X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Flttng-abi.c;h=a78205c4159392bf5b69d2aa87428dacfc8d8fff;hb=562376193c44ad44a9243cd880d5e424f0c25b04;hp=00d0a34eb7251fc6be3fd25d7d71f8b6604adf21;hpb=750b05f22826af9bce23e915ca4b9d8a15754797;p=lttng-modules.git diff --git a/src/lttng-abi.c b/src/lttng-abi.c index 00d0a34e..a78205c4 100644 --- a/src/lttng-abi.c +++ b/src/lttng-abi.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -44,6 +45,7 @@ #include #include #include +#include /* * This is LTTng's own personal way to create a system call as an external @@ -52,7 +54,7 @@ static struct proc_dir_entry *lttng_proc_dentry; -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) static const struct proc_ops lttng_proc_ops; #else static const struct file_operations lttng_proc_ops; @@ -68,6 +70,17 @@ static struct file_operations lttng_stream_ring_buffer_file_operations; static int put_u64(uint64_t val, unsigned long arg); static int put_u32(uint32_t val, unsigned long arg); +static int validate_zeroed_padding(char *p, size_t len) +{ + size_t i; + + for (i = 0; i < len; i++) { + if (p[i]) + return -1; + } + return 0; +} + /* * Teardown management: opened file descriptors keep a refcount on the module, * so it can only exit when all file descriptors are closed. @@ -106,6 +119,14 @@ fd_error: return ret; } +void event_notifier_send_notification_work_wakeup(struct irq_work *entry) +{ + struct lttng_event_notifier_group *event_notifier_group = + container_of(entry, struct lttng_event_notifier_group, + wakeup_pending); + wake_up_interruptible(&event_notifier_group->read_wait); +} + static int lttng_abi_create_event_notifier_group(void) { @@ -131,6 +152,9 @@ int lttng_abi_create_event_notifier_group(void) } event_notifier_group->file = event_notifier_group_file; + init_waitqueue_head(&event_notifier_group->read_wait); + init_irq_work(&event_notifier_group->wakeup_pending, + event_notifier_send_notification_work_wakeup); fd_install(event_notifier_group_fd, event_notifier_group_file); return event_notifier_group_fd; @@ -440,7 +464,7 @@ long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } } -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) static const struct proc_ops lttng_proc_ops = { .proc_ioctl = lttng_ioctl, #ifdef CONFIG_COMPAT @@ -583,6 +607,135 @@ int lttng_abi_session_set_creation_time(struct lttng_session *session, return 0; } +static +int lttng_counter_release(struct inode *inode, struct file *file) +{ + struct lttng_counter *counter = file->private_data; + + if (counter) { + /* + * Do not destroy the counter itself. Wait of the owner + * (event_notifier group) to be destroyed. + */ + fput(counter->owner); + } + + return 0; +} + +static +long lttng_counter_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct lttng_counter *counter = file->private_data; + size_t indexes[LTTNG_KERNEL_COUNTER_DIMENSION_MAX] = { 0 }; + int i; + + switch (cmd) { + case LTTNG_KERNEL_COUNTER_READ: + { + struct lttng_kernel_counter_read local_counter_read; + struct lttng_kernel_counter_read __user *ucounter_read = + (struct lttng_kernel_counter_read __user *) arg; + bool overflow, underflow; + int64_t value; + int32_t cpu; + int ret; + + if (copy_from_user(&local_counter_read, ucounter_read, + sizeof(local_counter_read))) + return -EFAULT; + if (validate_zeroed_padding(local_counter_read.padding, + sizeof(local_counter_read.padding))) + return -EINVAL; + + /* Cast all indexes into size_t. */ + for (i = 0; i < local_counter_read.index.number_dimensions; i++) + indexes[i] = (size_t) local_counter_read.index.dimension_indexes[i]; + cpu = local_counter_read.cpu; + + ret = lttng_kernel_counter_read(counter, indexes, cpu, &value, + &overflow, &underflow); + if (ret) + return ret; + local_counter_read.value.value = value; + local_counter_read.value.overflow = overflow; + local_counter_read.value.underflow = underflow; + + if (copy_to_user(&ucounter_read->value, &local_counter_read.value, + sizeof(local_counter_read.value))) + return -EFAULT; + + return 0; + } + case LTTNG_KERNEL_COUNTER_AGGREGATE: + { + struct lttng_kernel_counter_aggregate local_counter_aggregate; + struct lttng_kernel_counter_aggregate __user *ucounter_aggregate = + (struct lttng_kernel_counter_aggregate __user *) arg; + bool overflow, underflow; + int64_t value; + int ret; + + if (copy_from_user(&local_counter_aggregate, ucounter_aggregate, + sizeof(local_counter_aggregate))) + return -EFAULT; + if (validate_zeroed_padding(local_counter_aggregate.padding, + sizeof(local_counter_aggregate.padding))) + return -EINVAL; + + /* Cast all indexes into size_t. */ + for (i = 0; i < local_counter_aggregate.index.number_dimensions; i++) + indexes[i] = (size_t) local_counter_aggregate.index.dimension_indexes[i]; + + ret = lttng_kernel_counter_aggregate(counter, indexes, &value, + &overflow, &underflow); + if (ret) + return ret; + local_counter_aggregate.value.value = value; + local_counter_aggregate.value.overflow = overflow; + local_counter_aggregate.value.underflow = underflow; + + if (copy_to_user(&ucounter_aggregate->value, &local_counter_aggregate.value, + sizeof(local_counter_aggregate.value))) + return -EFAULT; + + return 0; + } + case LTTNG_KERNEL_COUNTER_CLEAR: + { + struct lttng_kernel_counter_clear local_counter_clear; + struct lttng_kernel_counter_clear __user *ucounter_clear = + (struct lttng_kernel_counter_clear __user *) arg; + + if (copy_from_user(&local_counter_clear, ucounter_clear, + sizeof(local_counter_clear))) + return -EFAULT; + if (validate_zeroed_padding(local_counter_clear.padding, + sizeof(local_counter_clear.padding))) + return -EINVAL; + + /* Cast all indexes into size_t. */ + for (i = 0; i < local_counter_clear.index.number_dimensions; i++) + indexes[i] = (size_t) local_counter_clear.index.dimension_indexes[i]; + + return lttng_kernel_counter_clear(counter, indexes); + } + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } +} + +static const struct file_operations lttng_counter_fops = { + .owner = THIS_MODULE, + .release = lttng_counter_release, + .unlocked_ioctl = lttng_counter_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = lttng_counter_ioctl, +#endif +}; + + static enum tracker_type get_tracker_type(struct lttng_kernel_tracker_args *tracker) { @@ -804,6 +957,229 @@ static const struct file_operations lttng_session_fops = { #endif }; +/* + * When encountering empty buffer, flush current sub-buffer if non-empty + * and retry (if new data available to read after flush). + */ +static +ssize_t lttng_event_notifier_group_notif_read(struct file *filp, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct lttng_event_notifier_group *event_notifier_group = filp->private_data; + struct channel *chan = event_notifier_group->chan; + struct lib_ring_buffer *buf = event_notifier_group->buf; + ssize_t read_count = 0, len; + size_t read_offset; + + might_sleep(); + if (!lttng_access_ok(VERIFY_WRITE, user_buf, count)) + return -EFAULT; + + /* Finish copy of previous record */ + if (*ppos != 0) { + if (read_count < count) { + len = chan->iter.len_left; + read_offset = *ppos; + goto skip_get_next; + } + } + + while (read_count < count) { + size_t copy_len, space_left; + + len = lib_ring_buffer_get_next_record(chan, buf); +len_test: + if (len < 0) { + /* + * Check if buffer is finalized (end of file). + */ + if (len == -ENODATA) { + /* A 0 read_count will tell about end of file */ + goto nodata; + } + if (filp->f_flags & O_NONBLOCK) { + if (!read_count) + read_count = -EAGAIN; + goto nodata; + } else { + int error; + + /* + * No data available at the moment, return what + * we got. + */ + if (read_count) + goto nodata; + + /* + * Wait for returned len to be >= 0 or -ENODATA. + */ + error = wait_event_interruptible( + event_notifier_group->read_wait, + ((len = lib_ring_buffer_get_next_record( + chan, buf)), len != -EAGAIN)); + CHAN_WARN_ON(chan, len == -EBUSY); + if (error) { + read_count = error; + goto nodata; + } + CHAN_WARN_ON(chan, len < 0 && len != -ENODATA); + goto len_test; + } + } + read_offset = buf->iter.read_offset; +skip_get_next: + space_left = count - read_count; + if (len <= space_left) { + copy_len = len; + chan->iter.len_left = 0; + *ppos = 0; + } else { + copy_len = space_left; + chan->iter.len_left = len - copy_len; + *ppos = read_offset + copy_len; + } + if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset, + &user_buf[read_count], + copy_len)) { + /* + * Leave the len_left and ppos values at their current + * state, as we currently have a valid event to read. + */ + return -EFAULT; + } + read_count += copy_len; + } + goto put_record; + +nodata: + *ppos = 0; + chan->iter.len_left = 0; + +put_record: + lib_ring_buffer_put_current_record(buf); + return read_count; +} + +/* + * If the ring buffer is non empty (even just a partial subbuffer), return that + * there is data available. Perform a ring buffer flush if we encounter a + * non-empty ring buffer which does not have any consumeable subbuffer available. + */ +static +unsigned int lttng_event_notifier_group_notif_poll(struct file *filp, + poll_table *wait) +{ + unsigned int mask = 0; + struct lttng_event_notifier_group *event_notifier_group = filp->private_data; + struct channel *chan = event_notifier_group->chan; + struct lib_ring_buffer *buf = event_notifier_group->buf; + const struct lib_ring_buffer_config *config = &chan->backend.config; + int finalized, disabled; + unsigned long consumed, offset; + size_t subbuffer_header_size = config->cb.subbuffer_header_size(); + + if (filp->f_mode & FMODE_READ) { + poll_wait_set_exclusive(wait); + poll_wait(filp, &event_notifier_group->read_wait, wait); + + finalized = lib_ring_buffer_is_finalized(config, buf); + disabled = lib_ring_buffer_channel_is_disabled(chan); + + /* + * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering + * finalized load before offsets loads. + */ + WARN_ON(atomic_long_read(&buf->active_readers) != 1); +retry: + if (disabled) + return POLLERR; + + offset = lib_ring_buffer_get_offset(config, buf); + consumed = lib_ring_buffer_get_consumed(config, buf); + + /* + * If there is no buffer available to consume. + */ + if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) { + /* + * If there is a non-empty subbuffer, flush and try again. + */ + if (subbuf_offset(offset, chan) > subbuffer_header_size) { + lib_ring_buffer_switch_remote(buf); + goto retry; + } + + if (finalized) + return POLLHUP; + else { + /* + * The memory barriers + * __wait_event()/wake_up_interruptible() take + * care of "raw_spin_is_locked" memory ordering. + */ + if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock)) + goto retry; + else + return 0; + } + } else { + if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) + >= chan->backend.buf_size) + return POLLPRI | POLLRDBAND; + else + return POLLIN | POLLRDNORM; + } + } + + return mask; +} + +/** + * lttng_event_notifier_group_notif_open - event_notifier ring buffer open file operation + * @inode: opened inode + * @file: opened file + * + * Open implementation. Makes sure only one open instance of a buffer is + * done at a given moment. + */ +static int lttng_event_notifier_group_notif_open(struct inode *inode, struct file *file) +{ + struct lttng_event_notifier_group *event_notifier_group = inode->i_private; + struct lib_ring_buffer *buf = event_notifier_group->buf; + + file->private_data = event_notifier_group; + return lib_ring_buffer_open(inode, file, buf); +} + +/** + * lttng_event_notifier_group_notif_release - event_notifier ring buffer release file operation + * @inode: opened inode + * @file: opened file + * + * Release implementation. + */ +static int lttng_event_notifier_group_notif_release(struct inode *inode, struct file *file) +{ + struct lttng_event_notifier_group *event_notifier_group = file->private_data; + struct lib_ring_buffer *buf = event_notifier_group->buf; + int ret; + + ret = lib_ring_buffer_release(inode, file, buf); + if (ret) + return ret; + fput(event_notifier_group->file); + return 0; +} + +static const struct file_operations lttng_event_notifier_group_notif_fops = { + .owner = THIS_MODULE, + .open = lttng_event_notifier_group_notif_open, + .release = lttng_event_notifier_group_notif_release, + .read = lttng_event_notifier_group_notif_read, + .poll = lttng_event_notifier_group_notif_poll, +}; + /** * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation * @filp: the file @@ -1307,6 +1683,41 @@ nomem: return ret; } +static +int lttng_abi_open_event_notifier_group_stream(struct file *notif_file) +{ + struct lttng_event_notifier_group *event_notifier_group = notif_file->private_data; + struct channel *chan = event_notifier_group->chan; + struct lib_ring_buffer *buf; + int ret; + void *stream_priv; + + buf = event_notifier_group->ops->buffer_read_open(chan); + if (!buf) + return -ENOENT; + + /* The event_notifier notification fd holds a reference on the event_notifier group */ + if (!atomic_long_add_unless(¬if_file->f_count, 1, LONG_MAX)) { + ret = -EOVERFLOW; + goto refcount_error; + } + event_notifier_group->buf = buf; + stream_priv = event_notifier_group; + ret = lttng_abi_create_stream_fd(notif_file, stream_priv, + <tng_event_notifier_group_notif_fops, + "[lttng_event_notifier_stream]"); + if (ret < 0) + goto fd_error; + + return ret; + +fd_error: + atomic_long_dec(¬if_file->f_count); +refcount_error: + event_notifier_group->ops->buffer_read_close(buf); + return ret; +} + static int lttng_abi_validate_event_param(struct lttng_kernel_event *event_param) { @@ -1314,6 +1725,8 @@ int lttng_abi_validate_event_param(struct lttng_kernel_event *event_param) switch (event_param->instrumentation) { case LTTNG_KERNEL_SYSCALL: switch (event_param->u.syscall.entryexit) { + case LTTNG_KERNEL_SYSCALL_ENTRY: /* Fall-through */ + case LTTNG_KERNEL_SYSCALL_EXIT: /* Fall-through */ case LTTNG_KERNEL_SYSCALL_ENTRYEXIT: break; default: @@ -1326,21 +1739,31 @@ int lttng_abi_validate_event_param(struct lttng_kernel_event *event_param) return -EINVAL; } switch (event_param->u.syscall.match) { - case LTTNG_SYSCALL_MATCH_NAME: + case LTTNG_KERNEL_SYSCALL_MATCH_NAME: + break; + default: + return -EINVAL; + } + break; + + case LTTNG_KERNEL_KRETPROBE: + switch (event_param->u.kretprobe.entryexit) { + case LTTNG_KERNEL_SYSCALL_ENTRYEXIT: break; + case LTTNG_KERNEL_SYSCALL_ENTRY: /* Fall-through */ + case LTTNG_KERNEL_SYSCALL_EXIT: /* Fall-through */ default: return -EINVAL; } break; - case LTTNG_KERNEL_TRACEPOINT: /* Fallthrough */ - case LTTNG_KERNEL_KPROBE: /* Fallthrough */ - case LTTNG_KERNEL_KRETPROBE: /* Fallthrough */ - case LTTNG_KERNEL_NOOP: /* Fallthrough */ + case LTTNG_KERNEL_TRACEPOINT: /* Fall-through */ + case LTTNG_KERNEL_KPROBE: /* Fall-through */ case LTTNG_KERNEL_UPROBE: break; - case LTTNG_KERNEL_FUNCTION: /* Fallthrough */ + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ + case LTTNG_KERNEL_NOOP: /* Fall-through */ default: return -EINVAL; } @@ -1391,8 +1814,11 @@ int lttng_abi_create_event(struct file *channel_file, ret = lttng_abi_validate_event_param(event_param); if (ret) goto event_error; - if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT - || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) { + + switch (event_param->instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: /* Fall-through */ + case LTTNG_KERNEL_SYSCALL: + { struct lttng_event_enabler *event_enabler; if (strutils_is_star_glob_pattern(event_param->name)) { @@ -1407,7 +1833,13 @@ int lttng_abi_create_event(struct file *channel_file, event_param, channel); } priv = event_enabler; - } else { + break; + } + + case LTTNG_KERNEL_KPROBE: /* Fall-through */ + case LTTNG_KERNEL_KRETPROBE: /* Fall-through */ + case LTTNG_KERNEL_UPROBE: + { struct lttng_event *event; /* @@ -1423,6 +1855,14 @@ int lttng_abi_create_event(struct file *channel_file, goto event_error; } priv = event; + break; + } + + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ + case LTTNG_KERNEL_NOOP: /* Fall-through */ + default: + ret = -EINVAL; + goto event_error; } event_file->private_data = priv; fd_install(event_fd, event_file); @@ -1438,11 +1878,380 @@ fd_error: return ret; } +static +long lttng_event_notifier_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct lttng_event_notifier *event_notifier; + struct lttng_event_notifier_enabler *event_notifier_enabler; + enum lttng_event_type *evtype = file->private_data; + + switch (cmd) { + case LTTNG_KERNEL_ENABLE: + switch (*evtype) { + case LTTNG_TYPE_EVENT: + event_notifier = file->private_data; + return lttng_event_notifier_enable(event_notifier); + case LTTNG_TYPE_ENABLER: + event_notifier_enabler = file->private_data; + return lttng_event_notifier_enabler_enable(event_notifier_enabler); + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } + case LTTNG_KERNEL_DISABLE: + switch (*evtype) { + case LTTNG_TYPE_EVENT: + event_notifier = file->private_data; + return lttng_event_notifier_disable(event_notifier); + case LTTNG_TYPE_ENABLER: + event_notifier_enabler = file->private_data; + return lttng_event_notifier_enabler_disable(event_notifier_enabler); + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } + case LTTNG_KERNEL_FILTER: + switch (*evtype) { + case LTTNG_TYPE_EVENT: + return -EINVAL; + case LTTNG_TYPE_ENABLER: + event_notifier_enabler = file->private_data; + return lttng_event_notifier_enabler_attach_filter_bytecode( + event_notifier_enabler, + (struct lttng_kernel_filter_bytecode __user *) arg); + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } + + case LTTNG_KERNEL_CAPTURE: + switch (*evtype) { + case LTTNG_TYPE_EVENT: + return -EINVAL; + case LTTNG_TYPE_ENABLER: + event_notifier_enabler = file->private_data; + return lttng_event_notifier_enabler_attach_capture_bytecode( + event_notifier_enabler, + (struct lttng_kernel_capture_bytecode __user *) arg); + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } + case LTTNG_KERNEL_ADD_CALLSITE: + switch (*evtype) { + case LTTNG_TYPE_EVENT: + event_notifier = file->private_data; + return lttng_event_notifier_add_callsite(event_notifier, + (struct lttng_kernel_event_callsite __user *) arg); + case LTTNG_TYPE_ENABLER: + return -EINVAL; + default: + WARN_ON_ONCE(1); + return -ENOSYS; + } + default: + return -ENOIOCTLCMD; + } +} + +static +int lttng_event_notifier_release(struct inode *inode, struct file *file) +{ + struct lttng_event_notifier *event_notifier; + struct lttng_event_notifier_enabler *event_notifier_enabler; + enum lttng_event_type *evtype = file->private_data; + + if (!evtype) + return 0; + + switch (*evtype) { + case LTTNG_TYPE_EVENT: + event_notifier = file->private_data; + if (event_notifier) + fput(event_notifier->group->file); + break; + case LTTNG_TYPE_ENABLER: + event_notifier_enabler = file->private_data; + if (event_notifier_enabler) + fput(event_notifier_enabler->group->file); + break; + default: + WARN_ON_ONCE(1); + break; + } + + return 0; +} + +static const struct file_operations lttng_event_notifier_fops = { + .owner = THIS_MODULE, + .release = lttng_event_notifier_release, + .unlocked_ioctl = lttng_event_notifier_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = lttng_event_notifier_ioctl, +#endif +}; + +static +int lttng_abi_create_event_notifier(struct file *event_notifier_group_file, + struct lttng_kernel_event_notifier *event_notifier_param) +{ + struct lttng_event_notifier_group *event_notifier_group = + event_notifier_group_file->private_data; + int event_notifier_fd, ret; + struct file *event_notifier_file; + void *priv; + + switch (event_notifier_param->event.instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: + case LTTNG_KERNEL_UPROBE: + break; + case LTTNG_KERNEL_KPROBE: + event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; + break; + case LTTNG_KERNEL_SYSCALL: + break; + case LTTNG_KERNEL_KRETPROBE: + /* Placing an event notifier on kretprobe is not supported. */ + case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_NOOP: + default: + ret = -EINVAL; + goto inval_instr; + } + + event_notifier_param->event.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; + + event_notifier_fd = lttng_get_unused_fd(); + if (event_notifier_fd < 0) { + ret = event_notifier_fd; + goto fd_error; + } + + event_notifier_file = anon_inode_getfile("[lttng_event_notifier]", + <tng_event_notifier_fops, + NULL, O_RDWR); + if (IS_ERR(event_notifier_file)) { + ret = PTR_ERR(event_notifier_file); + goto file_error; + } + + /* The event notifier holds a reference on the event notifier group. */ + if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) { + ret = -EOVERFLOW; + goto refcount_error; + } + + ret = lttng_abi_validate_event_param(&event_notifier_param->event); + if (ret) + goto event_notifier_error; + + switch (event_notifier_param->event.instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: /* Fall-through */ + case LTTNG_KERNEL_SYSCALL: + { + struct lttng_event_notifier_enabler *enabler; + + if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) { + /* + * If the event name is a star globbing pattern, + * we create the special star globbing enabler. + */ + enabler = lttng_event_notifier_enabler_create( + event_notifier_group, + LTTNG_ENABLER_FORMAT_STAR_GLOB, + event_notifier_param); + } else { + enabler = lttng_event_notifier_enabler_create( + event_notifier_group, + LTTNG_ENABLER_FORMAT_NAME, + event_notifier_param); + } + priv = enabler; + break; + } + + case LTTNG_KERNEL_KPROBE: /* Fall-through */ + case LTTNG_KERNEL_KRETPROBE: /* Fall-through */ + case LTTNG_KERNEL_UPROBE: + { + struct lttng_event_notifier *event_notifier; + + /* + * We tolerate no failure path after event notifier creation. + * It will stay invariant for the rest of the session. + */ + event_notifier = lttng_event_notifier_create(NULL, + event_notifier_param->event.token, + event_notifier_param->error_counter_index, + event_notifier_group, + event_notifier_param, NULL, + event_notifier_param->event.instrumentation); + WARN_ON_ONCE(!event_notifier); + if (IS_ERR(event_notifier)) { + ret = PTR_ERR(event_notifier); + goto event_notifier_error; + } + priv = event_notifier; + break; + } + + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ + case LTTNG_KERNEL_NOOP: /* Fall-through */ + default: + ret = -EINVAL; + goto event_notifier_error; + } + event_notifier_file->private_data = priv; + fd_install(event_notifier_fd, event_notifier_file); + return event_notifier_fd; + +event_notifier_error: + atomic_long_dec(&event_notifier_group_file->f_count); +refcount_error: + fput(event_notifier_file); +file_error: + put_unused_fd(event_notifier_fd); +fd_error: +inval_instr: + return ret; +} + +static +long lttng_abi_event_notifier_group_create_error_counter( + struct file *event_notifier_group_file, + const struct lttng_kernel_counter_conf *error_counter_conf) +{ + int counter_fd, ret; + char *counter_transport_name; + size_t counter_len; + struct lttng_counter *counter = NULL; + struct file *counter_file; + struct lttng_event_notifier_group *event_notifier_group = + (struct lttng_event_notifier_group *) event_notifier_group_file->private_data; + + if (error_counter_conf->arithmetic != LTTNG_KERNEL_COUNTER_ARITHMETIC_MODULAR) { + printk(KERN_ERR "LTTng: event_notifier: Error counter of the wrong arithmetic type.\n"); + return -EINVAL; + } + + if (error_counter_conf->number_dimensions != 1) { + printk(KERN_ERR "LTTng: event_notifier: Error counter has more than one dimension.\n"); + return -EINVAL; + } + + switch (error_counter_conf->bitness) { + case LTTNG_KERNEL_COUNTER_BITNESS_64: + counter_transport_name = "counter-per-cpu-64-modular"; + break; + case LTTNG_KERNEL_COUNTER_BITNESS_32: + counter_transport_name = "counter-per-cpu-32-modular"; + break; + default: + return -EINVAL; + } + + /* + * Lock sessions to provide mutual exclusion against concurrent + * modification of event_notifier group, which would result in + * overwriting the error counter if set concurrently. + */ + lttng_lock_sessions(); + + if (event_notifier_group->error_counter) { + printk(KERN_ERR "Error counter already created in event_notifier group\n"); + ret = -EBUSY; + goto fd_error; + } + + counter_fd = lttng_get_unused_fd(); + if (counter_fd < 0) { + ret = counter_fd; + goto fd_error; + } + + counter_file = anon_inode_getfile("[lttng_counter]", + <tng_counter_fops, + NULL, O_RDONLY); + if (IS_ERR(counter_file)) { + ret = PTR_ERR(counter_file); + goto file_error; + } + + counter_len = error_counter_conf->dimensions[0].size; + + if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) { + ret = -EOVERFLOW; + goto refcount_error; + } + + counter = lttng_kernel_counter_create(counter_transport_name, + 1, &counter_len); + if (!counter) { + ret = -EINVAL; + goto counter_error; + } + + event_notifier_group->error_counter_len = counter_len; + /* + * store-release to publish error counter matches load-acquire + * in record_error. Ensures the counter is created and the + * error_counter_len is set before they are used. + */ + lttng_smp_store_release(&event_notifier_group->error_counter, counter); + + counter->file = counter_file; + counter->owner = event_notifier_group->file; + counter_file->private_data = counter; + /* Ownership transferred. */ + counter = NULL; + + fd_install(counter_fd, counter_file); + lttng_unlock_sessions(); + + return counter_fd; + +counter_error: + atomic_long_dec(&event_notifier_group_file->f_count); +refcount_error: + fput(counter_file); +file_error: + put_unused_fd(counter_fd); +fd_error: + lttng_unlock_sessions(); + return ret; +} + static long lttng_event_notifier_group_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { switch (cmd) { + case LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD: + { + return lttng_abi_open_event_notifier_group_stream(file); + } + case LTTNG_KERNEL_EVENT_NOTIFIER_CREATE: + { + struct lttng_kernel_event_notifier uevent_notifier_param; + + if (copy_from_user(&uevent_notifier_param, + (struct lttng_kernel_event_notifier __user *) arg, + sizeof(uevent_notifier_param))) + return -EFAULT; + return lttng_abi_create_event_notifier(file, &uevent_notifier_param); + } + case LTTNG_KERNEL_COUNTER: + { + struct lttng_kernel_counter_conf uerror_counter_conf; + + if (copy_from_user(&uerror_counter_conf, + (struct lttng_kernel_counter_conf __user *) arg, + sizeof(uerror_counter_conf))) + return -EFAULT; + return lttng_abi_event_notifier_group_create_error_counter(file, + &uerror_counter_conf); + } default: return -ENOIOCTLCMD; } @@ -1813,7 +2622,8 @@ long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case LTTNG_TYPE_ENABLER: { event_enabler = file->private_data; - return lttng_event_enabler_attach_bytecode(event_enabler, + return lttng_event_enabler_attach_filter_bytecode( + event_enabler, (struct lttng_kernel_filter_bytecode __user *) arg); } default: