ring buffer: handle shmp errors

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

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 3dca862712ef4116a315eb2754a2b417fdeea7a1..8eafc51ff7a6b42c57afac6417ff2ac94ea40fd8 100644 (file)
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -187,7 +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;
@@ -199,7 +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)
@@ -214,10 +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);
@@ -421,6 +421,7 @@ 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;
 
@@ -436,6 +437,8 @@ 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.
@@ -443,8 +446,10 @@ 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);
@@ -470,6 +475,7 @@ 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;
@@ -483,6 +489,8 @@ 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.
@@ -490,7 +498,10 @@ 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);
@@ -517,6 +528,7 @@ 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;
@@ -529,9 +541,14 @@ 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));
 }
 
 /**
@@ -550,6 +567,7 @@ 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;
@@ -567,7 +585,12 @@ 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));
 }