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Commit | Line | Data |
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abaf6977 | 1 | /* |
ba180fd4 | 2 | * Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
abaf6977 GS |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
6 | #include <stdlib.h> | |
abaf6977 | 7 | #include <unistd.h> |
abaf6977 | 8 | #include <sched.h> |
ba180fd4 JD |
9 | #include <errno.h> |
10 | #include <string.h> | |
abaf6977 | 11 | #include <sys/mman.h> |
ba180fd4 JD |
12 | #include <sys/wait.h> |
13 | #include <asm/unistd.h> | |
14 | #include "as-layout.h" | |
510c72a3 | 15 | #include "init.h" |
edea1385 | 16 | #include "kern_util.h" |
abaf6977 | 17 | #include "mem.h" |
ba180fd4 | 18 | #include "os.h" |
ba180fd4 JD |
19 | #include "proc_mm.h" |
20 | #include "ptrace_user.h" | |
21 | #include "registers.h" | |
22 | #include "skas.h" | |
23 | #include "skas_ptrace.h" | |
ba180fd4 | 24 | #include "sysdep/stub.h" |
abaf6977 GS |
25 | |
26 | int is_skas_winch(int pid, int fd, void *data) | |
27 | { | |
17e05209 | 28 | return pid == getpgrp(); |
abaf6977 GS |
29 | } |
30 | ||
f30c2c98 JD |
31 | static int ptrace_dump_regs(int pid) |
32 | { | |
3e6f2ac4 JD |
33 | unsigned long regs[MAX_REG_NR]; |
34 | int i; | |
f30c2c98 | 35 | |
3e6f2ac4 JD |
36 | if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) |
37 | return -errno; | |
ba180fd4 JD |
38 | |
39 | printk(UM_KERN_ERR "Stub registers -\n"); | |
40 | for (i = 0; i < ARRAY_SIZE(regs); i++) | |
41 | printk(UM_KERN_ERR "\t%d - %lx\n", i, regs[i]); | |
f30c2c98 | 42 | |
3e6f2ac4 | 43 | return 0; |
f30c2c98 JD |
44 | } |
45 | ||
16dd07bc JD |
46 | /* |
47 | * Signals that are OK to receive in the stub - we'll just continue it. | |
48 | * SIGWINCH will happen when UML is inside a detached screen. | |
49 | */ | |
3d5ede6f | 50 | #define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH)) |
16dd07bc JD |
51 | |
52 | /* Signals that the stub will finish with - anything else is an error */ | |
ee3d9bd4 | 53 | #define STUB_DONE_MASK (1 << SIGTRAP) |
16dd07bc JD |
54 | |
55 | void wait_stub_done(int pid) | |
abaf6977 GS |
56 | { |
57 | int n, status, err; | |
58 | ||
ba180fd4 | 59 | while (1) { |
4dbed85a | 60 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL)); |
ba180fd4 | 61 | if ((n < 0) || !WIFSTOPPED(status)) |
16dd07bc JD |
62 | goto bad_wait; |
63 | ||
ba180fd4 | 64 | if (((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0) |
16dd07bc JD |
65 | break; |
66 | ||
67 | err = ptrace(PTRACE_CONT, pid, 0, 0); | |
3e6f2ac4 JD |
68 | if (err) { |
69 | printk(UM_KERN_ERR "wait_stub_done : continue failed, " | |
70 | "errno = %d\n", errno); | |
71 | fatal_sigsegv(); | |
72 | } | |
abaf6977 | 73 | } |
16dd07bc | 74 | |
ba180fd4 | 75 | if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0) |
16dd07bc JD |
76 | return; |
77 | ||
78 | bad_wait: | |
79 | err = ptrace_dump_regs(pid); | |
ba180fd4 JD |
80 | if (err) |
81 | printk(UM_KERN_ERR "Failed to get registers from stub, " | |
82 | "errno = %d\n", -err); | |
3e6f2ac4 JD |
83 | printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, " |
84 | "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno, | |
85 | status); | |
86 | fatal_sigsegv(); | |
abaf6977 GS |
87 | } |
88 | ||
89 | extern unsigned long current_stub_stack(void); | |
90 | ||
99764fa4 | 91 | static void get_skas_faultinfo(int pid, struct faultinfo *fi) |
abaf6977 GS |
92 | { |
93 | int err; | |
94 | ||
ba180fd4 | 95 | if (ptrace_faultinfo) { |
abaf6977 | 96 | err = ptrace(PTRACE_FAULTINFO, pid, 0, fi); |
3e6f2ac4 JD |
97 | if (err) { |
98 | printk(UM_KERN_ERR "get_skas_faultinfo - " | |
99 | "PTRACE_FAULTINFO failed, errno = %d\n", errno); | |
100 | fatal_sigsegv(); | |
101 | } | |
abaf6977 GS |
102 | |
103 | /* Special handling for i386, which has different structs */ | |
104 | if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo)) | |
105 | memset((char *)fi + sizeof(struct ptrace_faultinfo), 0, | |
106 | sizeof(struct faultinfo) - | |
107 | sizeof(struct ptrace_faultinfo)); | |
108 | } | |
109 | else { | |
2f56debd JD |
110 | unsigned long fpregs[FP_SIZE]; |
111 | ||
112 | err = get_fp_registers(pid, fpregs); | |
113 | if (err < 0) { | |
114 | printk(UM_KERN_ERR "save_fp_registers returned %d\n", | |
115 | err); | |
116 | fatal_sigsegv(); | |
117 | } | |
16dd07bc | 118 | err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV); |
3e6f2ac4 JD |
119 | if (err) { |
120 | printk(UM_KERN_ERR "Failed to continue stub, pid = %d, " | |
121 | "errno = %d\n", pid, errno); | |
122 | fatal_sigsegv(); | |
123 | } | |
16dd07bc | 124 | wait_stub_done(pid); |
abaf6977 | 125 | |
ba180fd4 JD |
126 | /* |
127 | * faultinfo is prepared by the stub-segv-handler at start of | |
abaf6977 GS |
128 | * the stub stack page. We just have to copy it. |
129 | */ | |
130 | memcpy(fi, (void *)current_stub_stack(), sizeof(*fi)); | |
2f56debd JD |
131 | |
132 | err = put_fp_registers(pid, fpregs); | |
133 | if (err < 0) { | |
134 | printk(UM_KERN_ERR "put_fp_registers returned %d\n", | |
135 | err); | |
136 | fatal_sigsegv(); | |
137 | } | |
abaf6977 GS |
138 | } |
139 | } | |
140 | ||
77bf4400 | 141 | static void handle_segv(int pid, struct uml_pt_regs * regs) |
abaf6977 | 142 | { |
77bf4400 JD |
143 | get_skas_faultinfo(pid, ®s->faultinfo); |
144 | segv(regs->faultinfo, 0, 1, NULL); | |
abaf6977 GS |
145 | } |
146 | ||
ba180fd4 JD |
147 | /* |
148 | * To use the same value of using_sysemu as the caller, ask it that value | |
149 | * (in local_using_sysemu | |
150 | */ | |
151 | static void handle_trap(int pid, struct uml_pt_regs *regs, | |
152 | int local_using_sysemu) | |
abaf6977 GS |
153 | { |
154 | int err, status; | |
155 | ||
e06173bd JD |
156 | if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) |
157 | fatal_sigsegv(); | |
158 | ||
abaf6977 | 159 | /* Mark this as a syscall */ |
18baddda | 160 | UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); |
abaf6977 GS |
161 | |
162 | if (!local_using_sysemu) | |
163 | { | |
966e803a | 164 | err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, |
abaf6977 | 165 | __NR_getpid); |
3e6f2ac4 JD |
166 | if (err < 0) { |
167 | printk(UM_KERN_ERR "handle_trap - nullifying syscall " | |
168 | "failed, errno = %d\n", errno); | |
169 | fatal_sigsegv(); | |
170 | } | |
abaf6977 GS |
171 | |
172 | err = ptrace(PTRACE_SYSCALL, pid, 0, 0); | |
3e6f2ac4 JD |
173 | if (err < 0) { |
174 | printk(UM_KERN_ERR "handle_trap - continuing to end of " | |
175 | "syscall failed, errno = %d\n", errno); | |
176 | fatal_sigsegv(); | |
177 | } | |
abaf6977 | 178 | |
4dbed85a | 179 | CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); |
ba180fd4 | 180 | if ((err < 0) || !WIFSTOPPED(status) || |
3e6f2ac4 JD |
181 | (WSTOPSIG(status) != SIGTRAP + 0x80)) { |
182 | err = ptrace_dump_regs(pid); | |
183 | if (err) | |
184 | printk(UM_KERN_ERR "Failed to get registers " | |
ba180fd4 | 185 | "from process, errno = %d\n", -err); |
3e6f2ac4 JD |
186 | printk(UM_KERN_ERR "handle_trap - failed to wait at " |
187 | "end of syscall, errno = %d, status = %d\n", | |
188 | errno, status); | |
189 | fatal_sigsegv(); | |
190 | } | |
abaf6977 GS |
191 | } |
192 | ||
193 | handle_syscall(regs); | |
194 | } | |
195 | ||
196 | extern int __syscall_stub_start; | |
abaf6977 GS |
197 | |
198 | static int userspace_tramp(void *stack) | |
199 | { | |
200 | void *addr; | |
537ae946 | 201 | int err; |
abaf6977 GS |
202 | |
203 | ptrace(PTRACE_TRACEME, 0, 0, 0); | |
204 | ||
a24864a1 | 205 | signal(SIGTERM, SIG_DFL); |
ee3d9bd4 | 206 | signal(SIGWINCH, SIG_IGN); |
a2f018bf | 207 | err = set_interval(); |
3e6f2ac4 JD |
208 | if (err) { |
209 | printk(UM_KERN_ERR "userspace_tramp - setting timer failed, " | |
210 | "errno = %d\n", err); | |
211 | exit(1); | |
212 | } | |
abaf6977 | 213 | |
ba180fd4 JD |
214 | if (!proc_mm) { |
215 | /* | |
216 | * This has a pte, but it can't be mapped in with the usual | |
abaf6977 GS |
217 | * tlb_flush mechanism because this is part of that mechanism |
218 | */ | |
09ee011e | 219 | int fd; |
ba180fd4 | 220 | unsigned long long offset; |
09ee011e | 221 | fd = phys_mapping(to_phys(&__syscall_stub_start), &offset); |
54ae36f2 | 222 | addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE, |
09ee011e | 223 | PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); |
ba180fd4 | 224 | if (addr == MAP_FAILED) { |
54ae36f2 JD |
225 | printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, " |
226 | "errno = %d\n", STUB_CODE, errno); | |
abaf6977 GS |
227 | exit(1); |
228 | } | |
229 | ||
ba180fd4 | 230 | if (stack != NULL) { |
abaf6977 | 231 | fd = phys_mapping(to_phys(stack), &offset); |
54ae36f2 | 232 | addr = mmap((void *) STUB_DATA, |
1ffb9164 | 233 | UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, |
abaf6977 | 234 | MAP_FIXED | MAP_SHARED, fd, offset); |
ba180fd4 JD |
235 | if (addr == MAP_FAILED) { |
236 | printk(UM_KERN_ERR "mapping segfault stack " | |
54ae36f2 JD |
237 | "at 0x%lx failed, errno = %d\n", |
238 | STUB_DATA, errno); | |
abaf6977 GS |
239 | exit(1); |
240 | } | |
241 | } | |
242 | } | |
ba180fd4 | 243 | if (!ptrace_faultinfo && (stack != NULL)) { |
4b84c69b JD |
244 | struct sigaction sa; |
245 | ||
54ae36f2 | 246 | unsigned long v = STUB_CODE + |
abaf6977 GS |
247 | (unsigned long) stub_segv_handler - |
248 | (unsigned long) &__syscall_stub_start; | |
249 | ||
54ae36f2 | 250 | set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE); |
4b84c69b | 251 | sigemptyset(&sa.sa_mask); |
9b25fcbd AV |
252 | sa.sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO; |
253 | sa.sa_sigaction = (void *) v; | |
4b84c69b | 254 | sa.sa_restorer = NULL; |
3e6f2ac4 JD |
255 | if (sigaction(SIGSEGV, &sa, NULL) < 0) { |
256 | printk(UM_KERN_ERR "userspace_tramp - setting SIGSEGV " | |
257 | "handler failed - errno = %d\n", errno); | |
258 | exit(1); | |
259 | } | |
abaf6977 GS |
260 | } |
261 | ||
512b6fb1 | 262 | kill(os_getpid(), SIGSTOP); |
ba180fd4 | 263 | return 0; |
abaf6977 GS |
264 | } |
265 | ||
266 | /* Each element set once, and only accessed by a single processor anyway */ | |
267 | #undef NR_CPUS | |
268 | #define NR_CPUS 1 | |
269 | int userspace_pid[NR_CPUS]; | |
270 | ||
271 | int start_userspace(unsigned long stub_stack) | |
272 | { | |
273 | void *stack; | |
274 | unsigned long sp; | |
3e6f2ac4 | 275 | int pid, status, n, flags, err; |
abaf6977 | 276 | |
c539ab73 JD |
277 | stack = mmap(NULL, UM_KERN_PAGE_SIZE, |
278 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
abaf6977 | 279 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
3e6f2ac4 JD |
280 | if (stack == MAP_FAILED) { |
281 | err = -errno; | |
282 | printk(UM_KERN_ERR "start_userspace : mmap failed, " | |
b5498832 | 283 | "errno = %d\n", errno); |
3e6f2ac4 JD |
284 | return err; |
285 | } | |
286 | ||
c539ab73 | 287 | sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
abaf6977 | 288 | |
4dbed85a | 289 | flags = CLONE_FILES; |
ba180fd4 JD |
290 | if (proc_mm) |
291 | flags |= CLONE_VM; | |
4dbed85a SG |
292 | else |
293 | flags |= SIGCHLD; | |
ba180fd4 | 294 | |
abaf6977 | 295 | pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack); |
3e6f2ac4 JD |
296 | if (pid < 0) { |
297 | err = -errno; | |
298 | printk(UM_KERN_ERR "start_userspace : clone failed, " | |
b5498832 | 299 | "errno = %d\n", errno); |
3e6f2ac4 JD |
300 | return err; |
301 | } | |
abaf6977 GS |
302 | |
303 | do { | |
4dbed85a | 304 | CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL)); |
3e6f2ac4 JD |
305 | if (n < 0) { |
306 | err = -errno; | |
307 | printk(UM_KERN_ERR "start_userspace : wait failed, " | |
b5498832 | 308 | "errno = %d\n", errno); |
3e6f2ac4 JD |
309 | goto out_kill; |
310 | } | |
ba180fd4 | 311 | } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM)); |
abaf6977 | 312 | |
3e6f2ac4 JD |
313 | if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) { |
314 | err = -EINVAL; | |
315 | printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got " | |
b5498832 | 316 | "status = %d\n", status); |
3e6f2ac4 JD |
317 | goto out_kill; |
318 | } | |
abaf6977 | 319 | |
ba180fd4 | 320 | if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, |
3e6f2ac4 JD |
321 | (void *) PTRACE_O_TRACESYSGOOD) < 0) { |
322 | err = -errno; | |
323 | printk(UM_KERN_ERR "start_userspace : PTRACE_OLDSETOPTIONS " | |
324 | "failed, errno = %d\n", errno); | |
325 | goto out_kill; | |
326 | } | |
abaf6977 | 327 | |
3e6f2ac4 JD |
328 | if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) { |
329 | err = -errno; | |
330 | printk(UM_KERN_ERR "start_userspace : munmap failed, " | |
331 | "errno = %d\n", errno); | |
332 | goto out_kill; | |
333 | } | |
abaf6977 | 334 | |
ba180fd4 | 335 | return pid; |
3e6f2ac4 JD |
336 | |
337 | out_kill: | |
338 | os_kill_ptraced_process(pid, 1); | |
339 | return err; | |
abaf6977 GS |
340 | } |
341 | ||
77bf4400 | 342 | void userspace(struct uml_pt_regs *regs) |
abaf6977 | 343 | { |
d2753a6d JD |
344 | struct itimerval timer; |
345 | unsigned long long nsecs, now; | |
abaf6977 | 346 | int err, status, op, pid = userspace_pid[0]; |
2ea5bc5e JD |
347 | /* To prevent races if using_sysemu changes under us.*/ |
348 | int local_using_sysemu; | |
abaf6977 | 349 | |
d2753a6d | 350 | if (getitimer(ITIMER_VIRTUAL, &timer)) |
5134d8fe | 351 | printk(UM_KERN_ERR "Failed to get itimer, errno = %d\n", errno); |
1a805219 JD |
352 | nsecs = timer.it_value.tv_sec * UM_NSEC_PER_SEC + |
353 | timer.it_value.tv_usec * UM_NSEC_PER_USEC; | |
d2753a6d JD |
354 | nsecs += os_nsecs(); |
355 | ||
ba180fd4 | 356 | while (1) { |
3e6f2ac4 JD |
357 | /* |
358 | * This can legitimately fail if the process loads a | |
359 | * bogus value into a segment register. It will | |
360 | * segfault and PTRACE_GETREGS will read that value | |
361 | * out of the process. However, PTRACE_SETREGS will | |
362 | * fail. In this case, there is nothing to do but | |
363 | * just kill the process. | |
364 | */ | |
d25f2e12 | 365 | if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) |
3e6f2ac4 | 366 | fatal_sigsegv(); |
abaf6977 | 367 | |
fbfe9c84 IL |
368 | if (put_fp_registers(pid, regs->fp)) |
369 | fatal_sigsegv(); | |
370 | ||
abaf6977 GS |
371 | /* Now we set local_using_sysemu to be used for one loop */ |
372 | local_using_sysemu = get_using_sysemu(); | |
373 | ||
2ea5bc5e JD |
374 | op = SELECT_PTRACE_OPERATION(local_using_sysemu, |
375 | singlestepping(NULL)); | |
abaf6977 | 376 | |
3e6f2ac4 JD |
377 | if (ptrace(op, pid, 0, 0)) { |
378 | printk(UM_KERN_ERR "userspace - ptrace continue " | |
379 | "failed, op = %d, errno = %d\n", op, errno); | |
380 | fatal_sigsegv(); | |
381 | } | |
abaf6977 | 382 | |
4dbed85a | 383 | CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); |
3e6f2ac4 JD |
384 | if (err < 0) { |
385 | printk(UM_KERN_ERR "userspace - wait failed, " | |
386 | "errno = %d\n", errno); | |
387 | fatal_sigsegv(); | |
388 | } | |
abaf6977 | 389 | |
77bf4400 | 390 | regs->is_user = 1; |
3e6f2ac4 JD |
391 | if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) { |
392 | printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, " | |
393 | "errno = %d\n", errno); | |
394 | fatal_sigsegv(); | |
395 | } | |
d25f2e12 | 396 | |
fbfe9c84 IL |
397 | if (get_fp_registers(pid, regs->fp)) { |
398 | printk(UM_KERN_ERR "userspace - get_fp_registers failed, " | |
399 | "errno = %d\n", errno); | |
400 | fatal_sigsegv(); | |
401 | } | |
402 | ||
abaf6977 GS |
403 | UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ |
404 | ||
ba180fd4 | 405 | if (WIFSTOPPED(status)) { |
16dd07bc | 406 | int sig = WSTOPSIG(status); |
5134d8fe | 407 | switch (sig) { |
abaf6977 | 408 | case SIGSEGV: |
ba180fd4 JD |
409 | if (PTRACE_FULL_FAULTINFO || |
410 | !ptrace_faultinfo) { | |
411 | get_skas_faultinfo(pid, | |
412 | ®s->faultinfo); | |
16dd07bc JD |
413 | (*sig_info[SIGSEGV])(SIGSEGV, regs); |
414 | } | |
abaf6977 GS |
415 | else handle_segv(pid, regs); |
416 | break; | |
417 | case SIGTRAP + 0x80: | |
418 | handle_trap(pid, regs, local_using_sysemu); | |
419 | break; | |
420 | case SIGTRAP: | |
421 | relay_signal(SIGTRAP, regs); | |
422 | break; | |
abaf6977 | 423 | case SIGVTALRM: |
d2753a6d | 424 | now = os_nsecs(); |
d25f2e12 | 425 | if (now < nsecs) |
d2753a6d JD |
426 | break; |
427 | block_signals(); | |
428 | (*sig_info[sig])(sig, regs); | |
429 | unblock_signals(); | |
1a805219 JD |
430 | nsecs = timer.it_value.tv_sec * |
431 | UM_NSEC_PER_SEC + | |
432 | timer.it_value.tv_usec * | |
433 | UM_NSEC_PER_USEC; | |
d2753a6d JD |
434 | nsecs += os_nsecs(); |
435 | break; | |
436 | case SIGIO: | |
abaf6977 GS |
437 | case SIGILL: |
438 | case SIGBUS: | |
439 | case SIGFPE: | |
440 | case SIGWINCH: | |
16dd07bc JD |
441 | block_signals(); |
442 | (*sig_info[sig])(sig, regs); | |
443 | unblock_signals(); | |
abaf6977 GS |
444 | break; |
445 | default: | |
96cee304 | 446 | printk(UM_KERN_ERR "userspace - child stopped " |
ba180fd4 | 447 | "with signal %d\n", sig); |
3e6f2ac4 | 448 | fatal_sigsegv(); |
abaf6977 | 449 | } |
abaf6977 GS |
450 | pid = userspace_pid[0]; |
451 | interrupt_end(); | |
452 | ||
453 | /* Avoid -ERESTARTSYS handling in host */ | |
ba180fd4 | 454 | if (PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET) |
18baddda | 455 | PT_SYSCALL_NR(regs->gp) = -1; |
abaf6977 GS |
456 | } |
457 | } | |
458 | } | |
abaf6977 | 459 | |
16dd07bc | 460 | static unsigned long thread_regs[MAX_REG_NR]; |
fbfe9c84 | 461 | static unsigned long thread_fp_regs[FP_SIZE]; |
16dd07bc JD |
462 | |
463 | static int __init init_thread_regs(void) | |
464 | { | |
fbfe9c84 | 465 | get_safe_registers(thread_regs, thread_fp_regs); |
16dd07bc | 466 | /* Set parent's instruction pointer to start of clone-stub */ |
54ae36f2 | 467 | thread_regs[REGS_IP_INDEX] = STUB_CODE + |
16dd07bc JD |
468 | (unsigned long) stub_clone_handler - |
469 | (unsigned long) &__syscall_stub_start; | |
54ae36f2 | 470 | thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE - |
16dd07bc JD |
471 | sizeof(void *); |
472 | #ifdef __SIGNAL_FRAMESIZE | |
473 | thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE; | |
474 | #endif | |
475 | return 0; | |
476 | } | |
477 | ||
478 | __initcall(init_thread_regs); | |
479 | ||
abaf6977 GS |
480 | int copy_context_skas0(unsigned long new_stack, int pid) |
481 | { | |
1a805219 | 482 | struct timeval tv = { .tv_sec = 0, .tv_usec = UM_USEC_PER_SEC / UM_HZ }; |
abaf6977 | 483 | int err; |
abaf6977 GS |
484 | unsigned long current_stack = current_stub_stack(); |
485 | struct stub_data *data = (struct stub_data *) current_stack; | |
486 | struct stub_data *child_data = (struct stub_data *) new_stack; | |
0a7675aa | 487 | unsigned long long new_offset; |
abaf6977 GS |
488 | int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset); |
489 | ||
ba180fd4 JD |
490 | /* |
491 | * prepare offset and fd of child's stack as argument for parent's | |
abaf6977 GS |
492 | * and child's mmap2 calls |
493 | */ | |
494 | *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset), | |
495 | .fd = new_fd, | |
496 | .timer = ((struct itimerval) | |
d2753a6d JD |
497 | { .it_value = tv, |
498 | .it_interval = tv }) }); | |
499 | ||
16dd07bc | 500 | err = ptrace_setregs(pid, thread_regs); |
3e6f2ac4 JD |
501 | if (err < 0) { |
502 | err = -errno; | |
503 | printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS " | |
504 | "failed, pid = %d, errno = %d\n", pid, -err); | |
505 | return err; | |
506 | } | |
abaf6977 | 507 | |
fbfe9c84 IL |
508 | err = put_fp_registers(pid, thread_fp_regs); |
509 | if (err < 0) { | |
510 | printk(UM_KERN_ERR "copy_context_skas0 : put_fp_registers " | |
511 | "failed, pid = %d, err = %d\n", pid, err); | |
512 | return err; | |
513 | } | |
514 | ||
abaf6977 GS |
515 | /* set a well known return code for detection of child write failure */ |
516 | child_data->err = 12345678; | |
517 | ||
ba180fd4 JD |
518 | /* |
519 | * Wait, until parent has finished its work: read child's pid from | |
abaf6977 GS |
520 | * parent's stack, and check, if bad result. |
521 | */ | |
16dd07bc | 522 | err = ptrace(PTRACE_CONT, pid, 0, 0); |
3e6f2ac4 JD |
523 | if (err) { |
524 | err = -errno; | |
525 | printk(UM_KERN_ERR "Failed to continue new process, pid = %d, " | |
526 | "errno = %d\n", pid, errno); | |
527 | return err; | |
528 | } | |
529 | ||
16dd07bc | 530 | wait_stub_done(pid); |
abaf6977 GS |
531 | |
532 | pid = data->err; | |
3e6f2ac4 JD |
533 | if (pid < 0) { |
534 | printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports " | |
535 | "error %d\n", -pid); | |
536 | return pid; | |
537 | } | |
abaf6977 | 538 | |
ba180fd4 JD |
539 | /* |
540 | * Wait, until child has finished too: read child's result from | |
abaf6977 GS |
541 | * child's stack and check it. |
542 | */ | |
16dd07bc | 543 | wait_stub_done(pid); |
3e6f2ac4 JD |
544 | if (child_data->err != STUB_DATA) { |
545 | printk(UM_KERN_ERR "copy_context_skas0 - stub-child reports " | |
546 | "error %ld\n", child_data->err); | |
547 | err = child_data->err; | |
548 | goto out_kill; | |
549 | } | |
abaf6977 GS |
550 | |
551 | if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, | |
3e6f2ac4 JD |
552 | (void *)PTRACE_O_TRACESYSGOOD) < 0) { |
553 | err = -errno; | |
554 | printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_OLDSETOPTIONS " | |
555 | "failed, errno = %d\n", errno); | |
556 | goto out_kill; | |
557 | } | |
abaf6977 GS |
558 | |
559 | return pid; | |
3e6f2ac4 JD |
560 | |
561 | out_kill: | |
562 | os_kill_ptraced_process(pid, 1); | |
563 | return err; | |
abaf6977 GS |
564 | } |
565 | ||
566 | /* | |
567 | * This is used only, if stub pages are needed, while proc_mm is | |
ef0470c0 | 568 | * available. Opening /proc/mm creates a new mm_context, which lacks |
abaf6977 GS |
569 | * the stub-pages. Thus, we map them using /proc/mm-fd |
570 | */ | |
3e6f2ac4 JD |
571 | int map_stub_pages(int fd, unsigned long code, unsigned long data, |
572 | unsigned long stack) | |
abaf6977 GS |
573 | { |
574 | struct proc_mm_op mmop; | |
575 | int n; | |
0a7675aa | 576 | unsigned long long code_offset; |
09ee011e JD |
577 | int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start), |
578 | &code_offset); | |
abaf6977 GS |
579 | |
580 | mmop = ((struct proc_mm_op) { .op = MM_MMAP, | |
581 | .u = | |
582 | { .mmap = | |
583 | { .addr = code, | |
c539ab73 | 584 | .len = UM_KERN_PAGE_SIZE, |
abaf6977 GS |
585 | .prot = PROT_EXEC, |
586 | .flags = MAP_FIXED | MAP_PRIVATE, | |
09ee011e JD |
587 | .fd = code_fd, |
588 | .offset = code_offset | |
abaf6977 | 589 | } } }); |
a61f334f | 590 | CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); |
ba180fd4 | 591 | if (n != sizeof(mmop)) { |
a61f334f | 592 | n = errno; |
ba180fd4 JD |
593 | printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, " |
594 | "offset = %llx\n", code, code_fd, | |
595 | (unsigned long long) code_offset); | |
3e6f2ac4 JD |
596 | printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code " |
597 | "failed, err = %d\n", n); | |
598 | return -n; | |
b4cf95c6 | 599 | } |
abaf6977 | 600 | |
ba180fd4 | 601 | if (stack) { |
0a7675aa | 602 | unsigned long long map_offset; |
abaf6977 GS |
603 | int map_fd = phys_mapping(to_phys((void *)stack), &map_offset); |
604 | mmop = ((struct proc_mm_op) | |
605 | { .op = MM_MMAP, | |
606 | .u = | |
607 | { .mmap = | |
608 | { .addr = data, | |
c539ab73 | 609 | .len = UM_KERN_PAGE_SIZE, |
abaf6977 GS |
610 | .prot = PROT_READ | PROT_WRITE, |
611 | .flags = MAP_FIXED | MAP_SHARED, | |
612 | .fd = map_fd, | |
613 | .offset = map_offset | |
614 | } } }); | |
a61f334f | 615 | CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); |
3e6f2ac4 JD |
616 | if (n != sizeof(mmop)) { |
617 | n = errno; | |
618 | printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for " | |
619 | "data failed, err = %d\n", n); | |
620 | return -n; | |
621 | } | |
abaf6977 | 622 | } |
3e6f2ac4 JD |
623 | |
624 | return 0; | |
abaf6977 GS |
625 | } |
626 | ||
3c917350 | 627 | void new_thread(void *stack, jmp_buf *buf, void (*handler)(void)) |
abaf6977 | 628 | { |
3c917350 | 629 | (*buf)[0].JB_IP = (unsigned long) handler; |
e1a79c40 JD |
630 | (*buf)[0].JB_SP = (unsigned long) stack + UM_THREAD_SIZE - |
631 | sizeof(void *); | |
abaf6977 GS |
632 | } |
633 | ||
e2216feb | 634 | #define INIT_JMP_NEW_THREAD 0 |
3c917350 JD |
635 | #define INIT_JMP_CALLBACK 1 |
636 | #define INIT_JMP_HALT 2 | |
637 | #define INIT_JMP_REBOOT 3 | |
abaf6977 | 638 | |
3c917350 | 639 | void switch_threads(jmp_buf *me, jmp_buf *you) |
abaf6977 | 640 | { |
ba180fd4 | 641 | if (UML_SETJMP(me) == 0) |
3c917350 | 642 | UML_LONGJMP(you, 1); |
abaf6977 GS |
643 | } |
644 | ||
ad28e029 | 645 | static jmp_buf initial_jmpbuf; |
abaf6977 GS |
646 | |
647 | /* XXX Make these percpu */ | |
648 | static void (*cb_proc)(void *arg); | |
649 | static void *cb_arg; | |
ad28e029 | 650 | static jmp_buf *cb_back; |
abaf6977 | 651 | |
3c917350 | 652 | int start_idle_thread(void *stack, jmp_buf *switch_buf) |
abaf6977 | 653 | { |
a5df0d1a | 654 | int n; |
abaf6977 | 655 | |
00361683 | 656 | set_handler(SIGWINCH); |
abaf6977 | 657 | |
77f6af77 JD |
658 | /* |
659 | * Can't use UML_SETJMP or UML_LONGJMP here because they save | |
660 | * and restore signals, with the possible side-effect of | |
661 | * trying to handle any signals which came when they were | |
662 | * blocked, which can't be done on this stack. | |
663 | * Signals must be blocked when jumping back here and restored | |
664 | * after returning to the jumper. | |
665 | */ | |
666 | n = setjmp(initial_jmpbuf); | |
5134d8fe | 667 | switch (n) { |
abaf6977 | 668 | case INIT_JMP_NEW_THREAD: |
3c917350 JD |
669 | (*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler; |
670 | (*switch_buf)[0].JB_SP = (unsigned long) stack + | |
e1a79c40 | 671 | UM_THREAD_SIZE - sizeof(void *); |
abaf6977 GS |
672 | break; |
673 | case INIT_JMP_CALLBACK: | |
674 | (*cb_proc)(cb_arg); | |
77f6af77 | 675 | longjmp(*cb_back, 1); |
abaf6977 GS |
676 | break; |
677 | case INIT_JMP_HALT: | |
678 | kmalloc_ok = 0; | |
ba180fd4 | 679 | return 0; |
abaf6977 GS |
680 | case INIT_JMP_REBOOT: |
681 | kmalloc_ok = 0; | |
ba180fd4 | 682 | return 1; |
abaf6977 | 683 | default: |
3e6f2ac4 JD |
684 | printk(UM_KERN_ERR "Bad sigsetjmp return in " |
685 | "start_idle_thread - %d\n", n); | |
686 | fatal_sigsegv(); | |
abaf6977 | 687 | } |
77f6af77 | 688 | longjmp(*switch_buf, 1); |
abaf6977 GS |
689 | } |
690 | ||
691 | void initial_thread_cb_skas(void (*proc)(void *), void *arg) | |
692 | { | |
ad28e029 | 693 | jmp_buf here; |
abaf6977 GS |
694 | |
695 | cb_proc = proc; | |
696 | cb_arg = arg; | |
697 | cb_back = &here; | |
698 | ||
699 | block_signals(); | |
ba180fd4 | 700 | if (UML_SETJMP(&here) == 0) |
ad28e029 | 701 | UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK); |
abaf6977 GS |
702 | unblock_signals(); |
703 | ||
704 | cb_proc = NULL; | |
705 | cb_arg = NULL; | |
706 | cb_back = NULL; | |
707 | } | |
708 | ||
709 | void halt_skas(void) | |
710 | { | |
711 | block_signals(); | |
ad28e029 | 712 | UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT); |
abaf6977 GS |
713 | } |
714 | ||
715 | void reboot_skas(void) | |
716 | { | |
717 | block_signals(); | |
ad28e029 | 718 | UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT); |
abaf6977 GS |
719 | } |
720 | ||
77bf4400 | 721 | void __switch_mm(struct mm_id *mm_idp) |
abaf6977 GS |
722 | { |
723 | int err; | |
724 | ||
77bf4400 | 725 | /* FIXME: need cpu pid in __switch_mm */ |
ba180fd4 | 726 | if (proc_mm) { |
abaf6977 GS |
727 | err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, |
728 | mm_idp->u.mm_fd); | |
3e6f2ac4 JD |
729 | if (err) { |
730 | printk(UM_KERN_ERR "__switch_mm - PTRACE_SWITCH_MM " | |
731 | "failed, errno = %d\n", errno); | |
732 | fatal_sigsegv(); | |
733 | } | |
abaf6977 GS |
734 | } |
735 | else userspace_pid[0] = mm_idp->u.pid; | |
736 | } |