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 | } | |
73c8f444 | 57 | kill(pid, SIGSTOP); |
1da177e4 LT |
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; |
9eae9b13 | 98 | return pid; |
1da177e4 LT |
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 | ||
7242a400 | 136 | /* Changed only during early boot */ |
cb66504d | 137 | int ptrace_faultinfo = 1; |
858259cf | 138 | int ptrace_ldt = 1; |
cb66504d | 139 | int proc_mm = 1; |
858259cf | 140 | int skas_needs_stub = 0; |
cb66504d PBG |
141 | |
142 | static int __init skas0_cmd_param(char *str, int* add) | |
143 | { | |
144 | ptrace_faultinfo = proc_mm = 0; | |
145 | return 0; | |
146 | } | |
147 | ||
9e3d862e PBG |
148 | /* The two __uml_setup would conflict, without this stupid alias. */ |
149 | ||
150 | static int __init mode_skas0_cmd_param(char *str, int* add) | |
151 | __attribute__((alias("skas0_cmd_param"))); | |
152 | ||
60d339f6 GS |
153 | __uml_setup("skas0", skas0_cmd_param, |
154 | "skas0\n" | |
155 | " Disables SKAS3 usage, so that SKAS0 is used, unless \n" | |
156 | " you specify mode=tt.\n\n"); | |
157 | ||
9e3d862e PBG |
158 | __uml_setup("mode=skas0", mode_skas0_cmd_param, |
159 | "mode=skas0\n" | |
160 | " Disables SKAS3 usage, so that SKAS0 is used, unless you \n" | |
161 | " specify mode=tt. Note that this was recently added - on \n" | |
162 | " older kernels you must use simply \"skas0\".\n\n"); | |
163 | ||
7242a400 | 164 | /* Changed only during early boot */ |
60d339f6 GS |
165 | static int force_sysemu_disabled = 0; |
166 | ||
1da177e4 LT |
167 | static int __init nosysemu_cmd_param(char *str, int* add) |
168 | { | |
169 | force_sysemu_disabled = 1; | |
170 | return 0; | |
171 | } | |
172 | ||
173 | __uml_setup("nosysemu", nosysemu_cmd_param, | |
60d339f6 GS |
174 | "nosysemu\n" |
175 | " Turns off syscall emulation patch for ptrace (SYSEMU) on.\n" | |
176 | " SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" | |
177 | " behaviour of ptrace() and helps reducing host context switch rate.\n" | |
178 | " To make it working, you need a kernel patch for your host, too.\n" | |
179 | " See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n" | |
180 | " information.\n\n"); | |
1da177e4 LT |
181 | |
182 | static void __init check_sysemu(void) | |
183 | { | |
b85e9680 | 184 | void *stack; |
9eae9b13 | 185 | int pid, n, status, count=0; |
1da177e4 | 186 | |
51694948 | 187 | printf("Checking syscall emulation patch for ptrace..."); |
1da177e4 | 188 | sysemu_supported = 0; |
b85e9680 | 189 | pid = start_ptraced_child(&stack); |
1da177e4 LT |
190 | |
191 | if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) | |
192 | goto fail; | |
193 | ||
194 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
195 | if (n < 0) | |
196 | panic("check_sysemu : wait failed, errno = %d", errno); | |
197 | if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) | |
198 | panic("check_sysemu : expected SIGTRAP, " | |
199 | "got status = %d", status); | |
200 | ||
201 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, | |
202 | os_getpid()); | |
203 | if(n < 0) | |
204 | panic("check_sysemu : failed to modify system " | |
205 | "call return, errno = %d", errno); | |
206 | ||
b85e9680 | 207 | if (stop_ptraced_child(pid, stack, 0, 0) < 0) |
1da177e4 LT |
208 | goto fail_stopped; |
209 | ||
210 | sysemu_supported = 1; | |
51694948 | 211 | printf("OK\n"); |
1da177e4 LT |
212 | set_using_sysemu(!force_sysemu_disabled); |
213 | ||
51694948 | 214 | printf("Checking advanced syscall emulation patch for ptrace..."); |
b85e9680 | 215 | pid = start_ptraced_child(&stack); |
f9dfefe4 BS |
216 | |
217 | if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, | |
218 | (void *) PTRACE_O_TRACESYSGOOD) < 0) | |
219 | panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", | |
220 | errno); | |
221 | ||
1da177e4 LT |
222 | while(1){ |
223 | count++; | |
224 | if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) | |
225 | goto fail; | |
226 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
227 | if(n < 0) | |
228 | panic("check_ptrace : wait failed, errno = %d", errno); | |
f9dfefe4 | 229 | if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){ |
1da177e4 | 230 | if (!count) |
f9dfefe4 BS |
231 | panic("check_ptrace : SYSEMU_SINGLESTEP " |
232 | "doesn't singlestep"); | |
1da177e4 LT |
233 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, |
234 | os_getpid()); | |
235 | if(n < 0) | |
236 | panic("check_sysemu : failed to modify system " | |
237 | "call return, errno = %d", errno); | |
238 | break; | |
239 | } | |
f9dfefe4 BS |
240 | else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP)) |
241 | count++; | |
242 | else | |
243 | panic("check_ptrace : expected SIGTRAP or " | |
244 | "(SIGTRAP|0x80), got status = %d", status); | |
1da177e4 | 245 | } |
b85e9680 | 246 | if (stop_ptraced_child(pid, stack, 0, 0) < 0) |
1da177e4 LT |
247 | goto fail_stopped; |
248 | ||
249 | sysemu_supported = 2; | |
51694948 | 250 | printf("OK\n"); |
1da177e4 LT |
251 | |
252 | if ( !force_sysemu_disabled ) | |
253 | set_using_sysemu(sysemu_supported); | |
254 | return; | |
255 | ||
256 | fail: | |
b85e9680 | 257 | stop_ptraced_child(pid, stack, 1, 0); |
1da177e4 | 258 | fail_stopped: |
51694948 | 259 | printf("missing\n"); |
1da177e4 LT |
260 | } |
261 | ||
60d339f6 | 262 | static void __init check_ptrace(void) |
1da177e4 | 263 | { |
b85e9680 | 264 | void *stack; |
1da177e4 LT |
265 | int pid, syscall, n, status; |
266 | ||
51694948 | 267 | printf("Checking that ptrace can change system call numbers..."); |
b85e9680 | 268 | pid = start_ptraced_child(&stack); |
1da177e4 | 269 | |
60d339f6 GS |
270 | if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) |
271 | panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno); | |
1da177e4 LT |
272 | |
273 | while(1){ | |
274 | if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) | |
60d339f6 | 275 | panic("check_ptrace : ptrace failed, errno = %d", |
1da177e4 LT |
276 | errno); |
277 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); | |
278 | if(n < 0) | |
279 | panic("check_ptrace : wait failed, errno = %d", errno); | |
f9dfefe4 BS |
280 | if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80))) |
281 | panic("check_ptrace : expected (SIGTRAP|0x80), " | |
1da177e4 | 282 | "got status = %d", status); |
60d339f6 | 283 | |
1da177e4 LT |
284 | syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, |
285 | 0); | |
286 | if(syscall == __NR_getpid){ | |
287 | n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, | |
288 | __NR_getppid); | |
289 | if(n < 0) | |
290 | panic("check_ptrace : failed to modify system " | |
291 | "call, errno = %d", errno); | |
292 | break; | |
293 | } | |
294 | } | |
b85e9680 | 295 | stop_ptraced_child(pid, stack, 0, 1); |
51694948 | 296 | printf("OK\n"); |
1da177e4 LT |
297 | check_sysemu(); |
298 | } | |
299 | ||
966a082f | 300 | extern void check_tmpexec(void); |
0f80bc85 | 301 | |
60d339f6 | 302 | void os_early_checks(void) |
1da177e4 | 303 | { |
60d339f6 | 304 | check_ptrace(); |
0f80bc85 JD |
305 | |
306 | /* Need to check this early because mmapping happens before the | |
307 | * kernel is running. | |
308 | */ | |
309 | check_tmpexec(); | |
1da177e4 LT |
310 | } |
311 | ||
d9838d86 BS |
312 | static int __init noprocmm_cmd_param(char *str, int* add) |
313 | { | |
314 | proc_mm = 0; | |
315 | return 0; | |
316 | } | |
317 | ||
318 | __uml_setup("noprocmm", noprocmm_cmd_param, | |
319 | "noprocmm\n" | |
320 | " Turns off usage of /proc/mm, even if host supports it.\n" | |
321 | " To support /proc/mm, the host needs to be patched using\n" | |
322 | " the current skas3 patch.\n\n"); | |
323 | ||
324 | static int __init noptracefaultinfo_cmd_param(char *str, int* add) | |
325 | { | |
326 | ptrace_faultinfo = 0; | |
327 | return 0; | |
328 | } | |
329 | ||
330 | __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param, | |
331 | "noptracefaultinfo\n" | |
332 | " Turns off usage of PTRACE_FAULTINFO, even if host supports\n" | |
333 | " it. To support PTRACE_FAULTINFO, the host needs to be patched\n" | |
334 | " using the current skas3 patch.\n\n"); | |
335 | ||
858259cf BS |
336 | static int __init noptraceldt_cmd_param(char *str, int* add) |
337 | { | |
338 | ptrace_ldt = 0; | |
339 | return 0; | |
340 | } | |
341 | ||
342 | __uml_setup("noptraceldt", noptraceldt_cmd_param, | |
343 | "noptraceldt\n" | |
344 | " Turns off usage of PTRACE_LDT, even if host supports it.\n" | |
345 | " To support PTRACE_LDT, the host needs to be patched using\n" | |
346 | " the current skas3 patch.\n\n"); | |
347 | ||
1da177e4 | 348 | #ifdef UML_CONFIG_MODE_SKAS |
858259cf | 349 | static inline void check_skas3_ptrace_faultinfo(void) |
1da177e4 LT |
350 | { |
351 | struct ptrace_faultinfo fi; | |
b85e9680 | 352 | void *stack; |
d67b569f | 353 | int pid, n; |
1da177e4 | 354 | |
858259cf | 355 | printf(" - PTRACE_FAULTINFO..."); |
b85e9680 | 356 | pid = start_ptraced_child(&stack); |
1da177e4 LT |
357 | |
358 | n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); | |
359 | if (n < 0) { | |
cb66504d | 360 | ptrace_faultinfo = 0; |
1da177e4 LT |
361 | if(errno == EIO) |
362 | printf("not found\n"); | |
60d339f6 | 363 | else |
1da177e4 | 364 | perror("not found"); |
d67b569f JD |
365 | } |
366 | else { | |
cb66504d PBG |
367 | if (!ptrace_faultinfo) |
368 | printf("found but disabled on command line\n"); | |
369 | else | |
370 | printf("found\n"); | |
1da177e4 LT |
371 | } |
372 | ||
373 | init_registers(pid); | |
b85e9680 | 374 | stop_ptraced_child(pid, stack, 1, 1); |
1da177e4 LT |
375 | } |
376 | ||
858259cf BS |
377 | static inline void check_skas3_ptrace_ldt(void) |
378 | { | |
379 | #ifdef PTRACE_LDT | |
380 | void *stack; | |
381 | int pid, n; | |
382 | unsigned char ldtbuf[40]; | |
383 | struct ptrace_ldt ldt_op = (struct ptrace_ldt) { | |
384 | .func = 2, /* read default ldt */ | |
385 | .ptr = ldtbuf, | |
386 | .bytecount = sizeof(ldtbuf)}; | |
387 | ||
388 | printf(" - PTRACE_LDT..."); | |
389 | pid = start_ptraced_child(&stack); | |
390 | ||
391 | n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op); | |
392 | if (n < 0) { | |
393 | if(errno == EIO) | |
394 | printf("not found\n"); | |
395 | else { | |
396 | perror("not found"); | |
397 | } | |
398 | ptrace_ldt = 0; | |
399 | } | |
400 | else { | |
401 | if(ptrace_ldt) | |
402 | printf("found\n"); | |
403 | else | |
404 | printf("found, but use is disabled\n"); | |
405 | } | |
406 | ||
407 | stop_ptraced_child(pid, stack, 1, 1); | |
408 | #else | |
409 | /* PTRACE_LDT might be disabled via cmdline option. | |
410 | * We want to override this, else we might use the stub | |
411 | * without real need | |
412 | */ | |
413 | ptrace_ldt = 1; | |
414 | #endif | |
415 | } | |
416 | ||
417 | static inline void check_skas3_proc_mm(void) | |
1da177e4 | 418 | { |
858259cf | 419 | printf(" - /proc/mm..."); |
73c8f444 | 420 | if (access("/proc/mm", W_OK) < 0) { |
9eae9b13 | 421 | proc_mm = 0; |
1da177e4 | 422 | printf("not found\n"); |
60d339f6 GS |
423 | } |
424 | else { | |
cb66504d PBG |
425 | if (!proc_mm) |
426 | printf("found but disabled on command line\n"); | |
427 | else | |
428 | printf("found\n"); | |
1da177e4 | 429 | } |
858259cf BS |
430 | } |
431 | ||
432 | int can_do_skas(void) | |
433 | { | |
434 | printf("Checking for the skas3 patch in the host:\n"); | |
435 | ||
436 | check_skas3_proc_mm(); | |
437 | check_skas3_ptrace_faultinfo(); | |
438 | check_skas3_ptrace_ldt(); | |
439 | ||
440 | if(!proc_mm || !ptrace_faultinfo || !ptrace_ldt) | |
441 | skas_needs_stub = 1; | |
1da177e4 | 442 | |
d67b569f | 443 | return 1; |
1da177e4 LT |
444 | } |
445 | #else | |
446 | int can_do_skas(void) | |
447 | { | |
9eae9b13 | 448 | return 0; |
1da177e4 LT |
449 | } |
450 | #endif | |
0f80bc85 | 451 | |
0f80bc85 JD |
452 | int __init parse_iomem(char *str, int *add) |
453 | { | |
454 | struct iomem_region *new; | |
73c8f444 | 455 | struct stat64 buf; |
0f80bc85 | 456 | char *file, *driver; |
73c8f444 | 457 | int fd, size; |
0f80bc85 JD |
458 | |
459 | driver = str; | |
460 | file = strchr(str,','); | |
461 | if(file == NULL){ | |
462 | printf("parse_iomem : failed to parse iomem\n"); | |
463 | goto out; | |
464 | } | |
465 | *file = '\0'; | |
466 | file++; | |
73c8f444 | 467 | fd = open(file, O_RDWR, 0); |
0f80bc85 JD |
468 | if(fd < 0){ |
469 | os_print_error(fd, "parse_iomem - Couldn't open io file"); | |
470 | goto out; | |
471 | } | |
472 | ||
73c8f444 JD |
473 | if(fstat64(fd, &buf) < 0){ |
474 | perror("parse_iomem - cannot stat_fd file"); | |
0f80bc85 JD |
475 | goto out_close; |
476 | } | |
477 | ||
478 | new = malloc(sizeof(*new)); | |
479 | if(new == NULL){ | |
480 | perror("Couldn't allocate iomem_region struct"); | |
481 | goto out_close; | |
482 | } | |
483 | ||
73c8f444 | 484 | size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1); |
0f80bc85 JD |
485 | |
486 | *new = ((struct iomem_region) { .next = iomem_regions, | |
487 | .driver = driver, | |
488 | .fd = fd, | |
489 | .size = size, | |
490 | .phys = 0, | |
491 | .virt = 0 }); | |
492 | iomem_regions = new; | |
493 | iomem_size += new->size + UM_KERN_PAGE_SIZE; | |
494 | ||
9eae9b13 | 495 | return 0; |
0f80bc85 | 496 | out_close: |
73c8f444 | 497 | close(fd); |
0f80bc85 | 498 | out: |
9eae9b13 | 499 | return 1; |
0f80bc85 JD |
500 | } |
501 | ||
8e367065 JD |
502 | |
503 | /* Changed during early boot */ | |
504 | int pty_output_sigio = 0; | |
505 | int pty_close_sigio = 0; | |
506 | ||
507 | /* Used as a flag during SIGIO testing early in boot */ | |
508 | static volatile int got_sigio = 0; | |
509 | ||
510 | static void __init handler(int sig) | |
511 | { | |
512 | got_sigio = 1; | |
513 | } | |
514 | ||
515 | struct openpty_arg { | |
516 | int master; | |
517 | int slave; | |
518 | int err; | |
519 | }; | |
520 | ||
521 | static void openpty_cb(void *arg) | |
522 | { | |
523 | struct openpty_arg *info = arg; | |
524 | ||
525 | info->err = 0; | |
526 | if(openpty(&info->master, &info->slave, NULL, NULL, NULL)) | |
527 | info->err = -errno; | |
528 | } | |
529 | ||
73c8f444 JD |
530 | static int async_pty(int master, int slave) |
531 | { | |
532 | int flags; | |
533 | ||
534 | flags = fcntl(master, F_GETFL); | |
535 | if(flags < 0) | |
536 | return -errno; | |
537 | ||
538 | if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) || | |
539 | (fcntl(master, F_SETOWN, os_getpid()) < 0)) | |
540 | return -errno; | |
541 | ||
542 | if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0)) | |
543 | return -errno; | |
544 | ||
545 | return(0); | |
546 | } | |
547 | ||
8e367065 JD |
548 | static void __init check_one_sigio(void (*proc)(int, int)) |
549 | { | |
550 | struct sigaction old, new; | |
551 | struct openpty_arg pty = { .master = -1, .slave = -1 }; | |
552 | int master, slave, err; | |
553 | ||
554 | initial_thread_cb(openpty_cb, &pty); | |
555 | if(pty.err){ | |
556 | printk("openpty failed, errno = %d\n", -pty.err); | |
557 | return; | |
558 | } | |
559 | ||
560 | master = pty.master; | |
561 | slave = pty.slave; | |
562 | ||
563 | if((master == -1) || (slave == -1)){ | |
564 | printk("openpty failed to allocate a pty\n"); | |
565 | return; | |
566 | } | |
567 | ||
568 | /* Not now, but complain so we now where we failed. */ | |
569 | err = raw(master); | |
570 | if (err < 0) | |
571 | panic("check_sigio : __raw failed, errno = %d\n", -err); | |
572 | ||
73c8f444 | 573 | err = async_pty(master, slave); |
8e367065 JD |
574 | if(err < 0) |
575 | panic("tty_fds : sigio_async failed, err = %d\n", -err); | |
576 | ||
577 | if(sigaction(SIGIO, NULL, &old) < 0) | |
578 | panic("check_sigio : sigaction 1 failed, errno = %d\n", errno); | |
579 | new = old; | |
580 | new.sa_handler = handler; | |
581 | if(sigaction(SIGIO, &new, NULL) < 0) | |
582 | panic("check_sigio : sigaction 2 failed, errno = %d\n", errno); | |
583 | ||
584 | got_sigio = 0; | |
585 | (*proc)(master, slave); | |
586 | ||
587 | close(master); | |
588 | close(slave); | |
589 | ||
590 | if(sigaction(SIGIO, &old, NULL) < 0) | |
591 | panic("check_sigio : sigaction 3 failed, errno = %d\n", errno); | |
592 | } | |
593 | ||
594 | static void tty_output(int master, int slave) | |
595 | { | |
596 | int n; | |
597 | char buf[512]; | |
598 | ||
599 | printk("Checking that host ptys support output SIGIO..."); | |
600 | ||
601 | memset(buf, 0, sizeof(buf)); | |
602 | ||
603 | while(os_write_file(master, buf, sizeof(buf)) > 0) ; | |
604 | if(errno != EAGAIN) | |
605 | panic("check_sigio : write failed, errno = %d\n", errno); | |
606 | while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ; | |
607 | ||
608 | if(got_sigio){ | |
609 | printk("Yes\n"); | |
610 | pty_output_sigio = 1; | |
611 | } | |
612 | else if(n == -EAGAIN) printk("No, enabling workaround\n"); | |
613 | else panic("check_sigio : read failed, err = %d\n", n); | |
614 | } | |
615 | ||
616 | static void tty_close(int master, int slave) | |
617 | { | |
618 | printk("Checking that host ptys support SIGIO on close..."); | |
619 | ||
620 | close(slave); | |
621 | if(got_sigio){ | |
622 | printk("Yes\n"); | |
623 | pty_close_sigio = 1; | |
624 | } | |
625 | else printk("No, enabling workaround\n"); | |
626 | } | |
627 | ||
628 | void __init check_sigio(void) | |
629 | { | |
630 | if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) && | |
631 | (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){ | |
632 | printk("No pseudo-terminals available - skipping pty SIGIO " | |
633 | "check\n"); | |
634 | return; | |
635 | } | |
636 | check_one_sigio(tty_output); | |
637 | check_one_sigio(tty_close); | |
638 | } | |
639 | ||
640 | void os_check_bugs(void) | |
641 | { | |
642 | check_ptrace(); | |
643 | check_sigio(); | |
8e367065 JD |
644 | } |
645 |