diff mbox series

[07/17] hw/vfio/helpers: Fix missing ERRP_GUARD() for error_prepend()

Message ID 20240229143914.1977550-8-zhao1.liu@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Cleanup up to fix missing ERRP_GUARD() for error_prepend() | expand

Commit Message

Zhao Liu Feb. 29, 2024, 2:39 p.m. UTC 
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 hw/vfio/helpers.c, there're 3 functions passing @errp to
error_prepend() without ERRP_GUARD():
 - vfio_set_irq_signaling()
 - vfio_device_get_name()
 - vfio_device_set_fd()

As the widely used helpers, their @errp parameters are so widely sourced
that it is necessary to protect them with ERRP_GUARD().

To avoid the issue like [1] said, add missing ERRP_GUARD() at their
beginning.

[1]: Issue description in the commit message of commit ae7c80a7bd73
     ("error: New macro ERRP_GUARD()").

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: "Cédric Le Goater" <clg@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 hw/vfio/helpers.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Cédric Le Goater Feb. 29, 2024, 6:22 p.m. UTC | #1 
On 2/29/24 15:39, Zhao Liu wrote:
> 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 hw/vfio/helpers.c, there're 3 functions passing @errp to
> error_prepend() without ERRP_GUARD():
>   - vfio_set_irq_signaling()
>   - vfio_device_get_name()
>   - vfio_device_set_fd()
> 
> As the widely used helpers, their @errp parameters are so widely sourced
> that it is necessary to protect them with ERRP_GUARD().
> 
> To avoid the issue like [1] said, add missing ERRP_GUARD() at their
> beginning.
> 
> [1]: Issue description in the commit message of commit ae7c80a7bd73
>       ("error: New macro ERRP_GUARD()").
> 
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: "Cédric Le Goater" <clg@redhat.com>
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/helpers.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
> index 678987080228..47b4096c05ee 100644
> --- a/hw/vfio/helpers.c
> +++ b/hw/vfio/helpers.c
> @@ -110,6 +110,7 @@ static const char *index_to_str(VFIODevice *vbasedev, int index)
>   int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
>                              int action, int fd, Error **errp)
>   {
> +    ERRP_GUARD();
>       struct vfio_irq_set *irq_set;
>       int argsz, ret = 0;
>       const char *name;
> @@ -613,6 +614,7 @@ bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
>   
>   int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
>   {
> +    ERRP_GUARD();
>       struct stat st;
>   
>       if (vbasedev->fd < 0) {
> @@ -644,6 +646,7 @@ int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
>   
>   void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp)
>   {
> +    ERRP_GUARD();
>       int fd = monitor_fd_param(monitor_cur(), str, errp);
>   
>       if (fd < 0) {
diff mbox series

Patch

diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
index 678987080228..47b4096c05ee 100644
--- a/hw/vfio/helpers.c
+++ b/hw/vfio/helpers.c
@@ -110,6 +110,7 @@  static const char *index_to_str(VFIODevice *vbasedev, int index)
 int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
                            int action, int fd, Error **errp)
 {
+    ERRP_GUARD();
     struct vfio_irq_set *irq_set;
     int argsz, ret = 0;
     const char *name;
@@ -613,6 +614,7 @@  bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
 
 int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
 {
+    ERRP_GUARD();
     struct stat st;
 
     if (vbasedev->fd < 0) {
@@ -644,6 +646,7 @@  int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
 
 void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp)
 {
+    ERRP_GUARD();
     int fd = monitor_fd_param(monitor_cur(), str, errp);
 
     if (fd < 0) {