xref: /openbmc/qemu/linux-user/qemu.h (revision 2f3e5e4c08c43daeec144adeeae9138176039b60)
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       brk;
33          abi_ulong       start_stack;
34          abi_ulong       stack_limit;
35          abi_ulong       vdso;
36          abi_ulong       entry;
37          abi_ulong       code_offset;
38          abi_ulong       data_offset;
39          abi_ulong       saved_auxv;
40          abi_ulong       auxv_len;
41          abi_ulong       argc;
42          abi_ulong       argv;
43          abi_ulong       envc;
44          abi_ulong       envp;
45          abi_ulong       file_string;
46          uint32_t        elf_flags;
47          int             personality;
48          abi_ulong       alignment;
49          bool            exec_stack;
50  
51          /* Generic semihosting knows about these pointers. */
52          abi_ulong       arg_strings;   /* strings for argv */
53          abi_ulong       env_strings;   /* strings for envp; ends arg_strings */
54  
55          /* The fields below are used in FDPIC mode.  */
56          abi_ulong       loadmap_addr;
57          uint16_t        nsegs;
58          void            *loadsegs;
59          abi_ulong       pt_dynamic_addr;
60          abi_ulong       interpreter_loadmap_addr;
61          abi_ulong       interpreter_pt_dynamic_addr;
62          struct image_info *other_info;
63  
64          /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
65          uint32_t        note_flags;
66  
67  #ifdef TARGET_MIPS
68          int             fp_abi;
69          int             interp_fp_abi;
70  #endif
71  };
72  
73  #ifdef TARGET_I386
74  /* Information about the current linux thread */
75  struct vm86_saved_state {
76      uint32_t eax; /* return code */
77      uint32_t ebx;
78      uint32_t ecx;
79      uint32_t edx;
80      uint32_t esi;
81      uint32_t edi;
82      uint32_t ebp;
83      uint32_t esp;
84      uint32_t eflags;
85      uint32_t eip;
86      uint16_t cs, ss, ds, es, fs, gs;
87  };
88  #endif
89  
90  #if defined(TARGET_ARM) && defined(TARGET_ABI32)
91  /* FPU emulator */
92  #include "nwfpe/fpa11.h"
93  #endif
94  
95  struct emulated_sigtable {
96      int pending; /* true if signal is pending */
97      target_siginfo_t info;
98  };
99  
100  typedef struct TaskState {
101      pid_t ts_tid;     /* tid (or pid) of this task */
102  #ifdef TARGET_ARM
103  # ifdef TARGET_ABI32
104      /* FPA state */
105      FPA11 fpa;
106  # endif
107  #endif
108  #if defined(TARGET_ARM) || defined(TARGET_RISCV)
109      int swi_errno;
110  #endif
111  #if defined(TARGET_I386) && !defined(TARGET_X86_64)
112      abi_ulong target_v86;
113      struct vm86_saved_state vm86_saved_regs;
114      struct target_vm86plus_struct vm86plus;
115      uint32_t v86flags;
116      uint32_t v86mask;
117  #endif
118      abi_ulong child_tidptr;
119  #ifdef TARGET_M68K
120      abi_ulong tp_value;
121  #endif
122  #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_RISCV)
123      /* Extra fields for semihosted binaries.  */
124      abi_ulong heap_base;
125      abi_ulong heap_limit;
126  #endif
127      abi_ulong stack_base;
128      int used; /* non zero if used */
129      struct image_info *info;
130      struct linux_binprm *bprm;
131  
132      struct emulated_sigtable sync_signal;
133      struct emulated_sigtable sigtab[TARGET_NSIG];
134      /*
135       * This thread's signal mask, as requested by the guest program.
136       * The actual signal mask of this thread may differ:
137       *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
138       *  + sometimes we block all signals to avoid races
139       */
140      sigset_t signal_mask;
141      /*
142       * The signal mask imposed by a guest sigsuspend syscall, if we are
143       * currently in the middle of such a syscall
144       */
145      sigset_t sigsuspend_mask;
146      /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
147      int in_sigsuspend;
148  
149      /*
150       * Nonzero if process_pending_signals() needs to do something (either
151       * handle a pending signal or unblock signals).
152       * This flag is written from a signal handler so should be accessed via
153       * the qatomic_read() and qatomic_set() functions. (It is not accessed
154       * from multiple threads.)
155       */
156      int signal_pending;
157  
158      /* This thread's sigaltstack, if it has one */
159      struct target_sigaltstack sigaltstack_used;
160  
161      /* Start time of task after system boot in clock ticks */
162      uint64_t start_boottime;
163  } TaskState;
164  
165  static inline TaskState *get_task_state(CPUState *cs)
166  {
167      return cs->opaque;
168  }
169  
170  abi_long do_brk(abi_ulong new_brk);
171  int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
172                      int flags, mode_t mode, bool safe);
173  ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
174  
175  /* user access */
176  
177  #define VERIFY_NONE  0
178  #define VERIFY_READ  PAGE_READ
179  #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
180  
181  static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
182  {
183      if (size == 0
184          ? !guest_addr_valid_untagged(addr)
185          : !guest_range_valid_untagged(addr, size)) {
186          return false;
187      }
188      return page_check_range((target_ulong)addr, size, type);
189  }
190  
191  static inline bool access_ok(CPUState *cpu, int type,
192                               abi_ulong addr, abi_ulong size)
193  {
194      return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
195  }
196  
197  /* NOTE __get_user and __put_user use host pointers and don't check access.
198     These are usually used to access struct data members once the struct has
199     been locked - usually with lock_user_struct.  */
200  
201  /*
202   * Tricky points:
203   * - Use __builtin_choose_expr to avoid type promotion from ?:,
204   * - Invalid sizes result in a compile time error stemming from
205   *   the fact that abort has no parameters.
206   * - It's easier to use the endian-specific unaligned load/store
207   *   functions than host-endian unaligned load/store plus tswapN.
208   * - The pragmas are necessary only to silence a clang false-positive
209   *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
210   * - gcc has bugs in its _Pragma() support in some versions, eg
211   *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
212   *   include the warning-suppression pragmas for clang
213   */
214  #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
215  #define PRAGMA_DISABLE_PACKED_WARNING                                   \
216      _Pragma("GCC diagnostic push");                                     \
217      _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
218  
219  #define PRAGMA_REENABLE_PACKED_WARNING          \
220      _Pragma("GCC diagnostic pop")
221  
222  #else
223  #define PRAGMA_DISABLE_PACKED_WARNING
224  #define PRAGMA_REENABLE_PACKED_WARNING
225  #endif
226  
227  #define __put_user_e(x, hptr, e)                                            \
228      do {                                                                    \
229          PRAGMA_DISABLE_PACKED_WARNING;                                      \
230          (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
231          __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
232          __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
233          __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
234              ((hptr), (x)), (void)0);                                        \
235          PRAGMA_REENABLE_PACKED_WARNING;                                     \
236      } while (0)
237  
238  #define __get_user_e(x, hptr, e)                                            \
239      do {                                                                    \
240          PRAGMA_DISABLE_PACKED_WARNING;                                      \
241          ((x) = (typeof(*hptr))(                                             \
242          __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
243          __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
244          __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
245          __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
246              (hptr)), (void)0);                                              \
247          PRAGMA_REENABLE_PACKED_WARNING;                                     \
248      } while (0)
249  
250  
251  #if TARGET_BIG_ENDIAN
252  # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
253  # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
254  #else
255  # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
256  # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
257  #endif
258  
259  /* put_user()/get_user() take a guest address and check access */
260  /* These are usually used to access an atomic data type, such as an int,
261   * that has been passed by address.  These internally perform locking
262   * and unlocking on the data type.
263   */
264  #define put_user(x, gaddr, target_type)					\
265  ({									\
266      abi_ulong __gaddr = (gaddr);					\
267      target_type *__hptr;						\
268      abi_long __ret = 0;							\
269      if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
270          __put_user((x), __hptr);				\
271          unlock_user(__hptr, __gaddr, sizeof(target_type));		\
272      } else								\
273          __ret = -TARGET_EFAULT;						\
274      __ret;								\
275  })
276  
277  #define get_user(x, gaddr, target_type)					\
278  ({									\
279      abi_ulong __gaddr = (gaddr);					\
280      target_type *__hptr;						\
281      abi_long __ret = 0;							\
282      if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
283          __get_user((x), __hptr);				\
284          unlock_user(__hptr, __gaddr, 0);				\
285      } else {								\
286          /* avoid warning */						\
287          (x) = 0;							\
288          __ret = -TARGET_EFAULT;						\
289      }									\
290      __ret;								\
291  })
292  
293  #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
294  #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
295  #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
296  #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
297  #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
298  #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
299  #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
300  #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
301  #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
302  #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
303  
304  #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
305  #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
306  #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
307  #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
308  #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
309  #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
310  #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
311  #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
312  #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
313  #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
314  
315  /* copy_from_user() and copy_to_user() are usually used to copy data
316   * buffers between the target and host.  These internally perform
317   * locking/unlocking of the memory.
318   */
319  int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
320  int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
321  
322  /* Functions for accessing guest memory.  The tget and tput functions
323     read/write single values, byteswapping as necessary.  The lock_user function
324     gets a pointer to a contiguous area of guest memory, but does not perform
325     any byteswapping.  lock_user may return either a pointer to the guest
326     memory, or a temporary buffer.  */
327  
328  /* Lock an area of guest memory into the host.  If copy is true then the
329     host area will have the same contents as the guest.  */
330  void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
331  
332  /* Unlock an area of guest memory.  The first LEN bytes must be
333     flushed back to guest memory. host_ptr = NULL is explicitly
334     allowed and does nothing. */
335  #ifndef DEBUG_REMAP
336  static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
337                                 ssize_t len)
338  {
339      /* no-op */
340  }
341  #else
342  void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
343  #endif
344  
345  /* Return the length of a string in target memory or -TARGET_EFAULT if
346     access error. */
347  ssize_t target_strlen(abi_ulong gaddr);
348  
349  /* Like lock_user but for null terminated strings.  */
350  void *lock_user_string(abi_ulong guest_addr);
351  
352  /* Helper macros for locking/unlocking a target struct.  */
353  #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
354      (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
355  #define unlock_user_struct(host_ptr, guest_addr, copy)		\
356      unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
357  
358  #endif /* QEMU_H */
359