gcc/config/alpha/host-osf.c

   1 /* Tru64 UNIX host-specific hook definitions.
   2    Copyright (C) 2011 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published
   8    by the Free Software Foundation; either version 3, or (at your
   9    option) any later version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT
  12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  14    License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GCC; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include <sys/mman.h>
  24 /* Inhibit inclusion of <sys/mount.h>, unnecessary and errors out due to
  25    use of poisoned bcmp, bcopy.  */
  26 #define _SYS_MOUNT_H_
  27 #include <sys/procfs.h>
  28 #include "hosthooks.h"
  29 #include "hosthooks-def.h"
  30
  31
  32 #undef HOST_HOOKS_GT_PCH_GET_ADDRESS
  33 #define HOST_HOOKS_GT_PCH_GET_ADDRESS osf_gt_pch_get_address
  34 #undef HOST_HOOKS_GT_PCH_USE_ADDRESS
  35 #define HOST_HOOKS_GT_PCH_USE_ADDRESS osf_gt_pch_use_address
  36
  37 /* The mmap ADDR parameter may be ignored without MAP_FIXED set.  Before we
  38    give up, check existing mappings with ioctl(PIOCMAP) to see if the space
  39    is really free.  */
  40
  41 static void *
  42 mmap_fixed (void *addr, size_t len, int prot, int flags, int fd, off_t off)
  43 {
  44   void *base;
  45
  46   base = mmap ((caddr_t) addr, len, prot, flags, fd, off);
  47
  48   if (base != addr)
  49     {
  50       /* PID_MAX is SHRT_MAX on Tru64 UNIX V4.0, but INT_MAX on V5.1.
  51          Allow for both.  "/proc/" + INT_MAX + '\0'.  */
  52       char pname[6+10+1];
  53       int procfd, nmap;
  54       prmap_t *pmap;
  55       int i, overlap = 0;
  56
  57       if (base != (void *) MAP_FAILED)
  58         munmap ((caddr_t) base, len);
  59
  60       /* Check if there's any mapping overlapping [addr, addr+len).  */
  61
  62       snprintf (pname, sizeof (pname), "/proc/%d", getpid ());
  63       procfd = open (pname, O_RDONLY);
  64       if (procfd == -1)
  65         return ((void *) MAP_FAILED);
  66       if (ioctl (procfd, PIOCNMAP, &nmap) == -1)
  67         return ((void *) MAP_FAILED);
  68       pmap = (prmap_t *) xmalloc (sizeof (*pmap) * (nmap+1));
  69       if (ioctl (procfd, PIOCMAP, pmap) == -1)
  70         return ((void *) MAP_FAILED);
  71
  72       /* It seems like pmap[] is sorted by address, but can we rely on
  73          that?  */
  74       for (i = 0; i < nmap; i++)
  75         {
  76           uintptr_t map_start = (uintptr_t) pmap[i].pr_vaddr;
  77           uintptr_t map_end = map_start + pmap[i].pr_size;
  78
  79           if ((uintptr_t) addr < map_end
  80               && (uintptr_t) addr+len > map_start)
  81             {
  82               overlap = 1;
  83               break;
  84             }
  85         }
  86       free (pmap);
  87       close (procfd);
  88
  89       if (!overlap)
  90         base = mmap ((caddr_t) addr, len, prot, flags | MAP_FIXED, fd, off);
  91       else
  92         base = mmap ((caddr_t) addr, len, prot, flags, fd, off);
  93     }
  94
  95   return base;
  96 }
  97
  98 /* For various ports, try to guess a fixed spot in the vm space that's
  99    probably free.  Take the middle between start of text segment and
 100    dynamic loader space.  See <sys/machine/addrconf.h> and Tru64 UNIX
 101    Assembly Language Programmer's Guide, p.6-18, Figure 6-3: Default Layout
 102    of Memory (User Program View).  */
 103 #define TRY_EMPTY_VM_SPACE      0x20050000000
 104
 105 /* Determine a location where we might be able to reliably allocate
 106    SIZE bytes.  FD is the PCH file, though we should return with the
 107    file unmapped.  */
 108
 109 static void *
 110 osf_gt_pch_get_address (size_t size, int fd)
 111 {
 112   void *addr;
 113
 114   addr = mmap_fixed ((caddr_t) TRY_EMPTY_VM_SPACE, size,
 115                      PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 116
 117   /* If we failed the map, that means there's *no* free space.  */
 118   if (addr == (void *) MAP_FAILED)
 119     return NULL;
 120   /* Unmap the area before returning.  */
 121   munmap ((caddr_t) addr, size);
 122
 123   return addr;
 124 }
 125
 126 /* Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
 127    mapping the data at BASE, -1 if we couldn't.  */
 128
 129 static int
 130 osf_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
 131 {
 132   void *addr;
 133
 134   /* We're called with size == 0 if we're not planning to load a PCH
 135      file at all.  This allows the hook to free any static space that
 136      we might have allocated at link time.  */
 137   if (size == 0)
 138     return -1;
 139
 140   addr = mmap_fixed ((caddr_t) base, size,
 141                      PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
 142
 143   return addr == base ? 1 : -1;
 144 }
 145
 146 \f
 147 const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;