debugreg.h 4.1 KB

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  1. //
  2. // Copyright 2026 Aarav Ravindra Kharade
  3. //
  4. // Licensed under the Apache License, Version 2.0 (the "License");
  5. // you may not use this file except in compliance with the License.
  6. // You may obtain a copy of the License at
  7. //
  8. // http://www.apache.org/licenses/LICENSE-2.0
  9. //
  10. // Unless required by applicable law or agreed to in writing, software
  11. // distributed under the License is distributed on an "AS IS" BASIS,
  12. // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. // See the License for the specific language governing permissions and
  14. // limitations under the License.
  15. //
  16. /* Copyright (C) 2001-2026 Free Software Foundation, Inc.
  17. This file is part of the GNU C Library.
  18. The GNU C Library is free software; you can redistribute it and/or
  19. modify it under the terms of the GNU Lesser General Public
  20. License as published by the Free Software Foundation; either
  21. version 2.1 of the License, or (at your option) any later version.
  22. The GNU C Library is distributed in the hope that it will be useful,
  23. but WITHOUT ANY WARRANTY; without even the implied warranty of
  24. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  25. Lesser General Public License for more details.
  26. You should have received a copy of the GNU Lesser General Public
  27. License along with the GNU C Library; if not, see
  28. <https://www.gnu.org/licenses/>. */
  29. #ifndef _SYS_DEBUGREG_H
  30. #define _SYS_DEBUGREG_H 1
  31. /* Indicate the register numbers for a number of the specific
  32. debug registers. Registers 0-3 contain the addresses we wish to trap on */
  33. #define DR_FIRSTADDR 0 /* u_debugreg[DR_FIRSTADDR] */
  34. #define DR_LASTADDR 3 /* u_debugreg[DR_LASTADDR] */
  35. #define DR_STATUS 6 /* u_debugreg[DR_STATUS] */
  36. #define DR_CONTROL 7 /* u_debugreg[DR_CONTROL] */
  37. /* Define a few things for the status register. We can use this to determine
  38. which debugging register was responsible for the trap. The other bits
  39. are either reserved or not of interest to us. */
  40. #define DR_TRAP0 (0x1) /* db0 */
  41. #define DR_TRAP1 (0x2) /* db1 */
  42. #define DR_TRAP2 (0x4) /* db2 */
  43. #define DR_TRAP3 (0x8) /* db3 */
  44. #define DR_STEP (0x4000) /* single-step */
  45. #define DR_SWITCH (0x8000) /* task switch */
  46. /* Now define a bunch of things for manipulating the control register.
  47. The top two bytes of the control register consist of 4 fields of 4
  48. bits - each field corresponds to one of the four debug registers,
  49. and indicates what types of access we trap on, and how large the data
  50. field is that we are looking at */
  51. #define DR_CONTROL_SHIFT 16 /* Skip this many bits in ctl register */
  52. #define DR_CONTROL_SIZE 4 /* 4 control bits per register */
  53. #define DR_RW_EXECUTE (0x0) /* Settings for the access types to trap on */
  54. #define DR_RW_WRITE (0x1)
  55. #define DR_RW_READ (0x3)
  56. #define DR_LEN_1 (0x0) /* Settings for data length to trap on */
  57. #define DR_LEN_2 (0x4)
  58. #define DR_LEN_4 (0xC)
  59. #ifdef __x86_64__
  60. # define DR_LEN_8 (0x8)
  61. #endif
  62. /* The low byte to the control register determine which registers are
  63. enabled. There are 4 fields of two bits. One bit is "local", meaning
  64. that the processor will reset the bit after a task switch and the other
  65. is global meaning that we have to explicitly reset the bit. With linux,
  66. you can use either one, since we explicitly zero the register when we enter
  67. kernel mode. */
  68. #define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit */
  69. #define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit */
  70. #define DR_ENABLE_SIZE 2 /* 2 enable bits per register */
  71. #define DR_LOCAL_ENABLE_MASK (0x55) /* Set local bits for all 4 regs */
  72. #define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */
  73. /* The second byte to the control register has a few special
  74. things. */
  75. #ifdef __x86_64__
  76. # define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00ULL) /* Reserved */
  77. #else
  78. # define DR_CONTROL_RESERVED (0x00FC00U) /* Reserved */
  79. #endif
  80. #define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */
  81. #define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */
  82. #endif /* sys/debugreg.h */