sysdeps/unix/sysv/linux/arm/mmap64.S

   1 /* Copyright (C) 2000-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19
  20         .syntax unified
  21
  22 #define EINVAL          22
  23
  24 #ifdef __ARMEB__
  25 # define LOW_OFFSET      8 + 4
  26 /* The initial + 4 is for the stack postdecrement.  */
  27 # define HIGH_OFFSET 4 + 8 + 0
  28 #else
  29 # define LOW_OFFSET      8 + 0
  30 # define HIGH_OFFSET 4 + 8 + 4
  31 #endif
  32
  33         /* The mmap2 system call takes six arguments, all in registers.  */
  34         .text
  35 ENTRY (__mmap64)
  36         ldr     ip, [sp, $LOW_OFFSET]
  37         push    { r5 }
  38         cfi_adjust_cfa_offset (4)
  39         cfi_rel_offset (r5, 0)
  40         ldr     r5, [sp, $HIGH_OFFSET]
  41         push    { r4 }
  42         cfi_adjust_cfa_offset (4)
  43         cfi_rel_offset (r4, 0)
  44         cfi_remember_state
  45         movs    r4, ip, lsl $20         @ check that offset is page-aligned
  46         mov     ip, ip, lsr $12
  47         it      eq
  48         movseq  r4, r5, lsr $12         @ check for overflow
  49         bne     .Linval
  50         ldr     r4, [sp, $8]            @ load fd
  51         orr     r5, ip, r5, lsl $20     @ compose page offset
  52         DO_CALL (mmap2, 0)
  53         cmn     r0, $4096
  54         pop     {r4, r5}
  55         cfi_adjust_cfa_offset (-8)
  56         cfi_restore (r4)
  57         cfi_restore (r5)
  58         it      cc
  59         RETINSTR(cc, lr)
  60         b       PLTJMP(syscall_error)
  61
  62         cfi_restore_state
  63 .Linval:
  64         mov     r0, $-EINVAL
  65         pop     {r4, r5}
  66         cfi_adjust_cfa_offset (-8)
  67         cfi_restore (r4)
  68         cfi_restore (r5)
  69         b       PLTJMP(syscall_error)
  70 PSEUDO_END (__mmap64)
  71
  72 weak_alias (__mmap64, mmap64)