diff options
Diffstat (limited to 'drivers/virt/coco/tsm.c')
| -rw-r--r-- | drivers/virt/coco/tsm.c | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/drivers/virt/coco/tsm.c b/drivers/virt/coco/tsm.c index 9432d4e303f1..8a638bc34d4a 100644 --- a/drivers/virt/coco/tsm.c +++ b/drivers/virt/coco/tsm.c @@ -15,6 +15,7 @@ static struct tsm_provider { const struct tsm_ops *ops; void *data; + atomic_t count; } provider; static DECLARE_RWSEM(tsm_rwsem); @@ -92,6 +93,10 @@ static ssize_t tsm_report_privlevel_store(struct config_item *cfg, if (rc) return rc; + guard(rwsem_write)(&tsm_rwsem); + if (!provider.ops) + return -ENXIO; + /* * The valid privilege levels that a TSM might accept, if it accepts a * privilege level setting at all, are a max of TSM_PRIVLEVEL_MAX (see @@ -101,7 +106,6 @@ static ssize_t tsm_report_privlevel_store(struct config_item *cfg, if (provider.ops->privlevel_floor > val || val > TSM_PRIVLEVEL_MAX) return -EINVAL; - guard(rwsem_write)(&tsm_rwsem); rc = try_advance_write_generation(report); if (rc) return rc; @@ -115,6 +119,10 @@ static ssize_t tsm_report_privlevel_floor_show(struct config_item *cfg, char *buf) { guard(rwsem_read)(&tsm_rwsem); + + if (!provider.ops) + return -ENXIO; + return sysfs_emit(buf, "%u\n", provider.ops->privlevel_floor); } CONFIGFS_ATTR_RO(tsm_report_, privlevel_floor); @@ -217,6 +225,9 @@ CONFIGFS_ATTR_RO(tsm_report_, generation); static ssize_t tsm_report_provider_show(struct config_item *cfg, char *buf) { guard(rwsem_read)(&tsm_rwsem); + if (!provider.ops) + return -ENXIO; + return sysfs_emit(buf, "%s\n", provider.ops->name); } CONFIGFS_ATTR_RO(tsm_report_, provider); @@ -284,7 +295,7 @@ static ssize_t tsm_report_read(struct tsm_report *report, void *buf, guard(rwsem_write)(&tsm_rwsem); ops = provider.ops; if (!ops) - return -ENOTTY; + return -ENXIO; if (!report->desc.inblob_len) return -EINVAL; @@ -421,12 +432,20 @@ static struct config_item *tsm_report_make_item(struct config_group *group, if (!state) return ERR_PTR(-ENOMEM); + atomic_inc(&provider.count); config_item_init_type_name(&state->cfg, name, &tsm_report_type); return &state->cfg; } +static void tsm_report_drop_item(struct config_group *group, struct config_item *item) +{ + config_item_put(item); + atomic_dec(&provider.count); +} + static struct configfs_group_operations tsm_report_group_ops = { .make_item = tsm_report_make_item, + .drop_item = tsm_report_drop_item, }; static const struct config_item_type tsm_reports_type = { @@ -459,6 +478,11 @@ int tsm_register(const struct tsm_ops *ops, void *priv) return -EBUSY; } + if (atomic_read(&provider.count)) { + pr_err("configfs/tsm/report not empty\n"); + return -EBUSY; + } + provider.ops = ops; provider.data = priv; return 0; @@ -470,6 +494,9 @@ int tsm_unregister(const struct tsm_ops *ops) guard(rwsem_write)(&tsm_rwsem); if (ops != provider.ops) return -EBUSY; + if (atomic_read(&provider.count)) + pr_warn("\"%s\" unregistered with items present in configfs/tsm/report\n", + provider.ops->name); provider.ops = NULL; provider.data = NULL; return 0; |