diff options
Diffstat (limited to 'kernel/relay.c')
-rw-r--r-- | kernel/relay.c | 185 |
1 files changed, 10 insertions, 175 deletions
diff --git a/kernel/relay.c b/kernel/relay.c index d1a67fbb819d..a8ae436dc77e 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -60,10 +60,7 @@ static const struct vm_operations_struct relay_file_mmap_ops = { */ static struct page **relay_alloc_page_array(unsigned int n_pages) { - const size_t pa_size = n_pages * sizeof(struct page *); - if (pa_size > PAGE_SIZE) - return vzalloc(pa_size); - return kzalloc(pa_size, GFP_KERNEL); + return kvcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); } /* @@ -94,7 +91,7 @@ static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) return -EINVAL; vma->vm_ops = &relay_file_mmap_ops; - vma->vm_flags |= VM_DONTEXPAND; + vm_flags_set(vma, VM_DONTEXPAND); vma->vm_private_data = buf; return 0; @@ -151,13 +148,13 @@ static struct rchan_buf *relay_create_buf(struct rchan *chan) { struct rchan_buf *buf; - if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t *)) + if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t)) return NULL; buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); if (!buf) return NULL; - buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t *), + buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t), GFP_KERNEL); if (!buf->padding) goto free_buf; @@ -378,7 +375,7 @@ static struct dentry *relay_create_buf_file(struct rchan *chan, */ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) { - struct rchan_buf *buf = NULL; + struct rchan_buf *buf; struct dentry *dentry; if (chan->is_global) @@ -440,7 +437,7 @@ int relay_prepare_cpu(unsigned int cpu) mutex_lock(&relay_channels_mutex); list_for_each_entry(chan, &relay_channels, list) { - if ((buf = *per_cpu_ptr(chan->buf, cpu))) + if (*per_cpu_ptr(chan->buf, cpu)) continue; buf = relay_open_buf(chan, cpu); if (!buf) { @@ -510,7 +507,7 @@ struct rchan *relay_open(const char *base_filename, chan->private_data = private_data; if (base_filename) { chan->has_base_filename = 1; - strlcpy(chan->base_filename, base_filename, NAME_MAX); + strscpy(chan->base_filename, base_filename, NAME_MAX); } chan->cb = cb; kref_init(&chan->kref); @@ -581,7 +578,7 @@ int relay_late_setup_files(struct rchan *chan, if (!chan || !base_filename) return -EINVAL; - strlcpy(chan->base_filename, base_filename, NAME_MAX); + strscpy(chan->base_filename, base_filename, NAME_MAX); mutex_lock(&relay_channels_mutex); /* Is chan already set up? */ @@ -992,7 +989,8 @@ static size_t relay_file_read_start_pos(struct rchan_buf *buf) size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; size_t consumed = buf->subbufs_consumed % n_subbufs; - size_t read_pos = consumed * subbuf_size + buf->bytes_consumed; + size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed) + % (n_subbufs * subbuf_size); read_subbuf = read_pos / subbuf_size; padding = buf->padding[read_subbuf]; @@ -1075,175 +1073,12 @@ static ssize_t relay_file_read(struct file *filp, return written; } -static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed) -{ - rbuf->bytes_consumed += bytes_consumed; - - if (rbuf->bytes_consumed >= rbuf->chan->subbuf_size) { - relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1); - rbuf->bytes_consumed %= rbuf->chan->subbuf_size; - } -} - -static void relay_pipe_buf_release(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) -{ - struct rchan_buf *rbuf; - - rbuf = (struct rchan_buf *)page_private(buf->page); - relay_consume_bytes(rbuf, buf->private); -} - -static const struct pipe_buf_operations relay_pipe_buf_ops = { - .release = relay_pipe_buf_release, - .try_steal = generic_pipe_buf_try_steal, - .get = generic_pipe_buf_get, -}; - -static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i) -{ -} - -/* - * subbuf_splice_actor - splice up to one subbuf's worth of data - */ -static ssize_t subbuf_splice_actor(struct file *in, - loff_t *ppos, - struct pipe_inode_info *pipe, - size_t len, - unsigned int flags, - int *nonpad_ret) -{ - unsigned int pidx, poff, total_len, subbuf_pages, nr_pages; - struct rchan_buf *rbuf = in->private_data; - unsigned int subbuf_size = rbuf->chan->subbuf_size; - uint64_t pos = (uint64_t) *ppos; - uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size; - size_t read_start = (size_t) do_div(pos, alloc_size); - size_t read_subbuf = read_start / subbuf_size; - size_t padding = rbuf->padding[read_subbuf]; - size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding; - struct page *pages[PIPE_DEF_BUFFERS]; - struct partial_page partial[PIPE_DEF_BUFFERS]; - struct splice_pipe_desc spd = { - .pages = pages, - .nr_pages = 0, - .nr_pages_max = PIPE_DEF_BUFFERS, - .partial = partial, - .ops = &relay_pipe_buf_ops, - .spd_release = relay_page_release, - }; - ssize_t ret; - - if (rbuf->subbufs_produced == rbuf->subbufs_consumed) - return 0; - if (splice_grow_spd(pipe, &spd)) - return -ENOMEM; - - /* - * Adjust read len, if longer than what is available - */ - if (len > (subbuf_size - read_start % subbuf_size)) - len = subbuf_size - read_start % subbuf_size; - - subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; - pidx = (read_start / PAGE_SIZE) % subbuf_pages; - poff = read_start & ~PAGE_MASK; - nr_pages = min_t(unsigned int, subbuf_pages, spd.nr_pages_max); - - for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) { - unsigned int this_len, this_end, private; - unsigned int cur_pos = read_start + total_len; - - if (!len) - break; - - this_len = min_t(unsigned long, len, PAGE_SIZE - poff); - private = this_len; - - spd.pages[spd.nr_pages] = rbuf->page_array[pidx]; - spd.partial[spd.nr_pages].offset = poff; - - this_end = cur_pos + this_len; - if (this_end >= nonpad_end) { - this_len = nonpad_end - cur_pos; - private = this_len + padding; - } - spd.partial[spd.nr_pages].len = this_len; - spd.partial[spd.nr_pages].private = private; - - len -= this_len; - total_len += this_len; - poff = 0; - pidx = (pidx + 1) % subbuf_pages; - - if (this_end >= nonpad_end) { - spd.nr_pages++; - break; - } - } - - ret = 0; - if (!spd.nr_pages) - goto out; - - ret = *nonpad_ret = splice_to_pipe(pipe, &spd); - if (ret < 0 || ret < total_len) - goto out; - - if (read_start + ret == nonpad_end) - ret += padding; - -out: - splice_shrink_spd(&spd); - return ret; -} - -static ssize_t relay_file_splice_read(struct file *in, - loff_t *ppos, - struct pipe_inode_info *pipe, - size_t len, - unsigned int flags) -{ - ssize_t spliced; - int ret; - int nonpad_ret = 0; - - ret = 0; - spliced = 0; - - while (len && !spliced) { - ret = subbuf_splice_actor(in, ppos, pipe, len, flags, &nonpad_ret); - if (ret < 0) - break; - else if (!ret) { - if (flags & SPLICE_F_NONBLOCK) - ret = -EAGAIN; - break; - } - - *ppos += ret; - if (ret > len) - len = 0; - else - len -= ret; - spliced += nonpad_ret; - nonpad_ret = 0; - } - - if (spliced) - return spliced; - - return ret; -} const struct file_operations relay_file_operations = { .open = relay_file_open, .poll = relay_file_poll, .mmap = relay_file_mmap, .read = relay_file_read, - .llseek = no_llseek, .release = relay_file_release, - .splice_read = relay_file_splice_read, }; EXPORT_SYMBOL_GPL(relay_file_operations); |