X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_frontend.c;h=768e2a12a3d62c2d069b212beeac8b7e7a839b24;hb=6f97f9c2bbc74605e3de2b05333ecf25fa52d6fc;hp=1396f44a26263a202867b6f9f2e115275e4d9b35;hpb=9c995331b51a9b9a8c85457a897fa89e770de111;p=lttng-ust.git diff --git a/libringbuffer/ring_buffer_frontend.c b/libringbuffer/ring_buffer_frontend.c index 1396f44a..768e2a12 100644 --- a/libringbuffer/ring_buffer_frontend.c +++ b/libringbuffer/ring_buffer_frontend.c @@ -72,7 +72,7 @@ #include "backend.h" #include "frontend.h" #include "shm.h" -#include "tlsfixup.h" +#include "rb-init.h" #include "../liblttng-ust/compat.h" /* For ENODATA */ /* Print DBG() messages about events lost only every 1048576 hits */ @@ -84,6 +84,7 @@ #define CLOCKID CLOCK_MONOTONIC #define LTTNG_UST_RING_BUFFER_GET_RETRY 10 #define LTTNG_UST_RING_BUFFER_RETRY_DELAY_MS 10 +#define RETRY_DELAY_MS 100 /* 100 ms. */ /* * Non-static to ensure the compiler does not optimize away the xor. @@ -149,6 +150,14 @@ static struct timer_signal_data timer_signal = { .lock = PTHREAD_MUTEX_INITIALIZER, }; +int lttng_ust_blocking_retry_timeout = + CONFIG_LTTNG_UST_DEFAULT_BLOCKING_RETRY_TIMEOUT_MS; + +void lttng_ust_ringbuffer_set_retry_timeout(int timeout) +{ + lttng_ust_blocking_retry_timeout = timeout; +} + /** * lib_ring_buffer_reset - Reset ring buffer to initial values. * @buf: Ring buffer. @@ -167,7 +176,7 @@ void lib_ring_buffer_reset(struct lttng_ust_lib_ring_buffer *buf, chan = shmp(handle, buf->backend.chan); if (!chan) - abort(); + return; config = &chan->backend.config; /* * Reset iterator first. It will put the subbuffer if it currently holds @@ -175,9 +184,18 @@ void lib_ring_buffer_reset(struct lttng_ust_lib_ring_buffer *buf, */ v_set(config, &buf->offset, 0); for (i = 0; i < chan->backend.num_subbuf; i++) { - v_set(config, &shmp_index(handle, buf->commit_hot, i)->cc, 0); - v_set(config, &shmp_index(handle, buf->commit_hot, i)->seq, 0); - v_set(config, &shmp_index(handle, buf->commit_cold, i)->cc_sb, 0); + struct commit_counters_hot *cc_hot; + struct commit_counters_cold *cc_cold; + + cc_hot = shmp_index(handle, buf->commit_hot, i); + if (!cc_hot) + return; + cc_cold = shmp_index(handle, buf->commit_cold, i); + if (!cc_cold) + return; + v_set(config, &cc_hot->cc, 0); + v_set(config, &cc_hot->seq, 0); + v_set(config, &cc_cold->cc_sb, 0); } uatomic_set(&buf->consumed, 0); uatomic_set(&buf->record_disabled, 0); @@ -313,6 +331,9 @@ int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf, { const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; struct channel *chan = caa_container_of(chanb, struct channel, backend); + struct lttng_ust_lib_ring_buffer_backend_subbuffer *wsb; + struct channel *shmp_chan; + struct commit_counters_hot *cc_hot; void *priv = channel_get_private(chan); size_t subbuf_header_size; uint64_t tsc; @@ -351,11 +372,26 @@ int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf, */ subbuf_header_size = config->cb.subbuffer_header_size(); v_set(config, &buf->offset, subbuf_header_size); - subbuffer_id_clear_noref(config, &shmp_index(handle, buf->backend.buf_wsb, 0)->id); - tsc = config->cb.ring_buffer_clock_read(shmp(handle, buf->backend.chan)); + wsb = shmp_index(handle, buf->backend.buf_wsb, 0); + if (!wsb) { + ret = -EPERM; + goto free_chanbuf; + } + subbuffer_id_clear_noref(config, &wsb->id); + shmp_chan = shmp(handle, buf->backend.chan); + if (!shmp_chan) { + ret = -EPERM; + goto free_chanbuf; + } + tsc = config->cb.ring_buffer_clock_read(shmp_chan); config->cb.buffer_begin(buf, tsc, 0, handle); - v_add(config, subbuf_header_size, &shmp_index(handle, buf->commit_hot, 0)->cc); - v_add(config, subbuf_header_size, &shmp_index(handle, buf->commit_hot, 0)->seq); + cc_hot = shmp_index(handle, buf->commit_hot, 0); + if (!cc_hot) { + ret = -EPERM; + goto free_chanbuf; + } + v_add(config, subbuf_header_size, &cc_hot->cc); + v_add(config, subbuf_header_size, &cc_hot->seq); if (config->cb.buffer_create) { ret = config->cb.buffer_create(buf, priv, cpu, chanb->name, handle); @@ -403,7 +439,7 @@ void lib_ring_buffer_channel_switch_timer(int sig, siginfo_t *si, void *uc) shmp(handle, chan->backend.buf[cpu].shmp); if (!buf) - abort(); + goto end; if (uatomic_read(&buf->active_readers)) lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, chan->handle); @@ -413,11 +449,12 @@ void lib_ring_buffer_channel_switch_timer(int sig, siginfo_t *si, void *uc) shmp(handle, chan->backend.buf[0].shmp); if (!buf) - abort(); + goto end; if (uatomic_read(&buf->active_readers)) lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, chan->handle); } +end: pthread_mutex_unlock(&wakeup_fd_mutex); return; } @@ -429,10 +466,14 @@ int lib_ring_buffer_poll_deliver(const struct lttng_ust_lib_ring_buffer_config * struct lttng_ust_shm_handle *handle) { unsigned long consumed_old, consumed_idx, commit_count, write_offset; + struct commit_counters_cold *cc_cold; consumed_old = uatomic_read(&buf->consumed); consumed_idx = subbuf_index(consumed_old, chan); - commit_count = v_read(config, &shmp_index(handle, buf->commit_cold, consumed_idx)->cc_sb); + cc_cold = shmp_index(handle, buf->commit_cold, consumed_idx); + if (!cc_cold) + return 0; + commit_count = v_read(config, &cc_cold->cc_sb); /* * No memory barrier here, since we are only interested * in a statistically correct polling result. The next poll will @@ -549,7 +590,7 @@ void lib_ring_buffer_channel_do_read(struct channel *chan) shmp(handle, chan->backend.buf[cpu].shmp); if (!buf) - abort(); + goto end; if (uatomic_read(&buf->active_readers) && lib_ring_buffer_poll_deliver(config, buf, chan, handle)) { @@ -561,13 +602,14 @@ void lib_ring_buffer_channel_do_read(struct channel *chan) shmp(handle, chan->backend.buf[0].shmp); if (!buf) - abort(); + goto end; if (uatomic_read(&buf->active_readers) && lib_ring_buffer_poll_deliver(config, buf, chan, handle)) { lib_ring_buffer_wakeup(buf, handle); } } +end: pthread_mutex_unlock(&wakeup_fd_mutex); } @@ -855,22 +897,25 @@ static void channel_print_errors(struct channel *chan, for_each_possible_cpu(cpu) { struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[cpu].shmp); - lib_ring_buffer_print_errors(chan, buf, cpu, handle); + if (buf) + lib_ring_buffer_print_errors(chan, buf, cpu, handle); } } else { struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[0].shmp); - lib_ring_buffer_print_errors(chan, buf, -1, handle); + if (buf) + lib_ring_buffer_print_errors(chan, buf, -1, handle); } } static void channel_free(struct channel *chan, - struct lttng_ust_shm_handle *handle) + struct lttng_ust_shm_handle *handle, + int consumer) { channel_backend_free(&chan->backend, handle); /* chan is freed by shm teardown */ - shm_object_table_destroy(handle->table); + shm_object_table_destroy(handle->table, consumer); free(handle); } @@ -993,7 +1038,7 @@ struct lttng_ust_shm_handle *channel_create(const struct lttng_ust_lib_ring_buff error_backend_init: error_append: - shm_object_table_destroy(handle->table); + shm_object_table_destroy(handle->table, 1); error_table_alloc: free(handle); return NULL; @@ -1025,7 +1070,7 @@ struct lttng_ust_shm_handle *channel_handle_create(void *data, return handle; error_table_object: - shm_object_table_destroy(handle->table); + shm_object_table_destroy(handle->table, 0); error_table_alloc: free(handle); return NULL; @@ -1053,9 +1098,10 @@ unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle) } static -void channel_release(struct channel *chan, struct lttng_ust_shm_handle *handle) +void channel_release(struct channel *chan, struct lttng_ust_shm_handle *handle, + int consumer) { - channel_free(chan, handle); + channel_free(chan, handle, consumer); } /** @@ -1087,7 +1133,7 @@ void channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle, * sessiond/consumer are keeping a reference on the shm file * descriptor directly. No need to refcount. */ - channel_release(chan, handle); + channel_release(chan, handle, consumer); return; } @@ -1188,6 +1234,8 @@ void lib_ring_buffer_release_read(struct lttng_ust_lib_ring_buffer *buf, { struct channel *chan = shmp(handle, buf->backend.chan); + if (!chan) + return; CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1); cmm_smp_mb(); uatomic_dec(&buf->active_readers); @@ -1207,11 +1255,15 @@ int lib_ring_buffer_snapshot(struct lttng_ust_lib_ring_buffer *buf, unsigned long *consumed, unsigned long *produced, struct lttng_ust_shm_handle *handle) { - struct channel *chan = shmp(handle, buf->backend.chan); - const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; + struct channel *chan; + const struct lttng_ust_lib_ring_buffer_config *config; unsigned long consumed_cur, write_offset; int finalized; + chan = shmp(handle, buf->backend.chan); + if (!chan) + return -EPERM; + config = &chan->backend.config; finalized = CMM_ACCESS_ONCE(buf->finalized); /* * Read finalized before counters. @@ -1262,9 +1314,12 @@ void lib_ring_buffer_move_consumer(struct lttng_ust_lib_ring_buffer *buf, struct lttng_ust_shm_handle *handle) { struct lttng_ust_lib_ring_buffer_backend *bufb = &buf->backend; - struct channel *chan = shmp(handle, bufb->chan); + struct channel *chan; unsigned long consumed; + chan = shmp(handle, bufb->chan); + if (!chan) + return; CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1); /* @@ -1290,11 +1345,16 @@ int lib_ring_buffer_get_subbuf(struct lttng_ust_lib_ring_buffer *buf, unsigned long consumed, struct lttng_ust_shm_handle *handle) { - struct channel *chan = shmp(handle, buf->backend.chan); - const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; + struct channel *chan; + const struct lttng_ust_lib_ring_buffer_config *config; unsigned long consumed_cur, consumed_idx, commit_count, write_offset; int ret, finalized, nr_retry = LTTNG_UST_RING_BUFFER_GET_RETRY; + struct commit_counters_cold *cc_cold; + chan = shmp(handle, buf->backend.chan); + if (!chan) + return -EPERM; + config = &chan->backend.config; retry: finalized = CMM_ACCESS_ONCE(buf->finalized); /* @@ -1303,7 +1363,10 @@ retry: cmm_smp_rmb(); consumed_cur = uatomic_read(&buf->consumed); consumed_idx = subbuf_index(consumed, chan); - commit_count = v_read(config, &shmp_index(handle, buf->commit_cold, consumed_idx)->cc_sb); + cc_cold = shmp_index(handle, buf->commit_cold, consumed_idx); + if (!cc_cold) + return -EPERM; + commit_count = v_read(config, &cc_cold->cc_sb); /* * Make sure we read the commit count before reading the buffer * data and the write offset. Correct consumed offset ordering @@ -1446,10 +1509,16 @@ void lib_ring_buffer_put_subbuf(struct lttng_ust_lib_ring_buffer *buf, struct lttng_ust_shm_handle *handle) { struct lttng_ust_lib_ring_buffer_backend *bufb = &buf->backend; - struct channel *chan = shmp(handle, bufb->chan); - const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; - unsigned long read_sb_bindex, consumed_idx, consumed; + struct channel *chan; + const struct lttng_ust_lib_ring_buffer_config *config; + unsigned long sb_bindex, consumed_idx, consumed; + struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages; + struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages; + chan = shmp(handle, bufb->chan); + if (!chan) + return; + config = &chan->backend.config; CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1); if (!buf->get_subbuf) { @@ -1469,11 +1538,16 @@ void lib_ring_buffer_put_subbuf(struct lttng_ust_lib_ring_buffer *buf, * Can be below zero if an iterator is used on a snapshot more than * once. */ - read_sb_bindex = subbuffer_id_get_index(config, bufb->buf_rsb.id); - v_add(config, v_read(config, - &shmp(handle, shmp_index(handle, bufb->array, read_sb_bindex)->shmp)->records_unread), - &bufb->records_read); - v_set(config, &shmp(handle, shmp_index(handle, bufb->array, read_sb_bindex)->shmp)->records_unread, 0); + sb_bindex = subbuffer_id_get_index(config, bufb->buf_rsb.id); + rpages = shmp_index(handle, bufb->array, sb_bindex); + if (!rpages) + return; + backend_pages = shmp(handle, rpages->shmp); + if (!backend_pages) + return; + v_add(config, v_read(config, &backend_pages->records_unread), + &bufb->records_read); + v_set(config, &backend_pages->records_unread, 0); CHAN_WARN_ON(chan, config->mode == RING_BUFFER_OVERWRITE && subbuffer_id_is_noref(config, bufb->buf_rsb.id)); subbuffer_id_set_noref(config, &bufb->buf_rsb.id); @@ -1509,10 +1583,18 @@ void lib_ring_buffer_print_subbuffer_errors(struct lttng_ust_lib_ring_buffer *bu { const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; unsigned long cons_idx, commit_count, commit_count_sb; + struct commit_counters_hot *cc_hot; + struct commit_counters_cold *cc_cold; cons_idx = subbuf_index(cons_offset, chan); - commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, cons_idx)->cc); - commit_count_sb = v_read(config, &shmp_index(handle, buf->commit_cold, cons_idx)->cc_sb); + cc_hot = shmp_index(handle, buf->commit_hot, cons_idx); + if (!cc_hot) + return; + cc_cold = shmp_index(handle, buf->commit_cold, cons_idx); + if (!cc_cold) + return; + commit_count = v_read(config, &cc_hot->cc); + commit_count_sb = v_read(config, &cc_cold->cc_sb); if (subbuf_offset(commit_count, chan) != 0) DBG("ring buffer %s, cpu %d: " @@ -1609,6 +1691,7 @@ void lib_ring_buffer_switch_old_start(struct lttng_ust_lib_ring_buffer *buf, const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; unsigned long oldidx = subbuf_index(offsets->old, chan); unsigned long commit_count; + struct commit_counters_hot *cc_hot; config->cb.buffer_begin(buf, tsc, oldidx, handle); @@ -1617,15 +1700,18 @@ void lib_ring_buffer_switch_old_start(struct lttng_ust_lib_ring_buffer *buf, * determine that the subbuffer is full. */ cmm_smp_wmb(); + cc_hot = shmp_index(handle, buf->commit_hot, oldidx); + if (!cc_hot) + return; v_add(config, config->cb.subbuffer_header_size(), - &shmp_index(handle, buf->commit_hot, oldidx)->cc); - commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, oldidx)->cc); + &cc_hot->cc); + commit_count = v_read(config, &cc_hot->cc); /* Check if the written buffer has to be delivered */ lib_ring_buffer_check_deliver(config, buf, chan, offsets->old, commit_count, oldidx, handle, tsc); - lib_ring_buffer_write_commit_counter(config, buf, chan, oldidx, + lib_ring_buffer_write_commit_counter(config, buf, chan, offsets->old + config->cb.subbuffer_header_size(), - commit_count, handle); + commit_count, handle, cc_hot); } /* @@ -1646,6 +1732,7 @@ void lib_ring_buffer_switch_old_end(struct lttng_ust_lib_ring_buffer *buf, const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; unsigned long oldidx = subbuf_index(offsets->old - 1, chan); unsigned long commit_count, padding_size, data_size; + struct commit_counters_hot *cc_hot; data_size = subbuf_offset(offsets->old - 1, chan) + 1; padding_size = chan->backend.subbuf_size - data_size; @@ -1657,12 +1744,16 @@ void lib_ring_buffer_switch_old_end(struct lttng_ust_lib_ring_buffer *buf, * determine that the subbuffer is full. */ cmm_smp_wmb(); - v_add(config, padding_size, &shmp_index(handle, buf->commit_hot, oldidx)->cc); - commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, oldidx)->cc); + cc_hot = shmp_index(handle, buf->commit_hot, oldidx); + if (!cc_hot) + return; + v_add(config, padding_size, &cc_hot->cc); + commit_count = v_read(config, &cc_hot->cc); lib_ring_buffer_check_deliver(config, buf, chan, offsets->old - 1, commit_count, oldidx, handle, tsc); - lib_ring_buffer_write_commit_counter(config, buf, chan, oldidx, - offsets->old + padding_size, commit_count, handle); + lib_ring_buffer_write_commit_counter(config, buf, chan, + offsets->old + padding_size, commit_count, handle, + cc_hot); } /* @@ -1682,6 +1773,7 @@ void lib_ring_buffer_switch_new_start(struct lttng_ust_lib_ring_buffer *buf, const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; unsigned long beginidx = subbuf_index(offsets->begin, chan); unsigned long commit_count; + struct commit_counters_hot *cc_hot; config->cb.buffer_begin(buf, tsc, beginidx, handle); @@ -1690,15 +1782,17 @@ void lib_ring_buffer_switch_new_start(struct lttng_ust_lib_ring_buffer *buf, * determine that the subbuffer is full. */ cmm_smp_wmb(); - v_add(config, config->cb.subbuffer_header_size(), - &shmp_index(handle, buf->commit_hot, beginidx)->cc); - commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, beginidx)->cc); + cc_hot = shmp_index(handle, buf->commit_hot, beginidx); + if (!cc_hot) + return; + v_add(config, config->cb.subbuffer_header_size(), &cc_hot->cc); + commit_count = v_read(config, &cc_hot->cc); /* Check if the written buffer has to be delivered */ lib_ring_buffer_check_deliver(config, buf, chan, offsets->begin, commit_count, beginidx, handle, tsc); - lib_ring_buffer_write_commit_counter(config, buf, chan, beginidx, + lib_ring_buffer_write_commit_counter(config, buf, chan, offsets->begin + config->cb.subbuffer_header_size(), - commit_count, handle); + commit_count, handle, cc_hot); } /* @@ -1769,6 +1863,7 @@ int lib_ring_buffer_try_switch_slow(enum switch_mode mode, if (caa_unlikely(off == 0)) { unsigned long sb_index, commit_count; + struct commit_counters_cold *cc_cold; /* * We are performing a SWITCH_FLUSH. There may be concurrent @@ -1785,9 +1880,10 @@ int lib_ring_buffer_try_switch_slow(enum switch_mode mode, /* Test new buffer integrity */ sb_index = subbuf_index(offsets->begin, chan); - commit_count = v_read(config, - &shmp_index(handle, buf->commit_cold, - sb_index)->cc_sb); + cc_cold = shmp_index(handle, buf->commit_cold, sb_index); + if (!cc_cold) + return -1; + commit_count = v_read(config, &cc_cold->cc_sb); reserve_commit_diff = (buf_trunc(offsets->begin, chan) >> chan->backend.num_subbuf_order) @@ -1845,12 +1941,17 @@ int lib_ring_buffer_try_switch_slow(enum switch_mode mode, void lib_ring_buffer_switch_slow(struct lttng_ust_lib_ring_buffer *buf, enum switch_mode mode, struct lttng_ust_shm_handle *handle) { - struct channel *chan = shmp(handle, buf->backend.chan); - const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; + struct channel *chan; + const struct lttng_ust_lib_ring_buffer_config *config; struct switch_offsets offsets; unsigned long oldidx; uint64_t tsc; + chan = shmp(handle, buf->backend.chan); + if (!chan) + return; + config = &chan->backend.config; + offsets.size = 0; /* @@ -1893,6 +1994,23 @@ void lib_ring_buffer_switch_slow(struct lttng_ust_lib_ring_buffer *buf, enum swi lib_ring_buffer_switch_old_end(buf, chan, &offsets, tsc, handle); } +static +bool handle_blocking_retry(int *timeout_left_ms) +{ + int timeout = *timeout_left_ms, delay; + + if (caa_likely(!timeout)) + return false; /* Do not retry, discard event. */ + if (timeout < 0) /* Wait forever. */ + delay = RETRY_DELAY_MS; + else + delay = min_t(int, timeout, RETRY_DELAY_MS); + (void) poll(NULL, 0, delay); + if (timeout > 0) + *timeout_left_ms -= delay; + return true; /* Retry. */ +} + /* * Returns : * 0 if ok @@ -1909,6 +2027,7 @@ int lib_ring_buffer_try_reserve_slow(struct lttng_ust_lib_ring_buffer *buf, const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config; struct lttng_ust_shm_handle *handle = ctx->handle; unsigned long reserve_commit_diff, offset_cmp; + int timeout_left_ms = lttng_ust_blocking_retry_timeout; retry: offsets->begin = offset_cmp = v_read(config, &buf->offset); @@ -1944,6 +2063,7 @@ retry: } if (caa_unlikely(offsets->switch_new_start)) { unsigned long sb_index, commit_count; + struct commit_counters_cold *cc_cold; /* * We are typically not filling the previous buffer completely. @@ -1962,9 +2082,10 @@ retry: * are not seen reordered when updated by another CPU. */ cmm_smp_rmb(); - commit_count = v_read(config, - &shmp_index(handle, buf->commit_cold, - sb_index)->cc_sb); + cc_cold = shmp_index(handle, buf->commit_cold, sb_index); + if (!cc_cold) + return -1; + commit_count = v_read(config, &cc_cold->cc_sb); /* Read buf->commit_cold[sb_index].cc_sb before buf->offset. */ cmm_smp_rmb(); if (caa_unlikely(offset_cmp != v_read(config, &buf->offset))) { @@ -1989,6 +2110,9 @@ retry: >= chan->backend.buf_size)) { unsigned long nr_lost; + if (handle_blocking_retry(&timeout_left_ms)) + goto retry; + /* * We do not overwrite non consumed buffers * and we are full : record is lost. @@ -2099,6 +2223,8 @@ int lib_ring_buffer_reserve_slow(struct lttng_ust_lib_ring_buffer_ctx *ctx) buf = shmp(handle, chan->backend.buf[ctx->cpu].shmp); else buf = shmp(handle, chan->backend.buf[0].shmp); + if (!buf) + return -EIO; ctx->buf = buf; offsets.size = 0; @@ -2164,8 +2290,14 @@ void lib_ring_buffer_vmcore_check_deliver(const struct lttng_ust_lib_ring_buffer unsigned long idx, struct lttng_ust_shm_handle *handle) { - if (config->oops == RING_BUFFER_OOPS_CONSISTENCY) - v_set(config, &shmp_index(handle, buf->commit_hot, idx)->seq, commit_count); + struct commit_counters_hot *cc_hot; + + if (config->oops != RING_BUFFER_OOPS_CONSISTENCY) + return; + cc_hot = shmp_index(handle, buf->commit_hot, idx); + if (!cc_hot) + return; + v_set(config, &cc_hot->seq, commit_count); } /* @@ -2207,6 +2339,7 @@ void lib_ring_buffer_check_deliver_slow(const struct lttng_ust_lib_ring_buffer_c { unsigned long old_commit_count = commit_count - chan->backend.subbuf_size; + struct commit_counters_cold *cc_cold; /* * If we succeeded at updating cc_sb below, we are the subbuffer @@ -2240,7 +2373,10 @@ void lib_ring_buffer_check_deliver_slow(const struct lttng_ust_lib_ring_buffer_c * commit_cold cc_sb update. */ cmm_smp_wmb(); - if (caa_likely(v_cmpxchg(config, &shmp_index(handle, buf->commit_cold, idx)->cc_sb, + cc_cold = shmp_index(handle, buf->commit_cold, idx); + if (!cc_cold) + return; + if (caa_likely(v_cmpxchg(config, &cc_cold->cc_sb, old_commit_count, old_commit_count + 1) == old_commit_count)) { /* @@ -2279,8 +2415,7 @@ void lib_ring_buffer_check_deliver_slow(const struct lttng_ust_lib_ring_buffer_c */ cmm_smp_mb(); /* End of exclusive subbuffer access */ - v_set(config, &shmp_index(handle, buf->commit_cold, idx)->cc_sb, - commit_count); + v_set(config, &cc_cold->cc_sb, commit_count); /* * Order later updates to reserve count after * the commit cold cc_sb update.