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[2/6] hw/display/macfb: Fix missing ERRP_GUARD() in macfb_nubus_realize()

Message ID 20240221094317.994454-3-zhao1.liu@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Fix missing ERRP_GUARD() when dereference @errp | expand

Commit Message

Zhao Liu Feb. 21, 2024, 9:43 a.m. UTC 
From: Zhao Liu <zhao1.liu@intel.com>

As the comment in qapi/error, dereferencing @errp requires
ERRP_GUARD():

* = Why, when and how to use ERRP_GUARD() =
*
* Without ERRP_GUARD(), use of the @errp parameter is restricted:
* - It must not be dereferenced, because it may be null.
* - It should not be passed to error_prepend() 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.
*
* Using it when it's not needed is safe, but please avoid cluttering
* the source with useless code.

Currently, since macfb_nubus_realize() - as a DeviceClass.realize()
method - doesn't get the NULL errp parameter, it doesn't trigger the
dereference issue.

To follow the requirement of errp, add missing ERRP_GUARD() in
macfb_nubus_realize().

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
Suggested by credit:
 Markus: Referred his explanation about ERRP_GUARD().
---
 hw/display/macfb.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/hw/display/macfb.c b/hw/display/macfb.c
index 418e99c8e18e..1ace341a0ff4 100644
--- a/hw/display/macfb.c
+++ b/hw/display/macfb.c
@@ -714,6 +714,7 @@  static void macfb_nubus_set_irq(void *opaque, int n, int level)
 
 static void macfb_nubus_realize(DeviceState *dev, Error **errp)
 {
+    ERRP_GUARD();
     NubusDevice *nd = NUBUS_DEVICE(dev);
     MacfbNubusState *s = NUBUS_MACFB(dev);
     MacfbNubusDeviceClass *ndc = NUBUS_MACFB_GET_CLASS(dev);