xref: /openbmc/qemu/linux-user/qemu.h (revision f3f2ad119347e8c086b72282febcaac5d731b343)
1 #ifndef QEMU_H
2 #define QEMU_H
3 
4 #include "cpu.h"
5 #include "accel/tcg/cpu-ldst.h"
6 
7 #include "user/abitypes.h"
8 #include "user/page-protection.h"
9 
10 #include "syscall_defs.h"
11 #include "target_syscall.h"
12 #include "accel/tcg/vcpu-state.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         bool            exec_stack;
49 
50         /* Generic semihosting knows about these pointers. */
51         abi_ulong       arg_strings;   /* strings for argv */
52         abi_ulong       env_strings;   /* strings for envp; ends arg_strings */
53 
54         /* The fields below are used in FDPIC mode.  */
55         abi_ulong       loadmap_addr;
56         uint16_t        nsegs;
57         void            *loadsegs;
58         abi_ulong       pt_dynamic_addr;
59         abi_ulong       interpreter_loadmap_addr;
60         abi_ulong       interpreter_pt_dynamic_addr;
61         struct image_info *other_info;
62 
63         /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
64         uint32_t        note_flags;
65 
66 #ifdef TARGET_MIPS
67         int             fp_abi;
68         int             interp_fp_abi;
69 #endif
70 };
71 
72 #ifdef TARGET_I386
73 /* Information about the current linux thread */
74 struct vm86_saved_state {
75     uint32_t eax; /* return code */
76     uint32_t ebx;
77     uint32_t ecx;
78     uint32_t edx;
79     uint32_t esi;
80     uint32_t edi;
81     uint32_t ebp;
82     uint32_t esp;
83     uint32_t eflags;
84     uint32_t eip;
85     uint16_t cs, ss, ds, es, fs, gs;
86 };
87 #endif
88 
89 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
90 /* FPU emulator */
91 #include "nwfpe/fpa11.h"
92 #endif
93 
94 struct emulated_sigtable {
95     int pending; /* true if signal is pending */
96     target_siginfo_t info;
97 };
98 
99 struct TaskState {
100     pid_t ts_tid;     /* tid (or pid) of this task */
101 #ifdef TARGET_ARM
102 # ifdef TARGET_ABI32
103     /* FPA state */
104     FPA11 fpa;
105 # endif
106 #endif
107 #if defined(TARGET_ARM) || defined(TARGET_RISCV)
108     int swi_errno;
109 #endif
110 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
111     abi_ulong target_v86;
112     struct vm86_saved_state vm86_saved_regs;
113     struct target_vm86plus_struct vm86plus;
114     uint32_t v86flags;
115     uint32_t v86mask;
116 #endif
117 #if defined(TARGET_I386)
118     /* Last syscall number. */
119     target_ulong orig_ax;
120 #endif
121     abi_ulong child_tidptr;
122 #ifdef TARGET_M68K
123     abi_ulong tp_value;
124 #endif
125 #if defined(TARGET_AARCH64)
126     vaddr gcs_base;
127     abi_ulong gcs_size;
128     abi_ulong gcs_el0_locked;
129 #endif
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     /* This thread's SYSCALL_USER_DISPATCH state, len=~0 means disabled */
164     vaddr sys_dispatch;
165     vaddr sys_dispatch_selector;
166     abi_ulong sys_dispatch_len;
167 
168     /* Start time of task after system boot in clock ticks */
169     uint64_t start_boottime;
170 };
171 
172 abi_long do_brk(abi_ulong new_brk);
173 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
174                     int flags, mode_t mode, bool safe);
175 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
176 
177 /* user access */
178 
179 #define VERIFY_NONE  0
180 #define VERIFY_READ  PAGE_READ
181 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
182 
183 static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
184 {
185     if (size == 0
186         ? !guest_addr_valid_untagged(addr)
187         : !guest_range_valid_untagged(addr, size)) {
188         return false;
189     }
190     return page_check_range((target_ulong)addr, size, type);
191 }
192 
193 static inline bool access_ok(CPUState *cpu, int type,
194                              abi_ulong addr, abi_ulong size)
195 {
196     return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
197 }
198 
199 /* NOTE __get_user and __put_user use host pointers and don't check access.
200    These are usually used to access struct data members once the struct has
201    been locked - usually with lock_user_struct.  */
202 
203 /*
204  * Tricky points:
205  * - Use __builtin_choose_expr to avoid type promotion from ?:,
206  * - Invalid sizes result in a compile time error stemming from
207  *   the fact that abort has no parameters.
208  * - It's easier to use the endian-specific unaligned load/store
209  *   functions than host-endian unaligned load/store plus tswapN.
210  * - The pragmas are necessary only to silence a clang false-positive
211  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
212  * - gcc has bugs in its _Pragma() support in some versions, eg
213  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
214  *   include the warning-suppression pragmas for clang
215  */
216 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
217 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
218     _Pragma("GCC diagnostic push");                                     \
219     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
220 
221 #define PRAGMA_REENABLE_PACKED_WARNING          \
222     _Pragma("GCC diagnostic pop")
223 
224 #else
225 #define PRAGMA_DISABLE_PACKED_WARNING
226 #define PRAGMA_REENABLE_PACKED_WARNING
227 #endif
228 
229 #define __put_user_e(x, hptr, e)                                            \
230     do {                                                                    \
231         PRAGMA_DISABLE_PACKED_WARNING;                                      \
232         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
233         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
234         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
235         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
236             ((hptr), (x)), (void)0);                                        \
237         PRAGMA_REENABLE_PACKED_WARNING;                                     \
238     } while (0)
239 
240 #define __get_user_e(x, hptr, e)                                            \
241     do {                                                                    \
242         PRAGMA_DISABLE_PACKED_WARNING;                                      \
243         ((x) = (typeof(*hptr))(                                             \
244         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
245         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
246         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
247         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
248             (hptr)), (void)0);                                              \
249         PRAGMA_REENABLE_PACKED_WARNING;                                     \
250     } while (0)
251 
252 
253 #if TARGET_BIG_ENDIAN
254 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
255 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
256 #else
257 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
258 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
259 #endif
260 
261 /* put_user()/get_user() take a guest address and check access */
262 /* These are usually used to access an atomic data type, such as an int,
263  * that has been passed by address.  These internally perform locking
264  * and unlocking on the data type.
265  */
266 #define put_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_WRITE, __gaddr, sizeof(target_type), 0))) { \
272         __put_user((x), __hptr);				\
273         unlock_user(__hptr, __gaddr, sizeof(target_type));		\
274     } else								\
275         __ret = -TARGET_EFAULT;						\
276     __ret;								\
277 })
278 
279 #define get_user(x, gaddr, target_type)					\
280 ({									\
281     abi_ulong __gaddr = (gaddr);					\
282     target_type *__hptr;						\
283     abi_long __ret = 0;							\
284     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
285         __get_user((x), __hptr);				\
286         unlock_user(__hptr, __gaddr, 0);				\
287     } else {								\
288         /* avoid warning */						\
289         (x) = 0;							\
290         __ret = -TARGET_EFAULT;						\
291     }									\
292     __ret;								\
293 })
294 
295 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
296 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
297 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
298 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
299 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
300 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
301 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
302 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
303 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
304 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
305 
306 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
307 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
308 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
309 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
310 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
311 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
312 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
313 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
314 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
315 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
316 
317 /* copy_from_user() and copy_to_user() are usually used to copy data
318  * buffers between the target and host.  These internally perform
319  * locking/unlocking of the memory.
320  */
321 int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
322 int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
323 
324 /*
325  * copy_struct_from_user() copies a target struct to a host struct, in
326  * a way that guarantees backwards-compatibility for struct syscall
327  * arguments.
328  *
329  * Similar to kernels uaccess.h:copy_struct_from_user()
330  */
331 int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize);
332 
333 /* Functions for accessing guest memory.  The tget and tput functions
334    read/write single values, byteswapping as necessary.  The lock_user function
335    gets a pointer to a contiguous area of guest memory, but does not perform
336    any byteswapping.  lock_user may return either a pointer to the guest
337    memory, or a temporary buffer.  */
338 
339 /* Lock an area of guest memory into the host.  If copy is true then the
340    host area will have the same contents as the guest.  */
341 void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
342 
343 /* Unlock an area of guest memory.  The first LEN bytes must be
344    flushed back to guest memory. host_ptr = NULL is explicitly
345    allowed and does nothing. */
346 #ifndef CONFIG_DEBUG_REMAP
347 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
348                                ssize_t len)
349 {
350     /* no-op */
351 }
352 #else
353 void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
354 #endif
355 
356 /* Return the length of a string in target memory or -TARGET_EFAULT if
357    access error. */
358 ssize_t target_strlen(abi_ulong gaddr);
359 
360 /* Like lock_user but for null terminated strings.  */
361 void *lock_user_string(abi_ulong guest_addr);
362 
363 /* Helper macros for locking/unlocking a target struct.  */
364 #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
365     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
366 #define unlock_user_struct(host_ptr, guest_addr, copy)		\
367     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
368 
369 /* Clone cpu state */
370 CPUArchState *cpu_copy(CPUArchState *env);
371 
372 void init_main_thread(CPUState *cs, struct image_info *info);
373 
374 #endif /* QEMU_H */
375