60253ed1e6
Requests are now created in the RngBackend parent class and the code path is shared by both rng-egd and rng-random. This commit fixes the rng-random implementation which processed only one request at a time and simply discarded all but the most recent one. In the guest this manifested as delayed completion of reads from virtio-rng, i.e. a read was completed only after another read was issued. By switching rng-random to use the same request queue as rng-egd, the unsafe stack-based allocation of the entropy buffer is eliminated and replaced with g_malloc. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Message-Id: <1456994238-9585-5-git-send-email-lprosek@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com>
145 lines
3.3 KiB
C
145 lines
3.3 KiB
C
/*
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* QEMU Random Number Generator Backend
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*
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* Copyright IBM, Corp. 2012
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "sysemu/rng.h"
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#include "qapi/qmp/qerror.h"
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#include "qom/object_interfaces.h"
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void rng_backend_request_entropy(RngBackend *s, size_t size,
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EntropyReceiveFunc *receive_entropy,
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void *opaque)
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{
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RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
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RngRequest *req;
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if (k->request_entropy) {
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req = g_malloc(sizeof(*req));
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req->offset = 0;
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req->size = size;
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req->receive_entropy = receive_entropy;
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req->opaque = opaque;
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req->data = g_malloc(req->size);
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k->request_entropy(s, req);
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s->requests = g_slist_append(s->requests, req);
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}
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}
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static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
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{
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RngBackend *s = RNG_BACKEND(obj);
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return s->opened;
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}
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static void rng_backend_complete(UserCreatable *uc, Error **errp)
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{
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object_property_set_bool(OBJECT(uc), true, "opened", errp);
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}
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static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
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{
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RngBackend *s = RNG_BACKEND(obj);
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RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
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Error *local_err = NULL;
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if (value == s->opened) {
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return;
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}
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if (!value && s->opened) {
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error_setg(errp, QERR_PERMISSION_DENIED);
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return;
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}
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if (k->opened) {
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k->opened(s, &local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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return;
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}
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}
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s->opened = true;
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}
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static void rng_backend_free_request(RngRequest *req)
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{
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g_free(req->data);
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g_free(req);
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}
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static void rng_backend_free_requests(RngBackend *s)
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{
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GSList *i;
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for (i = s->requests; i; i = i->next) {
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rng_backend_free_request(i->data);
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}
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g_slist_free(s->requests);
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s->requests = NULL;
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}
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void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
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{
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s->requests = g_slist_remove(s->requests, req);
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rng_backend_free_request(req);
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}
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static void rng_backend_init(Object *obj)
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{
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object_property_add_bool(obj, "opened",
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rng_backend_prop_get_opened,
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rng_backend_prop_set_opened,
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NULL);
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}
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static void rng_backend_finalize(Object *obj)
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{
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RngBackend *s = RNG_BACKEND(obj);
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rng_backend_free_requests(s);
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}
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static void rng_backend_class_init(ObjectClass *oc, void *data)
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{
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UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
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ucc->complete = rng_backend_complete;
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}
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static const TypeInfo rng_backend_info = {
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.name = TYPE_RNG_BACKEND,
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.parent = TYPE_OBJECT,
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.instance_size = sizeof(RngBackend),
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.instance_init = rng_backend_init,
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.instance_finalize = rng_backend_finalize,
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.class_size = sizeof(RngBackendClass),
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.class_init = rng_backend_class_init,
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.abstract = true,
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.interfaces = (InterfaceInfo[]) {
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{ TYPE_USER_CREATABLE },
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{ }
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}
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};
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static void register_types(void)
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{
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type_register_static(&rng_backend_info);
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}
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type_init(register_types);
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