libbb: make xrealloc_vector zero out the realloc'ed tail

[oweals/busybox.git] / miscutils / taskset.c

diff --git a/miscutils/taskset.c b/miscutils/taskset.c
index bf98ea15d1bf5056fcc9e26bd88d8a781cfa5cc8..b43d42e905374cef5a374cce97236b47946cf285 100644 (file)
--- a/miscutils/taskset.c
+++ b/miscutils/taskset.c
@@ -7,41 +7,62 @@
  */
 
 #include <sched.h>
-#include <getopt.h> /* optind */
 #include "libbb.h"
 
 #if ENABLE_FEATURE_TASKSET_FANCY
 #define TASKSET_PRINTF_MASK "%s"
-#define from_cpuset(x) __from_cpuset(&x)
 /* craft a string from the mask */
-static char *__from_cpuset(cpu_set_t *mask)
+static char *from_cpuset(cpu_set_t *mask)
 {
        int i;
-       char *ret = 0, *str = xzalloc(9);
+       char *ret = NULL;
+       char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
 
        for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
-               char val = 0;
+               int val = 0;
                int off;
                for (off = 0; off <= 3; ++off)
-                       if (CPU_ISSET(i+off, mask))
-                               val |= 1<<off;
-
+                       if (CPU_ISSET(i + off, mask))
+                               val |= 1 << off;
                if (!ret && val)
                        ret = str;
-               *str++ = (val-'0'<=9) ? (val+48) : (val+87);
+               *str++ = bb_hexdigits_upcase[val] | 0x20;
        }
        return ret;
 }
 #else
-#define TASKSET_PRINTF_MASK "%x"
-/* (void*) cast is for battling gcc: */
-/* "dereferencing type-punned pointer will break strict-aliasing rules" */
-#define from_cpuset(mask) (*(unsigned*)(void*)&(mask))
+#define TASKSET_PRINTF_MASK "%llx"
+static unsigned long long from_cpuset(cpu_set_t *mask)
+{
+       struct BUG_CPU_SETSIZE_is_too_small {
+               char BUG_CPU_SETSIZE_is_too_small[
+                       CPU_SETSIZE < sizeof(int) ? -1 : 1];
+       };
+       char *p = (void*)mask;
+
+       /* Take the least significant bits. Careful!
+        * Consider both CPU_SETSIZE=4 and CPU_SETSIZE=1024 cases
+        */
+#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;
+}
 #endif
 
 
 int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int taskset_main(int argc ATTRIBUTE_UNUSED, char **argv)
+int taskset_main(int argc UNUSED_PARAM, char **argv)
 {
        cpu_set_t mask;
        pid_t pid = 0;
@@ -79,7 +100,7 @@ int taskset_main(int argc ATTRIBUTE_UNUSED, char **argv)
                if (sched_getaffinity(pid, sizeof(mask), &mask) < 0)
                        bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
                printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
-                               pid, current_new, from_cpuset(mask));
+                               pid, current_new, from_cpuset(&mask));
                if (!*argv) {
                        /* Either it was just "-p <pid>",
                         * or it was "-p <aff> <pid>" and we came here
@@ -94,8 +115,10 @@ int taskset_main(int argc ATTRIBUTE_UNUSED, char **argv)
                unsigned i;
                /* Do not allow zero mask: */
                unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
+               enum { CNT_BIT = CPU_SETSIZE < sizeof(m)*8 ? CPU_SETSIZE : sizeof(m)*8 };
+
                CPU_ZERO(&mask);
-               for (i = 0; i < CPU_SETSIZE; i++) {
+               for (i = 0; i < CNT_BIT; i++) {
                        unsigned long long bit = (1ULL << i);
                        if (bit & m)
                                CPU_SET(i, &mask);