pread_write.c 3.3 KB

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  1. /* vi: set sw=4 ts=4:
  2. *
  3. * Copyright (C) 2002 by Erik Andersen <andersen@uclibc.org>
  4. * Based in part on the files
  5. * ./sysdeps/unix/sysv/linux/pwrite.c,
  6. * ./sysdeps/unix/sysv/linux/pread.c,
  7. * sysdeps/posix/pread.c
  8. * sysdeps/posix/pwrite.c
  9. * from GNU libc 2.2.5, but reworked considerably...
  10. *
  11. * This program is free software; you can redistribute it and/or modify it
  12. * under the terms of the GNU Library General Public License as published by
  13. * the Free Software Foundation; either version 2 of the License, or (at your
  14. * option) any later version.
  15. *
  16. * This program is distributed in the hope that it will be useful, but WITHOUT
  17. * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18. * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
  19. * for more details.
  20. *
  21. * You should have received a copy of the GNU Library General Public License
  22. * along with this program; if not, write to the Free Software Foundation,
  23. * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  24. */
  25. #define _GNU_SOURCE
  26. #define _LARGEFILE64_SOURCE
  27. #include <features.h>
  28. #undef __OPTIMIZE__
  29. /* We absolutely do _NOT_ want interfaces silently
  30. * * * renamed under us or very bad things will happen... */
  31. #ifdef __USE_FILE_OFFSET64
  32. # undef __USE_FILE_OFFSET64
  33. #endif
  34. #include <errno.h>
  35. #include <sys/types.h>
  36. #include <sys/syscall.h>
  37. #include <unistd.h>
  38. #include <stdint.h>
  39. #ifdef __NR_pread64 /* Newer kernels renamed but it's the same. */
  40. # ifdef __NR_pread
  41. # error "__NR_pread and __NR_pread64 both defined???"
  42. # endif
  43. # define __NR_pread __NR_pread64
  44. #endif
  45. #ifdef __NR_pread
  46. #define __NR___syscall_pread __NR_pread
  47. static inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf,
  48. size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo);
  49. ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
  50. {
  51. return(__syscall_pread(fd,buf,count,0,__LONG_LONG_PAIR((off_t)0,offset)));
  52. }
  53. weak_alias (__libc_pread, pread)
  54. #if defined __UCLIBC_HAS_LFS__
  55. ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
  56. {
  57. uint32_t low = offset & 0xffffffff;
  58. uint32_t high = offset >> 32;
  59. return(__syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR (high, low)));
  60. }
  61. weak_alias (__libc_pread64, pread64)
  62. #endif /* __UCLIBC_HAS_LFS__ */
  63. #endif /* __NR_pread */
  64. /**********************************************************************/
  65. #ifdef __NR_pwrite64 /* Newer kernels renamed but it's the same. */
  66. # ifdef __NR_pwrite
  67. # error "__NR_pwrite and __NR_pwrite64 both defined???"
  68. # endif
  69. # define __NR_pwrite __NR_pwrite64
  70. #endif
  71. #ifdef __NR_pwrite
  72. #define __NR___syscall_pwrite __NR_pwrite
  73. static inline _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
  74. size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo);
  75. ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
  76. {
  77. return(__syscall_pwrite(fd,buf,count,0,__LONG_LONG_PAIR((off_t)0,offset)));
  78. }
  79. weak_alias (__libc_pwrite, pwrite)
  80. #if defined __UCLIBC_HAS_LFS__
  81. ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
  82. {
  83. uint32_t low = offset & 0xffffffff;
  84. uint32_t high = offset >> 32;
  85. return(__syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR (high, low)));
  86. }
  87. weak_alias (__libc_pwrite64, pwrite64)
  88. #endif /* __UCLIBC_HAS_LFS__ */
  89. #endif /* __NR_pwrite */