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@@ -2439,7 +2439,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
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sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
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if (sret != -EBUSY)
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return sret;
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- sret = 0;
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trace_seq_reset(&iter->seq);
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@@ -2450,6 +2449,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
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goto out;
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}
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+waitagain:
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+ sret = 0;
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while (trace_empty(iter)) {
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if ((filp->f_flags & O_NONBLOCK)) {
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@@ -2556,8 +2557,13 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
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sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
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if (iter->seq.readpos >= iter->seq.len)
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trace_seq_reset(&iter->seq);
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+
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+ /*
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+ * If there was nothing to send to user, inspite of consuming trace
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+ * entries, go back to wait for more entries.
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+ */
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if (sret == -EBUSY)
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- sret = 0;
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+ goto waitagain;
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out:
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mutex_unlock(&trace_types_lock);
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