The compat (32bit) version of sys_shmctl on 64bit kernel returns incorrect
information. In this case is better to read data from /proc/sys/kernel/shm*.

--- util-linux-2.13-pre7/sys-utils/ipcs.c.kzak	2007-06-25 10:25:31.000000000 +0200
+++ util-linux-2.13-pre7/sys-utils/ipcs.c	2007-06-25 10:14:06.000000000 +0200
@@ -253,6 +253,26 @@
 		printf(" %-10d\n", ipcp->gid);
 }
 
+static unsigned long long
+shminfo_from_proc(const char *name, unsigned long def)
+{
+	char path[256];
+	char buf[64];
+	FILE *f;
+	unsigned long long res = def;
+
+	if (!name)
+		return res;
+
+	snprintf(path, sizeof(path), "/proc/sys/kernel/%s", name);
+
+	if (!(f = fopen(path, "r")))
+		return res;
+	if (fgets(buf, sizeof(buf), f))
+		res = atoll(buf);
+	fclose(f);
+	return res;
+}
 
 void do_shm (char format)
 {
@@ -268,7 +288,7 @@
 		printf (_("kernel not configured for shared memory\n"));
 		return;
 	}
-	
+
 	switch (format) {
 	case LIMITS:
 		printf (_("------ Shared Memory Limits --------\n"));
@@ -276,18 +296,15 @@
 			return;
 		/* glibc 2.1.3 and all earlier libc's have ints as fields
 		   of struct shminfo; glibc 2.1.91 has unsigned long; ach */
-		printf (_("max number of segments = %lu\n"),
-			(unsigned long) shminfo.shmmni);
-		printf (_("max seg size (kbytes) = %lu\n"),
-			(unsigned long) (shminfo.shmmax >> 10));
-		
+		printf (_("max number of segments = %llu\n"),
+			shminfo_from_proc("shmmni", shminfo.shmmni));
+		printf (_("max seg size (kbytes) = %llu\n"),
+			(shminfo_from_proc("shmmax", shminfo.shmmax) >> 10));
+
 		/* max shmem = pagesize * shminfo.shmall / 1024
-		 * 
-		 * note: that "shminfo.shmall * getpagesize()" is greater than ULONG_MAX (32bit)
-		 *       it means that better is "/" before "*" or use "long long"  
 		 */
-		printf (_("max total shared memory (kbytes) = %lu\n"),
-			getpagesize()/1024 * (unsigned long) shminfo.shmall);
+		printf (_("max total shared memory (kbytes) = %llu\n"),
+			getpagesize()/1024 * shminfo_from_proc("shmall", shminfo.shmall));
 		printf (_("min seg size (bytes) = %lu\n"),
 			(unsigned long) shminfo.shmmin);
 		return;