Fix: alignment of ring buffer shm space reservation

[lttng-ust.git] / libringbuffer / ring_buffer_backend.c

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 961f118a088f587ed60172d265d6c09c578b5106..2dea1db51f537ca344206ec3daca965cd0745301 100644 (file)
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -19,6 +19,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <unistd.h>
 #include <urcu/arch.h>
 #include <limits.h>
@@ -118,7 +119,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
                bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
 
        /* Allocate subbuffer packet counter table */
-       align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer));
+       align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_counts));
        set_shmp(bufb->buf_cnt, zalloc_shm(shmobj,
                                sizeof(struct lttng_ust_lib_ring_buffer_backend_counts)
                                * num_subbuf));
@@ -186,7 +187,7 @@ void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *buf
 
        chanb = &shmp(handle, bufb->chan)->backend;
        if (!chanb)
-               abort();
+               return;
        config = &chanb->config;
 
        num_subbuf_alloc = chanb->num_subbuf;
@@ -198,7 +199,7 @@ void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *buf
 
                sb = shmp_index(handle, bufb->buf_wsb, i);
                if (!sb)
-                       abort();
+                       return;
                sb->id = subbuffer_id(config, 0, 1, i);
        }
        if (chanb->extra_reader_sb)
@@ -213,10 +214,10 @@ void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *buf
 
                sbp = shmp_index(handle, bufb->array, i);
                if (!sbp)
-                       abort();
+                       return;
                pages = shmp(handle, sbp->shmp);
                if (!pages)
-                       abort();
+                       return;
                /* Don't reset mmap_offset */
                v_set(config, &pages->records_commit, 0);
                v_set(config, &pages->records_unread, 0);
@@ -321,6 +322,13 @@ int channel_backend_init(struct channel_backend *chanb,
        /* Per-cpu buffer size: control (prior to backend) */
        shmsize = offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer));
        shmsize += sizeof(struct lttng_ust_lib_ring_buffer);
+       shmsize += offset_align(shmsize, __alignof__(struct commit_counters_hot));
+       shmsize += sizeof(struct commit_counters_hot) * num_subbuf;
+       shmsize += offset_align(shmsize, __alignof__(struct commit_counters_cold));
+       shmsize += sizeof(struct commit_counters_cold) * num_subbuf;
+       /* Sampled timestamp end */
+       shmsize += offset_align(shmsize, __alignof__(uint64_t));
+       shmsize += sizeof(uint64_t) * num_subbuf;
 
        /* Per-cpu buffer size: backend */
        /* num_subbuf + 1 is the worse case */
@@ -333,11 +341,8 @@ int channel_backend_init(struct channel_backend *chanb,
        shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages) * num_subbuf_alloc;
        shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer));
        shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_subbuffer) * num_subbuf;
-       /* Per-cpu buffer size: control (after backend) */
-       shmsize += offset_align(shmsize, __alignof__(struct commit_counters_hot));
-       shmsize += sizeof(struct commit_counters_hot) * num_subbuf;
-       shmsize += offset_align(shmsize, __alignof__(struct commit_counters_cold));
-       shmsize += sizeof(struct commit_counters_cold) * num_subbuf;
+       shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_counts));
+       shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_counts) * num_subbuf;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
                struct lttng_ust_lib_ring_buffer *buf;
@@ -348,7 +353,7 @@ int channel_backend_init(struct channel_backend *chanb,
                        struct shm_object *shmobj;
 
                        shmobj = shm_object_table_alloc(handle->table, shmsize,
-                                       SHM_OBJECT_SHM, stream_fds[i]);
+                                       SHM_OBJECT_SHM, stream_fds[i], i);
                        if (!shmobj)
                                goto end;
                        align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -367,7 +372,7 @@ int channel_backend_init(struct channel_backend *chanb,
                struct lttng_ust_lib_ring_buffer *buf;
 
                shmobj = shm_object_table_alloc(handle->table, shmsize,
-                                       SHM_OBJECT_SHM, stream_fds[0]);
+                                       SHM_OBJECT_SHM, stream_fds[0], -1);
                if (!shmobj)
                        goto end;
                align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -420,6 +425,7 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        const struct lttng_ust_lib_ring_buffer_config *config;
        ssize_t orig_len;
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
+       struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
        unsigned long sb_bindex, id;
        void *src;
 
@@ -435,6 +441,8 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        id = bufb->buf_rsb.id;
        sb_bindex = subbuffer_id_get_index(config, id);
        rpages = shmp_index(handle, bufb->array, sb_bindex);
+       if (!rpages)
+               return 0;
        /*
         * Underlying layer should never ask for reads across
         * subbuffers.
@@ -442,8 +450,10 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
-       src = shmp_index(handle, shmp(handle, rpages->shmp)->p,
-                       offset & (chanb->subbuf_size - 1));
+       backend_pages = shmp(handle, rpages->shmp);
+       if (!backend_pages)
+               return 0;
+       src = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
        if (caa_unlikely(!src))
                return 0;
        memcpy(dest, src, len);
@@ -469,6 +479,7 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si
        ssize_t string_len, orig_offset;
        char *str;
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
+       struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
        unsigned long sb_bindex, id;
 
        chanb = &shmp(handle, bufb->chan)->backend;
@@ -482,6 +493,8 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si
        id = bufb->buf_rsb.id;
        sb_bindex = subbuffer_id_get_index(config, id);
        rpages = shmp_index(handle, bufb->array, sb_bindex);
+       if (!rpages)
+               return -EINVAL;
        /*
         * Underlying layer should never ask for reads across
         * subbuffers.
@@ -489,7 +502,10 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si
        CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
-       str = shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1));
+       backend_pages = shmp(handle, rpages->shmp);
+       if (!backend_pages)
+               return -EINVAL;
+       str = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
        if (caa_unlikely(!str))
                return -EINVAL;
        string_len = strnlen(str, len);
@@ -516,6 +532,7 @@ void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backe
                                          struct lttng_ust_shm_handle *handle)
 {
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
+       struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
        struct channel_backend *chanb;
        const struct lttng_ust_lib_ring_buffer_config *config;
        unsigned long sb_bindex, id;
@@ -528,9 +545,14 @@ void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backe
        id = bufb->buf_rsb.id;
        sb_bindex = subbuffer_id_get_index(config, id);
        rpages = shmp_index(handle, bufb->array, sb_bindex);
+       if (!rpages)
+               return NULL;
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
-       return shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1));
+       backend_pages = shmp(handle, rpages->shmp);
+       if (!backend_pages)
+               return NULL;
+       return shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
 }
 
 /**
@@ -549,6 +571,7 @@ void *lib_ring_buffer_offset_address(struct lttng_ust_lib_ring_buffer_backend *b
 {
        size_t sbidx;
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
+       struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
        struct channel_backend *chanb;
        const struct lttng_ust_lib_ring_buffer_config *config;
        unsigned long sb_bindex, id;
@@ -566,7 +589,12 @@ void *lib_ring_buffer_offset_address(struct lttng_ust_lib_ring_buffer_backend *b
        id = sb->id;
        sb_bindex = subbuffer_id_get_index(config, id);
        rpages = shmp_index(handle, bufb->array, sb_bindex);
+       if (!rpages)
+               return NULL;
        CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
                     && subbuffer_id_is_noref(config, id));
-       return shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1));
+       backend_pages = shmp(handle, rpages->shmp);
+       if (!backend_pages)
+               return NULL;
+       return shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
 }