On 9/8/22 20:30, Claudio Fontana wrote:
> improve error handling during module load, by changing:
>
> bool module_load_one(const char *prefix, const char *lib_name);
> void module_load_qom_one(const char *type);
>
> to:
>
> bool module_load_one(const char *prefix, const char *name, Error **errp);
> bool module_load_qom_one(const char *type, Error **errp);
>
> module_load_qom_one has been introduced in:
>
> commit 28457744c345 ("module: qom module support"), which built on top of
> module_load_one, but discarded the bool return value. Restore it.
>
> Adapt all callers to emit errors, or ignore them, or fail hard,
> as appropriate in each context.
>
> Signed-off-by: Claudio Fontana <cfont...@suse.de>
> ---
> audio/audio.c | 9 ++-
> block.c | 15 ++++-
> block/dmg.c | 18 +++++-
> hw/core/qdev.c | 10 ++-
> include/qemu/module.h | 38 ++++++++++--
> qom/object.c | 18 +++++-
> softmmu/qtest.c | 6 +-
> ui/console.c | 18 +++++-
> util/module.c | 140 ++++++++++++++++++++++++------------------
> 9 files changed, 194 insertions(+), 78 deletions(-)
>
> diff --git a/audio/audio.c b/audio/audio.c
> index 76b8735b44..cff7464c07 100644
> --- a/audio/audio.c
> +++ b/audio/audio.c
> @@ -72,6 +72,7 @@ void audio_driver_register(audio_driver *drv)
> audio_driver *audio_driver_lookup(const char *name)
> {
> struct audio_driver *d;
> + Error *local_err = NULL;
>
> QLIST_FOREACH(d, &audio_drivers, next) {
> if (strcmp(name, d->name) == 0) {
> @@ -79,7 +80,13 @@ audio_driver *audio_driver_lookup(const char *name)
> }
> }
>
> - audio_module_load_one(name);
> + if (!audio_module_load_one(name, &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + }
> + return NULL;
> + }
> +
> QLIST_FOREACH(d, &audio_drivers, next) {
> if (strcmp(name, d->name) == 0) {
> return d;
> diff --git a/block.c b/block.c
> index bc85f46eed..8b610c6d95 100644
> --- a/block.c
> +++ b/block.c
> @@ -464,7 +464,14 @@ BlockDriver *bdrv_find_format(const char *format_name)
> /* The driver isn't registered, maybe we need to load a module */
> for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
> if (!strcmp(block_driver_modules[i].format_name, format_name)) {
> - block_module_load_one(block_driver_modules[i].library_name);
> + Error *local_err = NULL;
> + if (!block_module_load_one(block_driver_modules[i].library_name,
> + &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + }
> + return NULL;
> + }
> break;
> }
> }
> @@ -976,7 +983,11 @@ BlockDriver *bdrv_find_protocol(const char *filename,
> for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
> if (block_driver_modules[i].protocol_name &&
> !strcmp(block_driver_modules[i].protocol_name, protocol)) {
> - block_module_load_one(block_driver_modules[i].library_name);
> + Error *local_err = NULL;
> + if (!block_module_load_one(block_driver_modules[i].library_name,
> + &local_err) && local_err) {
> + error_report_err(local_err);
> + }
> break;
> }
> }
> diff --git a/block/dmg.c b/block/dmg.c
> index 98db18d82a..11d184d39c 100644
> --- a/block/dmg.c
> +++ b/block/dmg.c
> @@ -434,6 +434,7 @@ static int dmg_open(BlockDriverState *bs, QDict *options,
> int flags,
> uint64_t plist_xml_offset, plist_xml_length;
> int64_t offset;
> int ret;
> + Error *local_err = NULL;
>
> ret = bdrv_apply_auto_read_only(bs, NULL, errp);
> if (ret < 0) {
> @@ -446,8 +447,21 @@ static int dmg_open(BlockDriverState *bs, QDict
> *options, int flags,
> return -EINVAL;
> }
>
> - block_module_load_one("dmg-bz2");
> - block_module_load_one("dmg-lzfse");
> + if (!block_module_load_one("dmg-bz2", &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + return -EINVAL;
> + }
> + warn_report("dmg-bz2 module not present, bz2 decomp unavailable");
> + }
> + local_err = NULL;
> + if (!block_module_load_one("dmg-lzfse", &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + return -EINVAL;
> + }
> + warn_report("dmg-lzfse module not present, lzfse decomp
> unavailable");
> + }
Hi Richard, Kevin, does this look ok now?
Thanks,
Claudio
>
> s->n_chunks = 0;
> s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 0806d8fcaa..5902c59c94 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -148,7 +148,15 @@ bool qdev_set_parent_bus(DeviceState *dev, BusState
> *bus, Error **errp)
> DeviceState *qdev_new(const char *name)
> {
> if (!object_class_by_name(name)) {
> - module_load_qom_one(name);
> + Error *local_err = NULL;
> + if (!module_load_qom_one(name, &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + } else {
> + error_report("could not find a module for type '%s'", name);
> + }
> + abort();
> + }
> }
> return DEVICE(object_new(name));
> }
> diff --git a/include/qemu/module.h b/include/qemu/module.h
> index 8c012bbe03..78d4c4de96 100644
> --- a/include/qemu/module.h
> +++ b/include/qemu/module.h
> @@ -61,16 +61,44 @@ typedef enum {
> #define fuzz_target_init(function) module_init(function, \
> MODULE_INIT_FUZZ_TARGET)
> #define migration_init(function) module_init(function, MODULE_INIT_MIGRATION)
> -#define block_module_load_one(lib) module_load_one("block-", lib)
> -#define ui_module_load_one(lib) module_load_one("ui-", lib)
> -#define audio_module_load_one(lib) module_load_one("audio-", lib)
> +#define block_module_load_one(lib, errp) module_load_one("block-", lib, errp)
> +#define ui_module_load_one(lib, errp) module_load_one("ui-", lib, errp)
> +#define audio_module_load_one(lib, errp) module_load_one("audio-", lib, errp)
>
> void register_module_init(void (*fn)(void), module_init_type type);
> void register_dso_module_init(void (*fn)(void), module_init_type type);
>
> void module_call_init(module_init_type type);
> -bool module_load_one(const char *prefix, const char *lib_name);
> -void module_load_qom_one(const char *type);
> +
> +/*
> + * module_load_one: attempt to load a module from a set of directories
> + *
> + * directories searched are:
> + * - getenv("QEMU_MODULE_DIR")
> + * - get_relocated_path(CONFIG_QEMU_MODDIR);
> + * - /var/run/qemu/${version_dir}
> + *
> + * prefix: a subsystem prefix, or the empty string ("audio-", ...,
> "")
> + * name: name of the module
> + * errp: error to set in case the module is found, but load failed.
> + *
> + * Return value: true on success (found and loaded);
> + * if module if found, but load failed, errp will be set.
> + * if module is not found, errp will not be set.
> + */
> +bool module_load_one(const char *prefix, const char *name, Error **errp);
> +
> +/*
> + * module_load_qom_one: attempt to load a module to provide a QOM type
> + *
> + * type: the type to be provided
> + * errp: error to set.
> + *
> + * Return value: true on success (found and loaded), false on failure.
> + * If a module is simply not found for the type,
> + * errp will not be set.
> + */
> +bool module_load_qom_one(const char *type, Error **errp);
> void module_load_qom_all(void);
> void module_allow_arch(const char *arch);
>
> diff --git a/qom/object.c b/qom/object.c
> index d34608558e..493e5ce231 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -526,8 +526,14 @@ void object_initialize(void *data, size_t size, const
> char *typename)
>
> #ifdef CONFIG_MODULES
> if (!type) {
> - module_load_qom_one(typename);
> - type = type_get_by_name(typename);
> + Error *local_err = NULL;
> + if (!module_load_qom_one(typename, &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + }
> + } else {
> + type = type_get_by_name(typename);
> + }
> }
> #endif
> if (!type) {
> @@ -1033,7 +1039,13 @@ ObjectClass *module_object_class_by_name(const char
> *typename)
> oc = object_class_by_name(typename);
> #ifdef CONFIG_MODULES
> if (!oc) {
> - module_load_qom_one(typename);
> + Error *local_err = NULL;
> + if (!module_load_qom_one(typename, &local_err)) {
> + if (local_err) {
> + error_report_err(local_err);
> + }
> + return NULL;
> + }
> oc = object_class_by_name(typename);
> }
> #endif
> diff --git a/softmmu/qtest.c b/softmmu/qtest.c
> index 76eb7bac56..bb83c7aae9 100644
> --- a/softmmu/qtest.c
> +++ b/softmmu/qtest.c
> @@ -753,12 +753,16 @@ static void qtest_process_command(CharBackend *chr,
> gchar **words)
> qtest_sendf(chr, "OK %"PRIi64"\n",
> (int64_t)qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> } else if (strcmp(words[0], "module_load") == 0) {
> + Error *local_err = NULL;
> g_assert(words[1] && words[2]);
>
> qtest_send_prefix(chr);
> - if (module_load_one(words[1], words[2])) {
> + if (module_load_one(words[1], words[2], &local_err)) {
> qtest_sendf(chr, "OK\n");
> } else {
> + if (local_err) {
> + error_report_err(local_err);
> + }
> qtest_sendf(chr, "FAIL\n");
> }
> } else if (qtest_enabled() && strcmp(words[0], "clock_set") == 0) {
> diff --git a/ui/console.c b/ui/console.c
> index 765892f84f..34dd206167 100644
> --- a/ui/console.c
> +++ b/ui/console.c
> @@ -2632,7 +2632,11 @@ bool qemu_display_find_default(DisplayOptions *opts)
>
> for (i = 0; i < (int)ARRAY_SIZE(prio); i++) {
> if (dpys[prio[i]] == NULL) {
> - ui_module_load_one(DisplayType_str(prio[i]));
> + Error *local_err = NULL;
> + if (!ui_module_load_one(DisplayType_str(prio[i]), &local_err)
> + && local_err) {
> + error_report_err(local_err);
> + }
> }
> if (dpys[prio[i]] == NULL) {
> continue;
> @@ -2650,7 +2654,11 @@ void qemu_display_early_init(DisplayOptions *opts)
> return;
> }
> if (dpys[opts->type] == NULL) {
> - ui_module_load_one(DisplayType_str(opts->type));
> + Error *local_err = NULL;
> + if (!ui_module_load_one(DisplayType_str(opts->type), &local_err)
> + && local_err) {
> + error_report_err(local_err);
> + }
> }
> if (dpys[opts->type] == NULL) {
> error_report("Display '%s' is not available.",
> @@ -2680,7 +2688,11 @@ void qemu_display_help(void)
> printf("none\n");
> for (idx = DISPLAY_TYPE_NONE; idx < DISPLAY_TYPE__MAX; idx++) {
> if (!dpys[idx]) {
> - ui_module_load_one(DisplayType_str(idx));
> + Error *local_err = NULL;
> + if (!ui_module_load_one(DisplayType_str(idx), &local_err)
> + && local_err) {
> + error_report_err(local_err);
> + }
> }
> if (dpys[idx]) {
> printf("%s\n", DisplayType_str(dpys[idx]->type));
> diff --git a/util/module.c b/util/module.c
> index 8563edd626..90ea8adf7d 100644
> --- a/util/module.c
> +++ b/util/module.c
> @@ -21,6 +21,7 @@
> #include "qemu/module.h"
> #include "qemu/cutils.h"
> #include "qemu/config-file.h"
> +#include "qapi/error.h"
> #ifdef CONFIG_MODULE_UPGRADES
> #include "qemu-version.h"
> #endif
> @@ -144,25 +145,22 @@ static bool module_check_arch(const QemuModinfo
> *modinfo)
> return true;
> }
>
> -static int module_load_file(const char *fname, bool export_symbols)
> +/*
> + * module_load_dso: attempt to load an existing dso file
> + *
> + * fname: full pathname of the file to load
> + * export_symbols: if true, add the symbols to the global name space
> + * errp: error to set.
> + *
> + * Return value: true on success, false on error, and errp will be set.
> + */
> +static bool module_load_dso(const char *fname, bool export_symbols,
> + Error **errp)
> {
> GModule *g_module;
> void (*sym)(void);
> - const char *dsosuf = CONFIG_HOST_DSOSUF;
> - int len = strlen(fname);
> - int suf_len = strlen(dsosuf);
> ModuleEntry *e, *next;
> - int ret, flags;
> -
> - if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
> - /* wrong suffix */
> - ret = -EINVAL;
> - goto out;
> - }
> - if (access(fname, F_OK)) {
> - ret = -ENOENT;
> - goto out;
> - }
> + int flags;
>
> assert(QTAILQ_EMPTY(&dso_init_list));
>
> @@ -172,46 +170,38 @@ static int module_load_file(const char *fname, bool
> export_symbols)
> }
> g_module = g_module_open(fname, flags);
> if (!g_module) {
> - fprintf(stderr, "Failed to open module: %s\n",
> - g_module_error());
> - ret = -EINVAL;
> - goto out;
> + error_setg(errp, "failed to open module: %s", g_module_error());
> + return false;
> }
> if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
> - fprintf(stderr, "Failed to initialize module: %s\n",
> - fname);
> - /* Print some info if this is a QEMU module (but from different
> build),
> - * this will make debugging user problems easier. */
> + error_setg(errp, "failed to initialize module: %s", fname);
> + /*
> + * Print some info if this is a QEMU module (but from different
> build),
> + * this will make debugging user problems easier.
> + */
> if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer
> *)&sym)) {
> - fprintf(stderr,
> - "Note: only modules from the same build can be
> loaded.\n");
> + error_append_hint(errp,
> + "Only modules from the same build can be loaded.\n");
> }
> g_module_close(g_module);
> - ret = -EINVAL;
> - } else {
> - QTAILQ_FOREACH(e, &dso_init_list, node) {
> - e->init();
> - register_module_init(e->init, e->type);
> - }
> - ret = 0;
> + return false;
> }
>
> + QTAILQ_FOREACH(e, &dso_init_list, node) {
> + e->init();
> + register_module_init(e->init, e->type);
> + }
> trace_module_load_module(fname);
> QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
> QTAILQ_REMOVE(&dso_init_list, e, node);
> g_free(e);
> }
> -out:
> - return ret;
> + return true;
> }
> -#endif
>
> -bool module_load_one(const char *prefix, const char *lib_name)
> +bool module_load_one(const char *prefix, const char *name, Error **errp)
> {
> bool success = false;
> -
> -#ifdef CONFIG_MODULES
> - char *fname = NULL;
> #ifdef CONFIG_MODULE_UPGRADES
> char *version_dir;
> #endif
> @@ -219,14 +209,13 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> char *dirs[5];
> char *module_name;
> int i = 0, n_dirs = 0;
> - int ret;
> bool export_symbols = false;
> static GHashTable *loaded_modules;
> const QemuModinfo *modinfo;
> const char **sl;
>
> if (!g_module_supported()) {
> - fprintf(stderr, "Module is not supported by system.\n");
> + error_setg(errp, "%s", "this platform does not support GLib
> modules");
> return false;
> }
>
> @@ -234,7 +223,7 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> loaded_modules = g_hash_table_new(g_str_hash, g_str_equal);
> }
>
> - module_name = g_strdup_printf("%s%s", prefix, lib_name);
> + module_name = g_strdup_printf("%s%s", prefix, name);
>
> if (g_hash_table_contains(loaded_modules, module_name)) {
> g_free(module_name);
> @@ -246,6 +235,8 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> if (modinfo->arch) {
> if (strcmp(modinfo->name, module_name) == 0) {
> if (!module_check_arch(modinfo)) {
> + error_setg(errp, "module arch does not match: "
> + "expected '%s', got '%s'", module_arch,
> modinfo->arch);
> return false;
> }
> }
> @@ -254,7 +245,9 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> if (strcmp(modinfo->name, module_name) == 0) {
> /* we depend on other module(s) */
> for (sl = modinfo->deps; *sl != NULL; sl++) {
> - module_load_one("", *sl);
> + if (!(module_load_one("", *sl, errp))) {
> + return false;
> + }
> }
> } else {
> for (sl = modinfo->deps; *sl != NULL; sl++) {
> @@ -283,16 +276,26 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> assert(n_dirs <= ARRAY_SIZE(dirs));
>
> for (i = 0; i < n_dirs; i++) {
> - fname = g_strdup_printf("%s/%s%s",
> - dirs[i], module_name, CONFIG_HOST_DSOSUF);
> - ret = module_load_file(fname, export_symbols);
> - g_free(fname);
> - fname = NULL;
> - /* Try loading until loaded a module file */
> - if (!ret) {
> - success = true;
> + char *fname = g_strdup_printf("%s/%s%s",
> + dirs[i], module_name,
> CONFIG_HOST_DSOSUF);
> + int ret = access(fname, F_OK);
> + if (ret != 0) {
> + if (errno == ENOENT || errno == ENOTDIR) {
> + /*
> + * if we don't find the module in this dir, try the next one.
> + * If we don't find it in any dir, that can be fine too: user
> + * did not install the module. We will return false in this
> + * case, with no error set.
> + */
> + continue;
> + }
> + /* most common is EACCES here */
> + error_setg_errno(errp, errno, "error trying to access %s",
> fname);
> break;
> }
> + success = module_load_dso(fname, export_symbols, errp);
> + g_free(fname);
> + break;
> }
>
> if (!success) {
> @@ -304,21 +307,20 @@ bool module_load_one(const char *prefix, const char
> *lib_name)
> g_free(dirs[i]);
> }
>
> -#endif
> return success;
> }
>
> -#ifdef CONFIG_MODULES
> -
> static bool module_loaded_qom_all;
>
> -void module_load_qom_one(const char *type)
> +bool module_load_qom_one(const char *type, Error **errp)
> {
> + bool found = false;
> const QemuModinfo *modinfo;
> const char **sl;
>
> if (!type) {
> - return;
> + error_setg(errp, "%s", "type is NULL");
> + return false;
> }
>
> trace_module_lookup_object_type(type);
> @@ -331,15 +333,26 @@ void module_load_qom_one(const char *type)
> }
> for (sl = modinfo->objs; *sl != NULL; sl++) {
> if (strcmp(type, *sl) == 0) {
> - module_load_one("", modinfo->name);
> + if (found) {
> + error_setg(errp, "multiple modules providing '%s'",
> type);
> + found = false;
> + break;
> + }
> + found = module_load_one("", modinfo->name, errp);
> + if (!found) {
> + /* errp optionally set in module_load_one */
> + break;
> + }
> }
> }
> }
> + return found;
> }
>
> void module_load_qom_all(void)
> {
> const QemuModinfo *modinfo;
> + Error *local_err = NULL;
>
> if (module_loaded_qom_all) {
> return;
> @@ -352,7 +365,9 @@ void module_load_qom_all(void)
> if (!module_check_arch(modinfo)) {
> continue;
> }
> - module_load_one("", modinfo->name);
> + if (!module_load_one("", modinfo->name, &local_err) && local_err) {
> + error_report_err(local_err);
> + }
> }
> module_loaded_qom_all = true;
> }
> @@ -368,7 +383,11 @@ void qemu_load_module_for_opts(const char *group)
> }
> for (sl = modinfo->opts; *sl != NULL; sl++) {
> if (strcmp(group, *sl) == 0) {
> - module_load_one("", modinfo->name);
> + Error *local_err = NULL;
> + if (!module_load_one("", modinfo->name, &local_err)
> + && local_err) {
> + error_report_err(local_err);
> + }
> }
> }
> }
> @@ -378,7 +397,8 @@ void qemu_load_module_for_opts(const char *group)
>
> void module_allow_arch(const char *arch) {}
> void qemu_load_module_for_opts(const char *group) {}
> -void module_load_qom_one(const char *type) {}
> +bool module_load_one(const char *prefix, const char *name, Error **errp) {
> return true; }
> +bool module_load_qom_one(const char *type, Error **errp) { return true; }
> void module_load_qom_all(void) {}
>
> #endif
