[PATCH v8 0/5] improve error handling for module load

[Claudio Fontana]

CHANGELOG:

v7 -> v8:

* fix a problem in module_load, where the module_name in v7 was mistakenly freed
  via g_free() also in the success code path, and instead module_name memory
  is owned by g_hash_table afer g_hash_table_add.

* add more text to the commit message to indicate areas of further improvements,
  and more details about changes.

* in PATCH 5/5, change the commit message to align with the change in v7,
  ie, we exit(), we do not abort().

v6 -> v7:

* changed instances of abort() to exit(1), for the CONFIG_MODULES case 
(Philippe).

* dmg: do not use a separate local error, use the existing errp (Kevin)

* block: do not use a separate local error, use the existing errp for
  bdrv_find_protocol (Markus)

v5 -> v6:

* added a patch by Kevin to handle the dmg warning about missing
  decompression submodules. (Kevin)

* added more verbose comments about all the affected callers of module_load
  and module_load_qom (Markus)

(OPEN ISSUE): change abort() to exit() when type not present even after loading 
module?

(Philippe)

v4 -> v5:

* added a patch to rename module_load_one and friends to module_load

* qdev_new: just reuse module_object_class_by_name, to avoid duplicating code

* changed return value of module_load to an int:
  -1 error (Error **errp set).
   0 module or dependencies not installed,
   1 loaded
   2 already loaded (or built-in)

   Adapted all callers.

* module_load: fixed some pre-existing memory leaks, used an out: label
  to do the cleanup.

v3 -> v4: (Richard)

* module_object_class_by_name: return NULL immediately on load error.
* audio_driver_lookup: same.
* bdrv_find_format: same.

* dmg_open: handle optional compression submodules better: f.e.,
  if "dmg-bz2" is not present, continue but offer a warning.
  If "dmg-bz2" load fails with error, error out and return.

* module_load_dso: add newline to error_append_hint.

v2 -> v3:

* take the file existence check outside of module_load_file,
  rename module_load_file to module_load_dso, will be called only on
  an existing file. This will simplify the return value. (Richard)

* move exported function documentation into header files (Richard)

v1 -> v2:

* do not treat the display help text any differently and do report
  module load _errors_. If the module does not exist (ENOENT, ENOTDIR),
  no error will be produced.

DESCRIPTION:

while investigating a permission issue in accel, where accel-tcg-x86_64.so
was not accessible, I noticed that no errors were produced regarding the
module load failure.

This series attempts to improve module_load_one and module_load_qom_one
to handle the error cases better and produce some errors.

Patch 1 is already reviewed and is about removing an unused existing
argument "mayfail" from the call stack.

Patch 2 is the real meat, and that one I would say is RFC.
Will follow up with comments on the specific questions I have.

Patch 3 finally adds a simple check in accel/, aborting if a module
is not found, but relying on the existing error report from
module_load_qom_one.

Claudio Fontana (4):
  module: removed unused function argument "mayfail"
  module: rename module_load_one to module_load
  module: add Error arguments to module_load and module_load_qom
  accel: abort if we fail to load the accelerator plugin

Kevin Wolf (1):
  dmg: warn when opening dmg images containing blocks of unknown type

 accel/accel-softmmu.c |   8 +-
 audio/audio.c         |  16 ++--
 block.c               |  20 +++-
 block/dmg.c           |  33 ++++++-
 hw/core/qdev.c        |  17 +++-
 include/qemu/module.h |  37 +++++++-
 qom/object.c          |  18 +++-
 softmmu/qtest.c       |   8 +-
 ui/console.c          |  18 +++-
 util/module.c         | 211 +++++++++++++++++++++++-------------------
 10 files changed, 260 insertions(+), 126 deletions(-)

-- 
2.26.2