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       arg_start;
  44         abi_ulong       arg_end;
  45         abi_ulong       arg_strings;
  46         abi_ulong       env_strings;
  47         abi_ulong       file_string;
  48         uint32_t        elf_flags;
  49         int             personality;
  50         abi_ulong       alignment;
  51
  52         /* The fields below are used in FDPIC mode.  */
  53         abi_ulong       loadmap_addr;
  54         uint16_t        nsegs;
  55         void            *loadsegs;
  56         abi_ulong       pt_dynamic_addr;
  57         abi_ulong       interpreter_loadmap_addr;
  58         abi_ulong       interpreter_pt_dynamic_addr;
  59         struct image_info *other_info;
  60
  61         /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
  62         uint32_t        note_flags;
  63
  64 #ifdef TARGET_MIPS
  65         int             fp_abi;
  66         int             interp_fp_abi;
  67 #endif
  68 };
  69
  70 #ifdef TARGET_I386
  71 /* Information about the current linux thread */
  72 struct vm86_saved_state {
  73     uint32_t eax; /* return code */
  74     uint32_t ebx;
  75     uint32_t ecx;
  76     uint32_t edx;
  77     uint32_t esi;
  78     uint32_t edi;
  79     uint32_t ebp;
  80     uint32_t esp;
  81     uint32_t eflags;
  82     uint32_t eip;
  83     uint16_t cs, ss, ds, es, fs, gs;
  84 };
  85 #endif
  86
  87 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  88 /* FPU emulator */
  89 #include "nwfpe/fpa11.h"
  90 #endif
  91
  92 struct emulated_sigtable {
  93     int pending; /* true if signal is pending */
  94     target_siginfo_t info;
  95 };
  96
  97 /*
  98  * NOTE: we force a big alignment so that the stack stored after is
  99  * aligned too
 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 } __attribute__((aligned(16))) TaskState;
 162
 163 abi_long do_brk(abi_ulong new_brk);
 164
 165 /* user access */
 166
 167 #define VERIFY_READ  PAGE_READ
 168 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
 169
 170 static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
 171 {
 172     if (size == 0
 173         ? !guest_addr_valid_untagged(addr)
 174         : !guest_range_valid_untagged(addr, size)) {
 175         return false;
 176     }
 177     return page_check_range((target_ulong)addr, size, type) == 0;
 178 }
 179
 180 static inline bool access_ok(CPUState *cpu, int type,
 181                              abi_ulong addr, abi_ulong size)
 182 {
 183     return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
 184 }
 185
 186 /* NOTE __get_user and __put_user use host pointers and don't check access.
 187    These are usually used to access struct data members once the struct has
 188    been locked - usually with lock_user_struct.  */
 189
 190 /*
 191  * Tricky points:
 192  * - Use __builtin_choose_expr to avoid type promotion from ?:,
 193  * - Invalid sizes result in a compile time error stemming from
 194  *   the fact that abort has no parameters.
 195  * - It's easier to use the endian-specific unaligned load/store
 196  *   functions than host-endian unaligned load/store plus tswapN.
 197  * - The pragmas are necessary only to silence a clang false-positive
 198  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
 199  * - gcc has bugs in its _Pragma() support in some versions, eg
 200  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
 201  *   include the warning-suppression pragmas for clang
 202  */
 203 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
 204 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
 205     _Pragma("GCC diagnostic push");                                     \
 206     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
 207
 208 #define PRAGMA_REENABLE_PACKED_WARNING          \
 209     _Pragma("GCC diagnostic pop")
 210
 211 #else
 212 #define PRAGMA_DISABLE_PACKED_WARNING
 213 #define PRAGMA_REENABLE_PACKED_WARNING
 214 #endif
 215
 216 #define __put_user_e(x, hptr, e)                                            \
 217     do {                                                                    \
 218         PRAGMA_DISABLE_PACKED_WARNING;                                      \
 219         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
 220         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
 221         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
 222         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
 223             ((hptr), (x)), (void)0);                                        \
 224         PRAGMA_REENABLE_PACKED_WARNING;                                     \
 225     } while (0)
 226
 227 #define __get_user_e(x, hptr, e)                                            \
 228     do {                                                                    \
 229         PRAGMA_DISABLE_PACKED_WARNING;                                      \
 230         ((x) = (typeof(*hptr))(                                             \
 231         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
 232         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
 233         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
 234         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
 235             (hptr)), (void)0);                                              \
 236         PRAGMA_REENABLE_PACKED_WARNING;                                     \
 237     } while (0)
 238
 239
 240 #ifdef TARGET_WORDS_BIGENDIAN
 241 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 242 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 243 #else
 244 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 245 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 246 #endif
 247
 248 /* put_user()/get_user() take a guest address and check access */
 249 /* These are usually used to access an atomic data type, such as an int,
 250  * that has been passed by address.  These internally perform locking
 251  * and unlocking on the data type.
 252  */
 253 #define put_user(x, gaddr, target_type)                                 \
 254 ({                                                                      \
 255     abi_ulong __gaddr = (gaddr);                                        \
 256     target_type *__hptr;                                                \
 257     abi_long __ret = 0;                                                 \
 258     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 259         __put_user((x), __hptr);                                \
 260         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 261     } else                                                              \
 262         __ret = -TARGET_EFAULT;                                         \
 263     __ret;                                                              \
 264 })
 265
 266 #define get_user(x, gaddr, target_type)                                 \
 267 ({                                                                      \
 268     abi_ulong __gaddr = (gaddr);                                        \
 269     target_type *__hptr;                                                \
 270     abi_long __ret = 0;                                                 \
 271     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 272         __get_user((x), __hptr);                                \
 273         unlock_user(__hptr, __gaddr, 0);                                \
 274     } else {                                                            \
 275         /* avoid warning */                                             \
 276         (x) = 0;                                                        \
 277         __ret = -TARGET_EFAULT;                                         \
 278     }                                                                   \
 279     __ret;                                                              \
 280 })
 281
 282 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 283 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 284 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 285 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 286 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 287 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 288 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 289 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 290 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 291 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 292
 293 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 294 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 295 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 296 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 297 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 298 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 299 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 300 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 301 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 302 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 303
 304 /* copy_from_user() and copy_to_user() are usually used to copy data
 305  * buffers between the target and host.  These internally perform
 306  * locking/unlocking of the memory.
 307  */
 308 int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
 309 int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
 310
 311 /* Functions for accessing guest memory.  The tget and tput functions
 312    read/write single values, byteswapping as necessary.  The lock_user function
 313    gets a pointer to a contiguous area of guest memory, but does not perform
 314    any byteswapping.  lock_user may return either a pointer to the guest
 315    memory, or a temporary buffer.  */
 316
 317 /* Lock an area of guest memory into the host.  If copy is true then the
 318    host area will have the same contents as the guest.  */
 319 void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
 320
 321 /* Unlock an area of guest memory.  The first LEN bytes must be
 322    flushed back to guest memory. host_ptr = NULL is explicitly
 323    allowed and does nothing. */
 324 #ifndef DEBUG_REMAP
 325 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 326                                ssize_t len)
 327 {
 328     /* no-op */
 329 }
 330 #else
 331 void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
 332 #endif
 333
 334 /* Return the length of a string in target memory or -TARGET_EFAULT if
 335    access error. */
 336 ssize_t target_strlen(abi_ulong gaddr);
 337
 338 /* Like lock_user but for null terminated strings.  */
 339 void *lock_user_string(abi_ulong guest_addr);
 340
 341 /* Helper macros for locking/unlocking a target struct.  */
 342 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 343     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 344 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 345     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 346
 347 #endif /* QEMU_H */