qemu/tpm.c
Markus Armbruster 668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00

249 lines
5.4 KiB
C

/*
* TPM configuration
*
* Copyright (C) 2011-2013 IBM Corporation
*
* 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 net.c
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-tpm.h"
#include "qapi/qmp/qerror.h"
#include "sysemu/tpm_backend.h"
#include "sysemu/tpm.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
static QLIST_HEAD(, TPMBackend) tpm_backends =
QLIST_HEAD_INITIALIZER(tpm_backends);
static const TPMBackendClass *
tpm_be_find_by_type(enum TpmType type)
{
ObjectClass *oc;
char *typename = g_strdup_printf("tpm-%s", TpmType_str(type));
oc = object_class_by_name(typename);
g_free(typename);
if (!object_class_dynamic_cast(oc, TYPE_TPM_BACKEND)) {
return NULL;
}
return TPM_BACKEND_CLASS(oc);
}
/*
* Walk the list of available TPM backend drivers and display them on the
* screen.
*/
static void tpm_display_backend_drivers(void)
{
int i;
fprintf(stderr, "Supported TPM types (choose only one):\n");
for (i = 0; i < TPM_TYPE__MAX; i++) {
const TPMBackendClass *bc = tpm_be_find_by_type(i);
if (!bc) {
continue;
}
fprintf(stderr, "%12s %s\n", TpmType_str(i), bc->desc);
}
fprintf(stderr, "\n");
}
/*
* Find the TPM with the given Id
*/
TPMBackend *qemu_find_tpm_be(const char *id)
{
TPMBackend *drv;
if (id) {
QLIST_FOREACH(drv, &tpm_backends, list) {
if (!strcmp(drv->id, id)) {
return drv;
}
}
}
return NULL;
}
static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
{
const char *value;
const char *id;
const TPMBackendClass *be;
TPMBackend *drv;
int i;
if (!QLIST_EMPTY(&tpm_backends)) {
error_setg(errp, "Only one TPM is allowed.");
return 1;
}
id = qemu_opts_id(opts);
if (id == NULL) {
error_setg(errp, QERR_MISSING_PARAMETER, "id");
return 1;
}
value = qemu_opt_get(opts, "type");
if (!value) {
error_setg(errp, QERR_MISSING_PARAMETER, "type");
tpm_display_backend_drivers();
return 1;
}
i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
if (be == NULL) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
"a TPM backend type");
tpm_display_backend_drivers();
return 1;
}
/* validate backend specific opts */
if (!qemu_opts_validate(opts, be->opts, errp)) {
return 1;
}
drv = be->create(opts);
if (!drv) {
return 1;
}
drv->id = g_strdup(id);
QLIST_INSERT_HEAD(&tpm_backends, drv, list);
return 0;
}
/*
* Walk the list of TPM backend drivers that are in use and call their
* destroy function to have them cleaned up.
*/
void tpm_cleanup(void)
{
TPMBackend *drv, *next;
QLIST_FOREACH_SAFE(drv, &tpm_backends, list, next) {
QLIST_REMOVE(drv, list);
object_unref(OBJECT(drv));
}
}
/*
* Initialize the TPM. Process the tpmdev command line options describing the
* TPM backend.
*/
void tpm_init(void)
{
qemu_opts_foreach(qemu_find_opts("tpmdev"),
tpm_init_tpmdev, NULL, &error_fatal);
}
/*
* Parse the TPM configuration options.
* To display all available TPM backends the user may use '-tpmdev help'
*/
int tpm_config_parse(QemuOptsList *opts_list, const char *optarg)
{
QemuOpts *opts;
if (!strcmp(optarg, "help")) {
tpm_display_backend_drivers();
return -1;
}
opts = qemu_opts_parse_noisily(opts_list, optarg, true);
if (!opts) {
return -1;
}
return 0;
}
/*
* Walk the list of active TPM backends and collect information about them.
*/
TPMInfoList *qmp_query_tpm(Error **errp)
{
TPMBackend *drv;
TPMInfoList *info, *head = NULL, *cur_item = NULL;
QLIST_FOREACH(drv, &tpm_backends, list) {
if (!drv->tpmif) {
continue;
}
info = g_new0(TPMInfoList, 1);
info->value = tpm_backend_query_tpm(drv);
if (!cur_item) {
head = cur_item = info;
} else {
cur_item->next = info;
cur_item = info;
}
}
return head;
}
TpmTypeList *qmp_query_tpm_types(Error **errp)
{
unsigned int i = 0;
TpmTypeList *head = NULL, *prev = NULL, *cur_item;
for (i = 0; i < TPM_TYPE__MAX; i++) {
if (!tpm_be_find_by_type(i)) {
continue;
}
cur_item = g_new0(TpmTypeList, 1);
cur_item->value = i;
if (prev) {
prev->next = cur_item;
}
if (!head) {
head = cur_item;
}
prev = cur_item;
}
return head;
}
TpmModelList *qmp_query_tpm_models(Error **errp)
{
TpmModelList *head = NULL, *prev = NULL, *cur_item;
GSList *e, *l = object_class_get_list(TYPE_TPM_IF, false);
for (e = l; e; e = e->next) {
TPMIfClass *c = TPM_IF_CLASS(e->data);
cur_item = g_new0(TpmModelList, 1);
cur_item->value = c->model;
if (prev) {
prev->next = cur_item;
}
if (!head) {
head = cur_item;
}
prev = cur_item;
}
g_slist_free(l);
return head;
}