headers/private/kernel/util/fs_trim_support.h

   1 /*
   2  * Copyright 2013, Axel Dörfler, axeld@pinc-software.de.
   3  * Distributed under the terms of the MIT license.
   4  */
   5 #ifndef _FS_TRIM_SUPPORT_H
   6 #define _FS_TRIM_SUPPORT_H
   7
   8
   9 #include <KernelExport.h>
  10
  11 #include <kernel.h>
  12 #include <syscall_restart.h>
  13
  14
  15 static inline status_t
  16 get_trim_data_from_user(void* buffer, size_t size, MemoryDeleter& deleter,
  17         fs_trim_data*& _trimData)
  18 {
  19         if (!is_called_via_syscall() && !IS_USER_ADDRESS(buffer)) {
  20                 // Called from kernel
  21                 _trimData = (fs_trim_data*)buffer;
  22                 return B_OK;
  23         }
  24
  25         // Called from userland
  26         if (!IS_USER_ADDRESS(buffer))
  27                 return B_BAD_ADDRESS;
  28
  29         uint32 count;
  30         if (user_memcpy(&count, buffer, sizeof(count)) != B_OK)
  31                 return B_BAD_ADDRESS;
  32
  33         size_t bytes = (count - 1) * sizeof(uint64) * 2 + sizeof(fs_trim_data);
  34         if (bytes > size)
  35                 return B_BAD_VALUE;
  36
  37         void* trimBuffer = malloc(bytes);
  38         if (trimBuffer == NULL)
  39                 return B_NO_MEMORY;
  40
  41         if (user_memcpy(trimBuffer, buffer, bytes) != B_OK) {
  42                 free(trimBuffer);
  43                 return B_BAD_ADDRESS;
  44         }
  45
  46         // The passed in MemoryDeleter needs to take care of freeing the buffer
  47         // later, since we had to allocate it.
  48         deleter.SetTo(trimBuffer);
  49
  50         _trimData = (fs_trim_data*)trimBuffer;
  51         return B_OK;
  52 }
  53
  54
  55 static inline status_t
  56 copy_trim_data_to_user(void* buffer, fs_trim_data* trimData)
  57 {
  58         if (!is_called_via_syscall() && !IS_USER_ADDRESS(buffer))
  59                 return B_OK;
  60
  61         if (!IS_USER_ADDRESS(buffer))
  62                 return B_BAD_ADDRESS;
  63
  64         // Do not copy any ranges
  65         return user_memcpy(buffer, trimData, sizeof(uint64) * 2);
  66 }
  67
  68
  69 #endif  // _FS_TRIM_SUPPORT_H