?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[PATCH] uml: Use klibc setjmp/longjmp
[linux-2.6/mini2440.git] / arch / um / os-Linux / skas / process.c
blob50418a5e7134521f990afb820e1da2f9f39d0da0
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
159 ptrace(PTRACE_TRACEME, 0, 0, 0);
160
161 init_new_thread_signals();
162 enable_timer();
163
164 if(!proc_mm){
165 /* This has a pte, but it can't be mapped in with the usual
166 * tlb_flush mechanism because this is part of that mechanism
167 */
168 int fd;
169 __u64 offset;
170 fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
171 addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
172 PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
173 if(addr == MAP_FAILED){
174 printk("mapping mmap stub failed, errno = %d\n",
175 errno);
176 exit(1);
177 }
178
179 if(stack != NULL){
180 fd = phys_mapping(to_phys(stack), &offset);
181 addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
182 PROT_READ | PROT_WRITE,
183 MAP_FIXED | MAP_SHARED, fd, offset);
184 if(addr == MAP_FAILED){
185 printk("mapping segfault stack failed, "
186 "errno = %d\n", errno);
187 exit(1);
188 }
189 }
190 }
191 if(!ptrace_faultinfo && (stack != NULL)){
192 unsigned long v = UML_CONFIG_STUB_CODE +
193 (unsigned long) stub_segv_handler -
194 (unsigned long) &__syscall_stub_start;
195
196 set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
197 set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
198 SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
199 SIGUSR1, -1);
200 }
201
202 os_stop_process(os_getpid());
203 return(0);
204 }
205
206 /* Each element set once, and only accessed by a single processor anyway */
207 #undef NR_CPUS
208 #define NR_CPUS 1
209 int userspace_pid[NR_CPUS];
210
211 int start_userspace(unsigned long stub_stack)
212 {
213 void *stack;
214 unsigned long sp;
215 int pid, status, n, flags;
216
217 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
218 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
219 if(stack == MAP_FAILED)
220 panic("start_userspace : mmap failed, errno = %d", errno);
221 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
222
223 flags = CLONE_FILES | SIGCHLD;
224 if(proc_mm) flags |= CLONE_VM;
225 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
226 if(pid < 0)
227 panic("start_userspace : clone failed, errno = %d", errno);
228
229 do {
230 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
231 if(n < 0)
232 panic("start_userspace : wait failed, errno = %d",
233 errno);
234 } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
235
236 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
237 panic("start_userspace : expected SIGSTOP, got status = %d",
238 status);
239
240 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
241 panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
242 errno);
243
244 if(munmap(stack, PAGE_SIZE) < 0)
245 panic("start_userspace : munmap failed, errno = %d\n", errno);
246
247 return(pid);
248 }
249
250 void userspace(union uml_pt_regs *regs)
251 {
252 int err, status, op, pid = userspace_pid[0];
253 int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
254
255 while(1){
256 restore_registers(pid, regs);
257
258 /* Now we set local_using_sysemu to be used for one loop */
259 local_using_sysemu = get_using_sysemu();
260
261 op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
262
263 err = ptrace(op, pid, 0, 0);
264 if(err)
265 panic("userspace - could not resume userspace process, "
266 "pid=%d, ptrace operation = %d, errno = %d\n",
267 pid, op, errno);
268
269 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
270 if(err < 0)
271 panic("userspace - waitpid failed, errno = %d\n",
272 errno);
273
274 regs->skas.is_user = 1;
275 save_registers(pid, regs);
276 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
277
278 if(WIFSTOPPED(status)){
279 switch(WSTOPSIG(status)){
280 case SIGSEGV:
281 if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
282 user_signal(SIGSEGV, regs, pid);
283 else handle_segv(pid, regs);
284 break;
285 case SIGTRAP + 0x80:
286 handle_trap(pid, regs, local_using_sysemu);
287 break;
288 case SIGTRAP:
289 relay_signal(SIGTRAP, regs);
290 break;
291 case SIGIO:
292 case SIGVTALRM:
293 case SIGILL:
294 case SIGBUS:
295 case SIGFPE:
296 case SIGWINCH:
297 user_signal(WSTOPSIG(status), regs, pid);
298 break;
299 default:
300 printk("userspace - child stopped with signal "
301 "%d\n", WSTOPSIG(status));
302 }
303 pid = userspace_pid[0];
304 interrupt_end();
305
306 /* Avoid -ERESTARTSYS handling in host */
307 if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
308 PT_SYSCALL_NR(regs->skas.regs) = -1;
309 }
310 }
311 }
312
313 int copy_context_skas0(unsigned long new_stack, int pid)
314 {
315 int err;
316 unsigned long regs[HOST_FRAME_SIZE];
317 unsigned long fp_regs[HOST_FP_SIZE];
318 unsigned long current_stack = current_stub_stack();
319 struct stub_data *data = (struct stub_data *) current_stack;
320 struct stub_data *child_data = (struct stub_data *) new_stack;
321 __u64 new_offset;
322 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
323
324 /* prepare offset and fd of child's stack as argument for parent's
325 * and child's mmap2 calls
326 */
327 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
328 .fd = new_fd,
329 .timer = ((struct itimerval)
330 { { 0, 1000000 / hz() },
331 { 0, 1000000 / hz() }})});
332 get_safe_registers(regs, fp_regs);
333
334 /* Set parent's instruction pointer to start of clone-stub */
335 regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
336 (unsigned long) stub_clone_handler -
337 (unsigned long) &__syscall_stub_start;
338 regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
339 sizeof(void *);
340 #ifdef __SIGNAL_FRAMESIZE
341 regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
342 #endif
343 err = ptrace_setregs(pid, regs);
344 if(err < 0)
345 panic("copy_context_skas0 : PTRACE_SETREGS failed, "
346 "pid = %d, errno = %d\n", pid, -err);
347
348 err = ptrace_setfpregs(pid, fp_regs);
349 if(err < 0)
350 panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
351 "pid = %d, errno = %d\n", pid, -err);
352
353 /* set a well known return code for detection of child write failure */
354 child_data->err = 12345678;
355
356 /* Wait, until parent has finished its work: read child's pid from
357 * parent's stack, and check, if bad result.
358 */
359 wait_stub_done(pid, 0, "copy_context_skas0");
360
361 pid = data->err;
362 if(pid < 0)
363 panic("copy_context_skas0 - stub-parent reports error %d\n",
364 -pid);
365
366 /* Wait, until child has finished too: read child's result from
367 * child's stack and check it.
368 */
369 wait_stub_done(pid, -1, "copy_context_skas0");
370 if (child_data->err != UML_CONFIG_STUB_DATA)
371 panic("copy_context_skas0 - stub-child reports error %ld\n",
372 child_data->err);
373
374 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
375 (void *)PTRACE_O_TRACESYSGOOD) < 0)
376 panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
377 "errno = %d\n", errno);
378
379 return pid;
380 }
381
382 /*
383 * This is used only, if stub pages are needed, while proc_mm is
384 * availabl. Opening /proc/mm creates a new mm_context, which lacks
385 * the stub-pages. Thus, we map them using /proc/mm-fd
386 */
387 void map_stub_pages(int fd, unsigned long code,
388 unsigned long data, unsigned long stack)
389 {
390 struct proc_mm_op mmop;
391 int n;
392 __u64 code_offset;
393 int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
394 &code_offset);
395
396 mmop = ((struct proc_mm_op) { .op = MM_MMAP,
397 .u =
398 { .mmap =
399 { .addr = code,
400 .len = PAGE_SIZE,
401 .prot = PROT_EXEC,
402 .flags = MAP_FIXED | MAP_PRIVATE,
403 .fd = code_fd,
404 .offset = code_offset
405 } } });
406 n = os_write_file(fd, &mmop, sizeof(mmop));
407 if(n != sizeof(mmop))
408 panic("map_stub_pages : /proc/mm map for code failed, "
409 "err = %d\n", -n);
410
411 if ( stack ) {
412 __u64 map_offset;
413 int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
414 mmop = ((struct proc_mm_op)
415 { .op = MM_MMAP,
416 .u =
417 { .mmap =
418 { .addr = data,
419 .len = PAGE_SIZE,
420 .prot = PROT_READ | PROT_WRITE,
421 .flags = MAP_FIXED | MAP_SHARED,
422 .fd = map_fd,
423 .offset = map_offset
424 } } });
425 n = os_write_file(fd, &mmop, sizeof(mmop));
426 if(n != sizeof(mmop))
427 panic("map_stub_pages : /proc/mm map for data failed, "
428 "err = %d\n", -n);
429 }
430 }
431
432 void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
433 void (*handler)(int))
434 {
435 unsigned long flags;
436 jmp_buf switch_buf, fork_buf;
437
438 *switch_buf_ptr = &switch_buf;
439 *fork_buf_ptr = &fork_buf;
440
441 /* Somewhat subtle - siglongjmp restores the signal mask before doing
442 * the longjmp. This means that when jumping from one stack to another
443 * when the target stack has interrupts enabled, an interrupt may occur
444 * on the source stack. This is bad when starting up a process because
445 * it's not supposed to get timer ticks until it has been scheduled.
446 * So, we disable interrupts around the sigsetjmp to ensure that
447 * they can't happen until we get back here where they are safe.
448 */
449 flags = get_signals();
450 block_signals();
451 if(UML_SETJMP(&fork_buf) == 0)
452 new_thread_proc(stack, handler);
453
454 remove_sigstack();
455
456 set_signals(flags);
457 }
458
459 #define INIT_JMP_NEW_THREAD 0
460 #define INIT_JMP_REMOVE_SIGSTACK 1
461 #define INIT_JMP_CALLBACK 2
462 #define INIT_JMP_HALT 3
463 #define INIT_JMP_REBOOT 4
464
465 void thread_wait(void *sw, void *fb)
466 {
467 jmp_buf buf, **switch_buf = sw, *fork_buf;
468
469 *switch_buf = &buf;
470 fork_buf = fb;
471 if(UML_SETJMP(&buf) == 0)
472 UML_LONGJMP(fork_buf, INIT_JMP_REMOVE_SIGSTACK);
473 }
474
475 void switch_threads(void *me, void *next)
476 {
477 jmp_buf my_buf, **me_ptr = me, *next_buf = next;
478
479 *me_ptr = &my_buf;
480 if(UML_SETJMP(&my_buf) == 0)
481 UML_LONGJMP(next_buf, 1);
482 }
483
484 static jmp_buf initial_jmpbuf;
485
486 /* XXX Make these percpu */
487 static void (*cb_proc)(void *arg);
488 static void *cb_arg;
489 static jmp_buf *cb_back;
490
491 int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
492 {
493 jmp_buf **switch_buf = switch_buf_ptr;
494 int n;
495
496 set_handler(SIGWINCH, (__sighandler_t) sig_handler,
497 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
498 SIGVTALRM, -1);
499
500 *fork_buf_ptr = &initial_jmpbuf;
501 n = UML_SETJMP(&initial_jmpbuf);
502 switch(n){
503 case INIT_JMP_NEW_THREAD:
504 new_thread_proc((void *) stack, new_thread_handler);
505 break;
506 case INIT_JMP_REMOVE_SIGSTACK:
507 remove_sigstack();
508 break;
509 case INIT_JMP_CALLBACK:
510 (*cb_proc)(cb_arg);
511 UML_LONGJMP(cb_back, 1);
512 break;
513 case INIT_JMP_HALT:
514 kmalloc_ok = 0;
515 return(0);
516 case INIT_JMP_REBOOT:
517 kmalloc_ok = 0;
518 return(1);
519 default:
520 panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
521 }
522 UML_LONGJMP(*switch_buf, 1);
523 }
524
525 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
526 {
527 jmp_buf here;
528
529 cb_proc = proc;
530 cb_arg = arg;
531 cb_back = &here;
532
533 block_signals();
534 if(UML_SETJMP(&here) == 0)
535 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
536 unblock_signals();
537
538 cb_proc = NULL;
539 cb_arg = NULL;
540 cb_back = NULL;
541 }
542
543 void halt_skas(void)
544 {
545 block_signals();
546 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
547 }
548
549 void reboot_skas(void)
550 {
551 block_signals();
552 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
553 }
554
555 void switch_mm_skas(struct mm_id *mm_idp)
556 {
557 int err;
558
559 #warning need cpu pid in switch_mm_skas
560 if(proc_mm){
561 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
562 mm_idp->u.mm_fd);
563 if(err)
564 panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
565 "errno = %d\n", errno);
566 }
567 else userspace_pid[0] = mm_idp->u.pid;
568 }
Support for the Chinese Samsung S3C2440 based development boards