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