1 files changed, 108 insertions, 109 deletions

diff --git a/miscutils/taskset.c b/miscutils/taskset.c
index fb352ab8d..94a07383a 100644
--- a/miscutils/taskset.c
+++ b/miscutils/taskset.c
@@ -8,7 +8,7 @@
 
 //config:config TASKSET
 //config:       bool "taskset"
-//config:       default n  # doesn't build on some non-x86 targets (m68k)
+//config:       default y
 //config:       help
 //config:         Retrieve or set a processes's CPU affinity.
 //config:         This requires sched_{g,s}etaffinity support in your libc.
@@ -18,15 +18,15 @@
 //config:       default y
 //config:       depends on TASKSET
 //config:       help
-//config:         Add code for fancy output. This merely silences a compiler-warning
-//config:         and adds about 135 Bytes. May be needed for machines with alot
-//config:         of CPUs.
+//config:         Needed for machines with more than 32-64 CPUs:
+//config:         affinity parameter 0xHHHHHHHHHHHHHHHHHHHH can be arbitrarily long
+//config:         in this case. Otherwise, it is limited to sizeof(long).
 
 //applet:IF_TASKSET(APPLET(taskset, BB_DIR_USR_BIN, BB_SUID_DROP))
 //kbuild:lib-$(CONFIG_TASKSET) += taskset.o
 
 //usage:#define taskset_trivial_usage
-//usage:       "[-p] [MASK] [PID | PROG ARGS]"
+//usage:       "[-p] [HEXMASK] PID | PROG ARGS"
 //usage:#define taskset_full_usage "\n\n"
 //usage:       "Set or get CPU affinity\n"
 //usage:     "\n        -p      Operate on an existing PID"
@@ -42,72 +42,81 @@
 //usage:       "$ taskset -p 1\n"
 //usage:       "pid 1's current affinity mask: 3\n"
 /*
- Not yet implemented:
+ * Not yet implemented:
  * -a/--all-tasks (affect all threads)
+ *      needs to get TIDs from /proc/PID/task/ and use _them_ as "pid" in sched_setaffinity(pid)
  * -c/--cpu-list  (specify CPUs via "1,3,5-7")
  */
 
 #include <sched.h>
 #include "libbb.h"
 
+typedef unsigned long ul;
+#define SZOF_UL (unsigned)(sizeof(ul))
+#define BITS_UL (unsigned)(sizeof(ul)*8)
+#define MASK_UL (unsigned)(sizeof(ul)*8 - 1)
+
 #if ENABLE_FEATURE_TASKSET_FANCY
 #define TASKSET_PRINTF_MASK "%s"
 /* craft a string from the mask */
-static char *from_cpuset(cpu_set_t *mask)
+static char *from_mask(const ul *mask, unsigned sz_in_bytes)
 {
-        int i;
-        char *ret = NULL;
-        char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
-
-        for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
-                int val = 0;
-                int off;
-                for (off = 0; off <= 3; ++off)
-                        if (CPU_ISSET(i + off, mask))
-                                val |= 1 << off;
-                if (!ret && val)
-                        ret = str;
-                *str++ = bb_hexdigits_upcase[val] | 0x20;
+        char *str = xzalloc((sz_in_bytes+1) * 2); /* we will leak it */
+        char *p = str;
+        for (;;) {
+                ul v = *mask++;
+                if (SZOF_UL == 4)
+                        p += sprintf(p, "%08lx", v);
+                if (SZOF_UL == 8)
+                        p += sprintf(p, "%016lx", v);
+                if (SZOF_UL == 16)
+                        p += sprintf(p, "%032lx", v); /* :) */
+                sz_in_bytes -= SZOF_UL;
+                if ((int)sz_in_bytes <= 0)
+                        break;
         }
-        return ret;
+        while (str[0] == '0' && str[1])
+                str++;
+        return str;
 }
 #else
-#define TASKSET_PRINTF_MASK "%llx"
-static unsigned long long from_cpuset(cpu_set_t *mask)
+#define TASKSET_PRINTF_MASK "%lx"
+static unsigned long long from_mask(ul *mask, unsigned sz_in_bytes UNUSED_PARAM)
 {
-        BUILD_BUG_ON(CPU_SETSIZE < 8*sizeof(int));
-
-        /* Take the least significant bits. Assume cpu_set_t is
-         * implemented as an array of unsigned long or unsigned
-         * int.
-         */
-        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;
+        return *mask;
 }
 #endif
 
+static unsigned long *get_aff(int pid, unsigned *sz)
+{
+        int r;
+        unsigned long *mask = NULL;
+        unsigned sz_in_bytes = *sz;
+
+        for (;;) {
+                mask = xrealloc(mask, sz_in_bytes);
+                r = sched_getaffinity(pid, sz_in_bytes, (void*)mask);
+                if (r == 0)
+                        break;
+                sz_in_bytes *= 2;
+                if (errno == EINVAL && (int)sz_in_bytes > 0)
+                        continue;
+                bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
+        }
+        //bb_error_msg("get mask[0]:%lx sz_in_bytes:%d", mask[0], sz_in_bytes);
+        *sz = sz_in_bytes;
+        return mask;
+}
 
 int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int taskset_main(int argc UNUSED_PARAM, char **argv)
 {
-        cpu_set_t mask;
+        ul *mask;
+        unsigned mask_size_in_bytes;
         pid_t pid = 0;
         unsigned opt_p;
         const char *current_new;
-        char *pid_str;
-        char *aff = aff; /* for compiler */
+        char *aff;
 
         /* NB: we mimic util-linux's taskset: -p does not take
          * an argument, i.e., "-pN" is NOT valid, only "-p N"!
@@ -118,102 +127,92 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
         opt_p = getopt32(argv, "+p");
         argv += optind;
 
+        aff = *argv++;
         if (opt_p) {
-                pid_str = *argv++;
+                char *pid_str = aff;
                 if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
-                        aff = pid_str;
                         pid_str = *argv; /* NB: *argv != NULL in this case */
                 }
                 /* else it was just "-p <pid>", and *argv == NULL */
                 pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1);
         } else {
-                aff = *argv++; /* <aff> <cmd...> */
+                /* <aff> <cmd...> */
                 if (!*argv)
                         bb_show_usage();
         }
 
-        current_new = "current\0new";
-        if (opt_p) {
+        mask_size_in_bytes = SZOF_UL;
+        current_new = "current";
  print_aff:
-                if (sched_getaffinity(pid, sizeof(mask), &mask) < 0)
-                        bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
+        mask = get_aff(pid, &mask_size_in_bytes);
+        if (opt_p) {
                 printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
-                                pid, current_new, from_cpuset(&mask));
-                if (!*argv) {
+                                pid, current_new, from_mask(mask, mask_size_in_bytes));
+                if (*argv == NULL) {
                         /* Either it was just "-p <pid>",
                          * or it was "-p <aff> <pid>" and we came here
                          * for the second time (see goto below) */
                         return EXIT_SUCCESS;
                 }
                 *argv = NULL;
-                current_new += 8; /* "new" */
+                current_new = "new";
         }
+        memset(mask, 0, mask_size_in_bytes);
+
+        /* Affinity was specified, translate it into mask */
+        /* it is always in hex, skip "0x" if it exists */
+        if (aff[0] == '0' && (aff[1]|0x20) == 'x')
+                aff += 2;
 
-        /* Affinity was specified, translate it into cpu_set_t */
-        CPU_ZERO(&mask);
         if (!ENABLE_FEATURE_TASKSET_FANCY) {
-                unsigned i;
-                unsigned long long m;
-
-                /* Do not allow zero mask: */
-                m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
-                i = 0;
-                do {
-                        if (m & 1)
-                                CPU_SET(i, &mask);
-                        i++;
-                        m >>= 1;
-                } while (m != 0);
+                mask[0] = xstrtoul(aff, 16);
         } else {
                 unsigned i;
-                char *last_byte;
-                char *bin;
-                uint8_t bit_in_byte;
-
-                /* Cheap way to get "long enough" buffer */
-                bin = xstrdup(aff);
-
-                if (aff[0] != '0' || (aff[1]|0x20) != 'x') {
-/* TODO: decimal/octal masks are still limited to 2^64 */
-                        unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
-                        bin += strlen(bin);
-                        last_byte = bin - 1;
-                        while (m) {
-                                *--bin = m & 0xff;
-                                m >>= 8;
-                        }
-                } else {
-                        /* aff is "0x.....", we accept very long masks in this form */
-                        last_byte = hex2bin(bin, aff + 2, INT_MAX);
-                        if (!last_byte) {
- bad_aff:
+                char *last_char;
+
+                i = 0; /* bit pos in mask[] */
+
+                /* aff is ASCII hex string, accept very long masks in this form.
+                 * Process hex string AABBCCDD... to ulong mask[]
+                 * from the rightmost nibble, which is least-significant.
+                 * Bits not fitting into mask[] are ignored: (example: 1234
+                 * in 12340000000000000000000000000000000000000ff)
+                 */
+                last_char = strchrnul(aff, '\0');
+                while (last_char > aff) {
+                        char c;
+                        ul val;
+
+                        last_char--;
+                        c = *last_char;
+                        if (isdigit(c))
+                                val = c - '0';
+                        else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
+                                val = (c|0x20) - ('a' - 10);
+                        else
                                 bb_error_msg_and_die("bad affinity '%s'", aff);
-                        }
-                        last_byte--; /* now points to the last byte */
-                }
 
-                i = 0;
-                bit_in_byte = 1;
-                while (last_byte >= bin) {
-                        if (bit_in_byte & *last_byte) {
-                                if (i >= CPU_SETSIZE)
-                                        goto bad_aff;
-                                CPU_SET(i, &mask);
+                        if (i < mask_size_in_bytes * 8) {
+                                mask[i / BITS_UL] |= val << (i & MASK_UL);
                                 //bb_error_msg("bit %d set", i);
                         }
-                        i++;
-                        /* bit_in_byte is uint8_t! & 0xff is implied */
-                        bit_in_byte = (bit_in_byte << 1);
-                        if (!bit_in_byte) {
-                                bit_in_byte = 1;
-                                last_byte--;
-                        }
+                        /* else:
+                         * We can error out here, but we don't.
+                         * For one, kernel itself ignores bits in mask[]
+                         * which do not map to any CPUs:
+                         * if mask[] has one 32-bit long element,
+                         * but you have only 8 CPUs, all bits beyond first 8
+                         * are ignored, silently.
+                         * No point in making bits past 31th to be errors.
+                         */
+                        i += 4;
                 }
         }
 
         /* Set pid's or our own (pid==0) affinity */
-        if (sched_setaffinity(pid, sizeof(mask), &mask))
+        if (sched_setaffinity(pid, mask_size_in_bytes, (void*)mask))
                 bb_perror_msg_and_die("can't %cet pid %d's affinity", 's', pid);
+        //bb_error_msg("set mask[0]:%lx", mask[0]);
 
         if (!argv[0]) /* "-p <aff> <pid> [...ignored...]" */
                 goto print_aff; /* print new affinity and exit */