compat_mq.c 4.0 KB

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  1. /*
  2. * ipc/compat_mq.c
  3. * 32 bit emulation for POSIX message queue system calls
  4. *
  5. * Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
  6. * Author: Arnd Bergmann <arnd@arndb.de>
  7. */
  8. #include <linux/compat.h>
  9. #include <linux/fs.h>
  10. #include <linux/kernel.h>
  11. #include <linux/mqueue.h>
  12. #include <linux/syscalls.h>
  13. #include <asm/uaccess.h>
  14. struct compat_mq_attr {
  15. compat_long_t mq_flags; /* message queue flags */
  16. compat_long_t mq_maxmsg; /* maximum number of messages */
  17. compat_long_t mq_msgsize; /* maximum message size */
  18. compat_long_t mq_curmsgs; /* number of messages currently queued */
  19. compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
  20. };
  21. static inline int get_compat_mq_attr(struct mq_attr *attr,
  22. const struct compat_mq_attr __user *uattr)
  23. {
  24. if (!access_ok(VERIFY_READ, uattr, sizeof *uattr))
  25. return -EFAULT;
  26. return __get_user(attr->mq_flags, &uattr->mq_flags)
  27. | __get_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  28. | __get_user(attr->mq_msgsize, &uattr->mq_msgsize)
  29. | __get_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  30. }
  31. static inline int put_compat_mq_attr(const struct mq_attr *attr,
  32. struct compat_mq_attr __user *uattr)
  33. {
  34. if (clear_user(uattr, sizeof *uattr))
  35. return -EFAULT;
  36. return __put_user(attr->mq_flags, &uattr->mq_flags)
  37. | __put_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  38. | __put_user(attr->mq_msgsize, &uattr->mq_msgsize)
  39. | __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  40. }
  41. asmlinkage long compat_sys_mq_open(const char __user *u_name,
  42. int oflag, compat_mode_t mode,
  43. struct compat_mq_attr __user *u_attr)
  44. {
  45. void __user *p = NULL;
  46. if (u_attr && oflag & O_CREAT) {
  47. struct mq_attr attr;
  48. p = compat_alloc_user_space(sizeof(attr));
  49. if (get_compat_mq_attr(&attr, u_attr) ||
  50. copy_to_user(p, &attr, sizeof(attr)))
  51. return -EFAULT;
  52. }
  53. return sys_mq_open(u_name, oflag, mode, p);
  54. }
  55. static int compat_prepare_timeout(struct timespec __user * *p,
  56. const struct compat_timespec __user *u)
  57. {
  58. struct timespec ts;
  59. if (!u) {
  60. *p = NULL;
  61. return 0;
  62. }
  63. *p = compat_alloc_user_space(sizeof(ts));
  64. if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
  65. return -EFAULT;
  66. return 0;
  67. }
  68. asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
  69. const char __user *u_msg_ptr,
  70. size_t msg_len, unsigned int msg_prio,
  71. const struct compat_timespec __user *u_abs_timeout)
  72. {
  73. struct timespec __user *u_ts;
  74. if (compat_prepare_timeout(&u_ts, u_abs_timeout))
  75. return -EFAULT;
  76. return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
  77. msg_prio, u_ts);
  78. }
  79. asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
  80. char __user *u_msg_ptr,
  81. size_t msg_len, unsigned int __user *u_msg_prio,
  82. const struct compat_timespec __user *u_abs_timeout)
  83. {
  84. struct timespec __user *u_ts;
  85. if (compat_prepare_timeout(&u_ts, u_abs_timeout))
  86. return -EFAULT;
  87. return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
  88. u_msg_prio, u_ts);
  89. }
  90. asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
  91. const struct compat_sigevent __user *u_notification)
  92. {
  93. struct sigevent __user *p = NULL;
  94. if (u_notification) {
  95. struct sigevent n;
  96. p = compat_alloc_user_space(sizeof(*p));
  97. if (get_compat_sigevent(&n, u_notification))
  98. return -EFAULT;
  99. if (n.sigev_notify == SIGEV_THREAD)
  100. n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
  101. if (copy_to_user(p, &n, sizeof(*p)))
  102. return -EFAULT;
  103. }
  104. return sys_mq_notify(mqdes, p);
  105. }
  106. asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes,
  107. const struct compat_mq_attr __user *u_mqstat,
  108. struct compat_mq_attr __user *u_omqstat)
  109. {
  110. struct mq_attr mqstat;
  111. struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
  112. long ret;
  113. if (u_mqstat) {
  114. if (get_compat_mq_attr(&mqstat, u_mqstat) ||
  115. copy_to_user(p, &mqstat, sizeof(mqstat)))
  116. return -EFAULT;
  117. }
  118. ret = sys_mq_getsetattr(mqdes,
  119. u_mqstat ? p : NULL,
  120. u_omqstat ? p + 1 : NULL);
  121. if (ret)
  122. return ret;
  123. if (u_omqstat) {
  124. if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
  125. put_compat_mq_attr(&mqstat, u_omqstat))
  126. return -EFAULT;
  127. }
  128. return 0;
  129. }