ptrace.h 10 KB

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  1. /* SPDX-License-Identifier: GPL-2.0-only */
  2. /*
  3. * Based on arch/arm/include/asm/ptrace.h
  4. *
  5. * Copyright (C) 1996-2003 Russell King
  6. * Copyright (C) 2012 ARM Ltd.
  7. */
  8. #ifndef __ASM_PTRACE_H
  9. #define __ASM_PTRACE_H
  10. #include <asm/cpufeature.h>
  11. #include <uapi/asm/ptrace.h>
  12. /* Current Exception Level values, as contained in CurrentEL */
  13. #define CurrentEL_EL1 (1 << 2)
  14. #define CurrentEL_EL2 (2 << 2)
  15. #define INIT_PSTATE_EL1 \
  16. (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
  17. #define INIT_PSTATE_EL2 \
  18. (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)
  19. /*
  20. * PMR values used to mask/unmask interrupts.
  21. *
  22. * GIC priority masking works as follows: if an IRQ's priority is a higher value
  23. * than the value held in PMR, that IRQ is masked. Lowering the value of PMR
  24. * means masking more IRQs (or at least that the same IRQs remain masked).
  25. *
  26. * To mask interrupts, we clear the most significant bit of PMR.
  27. *
  28. * Some code sections either automatically switch back to PSR.I or explicitly
  29. * require to not use priority masking. If bit GIC_PRIO_PSR_I_SET is included
  30. * in the priority mask, it indicates that PSR.I should be set and
  31. * interrupt disabling temporarily does not rely on IRQ priorities.
  32. */
  33. #define GIC_PRIO_IRQON 0xe0
  34. #define __GIC_PRIO_IRQOFF (GIC_PRIO_IRQON & ~0x80)
  35. #define __GIC_PRIO_IRQOFF_NS 0xa0
  36. #define GIC_PRIO_PSR_I_SET (1 << 4)
  37. #define GIC_PRIO_IRQOFF \
  38. ({ \
  39. extern struct static_key_false gic_nonsecure_priorities;\
  40. u8 __prio = __GIC_PRIO_IRQOFF; \
  41. \
  42. if (static_branch_unlikely(&gic_nonsecure_priorities)) \
  43. __prio = __GIC_PRIO_IRQOFF_NS; \
  44. \
  45. __prio; \
  46. })
  47. /* Additional SPSR bits not exposed in the UABI */
  48. #define PSR_MODE_THREAD_BIT (1 << 0)
  49. #define PSR_IL_BIT (1 << 20)
  50. /* AArch32-specific ptrace requests */
  51. #define COMPAT_PTRACE_GETREGS 12
  52. #define COMPAT_PTRACE_SETREGS 13
  53. #define COMPAT_PTRACE_GET_THREAD_AREA 22
  54. #define COMPAT_PTRACE_SET_SYSCALL 23
  55. #define COMPAT_PTRACE_GETVFPREGS 27
  56. #define COMPAT_PTRACE_SETVFPREGS 28
  57. #define COMPAT_PTRACE_GETHBPREGS 29
  58. #define COMPAT_PTRACE_SETHBPREGS 30
  59. /* SPSR_ELx bits for exceptions taken from AArch32 */
  60. #define PSR_AA32_MODE_MASK 0x0000001f
  61. #define PSR_AA32_MODE_USR 0x00000010
  62. #define PSR_AA32_MODE_FIQ 0x00000011
  63. #define PSR_AA32_MODE_IRQ 0x00000012
  64. #define PSR_AA32_MODE_SVC 0x00000013
  65. #define PSR_AA32_MODE_ABT 0x00000017
  66. #define PSR_AA32_MODE_HYP 0x0000001a
  67. #define PSR_AA32_MODE_UND 0x0000001b
  68. #define PSR_AA32_MODE_SYS 0x0000001f
  69. #define PSR_AA32_T_BIT 0x00000020
  70. #define PSR_AA32_F_BIT 0x00000040
  71. #define PSR_AA32_I_BIT 0x00000080
  72. #define PSR_AA32_A_BIT 0x00000100
  73. #define PSR_AA32_E_BIT 0x00000200
  74. #define PSR_AA32_PAN_BIT 0x00400000
  75. #define PSR_AA32_SSBS_BIT 0x00800000
  76. #define PSR_AA32_DIT_BIT 0x01000000
  77. #define PSR_AA32_Q_BIT 0x08000000
  78. #define PSR_AA32_V_BIT 0x10000000
  79. #define PSR_AA32_C_BIT 0x20000000
  80. #define PSR_AA32_Z_BIT 0x40000000
  81. #define PSR_AA32_N_BIT 0x80000000
  82. #define PSR_AA32_IT_MASK 0x0600fc00 /* If-Then execution state mask */
  83. #define PSR_AA32_GE_MASK 0x000f0000
  84. #ifdef CONFIG_CPU_BIG_ENDIAN
  85. #define PSR_AA32_ENDSTATE PSR_AA32_E_BIT
  86. #else
  87. #define PSR_AA32_ENDSTATE 0
  88. #endif
  89. /* AArch32 CPSR bits, as seen in AArch32 */
  90. #define COMPAT_PSR_DIT_BIT 0x00200000
  91. /*
  92. * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
  93. * process is located in memory.
  94. */
  95. #define COMPAT_PT_TEXT_ADDR 0x10000
  96. #define COMPAT_PT_DATA_ADDR 0x10004
  97. #define COMPAT_PT_TEXT_END_ADDR 0x10008
  98. /*
  99. * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
  100. * a syscall -- i.e., its most recent entry into the kernel from
  101. * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
  102. *
  103. * This must have the value -1, for ABI compatibility with ptrace etc.
  104. */
  105. #define NO_SYSCALL (-1)
  106. #ifndef __ASSEMBLY__
  107. #include <linux/bug.h>
  108. #include <linux/types.h>
  109. /* sizeof(struct user) for AArch32 */
  110. #define COMPAT_USER_SZ 296
  111. /* Architecturally defined mapping between AArch32 and AArch64 registers */
  112. #define compat_usr(x) regs[(x)]
  113. #define compat_fp regs[11]
  114. #define compat_sp regs[13]
  115. #define compat_lr regs[14]
  116. #define compat_sp_hyp regs[15]
  117. #define compat_lr_irq regs[16]
  118. #define compat_sp_irq regs[17]
  119. #define compat_lr_svc regs[18]
  120. #define compat_sp_svc regs[19]
  121. #define compat_lr_abt regs[20]
  122. #define compat_sp_abt regs[21]
  123. #define compat_lr_und regs[22]
  124. #define compat_sp_und regs[23]
  125. #define compat_r8_fiq regs[24]
  126. #define compat_r9_fiq regs[25]
  127. #define compat_r10_fiq regs[26]
  128. #define compat_r11_fiq regs[27]
  129. #define compat_r12_fiq regs[28]
  130. #define compat_sp_fiq regs[29]
  131. #define compat_lr_fiq regs[30]
  132. static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
  133. {
  134. unsigned long pstate;
  135. pstate = psr & ~COMPAT_PSR_DIT_BIT;
  136. if (psr & COMPAT_PSR_DIT_BIT)
  137. pstate |= PSR_AA32_DIT_BIT;
  138. return pstate;
  139. }
  140. static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
  141. {
  142. unsigned long psr;
  143. psr = pstate & ~PSR_AA32_DIT_BIT;
  144. if (pstate & PSR_AA32_DIT_BIT)
  145. psr |= COMPAT_PSR_DIT_BIT;
  146. return psr;
  147. }
  148. /*
  149. * This struct defines the way the registers are stored on the stack during an
  150. * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
  151. * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
  152. */
  153. struct pt_regs {
  154. union {
  155. struct user_pt_regs user_regs;
  156. struct {
  157. u64 regs[31];
  158. u64 sp;
  159. u64 pc;
  160. u64 pstate;
  161. };
  162. };
  163. u64 orig_x0;
  164. #ifdef __AARCH64EB__
  165. u32 unused2;
  166. s32 syscallno;
  167. #else
  168. s32 syscallno;
  169. u32 unused2;
  170. #endif
  171. u64 sdei_ttbr1;
  172. /* Only valid when ARM64_HAS_IRQ_PRIO_MASKING is enabled. */
  173. u64 pmr_save;
  174. u64 stackframe[2];
  175. /* Only valid for some EL1 exceptions. */
  176. u64 lockdep_hardirqs;
  177. u64 exit_rcu;
  178. };
  179. static inline bool in_syscall(struct pt_regs const *regs)
  180. {
  181. return regs->syscallno != NO_SYSCALL;
  182. }
  183. static inline void forget_syscall(struct pt_regs *regs)
  184. {
  185. regs->syscallno = NO_SYSCALL;
  186. }
  187. #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
  188. #define arch_has_single_step() (1)
  189. #ifdef CONFIG_COMPAT
  190. #define compat_thumb_mode(regs) \
  191. (((regs)->pstate & PSR_AA32_T_BIT))
  192. #else
  193. #define compat_thumb_mode(regs) (0)
  194. #endif
  195. #define user_mode(regs) \
  196. (((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
  197. #define compat_user_mode(regs) \
  198. (((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
  199. (PSR_MODE32_BIT | PSR_MODE_EL0t))
  200. #define processor_mode(regs) \
  201. ((regs)->pstate & PSR_MODE_MASK)
  202. #define irqs_priority_unmasked(regs) \
  203. (system_uses_irq_prio_masking() ? \
  204. (regs)->pmr_save == GIC_PRIO_IRQON : \
  205. true)
  206. #define interrupts_enabled(regs) \
  207. (!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))
  208. #define fast_interrupts_enabled(regs) \
  209. (!((regs)->pstate & PSR_F_BIT))
  210. static inline unsigned long user_stack_pointer(struct pt_regs *regs)
  211. {
  212. if (compat_user_mode(regs))
  213. return regs->compat_sp;
  214. return regs->sp;
  215. }
  216. extern int regs_query_register_offset(const char *name);
  217. extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
  218. unsigned int n);
  219. /**
  220. * regs_get_register() - get register value from its offset
  221. * @regs: pt_regs from which register value is gotten
  222. * @offset: offset of the register.
  223. *
  224. * regs_get_register returns the value of a register whose offset from @regs.
  225. * The @offset is the offset of the register in struct pt_regs.
  226. * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
  227. */
  228. static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
  229. {
  230. u64 val = 0;
  231. WARN_ON(offset & 7);
  232. offset >>= 3;
  233. switch (offset) {
  234. case 0 ... 30:
  235. val = regs->regs[offset];
  236. break;
  237. case offsetof(struct pt_regs, sp) >> 3:
  238. val = regs->sp;
  239. break;
  240. case offsetof(struct pt_regs, pc) >> 3:
  241. val = regs->pc;
  242. break;
  243. case offsetof(struct pt_regs, pstate) >> 3:
  244. val = regs->pstate;
  245. break;
  246. default:
  247. val = 0;
  248. }
  249. return val;
  250. }
  251. /*
  252. * Read a register given an architectural register index r.
  253. * This handles the common case where 31 means XZR, not SP.
  254. */
  255. static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
  256. {
  257. return (r == 31) ? 0 : regs->regs[r];
  258. }
  259. /*
  260. * Write a register given an architectural register index r.
  261. * This handles the common case where 31 means XZR, not SP.
  262. */
  263. static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
  264. unsigned long val)
  265. {
  266. if (r != 31)
  267. regs->regs[r] = val;
  268. }
  269. /* Valid only for Kernel mode traps. */
  270. static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
  271. {
  272. return regs->sp;
  273. }
  274. static inline unsigned long regs_return_value(struct pt_regs *regs)
  275. {
  276. unsigned long val = regs->regs[0];
  277. /*
  278. * Audit currently uses regs_return_value() instead of
  279. * syscall_get_return_value(). Apply the same sign-extension here until
  280. * audit is updated to use syscall_get_return_value().
  281. */
  282. if (compat_user_mode(regs))
  283. val = sign_extend64(val, 31);
  284. return val;
  285. }
  286. static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
  287. {
  288. regs->regs[0] = rc;
  289. }
  290. /**
  291. * regs_get_kernel_argument() - get Nth function argument in kernel
  292. * @regs: pt_regs of that context
  293. * @n: function argument number (start from 0)
  294. *
  295. * regs_get_argument() returns @n th argument of the function call.
  296. *
  297. * Note that this chooses the most likely register mapping. In very rare
  298. * cases this may not return correct data, for example, if one of the
  299. * function parameters is 16 bytes or bigger. In such cases, we cannot
  300. * get access the parameter correctly and the register assignment of
  301. * subsequent parameters will be shifted.
  302. */
  303. static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
  304. unsigned int n)
  305. {
  306. #define NR_REG_ARGUMENTS 8
  307. if (n < NR_REG_ARGUMENTS)
  308. return pt_regs_read_reg(regs, n);
  309. return 0;
  310. }
  311. /* We must avoid circular header include via sched.h */
  312. struct task_struct;
  313. int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
  314. static inline unsigned long instruction_pointer(struct pt_regs *regs)
  315. {
  316. return regs->pc;
  317. }
  318. static inline void instruction_pointer_set(struct pt_regs *regs,
  319. unsigned long val)
  320. {
  321. regs->pc = val;
  322. }
  323. static inline unsigned long frame_pointer(struct pt_regs *regs)
  324. {
  325. return regs->regs[29];
  326. }
  327. #define procedure_link_pointer(regs) ((regs)->regs[30])
  328. static inline void procedure_link_pointer_set(struct pt_regs *regs,
  329. unsigned long val)
  330. {
  331. procedure_link_pointer(regs) = val;
  332. }
  333. extern unsigned long profile_pc(struct pt_regs *regs);
  334. #endif /* __ASSEMBLY__ */
  335. #endif