qemu/linux-user/qemu.h
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   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 */
  25struct 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 */
  76struct 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
  96struct emulated_sigtable {
  97    int pending; /* true if signal is pending */
  98    target_siginfo_t info;
  99};
 100
 101typedef 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
 166abi_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
 173static 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
 183static 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 */
 311int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
 312int 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.  */
 322void *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
 328static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 329                               ssize_t len)
 330{
 331    /* no-op */
 332}
 333#else
 334void 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. */
 339ssize_t target_strlen(abi_ulong gaddr);
 340
 341/* Like lock_user but for null terminated strings.  */
 342void *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 */
 351