mem: decode hugetlb page size in mmap flags

[strace] / affinity.c

diff --git a/affinity.c b/affinity.c
index 55bc7e1263d778f3a0c9bfb40000524a5c4fa046..0eb109404c0b8ae5acf79f2a83882d0e66f1aee3 100644 (file)
--- a/affinity.c
+++ b/affinity.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2002-2004 Roland McGrath <roland@redhat.com>
- * Copyright (c) 2009-2015 Dmitry V. Levin <ldv@altlinux.org>
+ * Copyright (c) 2009-2016 Dmitry V. Levin <ldv@altlinux.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -27,56 +27,94 @@
  */
 
 #include "defs.h"
+#include <sched.h>
+
+static unsigned int
+get_cpuset_size(void)
+{
+       static unsigned int cpuset_size;
+
+       if (!cpuset_size) {
+               /*
+                * If the cpuset size passed to sched_getaffinity is less
+                * than necessary to store the bitmask, the kernel does not
+                * look at the mask pointer and fails with EINVAL.
+                *
+                * If the cpuset size is large enough, the kernel fails with
+                * EFAULT on inaccessible mask pointers.
+                *
+                * This undocumented kernel feature can be used to probe
+                * the kernel and find out the minimal valid cpuset size
+                * without allocating any memory for the CPU affinity mask.
+                */
+               cpuset_size = 128;
+               while (cpuset_size &&
+                      sched_getaffinity(0, cpuset_size, NULL) == -1 &&
+                      EINVAL == errno) {
+                       cpuset_size <<= 1;
+               }
+               if (!cpuset_size)
+                       cpuset_size = 128;
+       }
+
+       return cpuset_size;
+}
 
 static void
-print_affinitylist(struct tcb *tcp, const unsigned long addr, const unsigned int len)
+print_affinitylist(struct tcb *const tcp, const kernel_ulong_t addr,
+                  const unsigned int len)
 {
-       unsigned long w;
-       const unsigned int size = len * sizeof(w);
-       const unsigned long end = addr + size;
-       unsigned long cur, abbrev_end;
+       const unsigned int max_size = get_cpuset_size();
+       const unsigned int umove_size = len < max_size ? len : max_size;
+       const unsigned int size =
+               (umove_size + current_wordsize - 1) & -current_wordsize;
+       const unsigned int ncpu = size * 8;
+       void *cpu;
 
        if (!verbose(tcp) || (exiting(tcp) && syserror(tcp)) ||
-           !addr || !len || size / sizeof(w) != len || end < addr) {
+           !addr || !len || !(cpu = calloc(size, 1))) {
                printaddr(addr);
                return;
        }
 
-       if (abbrev(tcp)) {
-               abbrev_end = addr + max_strlen *  sizeof(w);
-               if (abbrev_end < addr)
-                       abbrev_end = end;
-       } else {
-               abbrev_end = end;
-       }
+       if (!umoven_or_printaddr(tcp, addr, umove_size, cpu)) {
+               int i = 0;
+               const char *sep = "";
 
-       tprints("[");
-       for (cur = addr; cur < end; cur += sizeof(w)) {
-               if (cur > addr)
-                       tprints(", ");
-               if (cur >= abbrev_end) {
-                       tprints("...");
-                       break;
+               tprints("[");
+               for (;; i++) {
+                       i = next_set_bit(cpu, i, ncpu);
+                       if (i < 0)
+                               break;
+                       tprintf("%s%d", sep, i);
+                       sep = ", ";
                }
-               if (umove_or_printaddr(tcp, cur, &w))
-                       break;
-               tprintf("%lx", w);
+               if (size < len)
+                       tprintf("%s...", sep);
+               tprints("]");
        }
-       tprints("]");
+
+       free(cpu);
 }
 
 SYS_FUNC(sched_setaffinity)
 {
-       tprintf("%ld, %lu, ", tcp->u_arg[0], tcp->u_arg[1]);
-       print_affinitylist(tcp, tcp->u_arg[2], tcp->u_arg[1]);
+       const int pid = tcp->u_arg[0];
+       const unsigned int len = tcp->u_arg[1];
+
+       tprintf("%d, %u, ", pid, len);
+       print_affinitylist(tcp, tcp->u_arg[2], len);
 
        return RVAL_DECODED;
 }
 
 SYS_FUNC(sched_getaffinity)
 {
+       const int pid = tcp->u_arg[0];
+       const unsigned int len = tcp->u_arg[1];
+
        if (entering(tcp)) {
-               tprintf("%ld, %lu, ", tcp->u_arg[0], tcp->u_arg[1]);
+               tprintf("%d, %u, ", pid, len);
        } else {
                print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
        }