38 | goto end; |
| 39 | } |
| 40 | |
| 41 | ret = lttng_msgpack_write_str(writer, "enum"); |
| 42 | if (ret) { |
| 43 | WARN_ON_ONCE(1); |
| 44 | goto end; |
| 45 | } |
| 46 | |
| 47 | ret = lttng_msgpack_write_str(writer, "value"); |
| 48 | if (ret) { |
| 49 | WARN_ON_ONCE(1); |
| 50 | goto end; |
| 51 | } |
| 52 | |
| 53 | switch (output->type) { |
| 54 | case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: |
| 55 | ret = lttng_msgpack_write_signed_integer(writer, output->u.s); |
| 56 | if (ret) { |
| 57 | WARN_ON_ONCE(1); |
| 58 | goto end; |
| 59 | } |
| 60 | break; |
| 61 | case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: |
| 62 | ret = lttng_msgpack_write_signed_integer(writer, output->u.u); |
| 63 | if (ret) { |
| 64 | WARN_ON_ONCE(1); |
| 65 | goto end; |
| 66 | } |
| 67 | break; |
| 68 | default: |
| 69 | WARN_ON(1); |
| 70 | } |
| 71 | |
| 72 | ret = lttng_msgpack_end_map(writer); |
| 73 | if (ret) |
| 74 | WARN_ON_ONCE(1); |
| 75 | |
| 76 | end: |
| 77 | return ret; |
| 78 | } |
| 79 | |
| 80 | static |
| 81 | int64_t capture_sequence_element_signed(uint8_t *ptr, |
| 82 | const struct lttng_integer_type *type) |
| 83 | { |
| 84 | int64_t value = 0; |
| 85 | unsigned int size = type->size; |
| 86 | bool byte_order_reversed = type->reverse_byte_order; |
| 87 | |
| 88 | switch (size) { |
| 89 | case 8: |
| 90 | value = *ptr; |
| 91 | break; |
| 92 | case 16: |
| 93 | { |
| 94 | int16_t tmp; |
| 95 | tmp = *(int16_t *) ptr; |
| 96 | if (byte_order_reversed) |
| 97 | __swab16s(&tmp); |
| 98 | |
| 99 | value = tmp; |
| 100 | break; |
| 101 | } |
| 102 | case 32: |
| 103 | { |
| 104 | int32_t tmp; |
| 105 | tmp = *(int32_t *) ptr; |
| 106 | if (byte_order_reversed) |
| 107 | __swab32s(&tmp); |
| 108 | |
| 109 | value = tmp; |
| 110 | break; |
| 111 | } |
| 112 | case 64: |
| 113 | { |
| 114 | int64_t tmp; |
| 115 | tmp = *(int64_t *) ptr; |
| 116 | if (byte_order_reversed) |
| 117 | __swab64s(&tmp); |
| 118 | |
| 119 | value = tmp; |
| 120 | break; |
| 121 | } |
| 122 | default: |
| 123 | WARN_ON(1); |
| 124 | } |
| 125 | |
| 126 | return value; |
| 127 | } |
| 128 | |
| 129 | static |
| 130 | uint64_t capture_sequence_element_unsigned(uint8_t *ptr, |
| 131 | const struct lttng_integer_type *type) |
| 132 | { |
| 133 | uint64_t value = 0; |
| 134 | unsigned int size = type->size; |
| 135 | bool byte_order_reversed = type->reverse_byte_order; |
| 136 | |
| 137 | switch (size) { |
| 138 | case 8: |
| 139 | value = *ptr; |
| 140 | break; |
| 141 | case 16: |
| 142 | { |
| 143 | uint16_t tmp; |
| 144 | tmp = *(uint16_t *) ptr; |
| 145 | if (byte_order_reversed) |
| 146 | __swab16s(&tmp); |
| 147 | |
| 148 | value = tmp; |
| 149 | break; |
| 150 | } |
| 151 | case 32: |
| 152 | { |
| 153 | uint32_t tmp; |
| 154 | tmp = *(uint32_t *) ptr; |
| 155 | if (byte_order_reversed) |
| 156 | __swab32s(&tmp); |
| 157 | |
| 158 | value = tmp; |
| 159 | break; |
| 160 | } |
| 161 | case 64: |
| 162 | { |
| 163 | uint64_t tmp; |
| 164 | tmp = *(uint64_t *) ptr; |
| 165 | if (byte_order_reversed) |
| 166 | __swab64s(&tmp); |
| 167 | |
| 168 | value = tmp; |
| 169 | break; |
| 170 | } |
| 171 | default: |
| 172 | WARN_ON(1); |
| 173 | } |
| 174 | |
| 175 | return value; |
| 176 | } |
| 177 | |
| 178 | static |
| 179 | int capture_sequence(struct lttng_msgpack_writer *writer, |
| 180 | struct lttng_interpreter_output *output) __attribute__ ((unused)); |
| 181 | int capture_sequence(struct lttng_msgpack_writer *writer, |
| 182 | struct lttng_interpreter_output *output) |
| 183 | { |
| 184 | const struct lttng_integer_type *integer_type = NULL; |
| 185 | const struct lttng_type *nested_type; |
| 186 | uint8_t *ptr; |
| 187 | bool signedness; |
| 188 | int ret, i; |
| 189 | |
| 190 | ret = lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem); |
| 191 | if (ret) { |
| 192 | WARN_ON_ONCE(1); |
| 193 | goto end; |
| 194 | } |
| 195 | |
| 196 | ptr = (uint8_t *) output->u.sequence.ptr; |
| 197 | nested_type = output->u.sequence.nested_type; |
| 198 | switch (nested_type->atype) { |
| 199 | case atype_integer: |
| 200 | integer_type = &nested_type->u.integer; |
| 201 | break; |
| 202 | case atype_enum_nestable: |
| 203 | /* Treat enumeration as an integer. */ |
| 204 | integer_type = &nested_type->u.enum_nestable.container_type->u.integer; |
| 205 | break; |
| 206 | default: |
| 207 | /* Capture of array of non-integer are not supported. */ |
| 208 | WARN_ON(1); |
| 209 | } |
| 210 | signedness = integer_type->signedness; |
| 211 | for (i = 0; i < output->u.sequence.nr_elem; i++) { |
| 212 | if (signedness) { |
| 213 | ret = lttng_msgpack_write_signed_integer(writer, |
| 214 | capture_sequence_element_signed(ptr, integer_type)); |
| 215 | if (ret) { |
| 216 | WARN_ON_ONCE(1); |
| 217 | goto end; |
| 218 | } |
| 219 | } else { |
| 220 | ret = lttng_msgpack_write_unsigned_integer(writer, |
| 221 | capture_sequence_element_unsigned(ptr, integer_type)); |
| 222 | if (ret) { |
| 223 | WARN_ON_ONCE(1); |
| 224 | goto end; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * We assume that alignment is smaller or equal to the size. |
| 230 | * This currently holds true but if it changes in the future, |
| 231 | * we will want to change the pointer arithmetics below to |
| 232 | * take into account that the next element might be further |
| 233 | * away. |
| 234 | */ |
| 235 | WARN_ON(integer_type->alignment > integer_type->size); |
| 236 | |
| 237 | /* Size is in number of bits. */ |
| 238 | ptr += (integer_type->size / CHAR_BIT) ; |
| 239 | } |
| 240 | |
| 241 | ret = lttng_msgpack_end_array(writer); |
| 242 | if (ret) |
| 243 | WARN_ON_ONCE(1); |
| 244 | end: |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | void lttng_event_notifier_notification_send(struct lttng_event_notifier *event_notifier) |
| 249 | { |
| 250 | struct lttng_event_notifier_group *event_notifier_group = event_notifier->group; |
| 251 | struct lib_ring_buffer_ctx ctx; |
| 252 | int ret; |
| 253 | |
| 254 | if (unlikely(!READ_ONCE(event_notifier->enabled))) |
| 255 | return; |
| 256 | |
| 257 | lib_ring_buffer_ctx_init(&ctx, event_notifier_group->chan, NULL, |
| 258 | sizeof(event_notifier->user_token), |
| 259 | lttng_alignof(event_notifier->user_token), -1); |
| 260 | ret = event_notifier_group->ops->event_reserve(&ctx, 0); |
| 261 | if (ret < 0) { |
| 262 | //TODO: error handling with counter maps |
| 263 | //silently drop for now. |
| 264 | WARN_ON_ONCE(1); |
| 265 | return; |
| 266 | } |
| 267 | lib_ring_buffer_align_ctx(&ctx, lttng_alignof(event_notifier->user_token)); |
| 268 | event_notifier_group->ops->event_write(&ctx, &event_notifier->user_token, |
| 269 | sizeof(event_notifier->user_token)); |
| 270 | event_notifier_group->ops->event_commit(&ctx); |
| 271 | irq_work_queue(&event_notifier_group->wakeup_pending); |
| 272 | } |