From: Zhao Liu <[email protected]>
As the comment in qapi/error, passing @errp to error_prepend() requires
ERRP_GUARD():
* = Why, when and how to use ERRP_GUARD() =
*
* Without ERRP_GUARD(), use of the @errp parameter is restricted:
...
* - It should not be passed to error_prepend(), error_vprepend() or
* error_append_hint(), because that doesn't work with &error_fatal.
* ERRP_GUARD() lifts these restrictions.
*
* To use ERRP_GUARD(), add it right at the beginning of the function.
* @errp can then be used without worrying about the argument being
* NULL or &error_fatal.
ERRP_GUARD() could avoid the case when @errp is the pointer of
error_fatal, the user can't see this additional information, because
exit() happens in error_setg earlier than information is added [1].
The migrate_params_check() passes @errp to error_prepend() without
ERRP_GUARD(), and it could be called from migration_object_init(),
where the passed @errp points to @error_fatal.
Therefore, the error message echoed in error_prepend() will be lost
because of the above issue.
To fix this, add missing ERRP_GUARD() at the beginning of this function.
[1]: Issue description in the commit message of commit ae7c80a7bd73
("error: New macro ERRP_GUARD()").
Cc: Peter Xu <[email protected]>
Cc: Fabiano Rosas <[email protected]>
Signed-off-by: Zhao Liu <[email protected]>
---
migration/options.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/migration/options.c b/migration/options.c
index 3e3e0b93b439..b98cd639979e 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -1057,6 +1057,8 @@ void migrate_params_init(MigrationParameters *params)
*/
bool migrate_params_check(MigrationParameters *params, Error **errp)
{
+ ERRP_GUARD();
+
if (params->has_compress_level &&
(params->compress_level > 9)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
--
2.34.1
