From 4016adc74aee696bca025e546edfd2ae8f57863b Mon Sep 17 00:00:00 2001 From: =?utf8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Fri, 13 Dec 2024 14:22:02 +0100 Subject: [PATCH] hw/nvram/fw_cfg: Skip FW_CFG_DATA_GENERATOR when no data to generate MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Allow the FW_CFG_DATA_GENERATOR interface get_data() handler to return NULL when there is nothing to generate. In that case fw_cfg_add_file_from_generator() will not add any item and return %true. Reported-by: Daniel P. Berrangé Reviewed-by: Daniel P. Berrangé Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20241213133352.10915-4-philmd@linaro.org> --- hw/nvram/fw_cfg.c | 3 ++- include/hw/nvram/fw_cfg.h | 13 ++++++++----- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index b94cd27bd8..46c62c8f09 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -1031,6 +1031,7 @@ bool fw_cfg_add_file_from_generator(FWCfgState *s, Object *parent, const char *part, const char *filename, Error **errp) { + ERRP_GUARD(); FWCfgDataGeneratorClass *klass; GByteArray *array; Object *obj; @@ -1048,7 +1049,7 @@ bool fw_cfg_add_file_from_generator(FWCfgState *s, } klass = FW_CFG_DATA_GENERATOR_GET_CLASS(obj); array = klass->get_data(obj, errp); - if (!array) { + if (*errp || !array) { return false; } size = array->len; diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index fcb06f18cc..6089681f42 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -30,8 +30,9 @@ struct FWCfgDataGeneratorClass { * @obj: the object implementing this interface * @errp: pointer to a NULL-initialized error object * - * Returns: reference to a byte array containing the data on success, - * or NULL on error. + * Returns: A byte array containing data to add, or NULL without + * @errp set if no data is required, or NULL with @errp + * set on failure. * * The caller should release the reference when no longer * required. @@ -298,14 +299,16 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data, * @parent: the object in which to resolve the @part * @errp: pointer to a NULL initialized error object * - * Add a new NAMED fw_cfg item with the content generated from the - * @part object. The data generated by the @part object is copied - * into the data structure of the fw_cfg device. + * If the @part object generates content, add a new NAMED fw_cfg item with it. + * The data generated by the @part object is copied into the data structure of + * the fw_cfg device. * The next available (unused) selector key starting at FW_CFG_FILE_FIRST * will be used; also, a new entry will be added to the file directory * structure residing at key value FW_CFG_FILE_DIR, containing the item name, * data size, and assigned selector key value. * + * If the @part object does not generate content, no fw_cfg item is added. + * * Returns: %true on success, %false on error. */ bool fw_cfg_add_file_from_generator(FWCfgState *s, -- 2.30.2