ifplugd: eliminate aliasing warnings

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 14 insertions, 10 deletions

diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index 58f56dbf1..3b59a63ff 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -131,18 +131,20 @@ static int network_ioctl(int request, void* data, const char *errmsg)
 
 static smallint detect_link_mii(void)
 {
-        struct ifreq ifreq;
-        struct mii_ioctl_data *mii = (void *)&ifreq.ifr_data;
+        /* char buffer instead of bona-fide struct avoids aliasing warning */
+        char buf[sizeof(struct ifreq)];
+        struct ifreq *ifreq = (void *)buf;
+        struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
 
-        set_ifreq_to_ifname(&ifreq);
+        set_ifreq_to_ifname(ifreq);
 
-        if (network_ioctl(SIOCGMIIPHY, &ifreq, "SIOCGMIIPHY") < 0) {
+        if (network_ioctl(SIOCGMIIPHY, ifreq, "SIOCGMIIPHY") < 0) {
                 return IFSTATUS_ERR;
         }
 
         mii->reg_num = 1;
 
-        if (network_ioctl(SIOCGMIIREG, &ifreq, "SIOCGMIIREG") < 0) {
+        if (network_ioctl(SIOCGMIIREG, ifreq, "SIOCGMIIREG") < 0) {
                 return IFSTATUS_ERR;
         }
 
@@ -151,18 +153,20 @@ static smallint detect_link_mii(void)
 
 static smallint detect_link_priv(void)
 {
-        struct ifreq ifreq;
-        struct mii_ioctl_data *mii = (void *)&ifreq.ifr_data;
+        /* char buffer instead of bona-fide struct avoids aliasing warning */
+        char buf[sizeof(struct ifreq)];
+        struct ifreq *ifreq = (void *)buf;
+        struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
 
-        set_ifreq_to_ifname(&ifreq);
+        set_ifreq_to_ifname(ifreq);
 
-        if (network_ioctl(SIOCDEVPRIVATE, &ifreq, "SIOCDEVPRIVATE") < 0) {
+        if (network_ioctl(SIOCDEVPRIVATE, ifreq, "SIOCDEVPRIVATE") < 0) {
                 return IFSTATUS_ERR;
         }
 
         mii->reg_num = 1;
 
-        if (network_ioctl(SIOCDEVPRIVATE+1, &ifreq, "SIOCDEVPRIVATE+1") < 0) {
+        if (network_ioctl(SIOCDEVPRIVATE+1, ifreq, "SIOCDEVPRIVATE+1") < 0) {
                 return IFSTATUS_ERR;
         }