X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-events.c;h=992ba58f2a96200650924dd6d0856b513b6eb529;hb=refs%2Fheads%2Fstable-2.7;hp=1ae894be3ea95b4e0ca11aaf90af605cd5b02a85;hpb=66fd8d5e4a6080f1b2db0f525c26c07e5b723aab;p=lttng-modules.git diff --git a/lttng-events.c b/lttng-events.c index 1ae894be..992ba58f 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -38,6 +38,8 @@ #include #include "wrapper/file.h" #include +#include +#include #include "wrapper/uuid.h" #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ @@ -48,6 +50,10 @@ #include "lttng-events.h" #include "lttng-tracer.h" #include "lttng-abi-old.h" +#include "lttng-endian.h" +#include "wrapper/vzalloc.h" +#include "wrapper/ringbuffer/backend.h" +#include "wrapper/ringbuffer/frontend.h" #define METADATA_CACHE_DEFAULT_SIZE 4096 @@ -131,12 +137,12 @@ struct lttng_session *lttng_session_create(void) GFP_KERNEL); if (!metadata_cache) goto err_free_session; - metadata_cache->data = kzalloc(METADATA_CACHE_DEFAULT_SIZE, - GFP_KERNEL); + metadata_cache->data = lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE); if (!metadata_cache->data) goto err_free_cache; metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE; kref_init(&metadata_cache->refcount); + mutex_init(&metadata_cache->lock); session->metadata_cache = metadata_cache; INIT_LIST_HEAD(&metadata_cache->metadata_stream); memcpy(&metadata_cache->uuid, &session->uuid, @@ -161,7 +167,7 @@ void metadata_cache_destroy(struct kref *kref) { struct lttng_metadata_cache *cache = container_of(kref, struct lttng_metadata_cache, refcount); - kfree(cache->data); + vfree(cache->data); kfree(cache); } @@ -233,6 +239,12 @@ int lttng_session_enable(struct lttng_session *session) /* We need to sync enablers with session before activation. */ lttng_session_sync_enablers(session); + /* Clear each stream's quiescent state. */ + list_for_each_entry(chan, &session->chan, list) { + if (chan->channel_type != METADATA_CHANNEL) + lib_ring_buffer_clear_quiescent_channel(chan->chan); + } + ACCESS_ONCE(session->active) = 1; ACCESS_ONCE(session->been_active) = 1; ret = _lttng_session_metadata_statedump(session); @@ -251,6 +263,7 @@ end: int lttng_session_disable(struct lttng_session *session) { int ret = 0; + struct lttng_channel *chan; mutex_lock(&sessions_mutex); if (!session->active) { @@ -262,6 +275,12 @@ int lttng_session_disable(struct lttng_session *session) /* Set transient enabler state to "disabled" */ session->tstate = 0; lttng_session_sync_enablers(session); + + /* Set each stream's quiescent state. */ + list_for_each_entry(chan, &session->chan, list) { + if (chan->channel_type != METADATA_CHANNEL) + lib_ring_buffer_set_quiescent_channel(chan->chan); + } end: mutex_unlock(&sessions_mutex); return ret; @@ -326,8 +345,23 @@ int lttng_event_enable(struct lttng_event *event) ret = -EEXIST; goto end; } - ACCESS_ONCE(event->enabled) = 1; - lttng_session_sync_enablers(event->chan->session); + switch (event->instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: + case LTTNG_KERNEL_SYSCALL: + ret = -EINVAL; + break; + case LTTNG_KERNEL_KPROBE: + case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_NOOP: + ACCESS_ONCE(event->enabled) = 1; + break; + case LTTNG_KERNEL_KRETPROBE: + ret = lttng_kretprobes_event_enable_state(event, 1); + break; + default: + WARN_ON_ONCE(1); + ret = -EINVAL; + } end: mutex_unlock(&sessions_mutex); return ret; @@ -346,8 +380,23 @@ int lttng_event_disable(struct lttng_event *event) ret = -EEXIST; goto end; } - ACCESS_ONCE(event->enabled) = 0; - lttng_session_sync_enablers(event->chan->session); + switch (event->instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: + case LTTNG_KERNEL_SYSCALL: + ret = -EINVAL; + break; + case LTTNG_KERNEL_KPROBE: + case LTTNG_KERNEL_FUNCTION: + case LTTNG_KERNEL_NOOP: + ACCESS_ONCE(event->enabled) = 0; + break; + case LTTNG_KERNEL_KRETPROBE: + ret = lttng_kretprobes_event_enable_state(event, 0); + break; + default: + WARN_ON_ONCE(1); + ret = -EINVAL; + } end: mutex_unlock(&sessions_mutex); return ret; @@ -535,7 +584,11 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, smp_wmb(); break; case LTTNG_KERNEL_KPROBE: - event->enabled = 1; + /* + * Needs to be explicitly enabled after creation, since + * we may want to apply filters. + */ + event->enabled = 0; event->registered = 1; /* * Populate lttng_event structure before event @@ -559,7 +612,11 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, struct lttng_event *event_return; /* kretprobe defines 2 events */ - event->enabled = 1; + /* + * Needs to be explicitly enabled after creation, since + * we may want to apply filters. + */ + event->enabled = 0; event->registered = 1; event_return = kmem_cache_zalloc(event_cache, GFP_KERNEL); @@ -570,7 +627,7 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, event_return->chan = chan; event_return->filter = filter; event_return->id = chan->free_event_id++; - event_return->enabled = 1; + event_return->enabled = 0; event_return->registered = 1; event_return->instrumentation = itype; /* @@ -605,7 +662,11 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, break; } case LTTNG_KERNEL_FUNCTION: - event->enabled = 1; + /* + * Needs to be explicitly enabled after creation, since + * we may want to apply filters. + */ + event->enabled = 0; event->registered = 1; /* * Populate lttng_event structure before event @@ -623,7 +684,11 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, break; case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_SYSCALL: - event->enabled = 1; + /* + * Needs to be explicitly enabled after creation, since + * we may want to apply filters. + */ + event->enabled = 0; event->registered = 0; event->desc = event_desc; if (!event->desc) { @@ -994,17 +1059,22 @@ int lttng_session_list_tracker_pids(struct lttng_session *session) ret = PTR_ERR(tracker_pids_list_file); goto file_error; } + if (atomic_long_add_unless(&session->file->f_count, + 1, INT_MAX) == INT_MAX) { + goto refcount_error; + } ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file); if (ret < 0) goto open_error; m = tracker_pids_list_file->private_data; m->private = session; fd_install(file_fd, tracker_pids_list_file); - atomic_long_inc(&session->file->f_count); return file_fd; open_error: + atomic_long_dec(&session->file->f_count); +refcount_error: fput(tracker_pids_list_file); file_error: put_unused_fd(file_fd); @@ -1438,10 +1508,12 @@ void lttng_session_lazy_sync_enablers(struct lttng_session *session) /* * Serialize at most one packet worth of metadata into a metadata * channel. - * We have exclusive access to our metadata buffer (protected by the - * sessions_mutex), so we can do racy operations such as looking for - * remaining space left in packet and write, since mutual exclusion - * protects us from concurrent writes. + * We grab the metadata cache mutex to get exclusive access to our metadata + * buffer and to the metadata cache. Exclusive access to the metadata buffer + * allows us to do racy operations such as looking for remaining space left in + * packet and write, since mutual exclusion protects us from concurrent writes. + * Mutual exclusion on the metadata cache allow us to read the cache content + * without racing against reallocation of the cache by updates. * Returns the number of bytes written in the channel, 0 if no data * was written and a negative value on error. */ @@ -1453,13 +1525,15 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, size_t len, reserve_len; /* - * Ensure we support mutiple get_next / put sequences followed - * by put_next. The metadata stream lock internally protects - * reading the metadata cache. It can indeed be read - * concurrently by "get_next_subbuf" and "flush" operations on - * the buffer invoked by different processes. + * Ensure we support mutiple get_next / put sequences followed by + * put_next. The metadata cache lock protects reading the metadata + * cache. It can indeed be read concurrently by "get_next_subbuf" and + * "flush" operations on the buffer invoked by different processes. + * Moreover, since the metadata cache memory can be reallocated, we + * need to have exclusive access against updates even though we only + * read it. */ - mutex_lock(&stream->lock); + mutex_lock(&stream->metadata_cache->lock); WARN_ON(stream->metadata_in < stream->metadata_out); if (stream->metadata_in != stream->metadata_out) goto end; @@ -1489,13 +1563,15 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, ret = reserve_len; end: - mutex_unlock(&stream->lock); + mutex_unlock(&stream->metadata_cache->lock); return ret; } /* * Write the metadata to the metadata cache. * Must be called with sessions_mutex held. + * The metadata cache lock protects us from concurrent read access from + * thread outputting metadata content to ring buffer. */ int lttng_metadata_printf(struct lttng_session *session, const char *fmt, ...) @@ -1514,6 +1590,7 @@ int lttng_metadata_printf(struct lttng_session *session, return -ENOMEM; len = strlen(str); + mutex_lock(&session->metadata_cache->lock); if (session->metadata_cache->metadata_written + len > session->metadata_cache->cache_alloc) { char *tmp_cache_realloc; @@ -1522,10 +1599,16 @@ int lttng_metadata_printf(struct lttng_session *session, tmp_cache_alloc_size = max_t(unsigned int, session->metadata_cache->cache_alloc + len, session->metadata_cache->cache_alloc << 1); - tmp_cache_realloc = krealloc(session->metadata_cache->data, - tmp_cache_alloc_size, GFP_KERNEL); + tmp_cache_realloc = lttng_vzalloc(tmp_cache_alloc_size); if (!tmp_cache_realloc) goto err; + if (session->metadata_cache->data) { + memcpy(tmp_cache_realloc, + session->metadata_cache->data, + session->metadata_cache->cache_alloc); + vfree(session->metadata_cache->data); + } + session->metadata_cache->cache_alloc = tmp_cache_alloc_size; session->metadata_cache->data = tmp_cache_realloc; } @@ -1533,6 +1616,7 @@ int lttng_metadata_printf(struct lttng_session *session, session->metadata_cache->metadata_written, str, len); session->metadata_cache->metadata_written += len; + mutex_unlock(&session->metadata_cache->lock); kfree(str); list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) @@ -1541,6 +1625,7 @@ int lttng_metadata_printf(struct lttng_session *session, return 0; err: + mutex_unlock(&session->metadata_cache->lock); kfree(str); return -ENOMEM; } @@ -1567,7 +1652,7 @@ int _lttng_field_statedump(struct lttng_session *session, ? "UTF8" : "ASCII", field->type.u.basic.integer.base, -#ifdef __BIG_ENDIAN +#if __BYTE_ORDER == __BIG_ENDIAN field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", @@ -1596,7 +1681,7 @@ int _lttng_field_statedump(struct lttng_session *session, ? "UTF8" : "ASCII", elem_type->u.basic.integer.base, -#ifdef __BIG_ENDIAN +#if __BYTE_ORDER == __BIG_ENDIAN elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", @@ -1622,7 +1707,7 @@ int _lttng_field_statedump(struct lttng_session *session, ? "UTF8" : "ASCII"), length_type->u.basic.integer.base, -#ifdef __BIG_ENDIAN +#if __BYTE_ORDER == __BIG_ENDIAN length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", @@ -1642,7 +1727,7 @@ int _lttng_field_statedump(struct lttng_session *session, ? "UTF8" : "ASCII"), elem_type->u.basic.integer.base, -#ifdef __BIG_ENDIAN +#if __BYTE_ORDER == __BIG_ENDIAN elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", @@ -1891,11 +1976,14 @@ int _lttng_event_header_declare(struct lttng_session *session) * taken at start of trace. * Yes, this is only an approximation. Yes, we can (and will) do better * in future versions. + * Return 0 if offset is negative. It may happen if the system sets + * the REALTIME clock to 0 after boot. */ static uint64_t measure_clock_offset(void) { - uint64_t offset, monotonic[2], realtime; + uint64_t monotonic_avg, monotonic[2], realtime; + int64_t offset; struct timespec rts = { 0, 0 }; unsigned long flags; @@ -1906,10 +1994,12 @@ uint64_t measure_clock_offset(void) monotonic[1] = trace_clock_read64(); local_irq_restore(flags); - offset = (monotonic[0] + monotonic[1]) >> 1; + monotonic_avg = (monotonic[0] + monotonic[1]) >> 1; realtime = (uint64_t) rts.tv_sec * NSEC_PER_SEC; realtime += rts.tv_nsec; - offset = realtime - offset; + offset = (int64_t) realtime - monotonic_avg; + if (offset < 0) + return 0; return offset; } @@ -1967,7 +2057,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session) CTF_SPEC_MAJOR, CTF_SPEC_MINOR, uuid_s, -#ifdef __BIG_ENDIAN +#if __BYTE_ORDER == __BIG_ENDIAN "be" #else "le" @@ -2121,6 +2211,9 @@ static int __init lttng_events_init(void) if (ret) return ret; ret = wrapper_get_pfnblock_flags_mask_init(); + if (ret) + return ret; + ret = wrapper_get_pageblock_flags_mask_init(); if (ret) return ret; ret = lttng_context_init();