Commit | Line | Data |
---|---|---|
60d339f6 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) |
3 | * Licensed under the GPL | |
4 | */ | |
5 | ||
8e367065 | 6 | #include <pty.h> |
1da177e4 | 7 | #include <stdio.h> |
0f80bc85 JD |
8 | #include <stddef.h> |
9 | #include <stdarg.h> | |
10 | #include <stdlib.h> | |
11 | #include <string.h> | |
1da177e4 LT |
12 | #include <unistd.h> |
13 | #include <signal.h> | |
14 | #include <sched.h> | |
0f80bc85 | 15 | #include <fcntl.h> |
1da177e4 | 16 | #include <errno.h> |
1da177e4 LT |
17 | #include <sys/time.h> |
18 | #include <sys/wait.h> | |
19 | #include <sys/mman.h> | |
20 | #include <asm/unistd.h> | |
21 | #include <asm/page.h> | |
0f80bc85 | 22 | #include <sys/types.h> |
1da177e4 LT |
23 | #include "user_util.h" |
24 | #include "kern_util.h" | |
25 | #include "user.h" | |
1da177e4 | 26 | #include "signal_kern.h" |
1da177e4 LT |
27 | #include "sysdep/ptrace.h" |
28 | #include "sysdep/sigcontext.h" | |
29 | #include "irq_user.h" | |
30 | #include "ptrace_user.h" | |
0f80bc85 | 31 | #include "mem_user.h" |
1da177e4 LT |
32 | #include "init.h" |
33 | #include "os.h" | |
34 | #include "uml-config.h" | |
1da177e4 LT |
35 | #include "choose-mode.h" |
36 | #include "mode.h" | |
d67b569f | 37 | #include "tempfile.h" |
0f80bc85 JD |
38 | #include "kern_constants.h" |
39 | ||
1da177e4 LT |
40 | #ifdef UML_CONFIG_MODE_SKAS |
41 | #include "skas.h" | |
42 | #include "skas_ptrace.h" | |
43 | #include "registers.h" | |
44 | #endif | |
45 | ||
b85e9680 | 46 | static int ptrace_child(void *arg) |
1da177e4 LT |
47 | { |
48 | int ret; | |
49 | int pid = os_getpid(), ppid = getppid(); | |
50 | int sc_result; | |
51 | ||
43b00fdb | 52 | change_sig(SIGWINCH, 0); |
1da177e4 LT |
53 | if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){ |
54 | perror("ptrace"); | |
55 | os_kill_process(pid, 0); | |
56 | } | |
57 | os_stop_process(pid); | |
58 | ||
59 | /*This syscall will be intercepted by the parent. Don't call more than | |
60 | * once, please.*/ | |
61 | sc_result = os_getpid(); | |
62 | ||
63 | if (sc_result == pid) | |
64 | ret = 1; /*Nothing modified by the parent, we are running | |
65 | normally.*/ | |
66 | else if (sc_result == ppid) | |
67 | ret = 0; /*Expected in check_ptrace and check_sysemu when they | |
68 | succeed in modifying the stack frame*/ | |
69 | else | |
70 | ret = 2; /*Serious trouble! This could be caused by a bug in | |
71 | host 2.6 SKAS3/2.6 patch before release -V6, together | |
72 | with a bug in the UML code itself.*/ | |
73 | _exit(ret); | |
74 | } | |
75 | ||
b85e9680 | 76 | static int start_ptraced_child(void **stack_out) |
1da177e4 | 77 | { |
b85e9680 JD |
78 | void *stack; |
79 | unsigned long sp; | |
1da177e4 | 80 | int pid, n, status; |
60d339f6 | 81 | |
b85e9680 JD |
82 | stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, |
83 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
84 | if(stack == MAP_FAILED) | |
85 | panic("check_ptrace : mmap failed, errno = %d", errno); | |
86 | sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); | |
87 | pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); | |
1da177e4 | 88 | if(pid < 0) |
60d339f6 | 89 | panic("start_ptraced_child : clone failed, errno = %d", errno); |
1da177e4 LT |
90 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); |
91 | if(n < 0) | |
60d339f6 | 92 | panic("check_ptrace : clone failed, errno = %d", errno); |
1da177e4 LT |
93 | if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) |
94 | panic("check_ptrace : expected SIGSTOP, got status = %d", | |
95 | status); | |
96 | ||
b85e9680 | 97 | *stack_out = stack; |
1da177e4 LT |
98 | return(pid); |
99 | } | |
100 | ||
60d339f6 GS |
101 | /* When testing for SYSEMU support, if it is one of the broken versions, we |
102 | * must just avoid using sysemu, not panic, but only if SYSEMU features are | |
103 | * broken. | |
1da177e4 | 104 | * So only for SYSEMU features we test mustpanic, while normal host features |
60d339f6 GS |
105 | * must work anyway! |
106 | */ | |
107 | static int stop_ptraced_child(int pid, void *stack, int exitcode, | |
108 | int mustpanic) | |
1da177e4 LT |
109 | { |
110 | int status, n, ret = 0; | |
111 | ||
112 | if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) | |
b85e9680 | 113 | panic("check_ptrace : ptrace failed, errno = %d", errno); |
1da177e4 LT |
114 | CATCH_EINTR(n = waitpid(pid, &status, 0)); |
115 | if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { | |
116 | int exit_with = WEXITSTATUS(status); | |
117 | if (exit_with == 2) | |
51694948 | 118 | printf("check_ptrace : child exited with status 2. " |
1da177e4 LT |
119 | "Serious trouble happening! Try updating your " |
120 | "host skas patch!\nDisabling SYSEMU support."); | |
51694948 | 121 | printf("check_ptrace : child exited with exitcode %d, while " |
1da177e4 LT |
122 | "expecting %d; status 0x%x", exit_with, |
123 | exitcode, status); | |
b85e9680 | 124 | if (mustpanic) |
1da177e4 LT |
125 | panic("\n"); |
126 | else | |
51694948 | 127 | printf("\n"); |
1da177e4 LT |
128 | ret = -1; |
129 | } | |
130 | ||
b85e9680 JD |
131 | if(munmap(stack, PAGE_SIZE) < 0) |
132 | panic("check_ptrace : munmap failed, errno = %d", errno); | |
1da177e4 LT |
133 | return ret; |
134 | } | |
135 | ||
cb66504d | 136 | int ptrace_faultinfo = 1; |
858259cf | 137 | int ptrace_ldt = 1; |
cb66504d | 138 | int proc_mm = 1; |
858259cf | 139 | int skas_needs_stub = 0; |
cb66504d PBG |
140 | |
141 | static int __init skas0_cmd_param(char *str, int* add) | |
142 | { | |
143 | ptrace_faultinfo = proc_mm = 0; | |
144 | return 0; | |
145 | } | |
146 | ||
9e3d862e PBG |
147 | /* The two __uml_setup would conflict, without this stupid alias. */ |
148 | ||
149 | static int __init mode_skas0_cmd_param(char *str, int* add) | |
150 | __attribute__((alias("skas0_cmd_param"))); | |
151 | ||
60d339f6 GS |
152 | __uml_setup("skas0", skas0_cmd_param, |
153 | "skas0\n" | |
154 | " Disables SKAS3 usage, so that SKAS0 is used, unless \n" | |
155 | " you specify mode=tt.\n\n"); | |
156 | ||
9e3d862e PBG |
157 | __uml_setup("mode=skas0", mode_skas0_cmd_param, |
158 | "mode=skas0\n" | |
159 | " Disables SKAS3 usage, so that SKAS0 is used, unless you \n" | |
160 | " specify mode=tt. Note that this was recently added - on \n" | |
161 | " older kernels you must use simply \"skas0\".\n\n"); | |
162 | ||
60d339f6 GS |
163 | static int force_sysemu_disabled = 0; |
164 | ||
1da177e4 LT |
165 | static int __init nosysemu_cmd_param(char *str, int* add) |
166 | { | |
167 | force_sysemu_disabled = 1; | |
168 | return 0; | |
169 | } | |
170 | ||
171 | __uml_setup("nosysemu", nosysemu_cmd_param, | |
60d339f6 GS |
172 | "nosysemu\n" |
173 | " Turns off syscall emulation patch for ptrace (SYSEMU) on.\n" | |
174 | " SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" | |
175 | " behaviour of ptrace() and helps reducing host context switch rate.\n" | |
176 | " To make it working, you need a kernel patch for your host, too.\n" | |
177 | " See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n" | |
178 | " information.\n\n"); | |
1da177e4 LT |
179 | |
180 | static void __init check_sysemu(void) | |
181 | { | |
b85e9680 | 182 | void *stack; |
f9dfefe4 | 183 | int pid, n, status, count=0; |
1da177e4 | 184 | |
51694948 | 185 | printf("Checking syscall emulation patch for ptrace..."); |
1da177e4 | 186 | sysemu_supported = 0; |
b85e9680 | 187 | pid = start_ptraced_child(&stack); |
1da177e4 LT |
188 | |
189 | if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) | |
190 | goto fail; | |
191 | ||
192 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
193 | if (n < 0) | |
194 | panic("check_sysemu : wait failed, errno = %d", errno); | |
195 | if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) | |
196 | panic("check_sysemu : expected SIGTRAP, " | |
197 | "got status = %d", status); | |
198 | ||
199 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, | |
200 | os_getpid()); | |
201 | if(n < 0) | |
202 | panic("check_sysemu : failed to modify system " | |
203 | "call return, errno = %d", errno); | |
204 | ||
b85e9680 | 205 | if (stop_ptraced_child(pid, stack, 0, 0) < 0) |
1da177e4 LT |
206 | goto fail_stopped; |
207 | ||
208 | sysemu_supported = 1; | |
51694948 | 209 | printf("OK\n"); |
1da177e4 LT |
210 | set_using_sysemu(!force_sysemu_disabled); |
211 | ||
51694948 | 212 | printf("Checking advanced syscall emulation patch for ptrace..."); |
b85e9680 | 213 | pid = start_ptraced_child(&stack); |
f9dfefe4 BS |
214 | |
215 | if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, | |
216 | (void *) PTRACE_O_TRACESYSGOOD) < 0) | |
217 | panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", | |
218 | errno); | |
219 | ||
1da177e4 LT |
220 | while(1){ |
221 | count++; | |
222 | if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) | |
223 | goto fail; | |
224 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
225 | if(n < 0) | |
226 | panic("check_ptrace : wait failed, errno = %d", errno); | |
f9dfefe4 | 227 | if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){ |
1da177e4 | 228 | if (!count) |
f9dfefe4 BS |
229 | panic("check_ptrace : SYSEMU_SINGLESTEP " |
230 | "doesn't singlestep"); | |
1da177e4 LT |
231 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, |
232 | os_getpid()); | |
233 | if(n < 0) | |
234 | panic("check_sysemu : failed to modify system " | |
235 | "call return, errno = %d", errno); | |
236 | break; | |
237 | } | |
f9dfefe4 BS |
238 | else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP)) |
239 | count++; | |
240 | else | |
241 | panic("check_ptrace : expected SIGTRAP or " | |
242 | "(SIGTRAP|0x80), got status = %d", status); | |
1da177e4 | 243 | } |
b85e9680 | 244 | if (stop_ptraced_child(pid, stack, 0, 0) < 0) |
1da177e4 LT |
245 | goto fail_stopped; |
246 | ||
247 | sysemu_supported = 2; | |
51694948 | 248 | printf("OK\n"); |
1da177e4 LT |
249 | |
250 | if ( !force_sysemu_disabled ) | |
251 | set_using_sysemu(sysemu_supported); | |
252 | return; | |
253 | ||
254 | fail: | |
b85e9680 | 255 | stop_ptraced_child(pid, stack, 1, 0); |
1da177e4 | 256 | fail_stopped: |
51694948 | 257 | printf("missing\n"); |
1da177e4 LT |
258 | } |
259 | ||
60d339f6 | 260 | static void __init check_ptrace(void) |
1da177e4 | 261 | { |
b85e9680 | 262 | void *stack; |
1da177e4 LT |
263 | int pid, syscall, n, status; |
264 | ||
51694948 | 265 | printf("Checking that ptrace can change system call numbers..."); |
b85e9680 | 266 | pid = start_ptraced_child(&stack); |
1da177e4 | 267 | |
60d339f6 GS |
268 | if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) |
269 | panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno); | |
1da177e4 LT |
270 | |
271 | while(1){ | |
272 | if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) | |
60d339f6 | 273 | panic("check_ptrace : ptrace failed, errno = %d", |
1da177e4 LT |
274 | errno); |
275 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
276 | if(n < 0) | |
277 | panic("check_ptrace : wait failed, errno = %d", errno); | |
f9dfefe4 BS |
278 | if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80))) |
279 | panic("check_ptrace : expected (SIGTRAP|0x80), " | |
1da177e4 | 280 | "got status = %d", status); |
60d339f6 | 281 | |
1da177e4 LT |
282 | syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, |
283 | 0); | |
284 | if(syscall == __NR_getpid){ | |
285 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, | |
286 | __NR_getppid); | |
287 | if(n < 0) | |
288 | panic("check_ptrace : failed to modify system " | |
289 | "call, errno = %d", errno); | |
290 | break; | |
291 | } | |
292 | } | |
b85e9680 | 293 | stop_ptraced_child(pid, stack, 0, 1); |
51694948 | 294 | printf("OK\n"); |
1da177e4 LT |
295 | check_sysemu(); |
296 | } | |
297 | ||
966a082f | 298 | extern void check_tmpexec(void); |
0f80bc85 | 299 | |
60d339f6 | 300 | void os_early_checks(void) |
1da177e4 | 301 | { |
60d339f6 | 302 | check_ptrace(); |
0f80bc85 JD |
303 | |
304 | /* Need to check this early because mmapping happens before the | |
305 | * kernel is running. | |
306 | */ | |
307 | check_tmpexec(); | |
1da177e4 LT |
308 | } |
309 | ||
d9838d86 BS |
310 | static int __init noprocmm_cmd_param(char *str, int* add) |
311 | { | |
312 | proc_mm = 0; | |
313 | return 0; | |
314 | } | |
315 | ||
316 | __uml_setup("noprocmm", noprocmm_cmd_param, | |
317 | "noprocmm\n" | |
318 | " Turns off usage of /proc/mm, even if host supports it.\n" | |
319 | " To support /proc/mm, the host needs to be patched using\n" | |
320 | " the current skas3 patch.\n\n"); | |
321 | ||
322 | static int __init noptracefaultinfo_cmd_param(char *str, int* add) | |
323 | { | |
324 | ptrace_faultinfo = 0; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param, | |
329 | "noptracefaultinfo\n" | |
330 | " Turns off usage of PTRACE_FAULTINFO, even if host supports\n" | |
331 | " it. To support PTRACE_FAULTINFO, the host needs to be patched\n" | |
332 | " using the current skas3 patch.\n\n"); | |
333 | ||
858259cf BS |
334 | static int __init noptraceldt_cmd_param(char *str, int* add) |
335 | { | |
336 | ptrace_ldt = 0; | |
337 | return 0; | |
338 | } | |
339 | ||
340 | __uml_setup("noptraceldt", noptraceldt_cmd_param, | |
341 | "noptraceldt\n" | |
342 | " Turns off usage of PTRACE_LDT, even if host supports it.\n" | |
343 | " To support PTRACE_LDT, the host needs to be patched using\n" | |
344 | " the current skas3 patch.\n\n"); | |
345 | ||
1da177e4 | 346 | #ifdef UML_CONFIG_MODE_SKAS |
858259cf | 347 | static inline void check_skas3_ptrace_faultinfo(void) |
1da177e4 LT |
348 | { |
349 | struct ptrace_faultinfo fi; | |
b85e9680 | 350 | void *stack; |
d67b569f | 351 | int pid, n; |
1da177e4 | 352 | |
858259cf | 353 | printf(" - PTRACE_FAULTINFO..."); |
b85e9680 | 354 | pid = start_ptraced_child(&stack); |
1da177e4 LT |
355 | |
356 | n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); | |
357 | if (n < 0) { | |
cb66504d | 358 | ptrace_faultinfo = 0; |
1da177e4 LT |
359 | if(errno == EIO) |
360 | printf("not found\n"); | |
60d339f6 | 361 | else |
1da177e4 | 362 | perror("not found"); |
d67b569f JD |
363 | } |
364 | else { | |
cb66504d PBG |
365 | if (!ptrace_faultinfo) |
366 | printf("found but disabled on command line\n"); | |
367 | else | |
368 | printf("found\n"); | |
1da177e4 LT |
369 | } |
370 | ||
371 | init_registers(pid); | |
b85e9680 | 372 | stop_ptraced_child(pid, stack, 1, 1); |
1da177e4 LT |
373 | } |
374 | ||
858259cf BS |
375 | static inline void check_skas3_ptrace_ldt(void) |
376 | { | |
377 | #ifdef PTRACE_LDT | |
378 | void *stack; | |
379 | int pid, n; | |
380 | unsigned char ldtbuf[40]; | |
381 | struct ptrace_ldt ldt_op = (struct ptrace_ldt) { | |
382 | .func = 2, /* read default ldt */ | |
383 | .ptr = ldtbuf, | |
384 | .bytecount = sizeof(ldtbuf)}; | |
385 | ||
386 | printf(" - PTRACE_LDT..."); | |
387 | pid = start_ptraced_child(&stack); | |
388 | ||
389 | n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op); | |
390 | if (n < 0) { | |
391 | if(errno == EIO) | |
392 | printf("not found\n"); | |
393 | else { | |
394 | perror("not found"); | |
395 | } | |
396 | ptrace_ldt = 0; | |
397 | } | |
398 | else { | |
399 | if(ptrace_ldt) | |
400 | printf("found\n"); | |
401 | else | |
402 | printf("found, but use is disabled\n"); | |
403 | } | |
404 | ||
405 | stop_ptraced_child(pid, stack, 1, 1); | |
406 | #else | |
407 | /* PTRACE_LDT might be disabled via cmdline option. | |
408 | * We want to override this, else we might use the stub | |
409 | * without real need | |
410 | */ | |
411 | ptrace_ldt = 1; | |
412 | #endif | |
413 | } | |
414 | ||
415 | static inline void check_skas3_proc_mm(void) | |
1da177e4 | 416 | { |
858259cf | 417 | printf(" - /proc/mm..."); |
1da177e4 | 418 | if (os_access("/proc/mm", OS_ACC_W_OK) < 0) { |
60d339f6 | 419 | proc_mm = 0; |
1da177e4 | 420 | printf("not found\n"); |
60d339f6 GS |
421 | } |
422 | else { | |
cb66504d PBG |
423 | if (!proc_mm) |
424 | printf("found but disabled on command line\n"); | |
425 | else | |
426 | printf("found\n"); | |
1da177e4 | 427 | } |
858259cf BS |
428 | } |
429 | ||
430 | int can_do_skas(void) | |
431 | { | |
432 | printf("Checking for the skas3 patch in the host:\n"); | |
433 | ||
434 | check_skas3_proc_mm(); | |
435 | check_skas3_ptrace_faultinfo(); | |
436 | check_skas3_ptrace_ldt(); | |
437 | ||
438 | if(!proc_mm || !ptrace_faultinfo || !ptrace_ldt) | |
439 | skas_needs_stub = 1; | |
1da177e4 | 440 | |
d67b569f | 441 | return 1; |
1da177e4 LT |
442 | } |
443 | #else | |
444 | int can_do_skas(void) | |
445 | { | |
446 | return(0); | |
447 | } | |
448 | #endif | |
0f80bc85 | 449 | |
0f80bc85 JD |
450 | int __init parse_iomem(char *str, int *add) |
451 | { | |
452 | struct iomem_region *new; | |
453 | struct uml_stat buf; | |
454 | char *file, *driver; | |
455 | int fd, err, size; | |
456 | ||
457 | driver = str; | |
458 | file = strchr(str,','); | |
459 | if(file == NULL){ | |
460 | printf("parse_iomem : failed to parse iomem\n"); | |
461 | goto out; | |
462 | } | |
463 | *file = '\0'; | |
464 | file++; | |
465 | fd = os_open_file(file, of_rdwr(OPENFLAGS()), 0); | |
466 | if(fd < 0){ | |
467 | os_print_error(fd, "parse_iomem - Couldn't open io file"); | |
468 | goto out; | |
469 | } | |
470 | ||
471 | err = os_stat_fd(fd, &buf); | |
472 | if(err < 0){ | |
473 | os_print_error(err, "parse_iomem - cannot stat_fd file"); | |
474 | goto out_close; | |
475 | } | |
476 | ||
477 | new = malloc(sizeof(*new)); | |
478 | if(new == NULL){ | |
479 | perror("Couldn't allocate iomem_region struct"); | |
480 | goto out_close; | |
481 | } | |
482 | ||
483 | size = (buf.ust_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1); | |
484 | ||
485 | *new = ((struct iomem_region) { .next = iomem_regions, | |
486 | .driver = driver, | |
487 | .fd = fd, | |
488 | .size = size, | |
489 | .phys = 0, | |
490 | .virt = 0 }); | |
491 | iomem_regions = new; | |
492 | iomem_size += new->size + UM_KERN_PAGE_SIZE; | |
493 | ||
494 | return(0); | |
495 | out_close: | |
496 | os_close_file(fd); | |
497 | out: | |
498 | return(1); | |
499 | } | |
500 | ||
8e367065 JD |
501 | |
502 | /* Changed during early boot */ | |
503 | int pty_output_sigio = 0; | |
504 | int pty_close_sigio = 0; | |
505 | ||
506 | /* Used as a flag during SIGIO testing early in boot */ | |
507 | static volatile int got_sigio = 0; | |
508 | ||
509 | static void __init handler(int sig) | |
510 | { | |
511 | got_sigio = 1; | |
512 | } | |
513 | ||
514 | struct openpty_arg { | |
515 | int master; | |
516 | int slave; | |
517 | int err; | |
518 | }; | |
519 | ||
520 | static void openpty_cb(void *arg) | |
521 | { | |
522 | struct openpty_arg *info = arg; | |
523 | ||
524 | info->err = 0; | |
525 | if(openpty(&info->master, &info->slave, NULL, NULL, NULL)) | |
526 | info->err = -errno; | |
527 | } | |
528 | ||
529 | static void __init check_one_sigio(void (*proc)(int, int)) | |
530 | { | |
531 | struct sigaction old, new; | |
532 | struct openpty_arg pty = { .master = -1, .slave = -1 }; | |
533 | int master, slave, err; | |
534 | ||
535 | initial_thread_cb(openpty_cb, &pty); | |
536 | if(pty.err){ | |
537 | printk("openpty failed, errno = %d\n", -pty.err); | |
538 | return; | |
539 | } | |
540 | ||
541 | master = pty.master; | |
542 | slave = pty.slave; | |
543 | ||
544 | if((master == -1) || (slave == -1)){ | |
545 | printk("openpty failed to allocate a pty\n"); | |
546 | return; | |
547 | } | |
548 | ||
549 | /* Not now, but complain so we now where we failed. */ | |
550 | err = raw(master); | |
551 | if (err < 0) | |
552 | panic("check_sigio : __raw failed, errno = %d\n", -err); | |
553 | ||
554 | err = os_sigio_async(master, slave); | |
555 | if(err < 0) | |
556 | panic("tty_fds : sigio_async failed, err = %d\n", -err); | |
557 | ||
558 | if(sigaction(SIGIO, NULL, &old) < 0) | |
559 | panic("check_sigio : sigaction 1 failed, errno = %d\n", errno); | |
560 | new = old; | |
561 | new.sa_handler = handler; | |
562 | if(sigaction(SIGIO, &new, NULL) < 0) | |
563 | panic("check_sigio : sigaction 2 failed, errno = %d\n", errno); | |
564 | ||
565 | got_sigio = 0; | |
566 | (*proc)(master, slave); | |
567 | ||
568 | close(master); | |
569 | close(slave); | |
570 | ||
571 | if(sigaction(SIGIO, &old, NULL) < 0) | |
572 | panic("check_sigio : sigaction 3 failed, errno = %d\n", errno); | |
573 | } | |
574 | ||
575 | static void tty_output(int master, int slave) | |
576 | { | |
577 | int n; | |
578 | char buf[512]; | |
579 | ||
580 | printk("Checking that host ptys support output SIGIO..."); | |
581 | ||
582 | memset(buf, 0, sizeof(buf)); | |
583 | ||
584 | while(os_write_file(master, buf, sizeof(buf)) > 0) ; | |
585 | if(errno != EAGAIN) | |
586 | panic("check_sigio : write failed, errno = %d\n", errno); | |
587 | while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ; | |
588 | ||
589 | if(got_sigio){ | |
590 | printk("Yes\n"); | |
591 | pty_output_sigio = 1; | |
592 | } | |
593 | else if(n == -EAGAIN) printk("No, enabling workaround\n"); | |
594 | else panic("check_sigio : read failed, err = %d\n", n); | |
595 | } | |
596 | ||
597 | static void tty_close(int master, int slave) | |
598 | { | |
599 | printk("Checking that host ptys support SIGIO on close..."); | |
600 | ||
601 | close(slave); | |
602 | if(got_sigio){ | |
603 | printk("Yes\n"); | |
604 | pty_close_sigio = 1; | |
605 | } | |
606 | else printk("No, enabling workaround\n"); | |
607 | } | |
608 | ||
609 | void __init check_sigio(void) | |
610 | { | |
611 | if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) && | |
612 | (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){ | |
613 | printk("No pseudo-terminals available - skipping pty SIGIO " | |
614 | "check\n"); | |
615 | return; | |
616 | } | |
617 | check_one_sigio(tty_output); | |
618 | check_one_sigio(tty_close); | |
619 | } | |
620 | ||
621 | void os_check_bugs(void) | |
622 | { | |
623 | check_ptrace(); | |
624 | check_sigio(); | |
8e367065 JD |
625 | } |
626 |