From: Zhao Liu <zhao1.liu@intel.com>
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].
In nvme.c, there're 3 functions passing @errp to error_prepend()
without ERRP_GUARD():
- nvme_init_queue()
- nvme_create_queue_pair()
- nvme_identify()
All these 3 functions take their @errp parameters from the
nvme_file_open(), which is a BlockDriver.bdrv_nvme() method and its
@errp points to its caller's local_err.
Though these 3 cases haven't trigger the issue like [1] said, to
follow the requirement of @errp, add missing ERRP_GUARD() at their
beginning.
[1]: Issue description in the commit message of commit ae7c80a7bd73
("error: New macro ERRP_GUARD()").
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Fam Zheng <fam@euphon.net>
Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
block/nvme.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/block/nvme.c b/block/nvme.c
index 0a0a0a6b36cd..3a3c6da73d29 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -168,6 +168,7 @@ static QemuOptsList runtime_opts = {
static bool nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,
unsigned nentries, size_t entry_bytes, Error **errp)
{
+ ERRP_GUARD();
size_t bytes;
int r;
@@ -221,6 +222,7 @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,
unsigned idx, size_t size,
Error **errp)
{
+ ERRP_GUARD();
int i, r;
NVMeQueuePair *q;
uint64_t prp_list_iova;
@@ -535,6 +537,7 @@ static int nvme_admin_cmd_sync(BlockDriverState *bs, NvmeCmd *cmd)
/* Returns true on success, false on failure. */
static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
{
+ ERRP_GUARD();
BDRVNVMeState *s = bs->opaque;
bool ret = false;
QEMU_AUTO_VFREE union {
--
2.34.1