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authorGennady Sharapov <Gennady.V.Sharapov@intel.com>2006-01-18 20:42:46 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-18 22:20:19 -0500
commitabaf69773d8dda98b917d94c07757f6520da7bec (patch)
tree1000669c13511044d1f545cff6af26c1b1d946fb /arch/um/os-Linux/skas/process.c
parentf45d9fc9d80678c2ee22c578e503055207c46fd0 (diff)
[PATCH] uml: move libc-dependent skas process handling
The serial UML OS-abstraction layer patch (um/kernel/skas dir). This moves all systemcalls from skas/process.c file under os-Linux dir and join skas/process.c and skas/process_kern.c files. Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/os-Linux/skas/process.c')
-rw-r--r--arch/um/os-Linux/skas/process.c565
1 files changed, 565 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 000000000000..f787854322c4
--- /dev/null
+++ b/arch/um/os-Linux/skas/process.c
@@ -0,0 +1,565 @@
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
38int 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
47void 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
88extern unsigned long current_stub_stack(void);
89
90void 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
116static 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)*/
123static 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
153extern int __syscall_stub_start;
154int stub_code_fd = -1;
155__u64 stub_code_offset;
156
157static int userspace_tramp(void *stack)
158{
159 void *addr;
160
161 ptrace(PTRACE_TRACEME, 0, 0, 0);
162
163 init_new_thread_signals(1);
164 enable_timer();
165
166 if(!proc_mm){
167 /* This has a pte, but it can't be mapped in with the usual
168 * tlb_flush mechanism because this is part of that mechanism
169 */
170 addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
171 PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
172 stub_code_fd, stub_code_offset);
173 if(addr == MAP_FAILED){
174 printk("mapping stub code failed, errno = %d\n",
175 errno);
176 exit(1);
177 }
178
179 if(stack != NULL){
180 int fd;
181 __u64 offset;
182 fd = phys_mapping(to_phys(stack), &offset);
183 addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
184 PROT_READ | PROT_WRITE,
185 MAP_FIXED | MAP_SHARED, fd, offset);
186 if(addr == MAP_FAILED){
187 printk("mapping stub stack failed, "
188 "errno = %d\n", errno);
189 exit(1);
190 }
191 }
192 }
193 if(!ptrace_faultinfo){
194 unsigned long v = UML_CONFIG_STUB_CODE +
195 (unsigned long) stub_segv_handler -
196 (unsigned long) &__syscall_stub_start;
197
198 set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
199 set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
200 SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
201 SIGUSR1, -1);
202 }
203
204 os_stop_process(os_getpid());
205 return(0);
206}
207
208/* Each element set once, and only accessed by a single processor anyway */
209#undef NR_CPUS
210#define NR_CPUS 1
211int userspace_pid[NR_CPUS];
212
213int start_userspace(unsigned long stub_stack)
214{
215 void *stack;
216 unsigned long sp;
217 int pid, status, n, flags;
218
219 if ( stub_code_fd == -1 )
220 stub_code_fd = phys_mapping(to_phys(&__syscall_stub_start),
221 &stub_code_offset);
222
223 stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
224 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
225 if(stack == MAP_FAILED)
226 panic("start_userspace : mmap failed, errno = %d", errno);
227 sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
228
229 flags = CLONE_FILES | SIGCHLD;
230 if(proc_mm) flags |= CLONE_VM;
231 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
232 if(pid < 0)
233 panic("start_userspace : clone failed, errno = %d", errno);
234
235 do {
236 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
237 if(n < 0)
238 panic("start_userspace : wait failed, errno = %d",
239 errno);
240 } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
241
242 if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
243 panic("start_userspace : expected SIGSTOP, got status = %d",
244 status);
245
246 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
247 panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
248 errno);
249
250 if(munmap(stack, PAGE_SIZE) < 0)
251 panic("start_userspace : munmap failed, errno = %d\n", errno);
252
253 return(pid);
254}
255
256void userspace(union uml_pt_regs *regs)
257{
258 int err, status, op, pid = userspace_pid[0];
259 int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
260
261 while(1){
262 restore_registers(pid, regs);
263
264 /* Now we set local_using_sysemu to be used for one loop */
265 local_using_sysemu = get_using_sysemu();
266
267 op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
268
269 err = ptrace(op, pid, 0, 0);
270 if(err)
271 panic("userspace - could not resume userspace process, "
272 "pid=%d, ptrace operation = %d, errno = %d\n",
273 op, errno);
274
275 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
276 if(err < 0)
277 panic("userspace - waitpid failed, errno = %d\n",
278 errno);
279
280 regs->skas.is_user = 1;
281 save_registers(pid, regs);
282 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
283
284 if(WIFSTOPPED(status)){
285 switch(WSTOPSIG(status)){
286 case SIGSEGV:
287 if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
288 user_signal(SIGSEGV, regs, pid);
289 else handle_segv(pid, regs);
290 break;
291 case SIGTRAP + 0x80:
292 handle_trap(pid, regs, local_using_sysemu);
293 break;
294 case SIGTRAP:
295 relay_signal(SIGTRAP, regs);
296 break;
297 case SIGIO:
298 case SIGVTALRM:
299 case SIGILL:
300 case SIGBUS:
301 case SIGFPE:
302 case SIGWINCH:
303 user_signal(WSTOPSIG(status), regs, pid);
304 break;
305 default:
306 printk("userspace - child stopped with signal "
307 "%d\n", WSTOPSIG(status));
308 }
309 again:
310 pid = userspace_pid[0];
311 interrupt_end();
312
313 /* Avoid -ERESTARTSYS handling in host */
314 if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
315 PT_SYSCALL_NR(regs->skas.regs) = -1;
316 }
317 }
318}
319#define INIT_JMP_NEW_THREAD 0
320#define INIT_JMP_REMOVE_SIGSTACK 1
321#define INIT_JMP_CALLBACK 2
322#define INIT_JMP_HALT 3
323#define INIT_JMP_REBOOT 4
324
325int copy_context_skas0(unsigned long new_stack, int pid)
326{
327 int err;
328 unsigned long regs[MAX_REG_NR];
329 unsigned long current_stack = current_stub_stack();
330 struct stub_data *data = (struct stub_data *) current_stack;
331 struct stub_data *child_data = (struct stub_data *) new_stack;
332 __u64 new_offset;
333 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
334
335 /* prepare offset and fd of child's stack as argument for parent's
336 * and child's mmap2 calls
337 */
338 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
339 .fd = new_fd,
340 .timer = ((struct itimerval)
341 { { 0, 1000000 / hz() },
342 { 0, 1000000 / hz() }})});
343 get_safe_registers(regs);
344
345 /* Set parent's instruction pointer to start of clone-stub */
346 regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
347 (unsigned long) stub_clone_handler -
348 (unsigned long) &__syscall_stub_start;
349 regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
350 sizeof(void *);
351#ifdef __SIGNAL_FRAMESIZE
352 regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
353#endif
354 err = ptrace_setregs(pid, regs);
355 if(err < 0)
356 panic("copy_context_skas0 : PTRACE_SETREGS failed, "
357 "pid = %d, errno = %d\n", pid, errno);
358
359 /* set a well known return code for detection of child write failure */
360 child_data->err = 12345678;
361
362 /* Wait, until parent has finished its work: read child's pid from
363 * parent's stack, and check, if bad result.
364 */
365 wait_stub_done(pid, 0, "copy_context_skas0");
366
367 pid = data->err;
368 if(pid < 0)
369 panic("copy_context_skas0 - stub-parent reports error %d\n",
370 pid);
371
372 /* Wait, until child has finished too: read child's result from
373 * child's stack and check it.
374 */
375 wait_stub_done(pid, -1, "copy_context_skas0");
376 if (child_data->err != UML_CONFIG_STUB_DATA)
377 panic("copy_context_skas0 - stub-child reports error %d\n",
378 child_data->err);
379
380 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
381 (void *)PTRACE_O_TRACESYSGOOD) < 0)
382 panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
383 "errno = %d\n", errno);
384
385 return pid;
386}
387
388/*
389 * This is used only, if stub pages are needed, while proc_mm is
390 * availabl. Opening /proc/mm creates a new mm_context, which lacks
391 * the stub-pages. Thus, we map them using /proc/mm-fd
392 */
393void map_stub_pages(int fd, unsigned long code,
394 unsigned long data, unsigned long stack)
395{
396 struct proc_mm_op mmop;
397 int n;
398
399 mmop = ((struct proc_mm_op) { .op = MM_MMAP,
400 .u =
401 { .mmap =
402 { .addr = code,
403 .len = PAGE_SIZE,
404 .prot = PROT_EXEC,
405 .flags = MAP_FIXED | MAP_PRIVATE,
406 .fd = stub_code_fd,
407 .offset = stub_code_offset
408 } } });
409 n = os_write_file(fd, &mmop, sizeof(mmop));
410 if(n != sizeof(mmop))
411 panic("map_stub_pages : /proc/mm map for code failed, "
412 "err = %d\n", -n);
413
414 if ( stack ) {
415 __u64 map_offset;
416 int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
417 mmop = ((struct proc_mm_op)
418 { .op = MM_MMAP,
419 .u =
420 { .mmap =
421 { .addr = data,
422 .len = PAGE_SIZE,
423 .prot = PROT_READ | PROT_WRITE,
424 .flags = MAP_FIXED | MAP_SHARED,
425 .fd = map_fd,
426 .offset = map_offset
427 } } });
428 n = os_write_file(fd, &mmop, sizeof(mmop));
429 if(n != sizeof(mmop))
430 panic("map_stub_pages : /proc/mm map for data failed, "
431 "err = %d\n", -n);
432 }
433}
434
435void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
436 void (*handler)(int))
437{
438 unsigned long flags;
439 sigjmp_buf switch_buf, fork_buf;
440
441 *switch_buf_ptr = &switch_buf;
442 *fork_buf_ptr = &fork_buf;
443
444 /* Somewhat subtle - siglongjmp restores the signal mask before doing
445 * the longjmp. This means that when jumping from one stack to another
446 * when the target stack has interrupts enabled, an interrupt may occur
447 * on the source stack. This is bad when starting up a process because
448 * it's not supposed to get timer ticks until it has been scheduled.
449 * So, we disable interrupts around the sigsetjmp to ensure that
450 * they can't happen until we get back here where they are safe.
451 */
452 flags = get_signals();
453 block_signals();
454 if(sigsetjmp(fork_buf, 1) == 0)
455 new_thread_proc(stack, handler);
456
457 remove_sigstack();
458
459 set_signals(flags);
460}
461
462void thread_wait(void *sw, void *fb)
463{
464 sigjmp_buf buf, **switch_buf = sw, *fork_buf;
465
466 *switch_buf = &buf;
467 fork_buf = fb;
468 if(sigsetjmp(buf, 1) == 0)
469 siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
470}
471
472void switch_threads(void *me, void *next)
473{
474 sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
475
476 *me_ptr = &my_buf;
477 if(sigsetjmp(my_buf, 1) == 0)
478 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;
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 = sigsetjmp(initial_jmpbuf, 1);
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 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 siglongjmp(**switch_buf, 1);
520}
521
522void initial_thread_cb_skas(void (*proc)(void *), void *arg)
523{
524 sigjmp_buf here;
525
526 cb_proc = proc;
527 cb_arg = arg;
528 cb_back = &here;
529
530 block_signals();
531 if(sigsetjmp(here, 1) == 0)
532 siglongjmp(initial_jmpbuf, INIT_JMP_CALLBACK);
533 unblock_signals();
534
535 cb_proc = NULL;
536 cb_arg = NULL;
537 cb_back = NULL;
538}
539
540void halt_skas(void)
541{
542 block_signals();
543 siglongjmp(initial_jmpbuf, INIT_JMP_HALT);
544}
545
546void reboot_skas(void)
547{
548 block_signals();
549 siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT);
550}
551
552void switch_mm_skas(struct mm_id *mm_idp)
553{
554 int err;
555
556#warning need cpu pid in switch_mm_skas
557 if(proc_mm){
558 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
559 mm_idp->u.mm_fd);
560 if(err)
561 panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
562 "errno = %d\n", errno);
563 }
564 else userspace_pid[0] = mm_idp->u.pid;
565}