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[PATCH] uml: timer cleanups
[linux-2.6/mini2440.git] / arch / um / os-Linux / skas / process.c
blob42e3d1ed802cadf01a6f06345daf8ecc327f05d5
1 /*
2 * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
4 */
5
6 #include <stdlib.h>
7 #include <string.h>
8 #include <unistd.h>
9 #include <errno.h>
10 #include <signal.h>
11 #include <sched.h>
12 #include "ptrace_user.h"
13 #include <sys/wait.h>
14 #include <sys/mman.h>
15 #include <sys/user.h>
16 #include <sys/time.h>
17 #include <asm/unistd.h>
18 #include <asm/types.h>
19 #include "user.h"
20 #include "sysdep/ptrace.h"
21 #include "user_util.h"
22 #include "kern_util.h"
23 #include "skas.h"
24 #include "stub-data.h"
25 #include "mm_id.h"
26 #include "sysdep/sigcontext.h"
27 #include "sysdep/stub.h"
28 #include "os.h"
29 #include "proc_mm.h"
30 #include "skas_ptrace.h"
31 #include "chan_user.h"
32 #include "registers.h"
33 #include "mem.h"
34 #include "uml-config.h"
35 #include "process.h"
36 #include "longjmp.h"
37
38 int is_skas_winch(int pid, int fd, void *data)
39 {
40 if(pid != os_getpgrp())
41 return(0);
42
43 register_winch_irq(-1, fd, -1, data);
44 return(1);
45 }
46
47 void wait_stub_done(int pid, int sig, char * fname)
48 {
49 int n, status, err;
50
51 do {
52 if ( sig != -1 ) {
53 err = ptrace(PTRACE_CONT, pid, 0, sig);
54 if(err)
55 panic("%s : continue failed, errno = %d\n",
56 fname, errno);
57 }
58 sig = 0;
59
60 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
61 } while((n >= 0) && WIFSTOPPED(status) &&
62 ((WSTOPSIG(status) == SIGVTALRM) ||
63 /* running UML inside a detached screen can cause
64 * SIGWINCHes
65 */
66 (WSTOPSIG(status) == SIGWINCH)));
67
68 if((n < 0) || !WIFSTOPPED(status) ||
69 (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
70 unsigned long regs[HOST_FRAME_SIZE];
71
72 if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
73 printk("Failed to get registers from stub, "
74 "errno = %d\n", errno);
75 else {
76 int i;
77
78 printk("Stub registers -\n");
79 for(i = 0; i < HOST_FRAME_SIZE; i++)
80 printk("\t%d - %lx\n", i, regs[i]);
81 }
82 panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
83 "pid = %d, n = %d, errno = %d, status = 0x%x\n",
84 fname, pid, n, errno, status);
85 }
86 }
87
88 extern unsigned long current_stub_stack(void);
89
90 void get_skas_faultinfo(int pid, struct faultinfo * fi)
91 {
92 int err;
93
94 if(ptrace_faultinfo){
95 err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
96 if(err)
97 panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
98 "errno = %d\n", errno);
99
100 /* Special handling for i386, which has different structs */
101 if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
102 memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
103 sizeof(struct faultinfo) -
104 sizeof(struct ptrace_faultinfo));
105 }
106 else {
107 wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
108
109 /* faultinfo is prepared by the stub-segv-handler at start of
110 * the stub stack page. We just have to copy it.
111 */
112 memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
113 }
114 }
115
116 static void handle_segv(int pid, union uml_pt_regs * regs)
117 {
118 get_skas_faultinfo(pid, &regs->skas.faultinfo);
119 segv(regs->skas.faultinfo, 0, 1, NULL);
120 }
121
122 /*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
123 static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
124 {
125 int err, status;
126
127 /* Mark this as a syscall */
128 UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
129
130 if (!local_using_sysemu)
131 {
132 err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
133 __NR_getpid);
134 if(err < 0)
135 panic("handle_trap - nullifying syscall failed errno = %d\n",
136 errno);
137
138 err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
139 if(err < 0)
140 panic("handle_trap - continuing to end of syscall failed, "
141 "errno = %d\n", errno);
142
143 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
144 if((err < 0) || !WIFSTOPPED(status) ||
145 (WSTOPSIG(status) != SIGTRAP + 0x80))
146 panic("handle_trap - failed to wait at end of syscall, "
147 "errno = %d, status = %d\n", errno, status);
148 }
149
150 handle_syscall(regs);
151 }
152
153 extern int __syscall_stub_start;
154
155 static int userspace_tramp(void *stack)
156 {
157 void *addr;
158 int err;
159
160 ptrace(PTRACE_TRACEME, 0, 0, 0);
161
162 init_new_thread_signals();
163 err = set_interval(1);
164 if(err)
165 panic("userspace_tramp - setting timer failed, errno = %d\n",
166 err);
167
168 if(!proc_mm){
169 /* This has a pte, but it can't be mapped in with the usual
170 * tlb_flush mechanism because this is part of that mechanism
171 */
172 int fd;
173 __u64 offset;
174 fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
175 addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
176 PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
177 if(addr == MAP_FAILED){
178 printk("mapping mmap stub failed, errno = %d\n",
179 errno);
180 exit(1);
181 }
182
183 if(stack != NULL){
184 fd = phys_mapping(to_phys(stack), &offset);
185 addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
186 PROT_READ | PROT_WRITE,
187 MAP_FIXED | MAP_SHARED, fd, offset);
188 if(addr == MAP_FAILED){
189 printk("mapping segfault stack failed, "
190 "errno = %d\n", errno);
191 exit(1);
192 }
193 }
194 }
195 if(!ptrace_faultinfo && (stack != NULL)){
196 struct sigaction sa;
197
198 unsigned long v = UML_CONFIG_STUB_CODE +
199 (unsigned long) stub_segv_handler -
200 (unsigned long) &__syscall_stub_start;
201
202 set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
203 sigemptyset(&sa.sa_mask);
204 sigaddset(&sa.sa_mask, SIGIO);
205 sigaddset(&sa.sa_mask, SIGWINCH);
206 sigaddset(&sa.sa_mask, SIGALRM);
207 sigaddset(&sa.sa_mask, SIGVTALRM);
208 sigaddset(&sa.sa_mask, SIGUSR1);
209 sa.sa_flags = SA_ONSTACK;
210 sa.sa_handler = (void *) v;
211 sa.sa_restorer = NULL;
212 if(sigaction(SIGSEGV, &sa, NULL) < 0)
213 panic("userspace_tramp - setting SIGSEGV handler "
214 "failed - errno = %d\n", errno);
215 }
216
217 os_stop_process(os_getpid());
218 return(0);
219 }
220
221 /* Each element set once, and only accessed by a single processor anyway */
222 #undef NR_CPUS
223 #define NR_CPUS 1
224 int userspace_pid[NR_CPUS];
225
226 int start_userspace(unsigned long stub_stack)
227 {
228 void *stack;
229 unsigned long sp;
230 int pid, status, n, flags;
231
232 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
233 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
234 if(stack == MAP_FAILED)
235 panic("start_userspace : mmap failed, errno = %d", errno);
236 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
237
238 flags = CLONE_FILES | SIGCHLD;
239 if(proc_mm) flags |= CLONE_VM;
240 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
241 if(pid < 0)
242 panic("start_userspace : clone failed, errno = %d", errno);
243
244 do {
245 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
246 if(n < 0)
247 panic("start_userspace : wait failed, errno = %d",
248 errno);
249 } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
250
251 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
252 panic("start_userspace : expected SIGSTOP, got status = %d",
253 status);
254
255 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
256 panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
257 errno);
258
259 if(munmap(stack, PAGE_SIZE) < 0)
260 panic("start_userspace : munmap failed, errno = %d\n", errno);
261
262 return(pid);
263 }
264
265 void userspace(union uml_pt_regs *regs)
266 {
267 int err, status, op, pid = userspace_pid[0];
268 int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
269
270 while(1){
271 restore_registers(pid, regs);
272
273 /* Now we set local_using_sysemu to be used for one loop */
274 local_using_sysemu = get_using_sysemu();
275
276 op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
277
278 err = ptrace(op, pid, 0, 0);
279 if(err)
280 panic("userspace - could not resume userspace process, "
281 "pid=%d, ptrace operation = %d, errno = %d\n",
282 pid, op, errno);
283
284 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
285 if(err < 0)
286 panic("userspace - waitpid failed, errno = %d\n",
287 errno);
288
289 regs->skas.is_user = 1;
290 save_registers(pid, regs);
291 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
292
293 if(WIFSTOPPED(status)){
294 switch(WSTOPSIG(status)){
295 case SIGSEGV:
296 if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
297 user_signal(SIGSEGV, regs, pid);
298 else handle_segv(pid, regs);
299 break;
300 case SIGTRAP + 0x80:
301 handle_trap(pid, regs, local_using_sysemu);
302 break;
303 case SIGTRAP:
304 relay_signal(SIGTRAP, regs);
305 break;
306 case SIGIO:
307 case SIGVTALRM:
308 case SIGILL:
309 case SIGBUS:
310 case SIGFPE:
311 case SIGWINCH:
312 user_signal(WSTOPSIG(status), regs, pid);
313 break;
314 default:
315 printk("userspace - child stopped with signal "
316 "%d\n", WSTOPSIG(status));
317 }
318 pid = userspace_pid[0];
319 interrupt_end();
320
321 /* Avoid -ERESTARTSYS handling in host */
322 if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
323 PT_SYSCALL_NR(regs->skas.regs) = -1;
324 }
325 }
326 }
327
328 int copy_context_skas0(unsigned long new_stack, int pid)
329 {
330 int err;
331 unsigned long regs[HOST_FRAME_SIZE];
332 unsigned long fp_regs[HOST_FP_SIZE];
333 unsigned long current_stack = current_stub_stack();
334 struct stub_data *data = (struct stub_data *) current_stack;
335 struct stub_data *child_data = (struct stub_data *) new_stack;
336 __u64 new_offset;
337 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
338
339 /* prepare offset and fd of child's stack as argument for parent's
340 * and child's mmap2 calls
341 */
342 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
343 .fd = new_fd,
344 .timer = ((struct itimerval)
345 { { 0, 1000000 / hz() },
346 { 0, 1000000 / hz() }})});
347 get_safe_registers(regs, fp_regs);
348
349 /* Set parent's instruction pointer to start of clone-stub */
350 regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
351 (unsigned long) stub_clone_handler -
352 (unsigned long) &__syscall_stub_start;
353 regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
354 sizeof(void *);
355 #ifdef __SIGNAL_FRAMESIZE
356 regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
357 #endif
358 err = ptrace_setregs(pid, regs);
359 if(err < 0)
360 panic("copy_context_skas0 : PTRACE_SETREGS failed, "
361 "pid = %d, errno = %d\n", pid, -err);
362
363 err = ptrace_setfpregs(pid, fp_regs);
364 if(err < 0)
365 panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
366 "pid = %d, errno = %d\n", pid, -err);
367
368 /* set a well known return code for detection of child write failure */
369 child_data->err = 12345678;
370
371 /* Wait, until parent has finished its work: read child's pid from
372 * parent's stack, and check, if bad result.
373 */
374 wait_stub_done(pid, 0, "copy_context_skas0");
375
376 pid = data->err;
377 if(pid < 0)
378 panic("copy_context_skas0 - stub-parent reports error %d\n",
379 -pid);
380
381 /* Wait, until child has finished too: read child's result from
382 * child's stack and check it.
383 */
384 wait_stub_done(pid, -1, "copy_context_skas0");
385 if (child_data->err != UML_CONFIG_STUB_DATA)
386 panic("copy_context_skas0 - stub-child reports error %ld\n",
387 child_data->err);
388
389 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
390 (void *)PTRACE_O_TRACESYSGOOD) < 0)
391 panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
392 "errno = %d\n", errno);
393
394 return pid;
395 }
396
397 /*
398 * This is used only, if stub pages are needed, while proc_mm is
399 * availabl. Opening /proc/mm creates a new mm_context, which lacks
400 * the stub-pages. Thus, we map them using /proc/mm-fd
401 */
402 void map_stub_pages(int fd, unsigned long code,
403 unsigned long data, unsigned long stack)
404 {
405 struct proc_mm_op mmop;
406 int n;
407 __u64 code_offset;
408 int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
409 &code_offset);
410
411 mmop = ((struct proc_mm_op) { .op = MM_MMAP,
412 .u =
413 { .mmap =
414 { .addr = code,
415 .len = PAGE_SIZE,
416 .prot = PROT_EXEC,
417 .flags = MAP_FIXED | MAP_PRIVATE,
418 .fd = code_fd,
419 .offset = code_offset
420 } } });
421 n = os_write_file(fd, &mmop, sizeof(mmop));
422 if(n != sizeof(mmop))
423 panic("map_stub_pages : /proc/mm map for code failed, "
424 "err = %d\n", -n);
425
426 if ( stack ) {
427 __u64 map_offset;
428 int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
429 mmop = ((struct proc_mm_op)
430 { .op = MM_MMAP,
431 .u =
432 { .mmap =
433 { .addr = data,
434 .len = PAGE_SIZE,
435 .prot = PROT_READ | PROT_WRITE,
436 .flags = MAP_FIXED | MAP_SHARED,
437 .fd = map_fd,
438 .offset = map_offset
439 } } });
440 n = os_write_file(fd, &mmop, sizeof(mmop));
441 if(n != sizeof(mmop))
442 panic("map_stub_pages : /proc/mm map for data failed, "
443 "err = %d\n", -n);
444 }
445 }
446
447 void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
448 void (*handler)(int))
449 {
450 unsigned long flags;
451 jmp_buf switch_buf, fork_buf;
452
453 *switch_buf_ptr = &switch_buf;
454 *fork_buf_ptr = &fork_buf;
455
456 /* Somewhat subtle - siglongjmp restores the signal mask before doing
457 * the longjmp. This means that when jumping from one stack to another
458 * when the target stack has interrupts enabled, an interrupt may occur
459 * on the source stack. This is bad when starting up a process because
460 * it's not supposed to get timer ticks until it has been scheduled.
461 * So, we disable interrupts around the sigsetjmp to ensure that
462 * they can't happen until we get back here where they are safe.
463 */
464 flags = get_signals();
465 block_signals();
466 if(UML_SETJMP(&fork_buf) == 0)
467 new_thread_proc(stack, handler);
468
469 remove_sigstack();
470
471 set_signals(flags);
472 }
473
474 #define INIT_JMP_NEW_THREAD 0
475 #define INIT_JMP_REMOVE_SIGSTACK 1
476 #define INIT_JMP_CALLBACK 2
477 #define INIT_JMP_HALT 3
478 #define INIT_JMP_REBOOT 4
479
480 void thread_wait(void *sw, void *fb)
481 {
482 jmp_buf buf, **switch_buf = sw, *fork_buf;
483
484 *switch_buf = &buf;
485 fork_buf = fb;
486 if(UML_SETJMP(&buf) == 0)
487 UML_LONGJMP(fork_buf, INIT_JMP_REMOVE_SIGSTACK);
488 }
489
490 void switch_threads(void *me, void *next)
491 {
492 jmp_buf my_buf, **me_ptr = me, *next_buf = next;
493
494 *me_ptr = &my_buf;
495 if(UML_SETJMP(&my_buf) == 0)
496 UML_LONGJMP(next_buf, 1);
497 }
498
499 static jmp_buf initial_jmpbuf;
500
501 /* XXX Make these percpu */
502 static void (*cb_proc)(void *arg);
503 static void *cb_arg;
504 static jmp_buf *cb_back;
505
506 int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
507 {
508 jmp_buf **switch_buf = switch_buf_ptr;
509 int n;
510
511 set_handler(SIGWINCH, (__sighandler_t) sig_handler,
512 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
513 SIGVTALRM, -1);
514
515 *fork_buf_ptr = &initial_jmpbuf;
516 n = UML_SETJMP(&initial_jmpbuf);
517 switch(n){
518 case INIT_JMP_NEW_THREAD:
519 new_thread_proc((void *) stack, new_thread_handler);
520 break;
521 case INIT_JMP_REMOVE_SIGSTACK:
522 remove_sigstack();
523 break;
524 case INIT_JMP_CALLBACK:
525 (*cb_proc)(cb_arg);
526 UML_LONGJMP(cb_back, 1);
527 break;
528 case INIT_JMP_HALT:
529 kmalloc_ok = 0;
530 return(0);
531 case INIT_JMP_REBOOT:
532 kmalloc_ok = 0;
533 return(1);
534 default:
535 panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
536 }
537 UML_LONGJMP(*switch_buf, 1);
538 }
539
540 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
541 {
542 jmp_buf here;
543
544 cb_proc = proc;
545 cb_arg = arg;
546 cb_back = &here;
547
548 block_signals();
549 if(UML_SETJMP(&here) == 0)
550 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
551 unblock_signals();
552
553 cb_proc = NULL;
554 cb_arg = NULL;
555 cb_back = NULL;
556 }
557
558 void halt_skas(void)
559 {
560 block_signals();
561 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
562 }
563
564 void reboot_skas(void)
565 {
566 block_signals();
567 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
568 }
569
570 void switch_mm_skas(struct mm_id *mm_idp)
571 {
572 int err;
573
574 #warning need cpu pid in switch_mm_skas
575 if(proc_mm){
576 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
577 mm_idp->u.mm_fd);
578 if(err)
579 panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
580 "errno = %d\n", errno);
581 }
582 else userspace_pid[0] = mm_idp->u.pid;
583 }
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