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-rw-r--r--arch/um/os-Linux/skas/process.c566
1 files changed, 566 insertions, 0 deletions
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
new file mode 100644
index 00000000000..120a21c5883
--- /dev/null
+++ b/arch/um/os-Linux/skas/process.c
@@ -0,0 +1,566 @@
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 <setjmp.h>
12#include <sched.h>
13#include "ptrace_user.h"
14#include <sys/wait.h>
15#include <sys/mman.h>
16#include <sys/user.h>
17#include <sys/time.h>
18#include <asm/unistd.h>
19#include <asm/types.h>
20#include "user.h"
21#include "sysdep/ptrace.h"
22#include "user_util.h"
23#include "kern_util.h"
24#include "skas.h"
25#include "stub-data.h"
26#include "mm_id.h"
27#include "sysdep/sigcontext.h"
28#include "sysdep/stub.h"
29#include "os.h"
30#include "proc_mm.h"
31#include "skas_ptrace.h"
32#include "chan_user.h"
33#include "registers.h"
34#include "mem.h"
35#include "uml-config.h"
36#include "process.h"
37#include "longjmp.h"
38
39int is_skas_winch(int pid, int fd, void *data)
40{
41 if(pid != os_getpgrp())
42 return(0);
43
44 register_winch_irq(-1, fd, -1, data);
45 return(1);
46}
47
48void wait_stub_done(int pid, int sig, char * fname)
49{
50 int n, status, err;
51
52 do {
53 if ( sig != -1 ) {
54 err = ptrace(PTRACE_CONT, pid, 0, sig);
55 if(err)
56 panic("%s : continue failed, errno = %d\n",
57 fname, errno);
58 }
59 sig = 0;
60
61 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
62 } while((n >= 0) && WIFSTOPPED(status) &&
63 ((WSTOPSIG(status) == SIGVTALRM) ||
64 /* running UML inside a detached screen can cause
65 * SIGWINCHes
66 */
67 (WSTOPSIG(status) == SIGWINCH)));
68
69 if((n < 0) || !WIFSTOPPED(status) ||
70 (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
71 unsigned long regs[HOST_FRAME_SIZE];
72
73 if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
74 printk("Failed to get registers from stub, "
75 "errno = %d\n", errno);
76 else {
77 int i;
78
79 printk("Stub registers -\n");
80 for(i = 0; i < HOST_FRAME_SIZE; i++)
81 printk("\t%d - %lx\n", i, regs[i]);
82 }
83 panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
84 "pid = %d, n = %d, errno = %d, status = 0x%x\n",
85 fname, pid, n, errno, status);
86 }
87}
88
89extern unsigned long current_stub_stack(void);
90
91void get_skas_faultinfo(int pid, struct faultinfo * fi)
92{
93 int err;
94
95 if(ptrace_faultinfo){
96 err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
97 if(err)
98 panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
99 "errno = %d\n", errno);
100
101 /* Special handling for i386, which has different structs */
102 if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
103 memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
104 sizeof(struct faultinfo) -
105 sizeof(struct ptrace_faultinfo));
106 }
107 else {
108 wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
109
110 /* faultinfo is prepared by the stub-segv-handler at start of
111 * the stub stack page. We just have to copy it.
112 */
113 memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
114 }
115}
116
117static void handle_segv(int pid, union uml_pt_regs * regs)
118{
119 get_skas_faultinfo(pid, &regs->skas.faultinfo);
120 segv(regs->skas.faultinfo, 0, 1, NULL);
121}
122
123/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
124static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
125{
126 int err, status;
127
128 /* Mark this as a syscall */
129 UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
130
131 if (!local_using_sysemu)
132 {
133 err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
134 __NR_getpid);
135 if(err < 0)
136 panic("handle_trap - nullifying syscall failed errno = %d\n",
137 errno);
138
139 err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
140 if(err < 0)
141 panic("handle_trap - continuing to end of syscall failed, "
142 "errno = %d\n", errno);
143
144 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
145 if((err < 0) || !WIFSTOPPED(status) ||
146 (WSTOPSIG(status) != SIGTRAP + 0x80))
147 panic("handle_trap - failed to wait at end of syscall, "
148 "errno = %d, status = %d\n", errno, status);
149 }
150
151 handle_syscall(regs);
152}
153
154extern int __syscall_stub_start;
155
156static int userspace_tramp(void *stack)
157{
158 void *addr;
159
160 ptrace(PTRACE_TRACEME, 0, 0, 0);
161
162 init_new_thread_signals(1);
163 enable_timer();
164
165 if(!proc_mm){
166 /* This has a pte, but it can't be mapped in with the usual
167 * tlb_flush mechanism because this is part of that mechanism
168 */
169 int fd;
170 __u64 offset;
171 fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
172 addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
173 PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
174 if(addr == MAP_FAILED){
175 printk("mapping mmap stub failed, errno = %d\n",
176 errno);
177 exit(1);
178 }
179
180 if(stack != NULL){
181 fd = phys_mapping(to_phys(stack), &offset);
182 addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
183 PROT_READ | PROT_WRITE,
184 MAP_FIXED | MAP_SHARED, fd, offset);
185 if(addr == MAP_FAILED){
186 printk("mapping segfault stack failed, "
187 "errno = %d\n", errno);
188 exit(1);
189 }
190 }
191 }
192 if(!ptrace_faultinfo && (stack != NULL)){
193 unsigned long v = UML_CONFIG_STUB_CODE +
194 (unsigned long) stub_segv_handler -
195 (unsigned long) &__syscall_stub_start;
196
197 set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
198 set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
199 SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
200 SIGUSR1, -1);
201 }
202
203 os_stop_process(os_getpid());
204 return(0);
205}
206
207/* Each element set once, and only accessed by a single processor anyway */
208#undef NR_CPUS
209#define NR_CPUS 1
210int userspace_pid[NR_CPUS];
211
212int start_userspace(unsigned long stub_stack)
213{
214 void *stack;
215 unsigned long sp;
216 int pid, status, n, flags;
217
218 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
219 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
220 if(stack == MAP_FAILED)
221 panic("start_userspace : mmap failed, errno = %d", errno);
222 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
223
224 flags = CLONE_FILES | SIGCHLD;
225 if(proc_mm) flags |= CLONE_VM;
226 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
227 if(pid < 0)
228 panic("start_userspace : clone failed, errno = %d", errno);
229
230 do {
231 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
232 if(n < 0)
233 panic("start_userspace : wait failed, errno = %d",
234 errno);
235 } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
236
237 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
238 panic("start_userspace : expected SIGSTOP, got status = %d",
239 status);
240
241 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
242 panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
243 errno);
244
245 if(munmap(stack, PAGE_SIZE) < 0)
246 panic("start_userspace : munmap failed, errno = %d\n", errno);
247
248 return(pid);
249}
250
251void userspace(union uml_pt_regs *regs)
252{
253 int err, status, op, pid = userspace_pid[0];
254 int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
255
256 while(1){
257 restore_registers(pid, regs);
258
259 /* Now we set local_using_sysemu to be used for one loop */
260 local_using_sysemu = get_using_sysemu();
261
262 op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
263
264 err = ptrace(op, pid, 0, 0);
265 if(err)
266 panic("userspace - could not resume userspace process, "
267 "pid=%d, ptrace operation = %d, errno = %d\n",
268 op, errno);
269
270 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
271 if(err < 0)
272 panic("userspace - waitpid failed, errno = %d\n",
273 errno);
274
275 regs->skas.is_user = 1;
276 save_registers(pid, regs);
277 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
278
279 if(WIFSTOPPED(status)){
280 switch(WSTOPSIG(status)){
281 case SIGSEGV:
282 if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
283 user_signal(SIGSEGV, regs, pid);
284 else handle_segv(pid, regs);
285 break;
286 case SIGTRAP + 0x80:
287 handle_trap(pid, regs, local_using_sysemu);
288 break;
289 case SIGTRAP:
290 relay_signal(SIGTRAP, regs);
291 break;
292 case SIGIO:
293 case SIGVTALRM:
294 case SIGILL:
295 case SIGBUS:
296 case SIGFPE:
297 case SIGWINCH:
298 user_signal(WSTOPSIG(status), regs, pid);
299 break;
300 default:
301 printk("userspace - child stopped with signal "
302 "%d\n", WSTOPSIG(status));
303 }
304 pid = userspace_pid[0];
305 interrupt_end();
306
307 /* Avoid -ERESTARTSYS handling in host */
308 if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
309 PT_SYSCALL_NR(regs->skas.regs) = -1;
310 }
311 }
312}
313#define INIT_JMP_NEW_THREAD 0
314#define INIT_JMP_REMOVE_SIGSTACK 1
315#define INIT_JMP_CALLBACK 2
316#define INIT_JMP_HALT 3
317#define INIT_JMP_REBOOT 4
318
319int copy_context_skas0(unsigned long new_stack, int pid)
320{
321 int err;
322 unsigned long regs[MAX_REG_NR];
323 unsigned long current_stack = current_stub_stack();
324 struct stub_data *data = (struct stub_data *) current_stack;
325 struct stub_data *child_data = (struct stub_data *) new_stack;
326 __u64 new_offset;
327 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
328
329 /* prepare offset and fd of child's stack as argument for parent's
330 * and child's mmap2 calls
331 */
332 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
333 .fd = new_fd,
334 .timer = ((struct itimerval)
335 { { 0, 1000000 / hz() },
336 { 0, 1000000 / hz() }})});
337 get_safe_registers(regs);
338
339 /* Set parent's instruction pointer to start of clone-stub */
340 regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
341 (unsigned long) stub_clone_handler -
342 (unsigned long) &__syscall_stub_start;
343 regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
344 sizeof(void *);
345#ifdef __SIGNAL_FRAMESIZE
346 regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
347#endif
348 err = ptrace_setregs(pid, regs);
349 if(err < 0)
350 panic("copy_context_skas0 : PTRACE_SETREGS failed, "
351 "pid = %d, errno = %d\n", pid, errno);
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 %d\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 */
387void 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
432void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
433 void (*handler)(int))
434{
435 unsigned long flags;
436 sigjmp_buf switch_buf, fork_buf;
437 int enable;
438
439 *switch_buf_ptr = &switch_buf;
440 *fork_buf_ptr = &fork_buf;
441
442 /* Somewhat subtle - siglongjmp restores the signal mask before doing
443 * the longjmp. This means that when jumping from one stack to another
444 * when the target stack has interrupts enabled, an interrupt may occur
445 * on the source stack. This is bad when starting up a process because
446 * it's not supposed to get timer ticks until it has been scheduled.
447 * So, we disable interrupts around the sigsetjmp to ensure that
448 * they can't happen until we get back here where they are safe.
449 */
450 flags = get_signals();
451 block_signals();
452 if(UML_SIGSETJMP(&fork_buf, enable) == 0)
453 new_thread_proc(stack, handler);
454
455 remove_sigstack();
456
457 set_signals(flags);
458}
459
460void thread_wait(void *sw, void *fb)
461{
462 sigjmp_buf buf, **switch_buf = sw, *fork_buf;
463 int enable;
464
465 *switch_buf = &buf;
466 fork_buf = fb;
467 if(UML_SIGSETJMP(&buf, enable) == 0)
468 siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
469}
470
471void switch_threads(void *me, void *next)
472{
473 sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
474 int enable;
475
476 *me_ptr = &my_buf;
477 if(UML_SIGSETJMP(&my_buf, enable) == 0)
478 UML_SIGLONGJMP(next_buf, 1);
479}
480
481static sigjmp_buf initial_jmpbuf;
482
483/* XXX Make these percpu */
484static void (*cb_proc)(void *arg);
485static void *cb_arg;
486static sigjmp_buf *cb_back;
487
488int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
489{
490 sigjmp_buf **switch_buf = switch_buf_ptr;
491 int n, enable;
492
493 set_handler(SIGWINCH, (__sighandler_t) sig_handler,
494 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
495 SIGVTALRM, -1);
496
497 *fork_buf_ptr = &initial_jmpbuf;
498 n = UML_SIGSETJMP(&initial_jmpbuf, enable);
499 switch(n){
500 case INIT_JMP_NEW_THREAD:
501 new_thread_proc((void *) stack, new_thread_handler);
502 break;
503 case INIT_JMP_REMOVE_SIGSTACK:
504 remove_sigstack();
505 break;
506 case INIT_JMP_CALLBACK:
507 (*cb_proc)(cb_arg);
508 UML_SIGLONGJMP(cb_back, 1);
509 break;
510 case INIT_JMP_HALT:
511 kmalloc_ok = 0;
512 return(0);
513 case INIT_JMP_REBOOT:
514 kmalloc_ok = 0;
515 return(1);
516 default:
517 panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
518 }
519 UML_SIGLONGJMP(*switch_buf, 1);
520}
521
522void initial_thread_cb_skas(void (*proc)(void *), void *arg)
523{
524 sigjmp_buf here;
525 int enable;
526
527 cb_proc = proc;
528 cb_arg = arg;
529 cb_back = &here;
530
531 block_signals();
532 if(UML_SIGSETJMP(&here, enable) == 0)
533 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
534 unblock_signals();
535
536 cb_proc = NULL;
537 cb_arg = NULL;
538 cb_back = NULL;
539}
540
541void halt_skas(void)
542{
543 block_signals();
544 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
545}
546
547void reboot_skas(void)
548{
549 block_signals();
550 UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
551}
552
553void switch_mm_skas(struct mm_id *mm_idp)
554{
555 int err;
556
557#warning need cpu pid in switch_mm_skas
558 if(proc_mm){
559 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
560 mm_idp->u.mm_fd);
561 if(err)
562 panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
563 "errno = %d\n", errno);
564 }
565 else userspace_pid[0] = mm_idp->u.pid;
566}
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-05 17:25:41 -0500