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Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index fb39dd43e00b..605142e06863 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -640,7 +640,8 @@ int ring_buffer_print_page_header(struct trace_buffer *buffer, struct trace_seq trace_seq_printf(s, "\tfield: char data;\t" "offset:%u;\tsize:%u;\tsigned:%u;\n", (unsigned int)offsetof(typeof(field), data), - (unsigned int)buffer->subbuf_size, + (unsigned int)(buffer ? buffer->subbuf_size : + PAGE_SIZE - BUF_PAGE_HDR_SIZE), (unsigned int)is_signed_type(char)); return !trace_seq_has_overflowed(s); diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index 0d0af53c0ce9..0d78e5f5fe98 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -1125,10 +1125,145 @@ static int remote_event_callback(const char *name, umode_t *mode, void **data, return 0; } +static ssize_t remote_events_dir_enable_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct trace_remote *remote = file_inode(filp)->i_private; + int i, ret; + u8 enable; + + ret = kstrtou8_from_user(ubuf, count, 10, &enable); + if (ret) + return ret; + + guard(mutex)(&remote->lock); + + for (i = 0; i < remote->nr_events; i++) { + struct remote_event *evt = &remote->events[i]; + + trace_remote_enable_event(remote, evt, enable); + } + + return count; +} + +static ssize_t remote_events_dir_enable_read(struct file *filp, char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct trace_remote *remote = file_inode(filp)->i_private; + const char enabled_char[] = {'0', '1', 'X'}; + char enabled_str[] = " \n"; + int i, enabled = -1; + + guard(mutex)(&remote->lock); + + for (i = 0; i < remote->nr_events; i++) { + struct remote_event *evt = &remote->events[i]; + + if (enabled == -1) { + enabled = evt->enabled; + } else if (enabled != evt->enabled) { + enabled = 2; + break; + } + } + + enabled_str[0] = enabled_char[enabled == -1 ? 0 : enabled]; + + return simple_read_from_buffer(ubuf, cnt, ppos, enabled_str, 2); +} + +static const struct file_operations remote_events_dir_enable_fops = { + .write = remote_events_dir_enable_write, + .read = remote_events_dir_enable_read, +}; + +static ssize_t +remote_events_dir_header_page_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) +{ + struct trace_seq *s; + int ret; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + + ring_buffer_print_page_header(NULL, s); + ret = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); + kfree(s); + + return ret; +} + +static const struct file_operations remote_events_dir_header_page_fops = { + .read = remote_events_dir_header_page_read, +}; + +static ssize_t +remote_events_dir_header_event_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) +{ + struct trace_seq *s; + int ret; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + + ring_buffer_print_entry_header(s); + ret = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); + kfree(s); + + return ret; +} + +static const struct file_operations remote_events_dir_header_event_fops = { + .read = remote_events_dir_header_event_read, +}; + +static int remote_events_dir_callback(const char *name, umode_t *mode, void **data, + const struct file_operations **fops) +{ + if (!strcmp(name, "enable")) { + *mode = TRACEFS_MODE_WRITE; + *fops = &remote_events_dir_enable_fops; + return 1; + } + + if (!strcmp(name, "header_page")) { + *mode = TRACEFS_MODE_READ; + *fops = &remote_events_dir_header_page_fops; + return 1; + } + + if (!strcmp(name, "header_event")) { + *mode = TRACEFS_MODE_READ; + *fops = &remote_events_dir_header_event_fops; + return 1; + } + + return 0; +} + static int trace_remote_init_eventfs(const char *remote_name, struct trace_remote *remote, struct remote_event *evt) { struct eventfs_inode *eventfs = remote->eventfs; + static struct eventfs_entry dir_entries[] = { + { + .name = "enable", + .callback = remote_events_dir_callback, + }, { + .name = "header_page", + .callback = remote_events_dir_callback, + }, { + .name = "header_event", + .callback = remote_events_dir_callback, + } + }; static struct eventfs_entry entries[] = { { .name = "enable", @@ -1144,7 +1279,8 @@ static int trace_remote_init_eventfs(const char *remote_name, struct trace_remot bool eventfs_create = false; if (!eventfs) { - eventfs = eventfs_create_events_dir("events", remote->dentry, NULL, 0, NULL); + eventfs = eventfs_create_events_dir("events", remote->dentry, dir_entries, + ARRAY_SIZE(dir_entries), remote); if (IS_ERR(eventfs)) return PTR_ERR(eventfs); -- 2.53.0.473.g4a7958ca14-goog