From: Amos Kong <akong@redhat.com>
Date: Thu, 21 Nov 2013 08:42:51 +0000 (+0800)
Subject: rng-egd: offset the point when repeatedly read from the buffer
X-Git-Tag: qemu-xen-4.4.0-rc3~11
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=7cfd037403ba34e8ed1ebfa4e7d6abec738e2000;p=qemu-upstream-4.4-testing.git

rng-egd: offset the point when repeatedly read from the buffer

The buffer content might be read out more than once, currently
we just repeatedly read the first data block, buffer offset is
missing.

Cc: qemu-stable@nongnu.org
Signed-off-by: Amos Kong <akong@redhat.com>
Message-id: 1385023371-8198-3-git-send-email-akong@redhat.com
Signed-off-by: Anthony Liguori <aliguori@amazon.com>
(cherry picked from commit 1eb1bd9eafa890f1f4d16ef5cb8b9239a86874d9)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---

diff --git a/backends/rng-egd.c b/backends/rng-egd.c
index 9e5a5366f..2962795a8 100644
--- a/backends/rng-egd.c
+++ b/backends/rng-egd.c
@@ -91,12 +91,14 @@ static int rng_egd_chr_can_read(void *opaque)
 static void rng_egd_chr_read(void *opaque, const uint8_t *buf, int size)
 {
     RngEgd *s = RNG_EGD(opaque);
+    size_t buf_offset = 0;
 
     while (size > 0 && s->requests) {
         RngRequest *req = s->requests->data;
         int len = MIN(size, req->size - req->offset);
 
-        memcpy(req->data + req->offset, buf, len);
+        memcpy(req->data + req->offset, buf + buf_offset, len);
+        buf_offset += len;
         req->offset += len;
         size -= len;