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@@ -3277,19 +3277,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
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info->tr = &global_trace;
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info->cpu = cpu;
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- info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
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+ info->spare = NULL;
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/* Force reading ring buffer for first read */
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info->read = (unsigned int)-1;
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- if (!info->spare)
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- goto out;
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filp->private_data = info;
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- return 0;
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-
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- out:
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- kfree(info);
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- return -ENOMEM;
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+ return nonseekable_open(inode, filp);
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}
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static ssize_t
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@@ -3304,6 +3298,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
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if (!count)
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return 0;
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+ if (!info->spare)
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+ info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
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+ if (!info->spare)
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+ return -ENOMEM;
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+
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/* Do we have previous read data to read? */
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if (info->read < PAGE_SIZE)
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goto read;
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@@ -3342,7 +3341,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
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{
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struct ftrace_buffer_info *info = file->private_data;
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- ring_buffer_free_read_page(info->tr->buffer, info->spare);
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+ if (info->spare)
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+ ring_buffer_free_read_page(info->tr->buffer, info->spare);
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kfree(info);
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return 0;
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@@ -3428,14 +3428,19 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
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int size, i;
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size_t ret;
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- /*
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- * We can't seek on a buffer input
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- */
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- if (unlikely(*ppos))
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- return -ESPIPE;
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+ if (*ppos & (PAGE_SIZE - 1)) {
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+ WARN_ONCE(1, "Ftrace: previous read must page-align\n");
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+ return -EINVAL;
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+ }
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+ if (len & (PAGE_SIZE - 1)) {
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+ WARN_ONCE(1, "Ftrace: splice_read should page-align\n");
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+ if (len < PAGE_SIZE)
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+ return -EINVAL;
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+ len &= PAGE_MASK;
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+ }
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- for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) {
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+ for (i = 0; i < PIPE_BUFFERS && len; i++, len -= PAGE_SIZE) {
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struct page *page;
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int r;
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@@ -3474,6 +3479,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
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spd.partial[i].offset = 0;
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spd.partial[i].private = (unsigned long)ref;
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spd.nr_pages++;
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+ *ppos += PAGE_SIZE;
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}
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spd.nr_pages = i;
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