* Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
*/
+#include <asm/barrier.h>
#include <linux/bug.h>
#include <lttng/lttng-bytecode.h>
#include <lttng/event-notifier-notification.h>
#include <lttng/events-internal.h>
#include <lttng/probe-user.h>
-#include <wrapper/barrier.h>
/*
* The capture buffer size needs to be below 1024 bytes to avoid the
*/
#define CAPTURE_BUFFER_SIZE 512
+#define MSG_WRITE_NIL_LEN 1
+
struct lttng_event_notifier_notification {
int notification_fd;
uint64_t event_notifier_token;
break;
default:
WARN_ON_ONCE(1);
+ ret = -1;
+ goto end;
}
ret = lttng_msgpack_end_map(writer);
}
static
-int64_t capture_sequence_element_signed(uint8_t *ptr,
- const struct lttng_kernel_type_integer *type)
+int capture_sequence_element_signed(uint8_t *ptr,
+ const struct lttng_kernel_type_integer *type,
+ int64_t *_value)
{
int64_t value = 0;
unsigned int size = type->size;
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(int8_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(int16_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(int16_t *) ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(int32_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(int32_t *) ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(int64_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(int64_t *) ptr;
}
}
default:
WARN_ON_ONCE(1);
+ return -1;
}
- return value;
+ *_value = value;
+ return 0;
}
static
-uint64_t capture_sequence_element_unsigned(uint8_t *ptr,
- const struct lttng_kernel_type_integer *type)
+int capture_sequence_element_unsigned(uint8_t *ptr,
+ const struct lttng_kernel_type_integer *type,
+ uint64_t *_value)
{
uint64_t value = 0;
unsigned int size = type->size;
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(uint8_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(uint16_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(uint16_t *) ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(uint32_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(uint32_t *) ptr;
}
if (user) {
if (lttng_copy_from_user_check_nofault(&tmp, ptr, sizeof(uint64_t)))
- tmp = 0;
+ return -1;
} else {
tmp = *(uint64_t *) ptr;
}
}
default:
WARN_ON_ONCE(1);
+ return -1;
}
- return value;
+ *_value = value;
+ return 0;
}
int capture_sequence(struct lttng_msgpack_writer *writer,
signedness = integer_type->signedness;
for (i = 0; i < output->u.sequence.nr_elem; i++) {
if (signedness) {
- ret = lttng_msgpack_write_signed_integer(writer,
- capture_sequence_element_signed(ptr, integer_type));
+ int64_t v;
+
+ ret = capture_sequence_element_signed(ptr, integer_type, &v);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_msgpack_write_signed_integer(writer, v);
if (ret) {
goto end;
}
} else {
- ret = lttng_msgpack_write_unsigned_integer(writer,
- capture_sequence_element_unsigned(ptr, integer_type));
+ uint64_t v;
+
+ ret = capture_sequence_element_unsigned(ptr, integer_type, &v);
+ if (ret) {
+ goto end;
+ }
+ ret = lttng_msgpack_write_unsigned_integer(writer, v);
if (ret) {
goto end;
}
int ret;
/*
- * lttng_smp_load_acquire paired with lttng_smp_store_release orders
- * creation of the error counter and setting error_counter_len
- * before the error_counter is used.
+ * smp_load_acquire paired with smp_store_release orders creation of
+ * the error counter and setting error_counter_len before the
+ * error_counter is used.
*/
- error_counter = lttng_smp_load_acquire(&event_notifier_group->error_counter);
+ error_counter = smp_load_acquire(&event_notifier_group->error_counter);
/* This group may not have an error counter attached to it. */
if (!error_counter)
return;
irq_work_queue(&event_notifier_group->wakeup_pending);
}
+/*
+ * Validate that the buffer has enough room to hold empty capture fields.
+ */
+static
+bool validate_buffer_len(struct lttng_event_notifier_notification *notif, size_t captures_left)
+{
+ if (notif->writer.end_write_pos - notif->writer.write_pos < MSG_WRITE_NIL_LEN * captures_left)
+ return false;
+ return true;
+}
+
void lttng_event_notifier_notification_send(struct lttng_kernel_event_notifier *event_notifier,
const char *stack_data,
struct lttng_kernel_probe_ctx *probe_ctx,
struct lttng_kernel_notification_ctx *notif_ctx)
{
struct lttng_event_notifier_notification notif = { 0 };
+ size_t captures_left;
- if (unlikely(!READ_ONCE(event_notifier->parent.enabled)))
- return;
+ if (notification_init(¬if, event_notifier))
+ goto error;
- if (notification_init(¬if, event_notifier)) {
- record_error(event_notifier);
- goto end;
- }
+ captures_left = event_notifier->priv->num_captures;
+ if (!validate_buffer_len(¬if, captures_left))
+ goto error;
if (unlikely(notif_ctx->eval_capture)) {
struct lttng_kernel_bytecode_runtime *capture_bc_runtime;
&event_notifier->priv->capture_bytecode_runtime_head, node) {
struct lttng_interpreter_output output;
uint8_t *save_pos;
- int ret;
+ int ret = -1;
lttng_msgpack_save_writer_pos(¬if.writer, &save_pos);
+ captures_left--;
if (capture_bc_runtime->interpreter_func(capture_bc_runtime,
stack_data, probe_ctx, &output) == LTTNG_KERNEL_BYTECODE_INTERPRETER_OK)
ret = notification_append_capture(¬if, &output);
- else
- ret = notification_append_empty_capture(¬if);
- if (ret) {
+ if (ret || !validate_buffer_len(¬if, captures_left)) {
/*
- * On append capture error, skip the field
- * capture by restoring the msgpack writer
- * position.
+ * On append capture error or if the generated
+ * buffer data would not leave enough room to
+ * write empty capture fields for the remaining
+ * fields, skip the field capture by restoring
+ * the msgpack writer position and writing an
+ * empty capture field.
*/
lttng_msgpack_restore_writer_pos(¬if.writer, save_pos);
+ ret = notification_append_empty_capture(¬if);
+ WARN_ON_ONCE(ret);
}
}
}
+ if (notif.has_captures && lttng_msgpack_end_array(¬if.writer))
+ goto error;
+
/*
* Send the notification (including the capture buffer) to the
* sessiond.
*/
notification_send(¬if, event_notifier);
-end:
+ return;
+
+error:
+ record_error(event_notifier);
return;
}
projects / lttng-modules.git / blobdiff