arch/arm64/include/asm/ptrace.h

   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
  11 #include <asm/cpufeature.h>
  12
  13 #include <uapi/asm/ptrace.h>
  14
  15 /* Current Exception Level values, as contained in CurrentEL */
  16 #define CurrentEL_EL1           (1 << 2)
  17 #define CurrentEL_EL2           (2 << 2)
  18
  19 #define INIT_PSTATE_EL1 \
  20         (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
  21 #define INIT_PSTATE_EL2 \
  22         (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)
  23
  24 #include <linux/irqchip/arm-gic-v3-prio.h>
  25
  26 #define GIC_PRIO_IRQON          GICV3_PRIO_UNMASKED
  27 #define GIC_PRIO_IRQOFF         GICV3_PRIO_IRQ
  28
  29 #define GIC_PRIO_PSR_I_SET      GICV3_PRIO_PSR_I_SET
  30
  31 /* Additional SPSR bits not exposed in the UABI */
  32 #define PSR_MODE_THREAD_BIT     (1 << 0)
  33 #define PSR_IL_BIT              (1 << 20)
  34
  35 /* AArch32-specific ptrace requests */
  36 #define COMPAT_PTRACE_GETREGS           12
  37 #define COMPAT_PTRACE_SETREGS           13
  38 #define COMPAT_PTRACE_GET_THREAD_AREA   22
  39 #define COMPAT_PTRACE_SET_SYSCALL       23
  40 #define COMPAT_PTRACE_GETVFPREGS        27
  41 #define COMPAT_PTRACE_SETVFPREGS        28
  42 #define COMPAT_PTRACE_GETHBPREGS        29
  43 #define COMPAT_PTRACE_SETHBPREGS        30
  44
  45 /* SPSR_ELx bits for exceptions taken from AArch32 */
  46 #define PSR_AA32_MODE_MASK      0x0000001f
  47 #define PSR_AA32_MODE_USR       0x00000010
  48 #define PSR_AA32_MODE_FIQ       0x00000011
  49 #define PSR_AA32_MODE_IRQ       0x00000012
  50 #define PSR_AA32_MODE_SVC       0x00000013
  51 #define PSR_AA32_MODE_ABT       0x00000017
  52 #define PSR_AA32_MODE_HYP       0x0000001a
  53 #define PSR_AA32_MODE_UND       0x0000001b
  54 #define PSR_AA32_MODE_SYS       0x0000001f
  55 #define PSR_AA32_T_BIT          0x00000020
  56 #define PSR_AA32_F_BIT          0x00000040
  57 #define PSR_AA32_I_BIT          0x00000080
  58 #define PSR_AA32_A_BIT          0x00000100
  59 #define PSR_AA32_E_BIT          0x00000200
  60 #define PSR_AA32_PAN_BIT        0x00400000
  61 #define PSR_AA32_SSBS_BIT       0x00800000
  62 #define PSR_AA32_DIT_BIT        0x01000000
  63 #define PSR_AA32_Q_BIT          0x08000000
  64 #define PSR_AA32_V_BIT          0x10000000
  65 #define PSR_AA32_C_BIT          0x20000000
  66 #define PSR_AA32_Z_BIT          0x40000000
  67 #define PSR_AA32_N_BIT          0x80000000
  68 #define PSR_AA32_IT_MASK        0x0600fc00      /* If-Then execution state mask */
  69 #define PSR_AA32_GE_MASK        0x000f0000
  70
  71 #ifdef CONFIG_CPU_BIG_ENDIAN
  72 #define PSR_AA32_ENDSTATE       PSR_AA32_E_BIT
  73 #else
  74 #define PSR_AA32_ENDSTATE       0
  75 #endif
  76
  77 /* AArch32 CPSR bits, as seen in AArch32 */
  78 #define COMPAT_PSR_DIT_BIT      0x00200000
  79
  80 /*
  81  * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
  82  * process is located in memory.
  83  */
  84 #define COMPAT_PT_TEXT_ADDR             0x10000
  85 #define COMPAT_PT_DATA_ADDR             0x10004
  86 #define COMPAT_PT_TEXT_END_ADDR         0x10008
  87
  88 /*
  89  * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
  90  * a syscall -- i.e., its most recent entry into the kernel from
  91  * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
  92  *
  93  * This must have the value -1, for ABI compatibility with ptrace etc.
  94  */
  95 #define NO_SYSCALL (-1)
  96
  97 #ifndef __ASSEMBLY__
  98 #include <linux/bug.h>
  99 #include <linux/types.h>
 100
 101 /* sizeof(struct user) for AArch32 */
 102 #define COMPAT_USER_SZ  296
 103
 104 /* Architecturally defined mapping between AArch32 and AArch64 registers */
 105 #define compat_usr(x)   regs[(x)]
 106 #define compat_fp       regs[11]
 107 #define compat_sp       regs[13]
 108 #define compat_lr       regs[14]
 109 #define compat_sp_hyp   regs[15]
 110 #define compat_lr_irq   regs[16]
 111 #define compat_sp_irq   regs[17]
 112 #define compat_lr_svc   regs[18]
 113 #define compat_sp_svc   regs[19]
 114 #define compat_lr_abt   regs[20]
 115 #define compat_sp_abt   regs[21]
 116 #define compat_lr_und   regs[22]
 117 #define compat_sp_und   regs[23]
 118 #define compat_r8_fiq   regs[24]
 119 #define compat_r9_fiq   regs[25]
 120 #define compat_r10_fiq  regs[26]
 121 #define compat_r11_fiq  regs[27]
 122 #define compat_r12_fiq  regs[28]
 123 #define compat_sp_fiq   regs[29]
 124 #define compat_lr_fiq   regs[30]
 125
 126 static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
 127 {
 128         unsigned long pstate;
 129
 130         pstate = psr & ~COMPAT_PSR_DIT_BIT;
 131
 132         if (psr & COMPAT_PSR_DIT_BIT)
 133                 pstate |= PSR_AA32_DIT_BIT;
 134
 135         return pstate;
 136 }
 137
 138 static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
 139 {
 140         unsigned long psr;
 141
 142         psr = pstate & ~PSR_AA32_DIT_BIT;
 143
 144         if (pstate & PSR_AA32_DIT_BIT)
 145                 psr |= COMPAT_PSR_DIT_BIT;
 146
 147         return psr;
 148 }
 149
 150 /*
 151  * This struct defines the way the registers are stored on the stack during an
 152  * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
 153  * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
 154  */
 155 struct pt_regs {
 156         union {
 157                 struct user_pt_regs user_regs;
 158                 struct {
 159                         u64 regs[31];
 160                         u64 sp;
 161                         u64 pc;
 162                         u64 pstate;
 163                 };
 164         };
 165         u64 orig_x0;
 166 #ifdef __AARCH64EB__
 167         u32 unused2;
 168         s32 syscallno;
 169 #else
 170         s32 syscallno;
 171         u32 unused2;
 172 #endif
 173         u64 sdei_ttbr1;
 174         /* Only valid when ARM64_HAS_GIC_PRIO_MASKING is enabled. */
 175         u64 pmr_save;
 176         u64 stackframe[2];
 177
 178         /* Only valid for some EL1 exceptions. */
 179         u64 lockdep_hardirqs;
 180         u64 exit_rcu;
 181 };
 182
 183 static inline bool in_syscall(struct pt_regs const *regs)
 184 {
 185         return regs->syscallno != NO_SYSCALL;
 186 }
 187
 188 static inline void forget_syscall(struct pt_regs *regs)
 189 {
 190         regs->syscallno = NO_SYSCALL;
 191 }
 192
 193 #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
 194
 195 #define arch_has_single_step()  (1)
 196
 197 #ifdef CONFIG_COMPAT
 198 #define compat_thumb_mode(regs) \
 199         (((regs)->pstate & PSR_AA32_T_BIT))
 200 #else
 201 #define compat_thumb_mode(regs) (0)
 202 #endif
 203
 204 #define user_mode(regs) \
 205         (((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
 206
 207 #define compat_user_mode(regs)  \
 208         (((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
 209          (PSR_MODE32_BIT | PSR_MODE_EL0t))
 210
 211 #define processor_mode(regs) \
 212         ((regs)->pstate & PSR_MODE_MASK)
 213
 214 #define irqs_priority_unmasked(regs)                                    \
 215         (system_uses_irq_prio_masking() ?                               \
 216                 (regs)->pmr_save == GIC_PRIO_IRQON :                    \
 217                 true)
 218
 219 #define interrupts_enabled(regs)                        \
 220         (!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))
 221
 222 #define fast_interrupts_enabled(regs) \
 223         (!((regs)->pstate & PSR_F_BIT))
 224
 225 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 226 {
 227         if (compat_user_mode(regs))
 228                 return regs->compat_sp;
 229         return regs->sp;
 230 }
 231
 232 extern int regs_query_register_offset(const char *name);
 233 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 234                                                unsigned int n);
 235
 236 /**
 237  * regs_get_register() - get register value from its offset
 238  * @regs:       pt_regs from which register value is gotten
 239  * @offset:     offset of the register.
 240  *
 241  * regs_get_register returns the value of a register whose offset from @regs.
 242  * The @offset is the offset of the register in struct pt_regs.
 243  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 244  */
 245 static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
 246 {
 247         u64 val = 0;
 248
 249         WARN_ON(offset & 7);
 250
 251         offset >>= 3;
 252         switch (offset) {
 253         case 0 ... 30:
 254                 val = regs->regs[offset];
 255                 break;
 256         case offsetof(struct pt_regs, sp) >> 3:
 257                 val = regs->sp;
 258                 break;
 259         case offsetof(struct pt_regs, pc) >> 3:
 260                 val = regs->pc;
 261                 break;
 262         case offsetof(struct pt_regs, pstate) >> 3:
 263                 val = regs->pstate;
 264                 break;
 265         default:
 266                 val = 0;
 267         }
 268
 269         return val;
 270 }
 271
 272 /*
 273  * Read a register given an architectural register index r.
 274  * This handles the common case where 31 means XZR, not SP.
 275  */
 276 static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
 277 {
 278         return (r == 31) ? 0 : regs->regs[r];
 279 }
 280
 281 /*
 282  * Write a register given an architectural register index r.
 283  * This handles the common case where 31 means XZR, not SP.
 284  */
 285 static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
 286                                      unsigned long val)
 287 {
 288         if (r != 31)
 289                 regs->regs[r] = val;
 290 }
 291
 292 /* Valid only for Kernel mode traps. */
 293 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 294 {
 295         return regs->sp;
 296 }
 297
 298 static inline unsigned long regs_return_value(struct pt_regs *regs)
 299 {
 300         unsigned long val = regs->regs[0];
 301
 302         /*
 303          * Audit currently uses regs_return_value() instead of
 304          * syscall_get_return_value(). Apply the same sign-extension here until
 305          * audit is updated to use syscall_get_return_value().
 306          */
 307         if (compat_user_mode(regs))
 308                 val = sign_extend64(val, 31);
 309
 310         return val;
 311 }
 312
 313 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 314 {
 315         regs->regs[0] = rc;
 316 }
 317
 318 /**
 319  * regs_get_kernel_argument() - get Nth function argument in kernel
 320  * @regs:       pt_regs of that context
 321  * @n:          function argument number (start from 0)
 322  *
 323  * regs_get_argument() returns @n th argument of the function call.
 324  *
 325  * Note that this chooses the most likely register mapping. In very rare
 326  * cases this may not return correct data, for example, if one of the
 327  * function parameters is 16 bytes or bigger. In such cases, we cannot
 328  * get access the parameter correctly and the register assignment of
 329  * subsequent parameters will be shifted.
 330  */
 331 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
 332                                                      unsigned int n)
 333 {
 334 #define NR_REG_ARGUMENTS 8
 335         if (n < NR_REG_ARGUMENTS)
 336                 return pt_regs_read_reg(regs, n);
 337         return 0;
 338 }
 339
 340 /* We must avoid circular header include via sched.h */
 341 struct task_struct;
 342 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
 343
 344 static inline unsigned long instruction_pointer(struct pt_regs *regs)
 345 {
 346         return regs->pc;
 347 }
 348 static inline void instruction_pointer_set(struct pt_regs *regs,
 349                 unsigned long val)
 350 {
 351         regs->pc = val;
 352 }
 353
 354 static inline unsigned long frame_pointer(struct pt_regs *regs)
 355 {
 356         return regs->regs[29];
 357 }
 358
 359 #define procedure_link_pointer(regs)    ((regs)->regs[30])
 360
 361 static inline void procedure_link_pointer_set(struct pt_regs *regs,
 362                                            unsigned long val)
 363 {
 364         procedure_link_pointer(regs) = val;
 365 }
 366
 367 extern unsigned long profile_pc(struct pt_regs *regs);
 368
 369 #endif /* __ASSEMBLY__ */
 370 #endif