aboutsummaryrefslogtreecommitdiff
path: root/linux-user/qemu.h
blob: 2e90a971753209f20429fdcb3492779b20ce2843 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
#ifndef QEMU_H
#define QEMU_H

#include "cpu.h"
#include "exec/cpu_ldst.h"

#include "user/abitypes.h"

#include "syscall_defs.h"
#include "target_syscall.h"
#include "accel/tcg/vcpu-state.h"

/*
 * This is the size of the host kernel's sigset_t, needed where we make
 * direct system calls that take a sigset_t pointer and a size.
 */
#define SIGSET_T_SIZE (_NSIG / 8)

/*
 * This struct is used to hold certain information about the image.
 * Basically, it replicates in user space what would be certain
 * task_struct fields in the kernel
 */
struct image_info {
        abi_ulong       load_bias;
        abi_ulong       load_addr;
        abi_ulong       start_code;
        abi_ulong       end_code;
        abi_ulong       start_data;
        abi_ulong       end_data;
        abi_ulong       brk;
        abi_ulong       start_stack;
        abi_ulong       stack_limit;
        abi_ulong       vdso;
        abi_ulong       entry;
        abi_ulong       code_offset;
        abi_ulong       data_offset;
        abi_ulong       saved_auxv;
        abi_ulong       auxv_len;
        abi_ulong       argc;
        abi_ulong       argv;
        abi_ulong       envc;
        abi_ulong       envp;
        abi_ulong       file_string;
        uint32_t        elf_flags;
        int             personality;
        abi_ulong       alignment;
        bool            exec_stack;

        /* Generic semihosting knows about these pointers. */
        abi_ulong       arg_strings;   /* strings for argv */
        abi_ulong       env_strings;   /* strings for envp; ends arg_strings */

        /* The fields below are used in FDPIC mode.  */
        abi_ulong       loadmap_addr;
        uint16_t        nsegs;
        void            *loadsegs;
        abi_ulong       pt_dynamic_addr;
        abi_ulong       interpreter_loadmap_addr;
        abi_ulong       interpreter_pt_dynamic_addr;
        struct image_info *other_info;

        /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
        uint32_t        note_flags;

#ifdef TARGET_MIPS
        int             fp_abi;
        int             interp_fp_abi;
#endif
};

#ifdef TARGET_I386
/* Information about the current linux thread */
struct vm86_saved_state {
    uint32_t eax; /* return code */
    uint32_t ebx;
    uint32_t ecx;
    uint32_t edx;
    uint32_t esi;
    uint32_t edi;
    uint32_t ebp;
    uint32_t esp;
    uint32_t eflags;
    uint32_t eip;
    uint16_t cs, ss, ds, es, fs, gs;
};
#endif

#if defined(TARGET_ARM) && defined(TARGET_ABI32)
/* FPU emulator */
#include "nwfpe/fpa11.h"
#endif

struct emulated_sigtable {
    int pending; /* true if signal is pending */
    target_siginfo_t info;
};

struct TaskState {
    pid_t ts_tid;     /* tid (or pid) of this task */
#ifdef TARGET_ARM
# ifdef TARGET_ABI32
    /* FPA state */
    FPA11 fpa;
# endif
#endif
#if defined(TARGET_ARM) || defined(TARGET_RISCV)
    int swi_errno;
#endif
#if defined(TARGET_I386) && !defined(TARGET_X86_64)
    abi_ulong target_v86;
    struct vm86_saved_state vm86_saved_regs;
    struct target_vm86plus_struct vm86plus;
    uint32_t v86flags;
    uint32_t v86mask;
#endif
    abi_ulong child_tidptr;
#ifdef TARGET_M68K
    abi_ulong tp_value;
#endif
#if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_RISCV)
    /* Extra fields for semihosted binaries.  */
    abi_ulong heap_base;
    abi_ulong heap_limit;
#endif
    abi_ulong stack_base;
    int used; /* non zero if used */
    struct image_info *info;
    struct linux_binprm *bprm;

    struct emulated_sigtable sync_signal;
    struct emulated_sigtable sigtab[TARGET_NSIG];
    /*
     * This thread's signal mask, as requested by the guest program.
     * The actual signal mask of this thread may differ:
     *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
     *  + sometimes we block all signals to avoid races
     */
    sigset_t signal_mask;
    /*
     * The signal mask imposed by a guest sigsuspend syscall, if we are
     * currently in the middle of such a syscall
     */
    sigset_t sigsuspend_mask;
    /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
    int in_sigsuspend;

    /*
     * Nonzero if process_pending_signals() needs to do something (either
     * handle a pending signal or unblock signals).
     * This flag is written from a signal handler so should be accessed via
     * the qatomic_read() and qatomic_set() functions. (It is not accessed
     * from multiple threads.)
     */
    int signal_pending;

    /* This thread's sigaltstack, if it has one */
    struct target_sigaltstack sigaltstack_used;

    /* Start time of task after system boot in clock ticks */
    uint64_t start_boottime;
};

abi_long do_brk(abi_ulong new_brk);
int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
                    int flags, mode_t mode, bool safe);
ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);

/* user access */

#define VERIFY_NONE  0
#define VERIFY_READ  PAGE_READ
#define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)

static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
{
    if (size == 0
        ? !guest_addr_valid_untagged(addr)
        : !guest_range_valid_untagged(addr, size)) {
        return false;
    }
    return page_check_range((target_ulong)addr, size, type);
}

static inline bool access_ok(CPUState *cpu, int type,
                             abi_ulong addr, abi_ulong size)
{
    return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
}

/* NOTE __get_user and __put_user use host pointers and don't check access.
   These are usually used to access struct data members once the struct has
   been locked - usually with lock_user_struct.  */

/*
 * Tricky points:
 * - Use __builtin_choose_expr to avoid type promotion from ?:,
 * - Invalid sizes result in a compile time error stemming from
 *   the fact that abort has no parameters.
 * - It's easier to use the endian-specific unaligned load/store
 *   functions than host-endian unaligned load/store plus tswapN.
 * - The pragmas are necessary only to silence a clang false-positive
 *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
 * - gcc has bugs in its _Pragma() support in some versions, eg
 *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
 *   include the warning-suppression pragmas for clang
 */
#if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
#define PRAGMA_DISABLE_PACKED_WARNING                                   \
    _Pragma("GCC diagnostic push");                                     \
    _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")

#define PRAGMA_REENABLE_PACKED_WARNING          \
    _Pragma("GCC diagnostic pop")

#else
#define PRAGMA_DISABLE_PACKED_WARNING
#define PRAGMA_REENABLE_PACKED_WARNING
#endif

#define __put_user_e(x, hptr, e)                                            \
    do {                                                                    \
        PRAGMA_DISABLE_PACKED_WARNING;                                      \
        (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
        __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
        __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
        __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
            ((hptr), (x)), (void)0);                                        \
        PRAGMA_REENABLE_PACKED_WARNING;                                     \
    } while (0)

#define __get_user_e(x, hptr, e)                                            \
    do {                                                                    \
        PRAGMA_DISABLE_PACKED_WARNING;                                      \
        ((x) = (typeof(*hptr))(                                             \
        __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
        __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
        __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
        __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
            (hptr)), (void)0);                                              \
        PRAGMA_REENABLE_PACKED_WARNING;                                     \
    } while (0)


#if TARGET_BIG_ENDIAN
# define __put_user(x, hptr)  __put_user_e(x, hptr, be)
# define __get_user(x, hptr)  __get_user_e(x, hptr, be)
#else
# define __put_user(x, hptr)  __put_user_e(x, hptr, le)
# define __get_user(x, hptr)  __get_user_e(x, hptr, le)
#endif

/* put_user()/get_user() take a guest address and check access */
/* These are usually used to access an atomic data type, such as an int,
 * that has been passed by address.  These internally perform locking
 * and unlocking on the data type.
 */
#define put_user(x, gaddr, target_type)					\
({									\
    abi_ulong __gaddr = (gaddr);					\
    target_type *__hptr;						\
    abi_long __ret = 0;							\
    if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
        __put_user((x), __hptr);				\
        unlock_user(__hptr, __gaddr, sizeof(target_type));		\
    } else								\
        __ret = -TARGET_EFAULT;						\
    __ret;								\
})

#define get_user(x, gaddr, target_type)					\
({									\
    abi_ulong __gaddr = (gaddr);					\
    target_type *__hptr;						\
    abi_long __ret = 0;							\
    if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
        __get_user((x), __hptr);				\
        unlock_user(__hptr, __gaddr, 0);				\
    } else {								\
        /* avoid warning */						\
        (x) = 0;							\
        __ret = -TARGET_EFAULT;						\
    }									\
    __ret;								\
})

#define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
#define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
#define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
#define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
#define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
#define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
#define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
#define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
#define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
#define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)

#define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
#define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
#define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
#define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
#define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
#define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
#define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
#define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
#define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
#define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)

/* copy_from_user() and copy_to_user() are usually used to copy data
 * buffers between the target and host.  These internally perform
 * locking/unlocking of the memory.
 */
int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);

/* Functions for accessing guest memory.  The tget and tput functions
   read/write single values, byteswapping as necessary.  The lock_user function
   gets a pointer to a contiguous area of guest memory, but does not perform
   any byteswapping.  lock_user may return either a pointer to the guest
   memory, or a temporary buffer.  */

/* Lock an area of guest memory into the host.  If copy is true then the
   host area will have the same contents as the guest.  */
void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);

/* Unlock an area of guest memory.  The first LEN bytes must be
   flushed back to guest memory. host_ptr = NULL is explicitly
   allowed and does nothing. */
#ifndef CONFIG_DEBUG_REMAP
static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
                               ssize_t len)
{
    /* no-op */
}
#else
void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
#endif

/* Return the length of a string in target memory or -TARGET_EFAULT if
   access error. */
ssize_t target_strlen(abi_ulong gaddr);

/* Like lock_user but for null terminated strings.  */
void *lock_user_string(abi_ulong guest_addr);

/* Helper macros for locking/unlocking a target struct.  */
#define lock_user_struct(type, host_ptr, guest_addr, copy)	\
    (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
#define unlock_user_struct(host_ptr, guest_addr, copy)		\
    unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)

#endif /* QEMU_H */