1 files changed, 18 insertions, 19 deletions

diff --git a/miscutils/taskset.c b/miscutils/taskset.c
index 100b1d926..fb352ab8d 100644
--- a/miscutils/taskset.c
+++ b/miscutils/taskset.c
@@ -75,27 +75,26 @@ static char *from_cpuset(cpu_set_t *mask)
 #define TASKSET_PRINTF_MASK "%llx"
 static unsigned long long from_cpuset(cpu_set_t *mask)
 {
-        char *p = (void*)mask;
+        BUILD_BUG_ON(CPU_SETSIZE < 8*sizeof(int));
 
-        BUILD_BUG_ON(CPU_SETSIZE < sizeof(int));
-
-        /* Take the least significant bits. Careful!
-         * Consider both CPU_SETSIZE=4 and CPU_SETSIZE=1024 cases
+        /* Take the least significant bits. Assume cpu_set_t is
+         * implemented as an array of unsigned long or unsigned
+         * int.
          */
-#if BB_BIG_ENDIAN
-        /* For big endian, it means LAST bits */
-        if (CPU_SETSIZE < sizeof(long))
-                p += CPU_SETSIZE - sizeof(int);
-        else if (CPU_SETSIZE < sizeof(long long))
-                p += CPU_SETSIZE - sizeof(long);
-        else
-                p += CPU_SETSIZE - sizeof(long long);
-#endif
-        if (CPU_SETSIZE < sizeof(long))
-                return *(unsigned*)p;
-        if (CPU_SETSIZE < sizeof(long long))
-                return *(unsigned long*)p;
-        return *(unsigned long long*)p;
+        if (CPU_SETSIZE < 8*sizeof(long))
+                return *(unsigned*)mask;
+        if (CPU_SETSIZE < 8*sizeof(long long))
+                return *(unsigned long*)mask;
+# if BB_BIG_ENDIAN
+        if (sizeof(long long) > sizeof(long)) {
+                /* We can put two long in the long long, but they have to
+                 * be swapped: the least significant word comes first in the
+                 * array */
+                unsigned long *p = (void*)mask;
+                return p[0] + ((unsigned long long)p[1] << (8*sizeof(long)));
+        }
+# endif
+        return *(unsigned long long*)mask;
 }
 #endif