rng random backend: check for -EAGAIN errors on read

Not handling EAGAIN triggers the assert

qemu/backends/rng-random.c:44:entropy_available: assertion failed: (len != -1)
Aborted (core dumped)

This happens when starting a guest with '-device virtio-rng-pci',
issuing a 'cat /dev/hwrng' in the guest, while also doing 'cat
/dev/random' on the host.

Reported-by: yunpingzheng <yunzheng@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Message-id: eacda84dfaf2d99cf6d250b678be4e4d6c2088fb.1366108096.git.amit.shah@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Amit Shah 2013-04-16 15:58:16 +05:30 committed by Anthony Liguori
parent 7dda5dc82a
commit acbbc03661

View File

@ -41,6 +41,9 @@ static void entropy_available(void *opaque)
ssize_t len; ssize_t len;
len = read(s->fd, buffer, s->size); len = read(s->fd, buffer, s->size);
if (len < 0 && errno == EAGAIN) {
return;
}
g_assert(len != -1); g_assert(len != -1);
s->receive_func(s->opaque, buffer, len); s->receive_func(s->opaque, buffer, len);