[Qemu-devel] [PULL for-4.0 3/4] hw/s390x/ipl: avoid taking address of fields in packed struct

From: Cornelia Huck <cohuck@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-s390x@nongnu.org, qemu-devel@nongnu.org,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>
Subject: [Qemu-devel] [PULL for-4.0 3/4] hw/s390x/ipl: avoid taking address of fields in packed struct
Date: Wed,  3 Apr 2019 12:05:04 +0200	[thread overview]
Message-ID: <20190403100505.7550-4-cohuck@redhat.com> (raw)
In-Reply-To: <20190403100505.7550-1-cohuck@redhat.com>

From: Daniel P. Berrangé <berrange@redhat.com>

Compiling with GCC 9 complains

hw/s390x/ipl.c: In function ‘s390_ipl_set_boot_menu’:
hw/s390x/ipl.c:256:25: warning: taking address of packed member of ‘struct QemuIplParameters’ may result in an unaligned pointer value [-Waddress-of-packed-member]
  256 |     uint32_t *timeout = &ipl->qipl.boot_menu_timeout;
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

This local variable is only present to save a little bit of
typing when setting the field later. Get rid of this to avoid
the warning about unaligned accesses.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190329111104.17223-14-berrange@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 hw/s390x/ipl.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 896888bf8f00..51b272e190a9 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -252,8 +252,6 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
 {
     QemuOptsList *plist = qemu_find_opts("boot-opts");
     QemuOpts *opts = QTAILQ_FIRST(&plist->head);
-    uint8_t *flags = &ipl->qipl.qipl_flags;
-    uint32_t *timeout = &ipl->qipl.boot_menu_timeout;
     const char *tmp;
     unsigned long splash_time = 0;
 
@@ -269,7 +267,7 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
     case S390_IPL_TYPE_CCW:
         /* In the absence of -boot menu, use zipl parameters */
         if (!qemu_opt_get(opts, "menu")) {
-            *flags |= QIPL_FLAG_BM_OPTS_ZIPL;
+            ipl->qipl.qipl_flags |= QIPL_FLAG_BM_OPTS_ZIPL;
             return;
         }
         break;
@@ -286,23 +284,23 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
         return;
     }
 
-    *flags |= QIPL_FLAG_BM_OPTS_CMD;
+    ipl->qipl.qipl_flags |= QIPL_FLAG_BM_OPTS_CMD;
 
     tmp = qemu_opt_get(opts, "splash-time");
 
     if (tmp && qemu_strtoul(tmp, NULL, 10, &splash_time)) {
         error_report("splash-time is invalid, forcing it to 0");
-        *timeout = 0;
+        ipl->qipl.boot_menu_timeout = 0;
         return;
     }
 
     if (splash_time > 0xffffffff) {
         error_report("splash-time is too large, forcing it to max value");
-        *timeout = 0xffffffff;
+        ipl->qipl.boot_menu_timeout = 0xffffffff;
         return;
     }
 
-    *timeout = cpu_to_be32(splash_time);
+    ipl->qipl.boot_menu_timeout = cpu_to_be32(splash_time);
 }
 
 static CcwDevice *s390_get_ccw_device(DeviceState *dev_st)
-- 
2.17.2
