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 #ifndef __ASSEMBLY__
  20
  21 #include <linux/build_bug.h>
  22 #include <linux/cache.h>
  23 #include <linux/init.h>
  24 #include <linux/stddef.h>
  25 #include <linux/string.h>
  26 #include <linux/thread_info.h>
  27
  28 #include <vdso/processor.h>
  29
  30 #include <asm/alternative.h>
  31 #include <asm/cpufeature.h>
  32 #include <asm/hw_breakpoint.h>
  33 #include <asm/kasan.h>
  34 #include <asm/lse.h>
  35 #include <asm/pgtable-hwdef.h>
  36 #include <asm/pointer_auth.h>
  37 #include <asm/ptrace.h>
  38 #include <asm/spectre.h>
  39 #include <asm/types.h>
  40
  41 /*
  42  * TASK_SIZE - the maximum size of a user space task.
  43  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  44  */
  45
  46 #define DEFAULT_MAP_WINDOW_64   (UL(1) << VA_BITS_MIN)
  47 #define TASK_SIZE_64            (UL(1) << vabits_actual)
  48 #define TASK_SIZE_MAX           (UL(1) << VA_BITS)
  49
  50 #ifdef CONFIG_COMPAT
  51 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
  52 /*
  53  * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
  54  * by the compat vectors page.
  55  */
  56 #define TASK_SIZE_32            UL(0x100000000)
  57 #else
  58 #define TASK_SIZE_32            (UL(0x100000000) - PAGE_SIZE)
  59 #endif /* CONFIG_ARM64_64K_PAGES */
  60 #define TASK_SIZE               (test_thread_flag(TIF_32BIT) ? \
  61                                 TASK_SIZE_32 : TASK_SIZE_64)
  62 #define TASK_SIZE_OF(tsk)       (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
  63                                 TASK_SIZE_32 : TASK_SIZE_64)
  64 #define DEFAULT_MAP_WINDOW      (test_thread_flag(TIF_32BIT) ? \
  65                                 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
  66 #else
  67 #define TASK_SIZE               TASK_SIZE_64
  68 #define DEFAULT_MAP_WINDOW      DEFAULT_MAP_WINDOW_64
  69 #endif /* CONFIG_COMPAT */
  70
  71 #ifdef CONFIG_ARM64_FORCE_52BIT
  72 #define STACK_TOP_MAX           TASK_SIZE_64
  73 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 4))
  74 #else
  75 #define STACK_TOP_MAX           DEFAULT_MAP_WINDOW_64
  76 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
  77 #endif /* CONFIG_ARM64_FORCE_52BIT */
  78
  79 #ifdef CONFIG_COMPAT
  80 #define AARCH32_VECTORS_BASE    0xffff0000
  81 #define STACK_TOP               (test_thread_flag(TIF_32BIT) ? \
  82                                 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
  83 #else
  84 #define STACK_TOP               STACK_TOP_MAX
  85 #endif /* CONFIG_COMPAT */
  86
  87 #ifndef CONFIG_ARM64_FORCE_52BIT
  88 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
  89                                 DEFAULT_MAP_WINDOW)
  90
  91 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
  92                                         base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
  93                                         base)
  94 #endif /* CONFIG_ARM64_FORCE_52BIT */
  95
  96 extern phys_addr_t arm64_dma_phys_limit;
  97 #define ARCH_LOW_ADDRESS_LIMIT  (arm64_dma_phys_limit - 1)
  98
  99 struct debug_info {
 100 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 101         /* Have we suspended stepping by a debugger? */
 102         int                     suspended_step;
 103         /* Allow breakpoints and watchpoints to be disabled for this thread. */
 104         int                     bps_disabled;
 105         int                     wps_disabled;
 106         /* Hardware breakpoints pinned to this task. */
 107         struct perf_event       *hbp_break[ARM_MAX_BRP];
 108         struct perf_event       *hbp_watch[ARM_MAX_WRP];
 109 #endif
 110 };
 111
 112 struct cpu_context {
 113         unsigned long x19;
 114         unsigned long x20;
 115         unsigned long x21;
 116         unsigned long x22;
 117         unsigned long x23;
 118         unsigned long x24;
 119         unsigned long x25;
 120         unsigned long x26;
 121         unsigned long x27;
 122         unsigned long x28;
 123         unsigned long fp;
 124         unsigned long sp;
 125         unsigned long pc;
 126 };
 127
 128 struct thread_struct {
 129         struct cpu_context      cpu_context;    /* cpu context */
 130
 131         /*
 132          * Whitelisted fields for hardened usercopy:
 133          * Maintainers must ensure manually that this contains no
 134          * implicit padding.
 135          */
 136         struct {
 137                 unsigned long   tp_value;       /* TLS register */
 138                 unsigned long   tp2_value;
 139                 struct user_fpsimd_state fpsimd_state;
 140         } uw;
 141
 142         unsigned int            fpsimd_cpu;
 143         void                    *sve_state;     /* SVE registers, if any */
 144         unsigned int            sve_vl;         /* SVE vector length */
 145         unsigned int            sve_vl_onexec;  /* SVE vl after next exec */
 146         unsigned long           fault_address;  /* fault info */
 147         unsigned long           fault_code;     /* ESR_EL1 value */
 148         struct debug_info       debug;          /* debugging */
 149 #ifdef CONFIG_ARM64_PTR_AUTH
 150         struct ptrauth_keys_user        keys_user;
 151 #ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
 152         struct ptrauth_keys_kernel      keys_kernel;
 153 #endif
 154 #endif
 155 #ifdef CONFIG_ARM64_MTE
 156         u64                     gcr_user_excl;
 157 #endif
 158         u64                     sctlr_user;
 159 };
 160
 161 #define SCTLR_USER_MASK                                                        \
 162         (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
 163          SCTLR_EL1_TCF0_MASK)
 164
 165 static inline void arch_thread_struct_whitelist(unsigned long *offset,
 166                                                 unsigned long *size)
 167 {
 168         /* Verify that there is no padding among the whitelisted fields: */
 169         BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
 170                      sizeof_field(struct thread_struct, uw.tp_value) +
 171                      sizeof_field(struct thread_struct, uw.tp2_value) +
 172                      sizeof_field(struct thread_struct, uw.fpsimd_state));
 173
 174         *offset = offsetof(struct thread_struct, uw);
 175         *size = sizeof_field(struct thread_struct, uw);
 176 }
 177
 178 #ifdef CONFIG_COMPAT
 179 #define task_user_tls(t)                                                \
 180 ({                                                                      \
 181         unsigned long *__tls;                                           \
 182         if (is_compat_thread(task_thread_info(t)))                      \
 183                 __tls = &(t)->thread.uw.tp2_value;                      \
 184         else                                                            \
 185                 __tls = &(t)->thread.uw.tp_value;                       \
 186         __tls;                                                          \
 187  })
 188 #else
 189 #define task_user_tls(t)        (&(t)->thread.uw.tp_value)
 190 #endif
 191
 192 /* Sync TPIDR_EL0 back to thread_struct for current */
 193 void tls_preserve_current_state(void);
 194
 195 #define INIT_THREAD {                           \
 196         .fpsimd_cpu = NR_CPUS,                  \
 197 }
 198
 199 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 200 {
 201         memset(regs, 0, sizeof(*regs));
 202         forget_syscall(regs);
 203         regs->pc = pc;
 204
 205         if (system_uses_irq_prio_masking())
 206                 regs->pmr_save = GIC_PRIO_IRQON;
 207 }
 208
 209 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 210                                 unsigned long sp)
 211 {
 212         start_thread_common(regs, pc);
 213         regs->pstate = PSR_MODE_EL0t;
 214         spectre_v4_enable_task_mitigation(current);
 215         regs->sp = sp;
 216 }
 217
 218 #ifdef CONFIG_COMPAT
 219 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 220                                        unsigned long sp)
 221 {
 222         start_thread_common(regs, pc);
 223         regs->pstate = PSR_AA32_MODE_USR;
 224         if (pc & 1)
 225                 regs->pstate |= PSR_AA32_T_BIT;
 226
 227 #ifdef __AARCH64EB__
 228         regs->pstate |= PSR_AA32_E_BIT;
 229 #endif
 230
 231         spectre_v4_enable_task_mitigation(current);
 232         regs->compat_sp = sp;
 233 }
 234 #endif
 235
 236 static inline bool is_ttbr0_addr(unsigned long addr)
 237 {
 238         /* entry assembly clears tags for TTBR0 addrs */
 239         return addr < TASK_SIZE;
 240 }
 241
 242 static inline bool is_ttbr1_addr(unsigned long addr)
 243 {
 244         /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
 245         return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
 246 }
 247
 248 /* Forward declaration, a strange C thing */
 249 struct task_struct;
 250
 251 /* Free all resources held by a thread. */
 252 extern void release_thread(struct task_struct *);
 253
 254 unsigned long get_wchan(struct task_struct *p);
 255
 256 void set_task_sctlr_el1(u64 sctlr);
 257
 258 /* Thread switching */
 259 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 260                                          struct task_struct *next);
 261
 262 #define task_pt_regs(p) \
 263         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 264
 265 #define KSTK_EIP(tsk)   ((unsigned long)task_pt_regs(tsk)->pc)
 266 #define KSTK_ESP(tsk)   user_stack_pointer(task_pt_regs(tsk))
 267
 268 /*
 269  * Prefetching support
 270  */
 271 #define ARCH_HAS_PREFETCH
 272 static inline void prefetch(const void *ptr)
 273 {
 274         asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
 275 }
 276
 277 #define ARCH_HAS_PREFETCHW
 278 static inline void prefetchw(const void *ptr)
 279 {
 280         asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
 281 }
 282
 283 #define ARCH_HAS_SPINLOCK_PREFETCH
 284 static inline void spin_lock_prefetch(const void *ptr)
 285 {
 286         asm volatile(ARM64_LSE_ATOMIC_INSN(
 287                      "prfm pstl1strm, %a0",
 288                      "nop") : : "p" (ptr));
 289 }
 290
 291 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 292 extern void __init minsigstksz_setup(void);
 293
 294 /*
 295  * Not at the top of the file due to a direct #include cycle between
 296  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
 297  * ensures that contents of processor.h are visible to fpsimd.h even if
 298  * processor.h is included first.
 299  *
 300  * These prctl helpers are the only things in this file that require
 301  * fpsimd.h.  The core code expects them to be in this header.
 302  */
 303 #include <asm/fpsimd.h>
 304
 305 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
 306 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
 307 #define SVE_GET_VL()    sve_get_current_vl()
 308
 309 /* PR_PAC_RESET_KEYS prctl */
 310 #define PAC_RESET_KEYS(tsk, arg)        ptrauth_prctl_reset_keys(tsk, arg)
 311
 312 /* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
 313 #define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)                                \
 314         ptrauth_set_enabled_keys(tsk, keys, enabled)
 315 #define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
 316
 317 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
 318 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
 319 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
 320 long get_tagged_addr_ctrl(struct task_struct *task);
 321 #define SET_TAGGED_ADDR_CTRL(arg)       set_tagged_addr_ctrl(current, arg)
 322 #define GET_TAGGED_ADDR_CTRL()          get_tagged_addr_ctrl(current)
 323 #endif
 324
 325 /*
 326  * For CONFIG_GCC_PLUGIN_STACKLEAK
 327  *
 328  * These need to be macros because otherwise we get stuck in a nightmare
 329  * of header definitions for the use of task_stack_page.
 330  */
 331
 332 #define current_top_of_stack()                                                          \
 333 ({                                                                                      \
 334         struct stack_info _info;                                                        \
 335         BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info));        \
 336         _info.high;                                                                     \
 337 })
 338 #define on_thread_stack()       (on_task_stack(current, current_stack_pointer, 1, NULL))
 339
 340 #endif /* __ASSEMBLY__ */
 341 #endif /* __ASM_PROCESSOR_H */