linux-user/qemu.h

   1 #ifndef QEMU_H
   2 #define QEMU_H
   3
   4 #include "cpu.h"
   5 #include "exec/cpu_ldst.h"
   6
   7 #undef DEBUG_REMAP
   8
   9 #include "exec/user/abitypes.h"
  10
  11 #include "syscall_defs.h"
  12 #include "target_syscall.h"
  13
  14 /*
  15  * This is the size of the host kernel's sigset_t, needed where we make
  16  * direct system calls that take a sigset_t pointer and a size.
  17  */
  18 #define SIGSET_T_SIZE (_NSIG / 8)
  19
  20 /*
  21  * This struct is used to hold certain information about the image.
  22  * Basically, it replicates in user space what would be certain
  23  * task_struct fields in the kernel
  24  */
  25 struct image_info {
  26         abi_ulong       load_bias;
  27         abi_ulong       load_addr;
  28         abi_ulong       start_code;
  29         abi_ulong       end_code;
  30         abi_ulong       start_data;
  31         abi_ulong       end_data;
  32         abi_ulong       brk;
  33         abi_ulong       start_stack;
  34         abi_ulong       stack_limit;
  35         abi_ulong       vdso;
  36         abi_ulong       entry;
  37         abi_ulong       code_offset;
  38         abi_ulong       data_offset;
  39         abi_ulong       saved_auxv;
  40         abi_ulong       auxv_len;
  41         abi_ulong       argc;
  42         abi_ulong       argv;
  43         abi_ulong       envc;
  44         abi_ulong       envp;
  45         abi_ulong       file_string;
  46         uint32_t        elf_flags;
  47         int             personality;
  48         abi_ulong       alignment;
  49         bool            exec_stack;
  50
  51         /* Generic semihosting knows about these pointers. */
  52         abi_ulong       arg_strings;   /* strings for argv */
  53         abi_ulong       env_strings;   /* strings for envp; ends arg_strings */
  54
  55         /* The fields below are used in FDPIC mode.  */
  56         abi_ulong       loadmap_addr;
  57         uint16_t        nsegs;
  58         void            *loadsegs;
  59         abi_ulong       pt_dynamic_addr;
  60         abi_ulong       interpreter_loadmap_addr;
  61         abi_ulong       interpreter_pt_dynamic_addr;
  62         struct image_info *other_info;
  63
  64         /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
  65         uint32_t        note_flags;
  66
  67 #ifdef TARGET_MIPS
  68         int             fp_abi;
  69         int             interp_fp_abi;
  70 #endif
  71 };
  72
  73 #ifdef TARGET_I386
  74 /* Information about the current linux thread */
  75 struct vm86_saved_state {
  76     uint32_t eax; /* return code */
  77     uint32_t ebx;
  78     uint32_t ecx;
  79     uint32_t edx;
  80     uint32_t esi;
  81     uint32_t edi;
  82     uint32_t ebp;
  83     uint32_t esp;
  84     uint32_t eflags;
  85     uint32_t eip;
  86     uint16_t cs, ss, ds, es, fs, gs;
  87 };
  88 #endif
  89
  90 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  91 /* FPU emulator */
  92 #include "nwfpe/fpa11.h"
  93 #endif
  94
  95 struct emulated_sigtable {
  96     int pending; /* true if signal is pending */
  97     target_siginfo_t info;
  98 };
  99
 100 typedef struct TaskState {
 101     pid_t ts_tid;     /* tid (or pid) of this task */
 102 #ifdef TARGET_ARM
 103 # ifdef TARGET_ABI32
 104     /* FPA state */
 105     FPA11 fpa;
 106 # endif
 107 #endif
 108 #if defined(TARGET_ARM) || defined(TARGET_RISCV)
 109     int swi_errno;
 110 #endif
 111 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
 112     abi_ulong target_v86;
 113     struct vm86_saved_state vm86_saved_regs;
 114     struct target_vm86plus_struct vm86plus;
 115     uint32_t v86flags;
 116     uint32_t v86mask;
 117 #endif
 118     abi_ulong child_tidptr;
 119 #ifdef TARGET_M68K
 120     abi_ulong tp_value;
 121 #endif
 122 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_RISCV)
 123     /* Extra fields for semihosted binaries.  */
 124     abi_ulong heap_base;
 125     abi_ulong heap_limit;
 126 #endif
 127     abi_ulong stack_base;
 128     int used; /* non zero if used */
 129     struct image_info *info;
 130     struct linux_binprm *bprm;
 131
 132     struct emulated_sigtable sync_signal;
 133     struct emulated_sigtable sigtab[TARGET_NSIG];
 134     /*
 135      * This thread's signal mask, as requested by the guest program.
 136      * The actual signal mask of this thread may differ:
 137      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
 138      *  + sometimes we block all signals to avoid races
 139      */
 140     sigset_t signal_mask;
 141     /*
 142      * The signal mask imposed by a guest sigsuspend syscall, if we are
 143      * currently in the middle of such a syscall
 144      */
 145     sigset_t sigsuspend_mask;
 146     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
 147     int in_sigsuspend;
 148
 149     /*
 150      * Nonzero if process_pending_signals() needs to do something (either
 151      * handle a pending signal or unblock signals).
 152      * This flag is written from a signal handler so should be accessed via
 153      * the qatomic_read() and qatomic_set() functions. (It is not accessed
 154      * from multiple threads.)
 155      */
 156     int signal_pending;
 157
 158     /* This thread's sigaltstack, if it has one */
 159     struct target_sigaltstack sigaltstack_used;
 160
 161     /* Start time of task after system boot in clock ticks */
 162     uint64_t start_boottime;
 163 } TaskState;
 164
 165 static inline TaskState *get_task_state(CPUState *cs)
 166 {
 167     return cs->opaque;
 168 }
 169
 170 abi_long do_brk(abi_ulong new_brk);
 171 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
 172                     int flags, mode_t mode, bool safe);
 173 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
 174
 175 /* user access */
 176
 177 #define VERIFY_NONE  0
 178 #define VERIFY_READ  PAGE_READ
 179 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
 180
 181 static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
 182 {
 183     if (size == 0
 184         ? !guest_addr_valid_untagged(addr)
 185         : !guest_range_valid_untagged(addr, size)) {
 186         return false;
 187     }
 188     return page_check_range((target_ulong)addr, size, type);
 189 }
 190
 191 static inline bool access_ok(CPUState *cpu, int type,
 192                              abi_ulong addr, abi_ulong size)
 193 {
 194     return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
 195 }
 196
 197 /* NOTE __get_user and __put_user use host pointers and don't check access.
 198    These are usually used to access struct data members once the struct has
 199    been locked - usually with lock_user_struct.  */
 200
 201 /*
 202  * Tricky points:
 203  * - Use __builtin_choose_expr to avoid type promotion from ?:,
 204  * - Invalid sizes result in a compile time error stemming from
 205  *   the fact that abort has no parameters.
 206  * - It's easier to use the endian-specific unaligned load/store
 207  *   functions than host-endian unaligned load/store plus tswapN.
 208  * - The pragmas are necessary only to silence a clang false-positive
 209  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
 210  * - gcc has bugs in its _Pragma() support in some versions, eg
 211  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
 212  *   include the warning-suppression pragmas for clang
 213  */
 214 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
 215 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
 216     _Pragma("GCC diagnostic push");                                     \
 217     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
 218
 219 #define PRAGMA_REENABLE_PACKED_WARNING          \
 220     _Pragma("GCC diagnostic pop")
 221
 222 #else
 223 #define PRAGMA_DISABLE_PACKED_WARNING
 224 #define PRAGMA_REENABLE_PACKED_WARNING
 225 #endif
 226
 227 #define __put_user_e(x, hptr, e)                                            \
 228     do {                                                                    \
 229         PRAGMA_DISABLE_PACKED_WARNING;                                      \
 230         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
 231         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
 232         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
 233         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
 234             ((hptr), (x)), (void)0);                                        \
 235         PRAGMA_REENABLE_PACKED_WARNING;                                     \
 236     } while (0)
 237
 238 #define __get_user_e(x, hptr, e)                                            \
 239     do {                                                                    \
 240         PRAGMA_DISABLE_PACKED_WARNING;                                      \
 241         ((x) = (typeof(*hptr))(                                             \
 242         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
 243         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
 244         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
 245         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
 246             (hptr)), (void)0);                                              \
 247         PRAGMA_REENABLE_PACKED_WARNING;                                     \
 248     } while (0)
 249
 250
 251 #if TARGET_BIG_ENDIAN
 252 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 253 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 254 #else
 255 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 256 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 257 #endif
 258
 259 /* put_user()/get_user() take a guest address and check access */
 260 /* These are usually used to access an atomic data type, such as an int,
 261  * that has been passed by address.  These internally perform locking
 262  * and unlocking on the data type.
 263  */
 264 #define put_user(x, gaddr, target_type)                                 \
 265 ({                                                                      \
 266     abi_ulong __gaddr = (gaddr);                                        \
 267     target_type *__hptr;                                                \
 268     abi_long __ret = 0;                                                 \
 269     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 270         __put_user((x), __hptr);                                \
 271         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 272     } else                                                              \
 273         __ret = -TARGET_EFAULT;                                         \
 274     __ret;                                                              \
 275 })
 276
 277 #define get_user(x, gaddr, target_type)                                 \
 278 ({                                                                      \
 279     abi_ulong __gaddr = (gaddr);                                        \
 280     target_type *__hptr;                                                \
 281     abi_long __ret = 0;                                                 \
 282     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 283         __get_user((x), __hptr);                                \
 284         unlock_user(__hptr, __gaddr, 0);                                \
 285     } else {                                                            \
 286         /* avoid warning */                                             \
 287         (x) = 0;                                                        \
 288         __ret = -TARGET_EFAULT;                                         \
 289     }                                                                   \
 290     __ret;                                                              \
 291 })
 292
 293 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 294 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 295 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 296 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 297 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 298 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 299 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 300 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 301 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 302 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 303
 304 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 305 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 306 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 307 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 308 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 309 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 310 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 311 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 312 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 313 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 314
 315 /* copy_from_user() and copy_to_user() are usually used to copy data
 316  * buffers between the target and host.  These internally perform
 317  * locking/unlocking of the memory.
 318  */
 319 int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
 320 int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
 321
 322 /* Functions for accessing guest memory.  The tget and tput functions
 323    read/write single values, byteswapping as necessary.  The lock_user function
 324    gets a pointer to a contiguous area of guest memory, but does not perform
 325    any byteswapping.  lock_user may return either a pointer to the guest
 326    memory, or a temporary buffer.  */
 327
 328 /* Lock an area of guest memory into the host.  If copy is true then the
 329    host area will have the same contents as the guest.  */
 330 void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
 331
 332 /* Unlock an area of guest memory.  The first LEN bytes must be
 333    flushed back to guest memory. host_ptr = NULL is explicitly
 334    allowed and does nothing. */
 335 #ifndef DEBUG_REMAP
 336 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 337                                ssize_t len)
 338 {
 339     /* no-op */
 340 }
 341 #else
 342 void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
 343 #endif
 344
 345 /* Return the length of a string in target memory or -TARGET_EFAULT if
 346    access error. */
 347 ssize_t target_strlen(abi_ulong gaddr);
 348
 349 /* Like lock_user but for null terminated strings.  */
 350 void *lock_user_string(abi_ulong guest_addr);
 351
 352 /* Helper macros for locking/unlocking a target struct.  */
 353 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 354     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 355 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 356     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 357
 358 #endif /* QEMU_H */