From e1081e3bffe0449e714c87ad1f82baf291b0a287 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Mon, 11 Mar 2024 11:38:00 +0800 Subject: [PATCH] block/qcow2-bitmap: Fix missing ERRP_GUARD() for error_prepend() 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 &error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. The qcow2_co_can_store_new_dirty_bitmap() passes @errp to error_prepend(). As a BlockDriver.bdrv_co_can_store_new_dirty_bitmap method, it's called by bdrv_co_can_store_new_dirty_bitmap(). Its caller is not being called anywhere, but as the API in include/block/block-io.h, we can't ensure what kind of @errp future users will pass in. To avoid potential issues as [1] said, add missing ERRP_GUARD() at the beginning of qcow2_co_can_store_new_dirty_bitmap(). [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: Kevin Wolf Cc: Hanna Reitz Cc: Eric Blake Cc: Vladimir Sementsov-Ogievskiy Cc: John Snow Cc: qemu-block@nongnu.org Signed-off-by: Zhao Liu Reviewed-by: Vladimir Sementsov-Ogievskiy Message-ID: <20240311033822.3142585-8-zhao1.liu@linux.intel.com> Signed-off-by: Thomas Huth --- block/qcow2-bitmap.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 0e567ed588..874ea56948 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1710,6 +1710,7 @@ bool coroutine_fn qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, uint32_t granularity, Error **errp) { + ERRP_GUARD(); BDRVQcow2State *s = bs->opaque; BdrvDirtyBitmap *bitmap; uint64_t bitmap_directory_size = 0;