qemu/backends/tpm.c
Markus Armbruster 65cd9064e1 qom: Clean up fragile use of error_is_set() in set() methods
Using error_is_set(ERRP) to find out whether a function failed is
either wrong, fragile, or unnecessarily opaque.  It's wrong when ERRP
may be null, because errors go undetected when it is.  It's fragile
when proving ERRP non-null involves a non-local argument.  Else, it's
unnecessarily opaque (see commit 84d18f0).

I guess the error_is_set(errp) in the ObjectProperty set() methods are
merely fragile right now, because I can't find a call chain that
passes a null errp argument.

Make the code more robust and more obviously correct: receive the
error in a local variable, then propagate it through the parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-05-05 19:08:49 +02:00

193 lines
4.4 KiB
C

/*
* QEMU TPM Backend
*
* Copyright IBM, Corp. 2013
*
* Authors:
* Stefan Berger <stefanb@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* Based on backends/rng.c by Anthony Liguori
*/
#include "sysemu/tpm_backend.h"
#include "qapi/qmp/qerror.h"
#include "sysemu/tpm.h"
#include "qemu/thread.h"
#include "sysemu/tpm_backend_int.h"
enum TpmType tpm_backend_get_type(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->type;
}
const char *tpm_backend_get_desc(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->desc();
}
void tpm_backend_destroy(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->destroy(s);
}
int tpm_backend_init(TPMBackend *s, TPMState *state,
TPMRecvDataCB *datacb)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->init(s, state, datacb);
}
int tpm_backend_startup_tpm(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->startup_tpm(s);
}
bool tpm_backend_had_startup_error(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->had_startup_error(s);
}
size_t tpm_backend_realloc_buffer(TPMBackend *s, TPMSizedBuffer *sb)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->realloc_buffer(sb);
}
void tpm_backend_deliver_request(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
k->ops->deliver_request(s);
}
void tpm_backend_reset(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
k->ops->reset(s);
}
void tpm_backend_cancel_cmd(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
k->ops->cancel_cmd(s);
}
bool tpm_backend_get_tpm_established_flag(TPMBackend *s)
{
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
return k->ops->get_tpm_established_flag(s);
}
static bool tpm_backend_prop_get_opened(Object *obj, Error **errp)
{
TPMBackend *s = TPM_BACKEND(obj);
return s->opened;
}
void tpm_backend_open(TPMBackend *s, Error **errp)
{
object_property_set_bool(OBJECT(s), true, "opened", errp);
}
static void tpm_backend_prop_set_opened(Object *obj, bool value, Error **errp)
{
TPMBackend *s = TPM_BACKEND(obj);
TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
Error *local_err = NULL;
if (value == s->opened) {
return;
}
if (!value && s->opened) {
error_set(errp, QERR_PERMISSION_DENIED);
return;
}
if (k->opened) {
k->opened(s, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
s->opened = true;
}
static void tpm_backend_instance_init(Object *obj)
{
object_property_add_bool(obj, "opened",
tpm_backend_prop_get_opened,
tpm_backend_prop_set_opened,
NULL);
}
void tpm_backend_thread_deliver_request(TPMBackendThread *tbt)
{
g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_PROCESS_CMD, NULL);
}
void tpm_backend_thread_create(TPMBackendThread *tbt,
GFunc func, gpointer user_data)
{
if (!tbt->pool) {
tbt->pool = g_thread_pool_new(func, user_data, 1, TRUE, NULL);
g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_INIT, NULL);
}
}
void tpm_backend_thread_end(TPMBackendThread *tbt)
{
if (tbt->pool) {
g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_END, NULL);
g_thread_pool_free(tbt->pool, FALSE, TRUE);
tbt->pool = NULL;
}
}
void tpm_backend_thread_tpm_reset(TPMBackendThread *tbt,
GFunc func, gpointer user_data)
{
if (!tbt->pool) {
tpm_backend_thread_create(tbt, func, user_data);
} else {
g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_TPM_RESET,
NULL);
}
}
static const TypeInfo tpm_backend_info = {
.name = TYPE_TPM_BACKEND,
.parent = TYPE_OBJECT,
.instance_size = sizeof(TPMBackend),
.instance_init = tpm_backend_instance_init,
.class_size = sizeof(TPMBackendClass),
.abstract = true,
};
static void register_types(void)
{
type_register_static(&tpm_backend_info);
}
type_init(register_types);