arch/arm64/include/asm/processor.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Based on arch/arm/include/asm/processor.h
   4  *
   5  * Copyright (C) 1995-1999 Russell King
   6  * Copyright (C) 2012 ARM Ltd.
   7  */
   8 #ifndef __ASM_PROCESSOR_H
   9 #define __ASM_PROCESSOR_H
  10
  11 /*
  12  * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
  13  * no point in shifting all network buffers by 2 bytes just to make some IP
  14  * header fields appear aligned in memory, potentially sacrificing some DMA
  15  * performance on some platforms.
  16  */
  17 #define NET_IP_ALIGN    0
  18
  19 #define MTE_CTRL_GCR_USER_EXCL_SHIFT    0
  20 #define MTE_CTRL_GCR_USER_EXCL_MASK     0xffff
  21
  22 #define MTE_CTRL_TCF_SYNC               (1UL << 16)
  23 #define MTE_CTRL_TCF_ASYNC              (1UL << 17)
  24
  25 #ifndef __ASSEMBLY__
  26
  27 #include <linux/build_bug.h>
  28 #include <linux/cache.h>
  29 #include <linux/init.h>
  30 #include <linux/stddef.h>
  31 #include <linux/string.h>
  32 #include <linux/thread_info.h>
  33
  34 #include <vdso/processor.h>
  35
  36 #include <asm/alternative.h>
  37 #include <asm/cpufeature.h>
  38 #include <asm/hw_breakpoint.h>
  39 #include <asm/kasan.h>
  40 #include <asm/lse.h>
  41 #include <asm/pgtable-hwdef.h>
  42 #include <asm/pointer_auth.h>
  43 #include <asm/ptrace.h>
  44 #include <asm/spectre.h>
  45 #include <asm/types.h>
  46
  47 /*
  48  * TASK_SIZE - the maximum size of a user space task.
  49  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  50  */
  51
  52 #define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  53 #define TASK_SIZE_64            (UL(1) << vabits_actual)
  54 #define TASK_SIZE_MAX           (UL(1) << VA_BITS)
  55
  56 #ifdef CONFIG_COMPAT
  57 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  58 /*
  59  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  60  * by the compat vectors page.
  61  */
  62 #define TASK_SIZE_32            UL(0x100000000)
  63 #else
  64 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  65 #endif /* CONFIG_ARM64_64K_PAGES */
  66 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  67                                 TASK_SIZE_32 : TASK_SIZE_64)
  68 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  69                                 TASK_SIZE_32 : TASK_SIZE_64)
  70 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  71                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  72 #else
  73 #define TASK_SIZE               TASK_SIZE_64
  74 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  75 #endif /* CONFIG_COMPAT */
  76
  77 #ifdef CONFIG_ARM64_FORCE_52BIT
  78 #define STACK_TOP_MAX           TASK_SIZE_64
  79 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  80 #else
  81 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  82 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  83 #endif /* CONFIG_ARM64_FORCE_52BIT */
  84
  85 #ifdef CONFIG_COMPAT
  86 #define AARCH32_VECTORS_BASE    0xffff0000
  87 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  88                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  89 #else
  90 #define STACK_TOP               STACK_TOP_MAX
  91 #endif /* CONFIG_COMPAT */
  92
  93 #ifndef CONFIG_ARM64_FORCE_52BIT
  94 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  95                                 DEFAULT_MAP_WINDOW)
  96
  97 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  98                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  99                                         base)
 100 #endif /* CONFIG_ARM64_FORCE_52BIT */
 101
 102 extern phys_addr_t arm64_dma_phys_limit;
 103 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
 104
 105 struct debug_info {
 106 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 107         /* Have we suspended stepping by a debugger? */
 108         int                     suspended_step;
 109         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 110         int                     bps_disabled;
 111         int                     wps_disabled;
 112         /* Hardware breakpoints pinned to this task. */
 113         struct perf_event       *hbp_break[ARM_MAX_BRP];
 114         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 115 #endif
 116 };
 117
 118 struct cpu_context {
 119         unsigned long x19;
 120         unsigned long x20;
 121         unsigned long x21;
 122         unsigned long x22;
 123         unsigned long x23;
 124         unsigned long x24;
 125         unsigned long x25;
 126         unsigned long x26;
 127         unsigned long x27;
 128         unsigned long x28;
 129         unsigned long fp;
 130         unsigned long sp;
 131         unsigned long pc;
 132 };
 133
 134 struct thread_struct {
 135         struct cpu_context      cpu_context;    /* cpu context */
 136
 137         /*
 138          * Whitelisted fields for hardened usercopy:
 139          * Maintainers must ensure manually that this contains no
 140          * implicit padding.
 141          */
 142         struct {
 143                 unsigned long   tp_value;       /* TLS register */
 144                 unsigned long   tp2_value;
 145                 struct user_fpsimd_state fpsimd_state;
 146         } uw;
 147
 148         unsigned int            fpsimd_cpu;
 149         void                    *sve_state;     /* SVE registers, if any */
 150         unsigned int            sve_vl;         /* SVE vector length */
 151         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 152         unsigned long           fault_address;  /* fault info */
 153         unsigned long           fault_code;     /* ESR_EL1 value */
 154         struct debug_info       debug;          /* debugging */
 155 #ifdef CONFIG_ARM64_PTR_AUTH
 156         struct ptrauth_keys_user        keys_user;
 157 #ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
 158         struct ptrauth_keys_kernel      keys_kernel;
 159 #endif
 160 #endif
 161 #ifdef CONFIG_ARM64_MTE
 162         u64                     mte_ctrl;
 163 #endif
 164         u64                     sctlr_user;
 165 };
 166
 167 #define SCTLR_USER_MASK                                                        \
 168         (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
 169          SCTLR_EL1_TCF0_MASK)
 170
 171 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 172                                                 unsigned long *size)
 173 {
 174         /* Verify that there is no padding among the whitelisted fields: */
 175         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 176                      sizeof_field(struct thread_struct, uw.tp_value) +
 177                      sizeof_field(struct thread_struct, uw.tp2_value) +
 178                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 179
 180         *offset = offsetof(struct thread_struct, uw);
 181         *size = sizeof_field(struct thread_struct, uw);
 182 }
 183
 184 #ifdef CONFIG_COMPAT
 185 #define task_user_tls(t)                                                \
 186 ({                                                                      \
 187         unsigned long *__tls;                                           \
 188         if (is_compat_thread(task_thread_info(t)))                      \
 189                 __tls = &(t)->thread.uw.tp2_value;                      \
 190         else                                                            \
 191                 __tls = &(t)->thread.uw.tp_value;                       \
 192         __tls;                                                          \
 193  })
 194 #else
 195 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 196 #endif
 197
 198 /* Sync TPIDR_EL0 back to thread_struct for current */
 199 void tls_preserve_current_state(void);
 200
 201 #define INIT_THREAD {                           \
 202         .fpsimd_cpu = NR_CPUS,                  \
 203 }
 204
 205 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 206 {
 207         memset(regs, 0, sizeof(*regs));
 208         forget_syscall(regs);
 209         regs->pc = pc;
 210
 211         if (system_uses_irq_prio_masking())
 212                 regs->pmr_save = GIC_PRIO_IRQON;
 213 }
 214
 215 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 216                                 unsigned long sp)
 217 {
 218         start_thread_common(regs, pc);
 219         regs->pstate = PSR_MODE_EL0t;
 220         spectre_v4_enable_task_mitigation(current);
 221         regs->sp = sp;
 222 }
 223
 224 #ifdef CONFIG_COMPAT
 225 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 226                                        unsigned long sp)
 227 {
 228         start_thread_common(regs, pc);
 229         regs->pstate = PSR_AA32_MODE_USR;
 230         if (pc & 1)
 231                 regs->pstate |= PSR_AA32_T_BIT;
 232
 233 #ifdef __AARCH64EB__
 234         regs->pstate |= PSR_AA32_E_BIT;
 235 #endif
 236
 237         spectre_v4_enable_task_mitigation(current);
 238         regs->compat_sp = sp;
 239 }
 240 #endif
 241
 242 static inline bool is_ttbr0_addr(unsigned long addr)
 243 {
 244         /* entry assembly clears tags for TTBR0 addrs */
 245         return addr < TASK_SIZE;
 246 }
 247
 248 static inline bool is_ttbr1_addr(unsigned long addr)
 249 {
 250         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 251         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 252 }
 253
 254 /* Forward declaration, a strange C thing */
 255 struct task_struct;
 256
 257 /* Free all resources held by a thread. */
 258 extern void release_thread(struct task_struct *);
 259
 260 unsigned long get_wchan(struct task_struct *p);
 261
 262 void update_sctlr_el1(u64 sctlr);
 263
 264 /* Thread switching */
 265 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 266                                          struct task_struct *next);
 267
 268 #define task_pt_regs(p) \
 269         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 270
 271 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 272 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 273
 274 /*
 275  * Prefetching support
 276  */
 277 #define ARCH_HAS_PREFETCH
 278 static inline void prefetch(const void *ptr)
 279 {
 280         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 281 }
 282
 283 #define ARCH_HAS_PREFETCHW
 284 static inline void prefetchw(const void *ptr)
 285 {
 286         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 287 }
 288
 289 #define ARCH_HAS_SPINLOCK_PREFETCH
 290 static inline void spin_lock_prefetch(const void *ptr)
 291 {
 292         asm volatile(ARM64_LSE_ATOMIC_INSN(
 293                      "prfm pstl1strm, %a0",
 294                      "nop") : : "p" (ptr));
 295 }
 296
 297 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 298 extern void __init minsigstksz_setup(void);
 299
 300 /*
 301  * Not at the top of the file due to a direct #include cycle between
 302  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 303  * ensures that contents of processor.h are visible to fpsimd.h even if
 304  * processor.h is included first.
 305  *
 306  * These prctl helpers are the only things in this file that require
 307  * fpsimd.h.  The core code expects them to be in this header.
 308  */
 309 #include <asm/fpsimd.h>
 310
 311 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 312 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 313 #define SVE_GET_VL()    sve_get_current_vl()
 314
 315 /* PR_PAC_RESET_KEYS prctl */
 316 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 317
 318 /* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
 319 #define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)                                \
 320         ptrauth_set_enabled_keys(tsk, keys, enabled)
 321 #define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
 322
 323 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 324 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 325 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 326 long get_tagged_addr_ctrl(struct task_struct *task);
 327 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 328 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 329 #endif
 330
 331 /*
 332  * For CONFIG_GCC_PLUGIN_STACKLEAK
 333  *
 334  * These need to be macros because otherwise we get stuck in a nightmare
 335  * of header definitions for the use of task_stack_page.
 336  */
 337
 338 #define current_top_of_stack()                                                          \
 339 ({                                                                                      \
 340         struct stack_info _info;                                                        \
 341         BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info));        \
 342         _info.high;                                                                     \
 343 })
 344 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, 1, NULL))
 345
 346 #endif /* __ASSEMBLY__ */
 347 #endif /* __ASM_PROCESSOR_H */