ppc64: various fixes to sys32_sysinfo, from Will Schmidt

arch/ppc64/kernel/sys_ppc32.c

@@ -1136,7 +1136,11 @@ struct sysinfo32 {
         u32 totalswap;
         u32 freeswap;
         unsigned short procs;
-        char _f[22];
+	unsigned short pad;
+	u32 totalhigh;
+	u32 freehigh;
+	u32 mem_unit;
+	char _f[20-2*sizeof(long)-sizeof(int)];
 };
 
 extern asmlinkage long sys_sysinfo(struct sysinfo *info);
@@ -1145,11 +1149,30 @@ asmlinkage long sys32_sysinfo(struct sysinfo32 *info)
 {
 	struct sysinfo s;
 	int ret, err;
+	int bitcount=0;
 	mm_segment_t old_fs = get_fs ();
 	
 	set_fs (KERNEL_DS);
 	ret = sys_sysinfo(&s);
 	set_fs (old_fs);
+	/* Check to see if any memory value is too large for 32-bit and
+         * scale down if needed.
+         */
+	if ((s.totalram >> 32) || (s.totalswap >> 32)) {
+	    while (s.mem_unit < PAGE_SIZE) {
+		s.mem_unit <<= 1;
+		bitcount++;
+	    }
+	    s.totalram >>=bitcount;
+	    s.freeram >>= bitcount;
+	    s.sharedram >>= bitcount;
+	    s.bufferram >>= bitcount;
+	    s.totalswap >>= bitcount;
+	    s.freeswap >>= bitcount;
+	    s.totalhigh >>= bitcount;
+	    s.freehigh >>= bitcount;
+	}
+
 	err = put_user (s.uptime, &info->uptime);
 	err |= __put_user (s.loads[0], &info->loads[0]);
 	err |= __put_user (s.loads[1], &info->loads[1]);
@@ -1161,6 +1184,9 @@ asmlinkage long sys32_sysinfo(struct sysinfo32 *info)
 	err |= __put_user (s.totalswap, &info->totalswap);
 	err |= __put_user (s.freeswap, &info->freeswap);
 	err |= __put_user (s.procs, &info->procs);
+	err |= __put_user (s.totalhigh, &info->totalhigh);
+	err |= __put_user (s.freehigh, &info->freehigh);
+	err |= __put_user (s.mem_unit, &info->mem_unit);
 	if (err)
 		return -EFAULT;