xref: /openbmc/qemu/target/mips/tcg/sysemu/mips-semi.c (revision 3cc72cdb)
1 /*
2  * Unified Hosting Interface syscalls.
3  *
4  * Copyright (c) 2015 Imagination Technologies
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "qemu/log.h"
23 #include "gdbstub/syscalls.h"
24 #include "gdbstub/helpers.h"
25 #include "semihosting/uaccess.h"
26 #include "semihosting/semihost.h"
27 #include "semihosting/console.h"
28 #include "semihosting/syscalls.h"
29 #include "internal.h"
30 
31 typedef enum UHIOp {
32     UHI_exit = 1,
33     UHI_open = 2,
34     UHI_close = 3,
35     UHI_read = 4,
36     UHI_write = 5,
37     UHI_lseek = 6,
38     UHI_unlink = 7,
39     UHI_fstat = 8,
40     UHI_argc = 9,
41     UHI_argnlen = 10,
42     UHI_argn = 11,
43     UHI_plog = 13,
44     UHI_assert = 14,
45     UHI_pread = 19,
46     UHI_pwrite = 20,
47     UHI_link = 22
48 } UHIOp;
49 
50 typedef struct UHIStat {
51     int16_t uhi_st_dev;
52     uint16_t uhi_st_ino;
53     uint32_t uhi_st_mode;
54     uint16_t uhi_st_nlink;
55     uint16_t uhi_st_uid;
56     uint16_t uhi_st_gid;
57     int16_t uhi_st_rdev;
58     uint64_t uhi_st_size;
59     uint64_t uhi_st_atime;
60     uint64_t uhi_st_spare1;
61     uint64_t uhi_st_mtime;
62     uint64_t uhi_st_spare2;
63     uint64_t uhi_st_ctime;
64     uint64_t uhi_st_spare3;
65     uint64_t uhi_st_blksize;
66     uint64_t uhi_st_blocks;
67     uint64_t uhi_st_spare4[2];
68 } UHIStat;
69 
70 enum UHIOpenFlags {
71     UHIOpen_RDONLY = 0x0,
72     UHIOpen_WRONLY = 0x1,
73     UHIOpen_RDWR   = 0x2,
74     UHIOpen_APPEND = 0x8,
75     UHIOpen_CREAT  = 0x200,
76     UHIOpen_TRUNC  = 0x400,
77     UHIOpen_EXCL   = 0x800
78 };
79 
80 enum UHIErrno {
81     UHI_EACCESS         = 13,
82     UHI_EAGAIN          = 11,
83     UHI_EBADF           = 9,
84     UHI_EBADMSG         = 77,
85     UHI_EBUSY           = 16,
86     UHI_ECONNRESET      = 104,
87     UHI_EEXIST          = 17,
88     UHI_EFBIG           = 27,
89     UHI_EINTR           = 4,
90     UHI_EINVAL          = 22,
91     UHI_EIO             = 5,
92     UHI_EISDIR          = 21,
93     UHI_ELOOP           = 92,
94     UHI_EMFILE          = 24,
95     UHI_EMLINK          = 31,
96     UHI_ENAMETOOLONG    = 91,
97     UHI_ENETDOWN        = 115,
98     UHI_ENETUNREACH     = 114,
99     UHI_ENFILE          = 23,
100     UHI_ENOBUFS         = 105,
101     UHI_ENOENT          = 2,
102     UHI_ENOMEM          = 12,
103     UHI_ENOSPC          = 28,
104     UHI_ENOSR           = 63,
105     UHI_ENOTCONN        = 128,
106     UHI_ENOTDIR         = 20,
107     UHI_ENXIO           = 6,
108     UHI_EOVERFLOW       = 139,
109     UHI_EPERM           = 1,
110     UHI_EPIPE           = 32,
111     UHI_ERANGE          = 34,
112     UHI_EROFS           = 30,
113     UHI_ESPIPE          = 29,
114     UHI_ETIMEDOUT       = 116,
115     UHI_ETXTBSY         = 26,
116     UHI_EWOULDBLOCK     = 11,
117     UHI_EXDEV           = 18,
118 };
119 
120 static void report_fault(CPUMIPSState *env)
121 {
122     int op = env->active_tc.gpr[25];
123     error_report("Fault during UHI operation %d", op);
124     abort();
125 }
126 
127 static void uhi_cb(CPUState *cs, uint64_t ret, int err)
128 {
129     CPUMIPSState *env = cpu_env(cs);
130 
131 #define E(N) case E##N: err = UHI_E##N; break
132 
133     switch (err) {
134     case 0:
135         break;
136     E(PERM);
137     E(NOENT);
138     E(INTR);
139     E(BADF);
140     E(BUSY);
141     E(EXIST);
142     E(NOTDIR);
143     E(ISDIR);
144     E(INVAL);
145     E(NFILE);
146     E(MFILE);
147     E(FBIG);
148     E(NOSPC);
149     E(SPIPE);
150     E(ROFS);
151     E(NAMETOOLONG);
152     default:
153         err = UHI_EINVAL;
154         break;
155     case EFAULT:
156         report_fault(env);
157     }
158 
159 #undef E
160 
161     env->active_tc.gpr[2] = ret;
162     env->active_tc.gpr[3] = err;
163 }
164 
165 static void uhi_fstat_cb(CPUState *cs, uint64_t ret, int err)
166 {
167     QEMU_BUILD_BUG_ON(sizeof(UHIStat) < sizeof(struct gdb_stat));
168 
169     if (!err) {
170         CPUMIPSState *env = cpu_env(cs);
171         target_ulong addr = env->active_tc.gpr[5];
172         UHIStat *dst = lock_user(VERIFY_WRITE, addr, sizeof(UHIStat), 1);
173         struct gdb_stat s;
174 
175         if (!dst) {
176             report_fault(env);
177         }
178 
179         memcpy(&s, dst, sizeof(struct gdb_stat));
180         memset(dst, 0, sizeof(UHIStat));
181 
182         dst->uhi_st_dev = tswap16(be32_to_cpu(s.gdb_st_dev));
183         dst->uhi_st_ino = tswap16(be32_to_cpu(s.gdb_st_ino));
184         dst->uhi_st_mode = tswap32(be32_to_cpu(s.gdb_st_mode));
185         dst->uhi_st_nlink = tswap16(be32_to_cpu(s.gdb_st_nlink));
186         dst->uhi_st_uid = tswap16(be32_to_cpu(s.gdb_st_uid));
187         dst->uhi_st_gid = tswap16(be32_to_cpu(s.gdb_st_gid));
188         dst->uhi_st_rdev = tswap16(be32_to_cpu(s.gdb_st_rdev));
189         dst->uhi_st_size = tswap64(be64_to_cpu(s.gdb_st_size));
190         dst->uhi_st_atime = tswap64(be32_to_cpu(s.gdb_st_atime));
191         dst->uhi_st_mtime = tswap64(be32_to_cpu(s.gdb_st_mtime));
192         dst->uhi_st_ctime = tswap64(be32_to_cpu(s.gdb_st_ctime));
193         dst->uhi_st_blksize = tswap64(be64_to_cpu(s.gdb_st_blksize));
194         dst->uhi_st_blocks = tswap64(be64_to_cpu(s.gdb_st_blocks));
195 
196         unlock_user(dst, addr, sizeof(UHIStat));
197     }
198 
199     uhi_cb(cs, ret, err);
200 }
201 
202 void mips_semihosting(CPUMIPSState *env)
203 {
204     CPUState *cs = env_cpu(env);
205     target_ulong *gpr = env->active_tc.gpr;
206     const UHIOp op = gpr[25];
207     char *p;
208 
209     switch (op) {
210     case UHI_exit:
211         gdb_exit(gpr[4]);
212         exit(gpr[4]);
213 
214     case UHI_open:
215         {
216             target_ulong fname = gpr[4];
217             int ret = -1;
218 
219             p = lock_user_string(fname);
220             if (!p) {
221                 report_fault(env);
222             }
223             if (!strcmp("/dev/stdin", p)) {
224                 ret = 0;
225             } else if (!strcmp("/dev/stdout", p)) {
226                 ret = 1;
227             } else if (!strcmp("/dev/stderr", p)) {
228                 ret = 2;
229             }
230             unlock_user(p, fname, 0);
231 
232             /* FIXME: reusing a guest fd doesn't seem correct. */
233             if (ret >= 0) {
234                 gpr[2] = ret;
235                 break;
236             }
237 
238             semihost_sys_open(cs, uhi_cb, fname, 0, gpr[5], gpr[6]);
239         }
240         break;
241 
242     case UHI_close:
243         semihost_sys_close(cs, uhi_cb, gpr[4]);
244         break;
245     case UHI_read:
246         semihost_sys_read(cs, uhi_cb, gpr[4], gpr[5], gpr[6]);
247         break;
248     case UHI_write:
249         semihost_sys_write(cs, uhi_cb, gpr[4], gpr[5], gpr[6]);
250         break;
251     case UHI_lseek:
252         semihost_sys_lseek(cs, uhi_cb, gpr[4], gpr[5], gpr[6]);
253         break;
254     case UHI_unlink:
255         semihost_sys_remove(cs, uhi_cb, gpr[4], 0);
256         break;
257     case UHI_fstat:
258         semihost_sys_fstat(cs, uhi_fstat_cb, gpr[4], gpr[5]);
259         break;
260 
261     case UHI_argc:
262         gpr[2] = semihosting_get_argc();
263         break;
264     case UHI_argnlen:
265         {
266             const char *s = semihosting_get_arg(gpr[4]);
267             gpr[2] = s ? strlen(s) : -1;
268         }
269         break;
270     case UHI_argn:
271         {
272             const char *s = semihosting_get_arg(gpr[4]);
273             target_ulong addr;
274             size_t len;
275 
276             if (!s) {
277                 gpr[2] = -1;
278                 break;
279             }
280             len = strlen(s) + 1;
281             addr = gpr[5];
282             p = lock_user(VERIFY_WRITE, addr, len, 0);
283             if (!p) {
284                 report_fault(env);
285             }
286             memcpy(p, s, len);
287             unlock_user(p, addr, len);
288             gpr[2] = 0;
289         }
290         break;
291 
292     case UHI_plog:
293         {
294             target_ulong addr = gpr[4];
295             ssize_t len = target_strlen(addr);
296             GString *str;
297             char *pct_d;
298 
299             if (len < 0) {
300                 report_fault(env);
301             }
302             p = lock_user(VERIFY_READ, addr, len, 1);
303             if (!p) {
304                 report_fault(env);
305             }
306 
307             pct_d = strstr(p, "%d");
308             if (!pct_d) {
309                 unlock_user(p, addr, 0);
310                 semihost_sys_write(cs, uhi_cb, 2, addr, len);
311                 break;
312             }
313 
314             str = g_string_new_len(p, pct_d - p);
315             g_string_append_printf(str, "%d%s", (int)gpr[5], pct_d + 2);
316             unlock_user(p, addr, 0);
317 
318             /*
319              * When we're using gdb, we need a guest address, so
320              * drop the string onto the stack below the stack pointer.
321              */
322             if (use_gdb_syscalls()) {
323                 addr = gpr[29] - str->len;
324                 p = lock_user(VERIFY_WRITE, addr, str->len, 0);
325                 if (!p) {
326                     report_fault(env);
327                 }
328                 memcpy(p, str->str, str->len);
329                 unlock_user(p, addr, str->len);
330                 semihost_sys_write(cs, uhi_cb, 2, addr, str->len);
331             } else {
332                 gpr[2] = qemu_semihosting_console_write(str->str, str->len);
333             }
334             g_string_free(str, true);
335         }
336         break;
337 
338     case UHI_assert:
339         {
340             const char *msg, *file;
341 
342             msg = lock_user_string(gpr[4]);
343             if (!msg) {
344                 msg = "<EFAULT>";
345             }
346             file = lock_user_string(gpr[5]);
347             if (!file) {
348                 file = "<EFAULT>";
349             }
350 
351             error_report("UHI assertion \"%s\": file \"%s\", line %d",
352                          msg, file, (int)gpr[6]);
353             abort();
354         }
355 
356     default:
357         error_report("Unknown UHI operation %d", op);
358         abort();
359     }
360     return;
361 }
362