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