}
EXPORT_SYMBOL_GPL(_lib_ring_buffer_strcpy);
+/**
+ * _lib_ring_buffer_pstrcpy - write to a buffer backend P-string
+ * @bufb : buffer backend
+ * @src : source pointer to copy from
+ * @len : length of data to copy
+ * @pad : character to use for padding
+ *
+ * This function copies up to @len bytes of data from a source pointer
+ * to a Pascal String into the buffer backend. If a terminating '\0'
+ * character is found in @src before @len characters are copied, pad the
+ * buffer with @pad characters (e.g. '\0').
+ *
+ * The length of the pascal strings in the ring buffer is explicit: it
+ * is either the array or sequence length.
+ */
+void _lib_ring_buffer_pstrcpy(struct lttng_kernel_ring_buffer_backend *bufb,
+ size_t offset, const char *src, size_t len, int pad)
+{
+ struct channel_backend *chanb = &bufb->chan->backend;
+ const struct lttng_kernel_ring_buffer_config *config = &chanb->config;
+ size_t sbidx, index, bytes_left_in_page;
+ struct lttng_kernel_ring_buffer_backend_pages *rpages;
+ unsigned long sb_bindex, id;
+ bool src_terminated = false;
+
+ CHAN_WARN_ON(chanb, !len);
+ do {
+ sbidx = offset >> chanb->subbuf_size_order;
+ index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT;
+
+ /*
+ * Underlying layer should never ask for writes across
+ * subbuffers.
+ */
+ CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
+
+ bytes_left_in_page = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
+ id = bufb->buf_wsb[sbidx].id;
+ sb_bindex = subbuffer_id_get_index(config, id);
+ rpages = bufb->array[sb_bindex];
+ CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
+ && subbuffer_id_is_noref(config, id));
+
+ if (likely(!src_terminated)) {
+ size_t count, to_copy;
+
+ to_copy = bytes_left_in_page;
+ count = lib_ring_buffer_do_strcpy(config,
+ rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ src, to_copy);
+ offset += count;
+ /* Padding */
+ if (unlikely(count < to_copy)) {
+ size_t pad_len = to_copy - count;
+
+ /* Next pages will have padding */
+ src_terminated = true;
+ lib_ring_buffer_do_memset(rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ pad, pad_len);
+ offset += pad_len;
+ }
+ } else {
+ size_t pad_len;
+
+ pad_len = bytes_left_in_page;
+ lib_ring_buffer_do_memset(rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ pad, pad_len);
+ offset += pad_len;
+ }
+ len -= bytes_left_in_page;
+ if (!src_terminated)
+ src += bytes_left_in_page;
+ } while (unlikely(len));
+}
+EXPORT_SYMBOL_GPL(_lib_ring_buffer_pstrcpy);
+
/**
* lib_ring_buffer_copy_from_user_inatomic - write user data to a ring_buffer buffer.
* @bufb : buffer backend
}
EXPORT_SYMBOL_GPL(_lib_ring_buffer_strcpy_from_user_inatomic);
+/**
+ * _lib_ring_buffer_pstrcpy_from_user_inatomic - write userspace string to a buffer backend P-string
+ * @bufb : buffer backend
+ * @src : source pointer to copy from
+ * @len : length of data to copy
+ * @pad : character to use for padding
+ *
+ * This function copies up to @len bytes of data from a source pointer
+ * to a Pascal String into the buffer backend. If a terminating '\0'
+ * character is found in @src before @len characters are copied, pad the
+ * buffer with @pad characters (e.g. '\0').
+ *
+ * The length of the pascal strings in the ring buffer is explicit: it
+ * is either the array or sequence length.
+ *
+ * This function deals with userspace pointers, it should never be called
+ * directly without having the src pointer checked with access_ok()
+ * previously.
+ */
+void _lib_ring_buffer_pstrcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_backend *bufb,
+ size_t offset, const char __user *src, size_t len, int pad)
+{
+ struct channel_backend *chanb = &bufb->chan->backend;
+ const struct lttng_kernel_ring_buffer_config *config = &chanb->config;
+ size_t sbidx, index, bytes_left_in_page;
+ struct lttng_kernel_ring_buffer_backend_pages *rpages;
+ unsigned long sb_bindex, id;
+ bool src_terminated = false;
+
+ CHAN_WARN_ON(chanb, !len);
+ do {
+ sbidx = offset >> chanb->subbuf_size_order;
+ index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT;
+
+ /*
+ * Underlying layer should never ask for writes across
+ * subbuffers.
+ */
+ CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
+
+ bytes_left_in_page = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
+ id = bufb->buf_wsb[sbidx].id;
+ sb_bindex = subbuffer_id_get_index(config, id);
+ rpages = bufb->array[sb_bindex];
+ CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
+ && subbuffer_id_is_noref(config, id));
+
+ if (likely(!src_terminated)) {
+ size_t count, to_copy;
+
+ to_copy = bytes_left_in_page;
+ count = lib_ring_buffer_do_strcpy_from_user_inatomic(config,
+ rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ src, to_copy);
+ offset += count;
+ /* Padding */
+ if (unlikely(count < to_copy)) {
+ size_t pad_len = to_copy - count;
+
+ /* Next pages will have padding */
+ src_terminated = true;
+ lib_ring_buffer_do_memset(rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ pad, pad_len);
+ offset += pad_len;
+ }
+ } else {
+ size_t pad_len;
+
+ pad_len = bytes_left_in_page;
+ lib_ring_buffer_do_memset(rpages->p[index].virt
+ + (offset & ~PAGE_MASK),
+ pad, pad_len);
+ offset += pad_len;
+ }
+ len -= bytes_left_in_page;
+ if (!src_terminated)
+ src += bytes_left_in_page;
+ } while (unlikely(len));
+}
+EXPORT_SYMBOL_GPL(_lib_ring_buffer_pstrcpy_from_user_inatomic);
+
/**
* lib_ring_buffer_read - read data from ring_buffer_buffer.
* @bufb : buffer backend
projects / lttng-modules.git / blobdiff