1 /*-
2 * Copyright (c) 1994-1996 Søren Schmidt
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/exec.h>
35 #include <sys/fcntl.h>
36 #include <sys/imgact.h>
37 #include <sys/imgact_aout.h>
38 #include <sys/imgact_elf.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/signalvar.h>
46 #include <sys/syscallsubr.h>
47 #include <sys/sysctl.h>
48 #include <sys/sysent.h>
49 #include <sys/sysproto.h>
50 #include <sys/vnode.h>
51 #include <sys/eventhandler.h>
52
53 #include <vm/vm.h>
54 #include <vm/pmap.h>
55 #include <vm/vm_extern.h>
56 #include <vm/vm_map.h>
57 #include <vm/vm_object.h>
58 #include <vm/vm_page.h>
59 #include <vm/vm_param.h>
60
61 #include <machine/cpu.h>
62 #include <machine/cputypes.h>
63 #include <machine/md_var.h>
64 #include <machine/pcb.h>
65
66 #include <i386/linux/linux.h>
67 #include <i386/linux/linux_proto.h>
68 #include <compat/linux/linux_emul.h>
69 #include <compat/linux/linux_futex.h>
70 #include <compat/linux/linux_ioctl.h>
71 #include <compat/linux/linux_mib.h>
72 #include <compat/linux/linux_misc.h>
73 #include <compat/linux/linux_signal.h>
74 #include <compat/linux/linux_util.h>
75 #include <compat/linux/linux_vdso.h>
76
77 MODULE_VERSION(linux, 1);
78
79 #if defined(DEBUG)
80 SYSCTL_PROC(_compat_linux, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
81 linux_sysctl_debug, "A", "Linux debugging control");
82 #endif
83
84 /*
85 * Allow the sendsig functions to use the ldebug() facility even though they
86 * are not syscalls themselves. Map them to syscall 0. This is slightly less
87 * bogus than using ldebug(sigreturn).
88 */
89 #define LINUX_SYS_linux_rt_sendsig 0
90 #define LINUX_SYS_linux_sendsig 0
91
92 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings))
93
94 static int linux_szsigcode;
95 static vm_object_t linux_shared_page_obj;
96 static char *linux_shared_page_mapping;
97 extern char _binary_linux_locore_o_start;
98 extern char _binary_linux_locore_o_end;
99
100 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
101
102 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
103
104 static int linux_fixup(register_t **stack_base,
105 struct image_params *iparams);
106 static int linux_fixup_elf(register_t **stack_base,
107 struct image_params *iparams);
108 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
109 static void linux_exec_setregs(struct thread *td,
110 struct image_params *imgp, u_long stack);
111 static register_t *linux_copyout_strings(struct image_params *imgp);
112 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
113 static void linux_vdso_install(void *param);
114 static void linux_vdso_deinstall(void *param);
115
116 static int linux_szplatform;
117 const char *linux_kplatform;
118
119 static eventhandler_tag linux_exit_tag;
120 static eventhandler_tag linux_exec_tag;
121 static eventhandler_tag linux_thread_dtor_tag;
122
123 #define LINUX_T_UNKNOWN 255
124 static int _bsd_to_linux_trapcode[] = {
125 LINUX_T_UNKNOWN, /* 0 */
126 6, /* 1 T_PRIVINFLT */
127 LINUX_T_UNKNOWN, /* 2 */
128 3, /* 3 T_BPTFLT */
129 LINUX_T_UNKNOWN, /* 4 */
130 LINUX_T_UNKNOWN, /* 5 */
131 16, /* 6 T_ARITHTRAP */
132 254, /* 7 T_ASTFLT */
133 LINUX_T_UNKNOWN, /* 8 */
134 13, /* 9 T_PROTFLT */
135 1, /* 10 T_TRCTRAP */
136 LINUX_T_UNKNOWN, /* 11 */
137 14, /* 12 T_PAGEFLT */
138 LINUX_T_UNKNOWN, /* 13 */
139 17, /* 14 T_ALIGNFLT */
140 LINUX_T_UNKNOWN, /* 15 */
141 LINUX_T_UNKNOWN, /* 16 */
142 LINUX_T_UNKNOWN, /* 17 */
143 0, /* 18 T_DIVIDE */
144 2, /* 19 T_NMI */
145 4, /* 20 T_OFLOW */
146 5, /* 21 T_BOUND */
147 7, /* 22 T_DNA */
148 8, /* 23 T_DOUBLEFLT */
149 9, /* 24 T_FPOPFLT */
150 10, /* 25 T_TSSFLT */
151 11, /* 26 T_SEGNPFLT */
152 12, /* 27 T_STKFLT */
153 18, /* 28 T_MCHK */
154 19, /* 29 T_XMMFLT */
155 15 /* 30 T_RESERVED */
156 };
157 #define bsd_to_linux_trapcode(code) \
158 ((code)<nitems(_bsd_to_linux_trapcode)? \
159 _bsd_to_linux_trapcode[(code)]: \
160 LINUX_T_UNKNOWN)
161
162 LINUX_VDSO_SYM_INTPTR(linux_sigcode);
163 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
164 LINUX_VDSO_SYM_INTPTR(linux_vsyscall);
165
166 /*
167 * If FreeBSD & Linux have a difference of opinion about what a trap
168 * means, deal with it here.
169 *
170 * MPSAFE
171 */
172 static int
173 linux_translate_traps(int signal, int trap_code)
174 {
175 if (signal != SIGBUS)
176 return (signal);
177 switch (trap_code) {
178 case T_PROTFLT:
179 case T_TSSFLT:
180 case T_DOUBLEFLT:
181 case T_PAGEFLT:
182 return (SIGSEGV);
183 default:
184 return (signal);
185 }
186 }
187
188 static int
189 linux_fixup(register_t **stack_base, struct image_params *imgp)
190 {
191 register_t *argv, *envp;
192
193 argv = *stack_base;
194 envp = *stack_base + (imgp->args->argc + 1);
195 (*stack_base)--;
196 suword(*stack_base, (intptr_t)(void *)envp);
197 (*stack_base)--;
198 suword(*stack_base, (intptr_t)(void *)argv);
199 (*stack_base)--;
200 suword(*stack_base, imgp->args->argc);
201 return (0);
202 }
203
204 static int
205 linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
206 {
207 struct proc *p;
208 Elf32_Auxargs *args;
209 Elf32_Addr *uplatform;
210 struct ps_strings *arginfo;
211 register_t *pos;
212 int issetugid;
213
214 KASSERT(curthread->td_proc == imgp->proc,
215 ("unsafe linux_fixup_elf(), should be curproc"));
216
217 p = imgp->proc;
218 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
219 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
220 uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
221 args = (Elf32_Auxargs *)imgp->auxargs;
222 pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
223
224 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
225 imgp->proc->p_sysent->sv_shared_page_base);
226 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall);
227 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
228
229 /*
230 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
231 * as it has appeared in the 2.4.0-rc7 first time.
232 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
233 * glibc falls back to the hard-coded CLK_TCK value when aux entry
234 * is not present.
235 * Also see linux_times() implementation.
236 */
237 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
238 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
239 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
240 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
241 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
242 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
243 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
244 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
245 AUXARGS_ENTRY(pos, AT_BASE, args->base);
246 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
247 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
248 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
249 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
250 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
251 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
252 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
253 if (imgp->execpathp != 0)
254 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
255 if (args->execfd != -1)
256 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
257 AUXARGS_ENTRY(pos, AT_NULL, 0);
258
259 free(imgp->auxargs, M_TEMP);
260 imgp->auxargs = NULL;
261
262 (*stack_base)--;
263 suword(*stack_base, (register_t)imgp->args->argc);
264 return (0);
265 }
266
267 /*
268 * Copied from kern/kern_exec.c
269 */
270 static register_t *
271 linux_copyout_strings(struct image_params *imgp)
272 {
273 int argc, envc;
274 char **vectp;
275 char *stringp, *destp;
276 register_t *stack_base;
277 struct ps_strings *arginfo;
278 char canary[LINUX_AT_RANDOM_LEN];
279 size_t execpath_len;
280 struct proc *p;
281
282 /* Calculate string base and vector table pointers. */
283 p = imgp->proc;
284 if (imgp->execpath != NULL && imgp->auxargs != NULL)
285 execpath_len = strlen(imgp->execpath) + 1;
286 else
287 execpath_len = 0;
288 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
289 destp = (caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform -
290 roundup(sizeof(canary), sizeof(char *)) -
291 roundup(execpath_len, sizeof(char *)) -
292 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
293
294 /* Install LINUX_PLATFORM. */
295 copyout(linux_kplatform, ((caddr_t)arginfo - linux_szplatform),
296 linux_szplatform);
297
298 if (execpath_len != 0) {
299 imgp->execpathp = (uintptr_t)arginfo -
300 linux_szplatform - execpath_len;
301 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
302 }
303
304 /* Prepare the canary for SSP. */
305 arc4rand(canary, sizeof(canary), 0);
306 imgp->canary = (uintptr_t)arginfo - linux_szplatform -
307 roundup(execpath_len, sizeof(char *)) -
308 roundup(sizeof(canary), sizeof(char *));
309 copyout(canary, (void *)imgp->canary, sizeof(canary));
310
311 vectp = (char **)destp;
312 if (imgp->auxargs) {
313 /*
314 * Allocate room on the stack for the ELF auxargs
315 * array. It has LINUX_AT_COUNT entries.
316 */
317 vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo),
318 sizeof(*vectp));
319 }
320
321 /*
322 * Allocate room for the argv[] and env vectors including the
323 * terminating NULL pointers.
324 */
325 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
326
327 /* vectp also becomes our initial stack base. */
328 stack_base = (register_t *)vectp;
329
330 stringp = imgp->args->begin_argv;
331 argc = imgp->args->argc;
332 envc = imgp->args->envc;
333
334 /* Copy out strings - arguments and environment. */
335 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
336
337 /* Fill in "ps_strings" struct for ps, w, etc. */
338 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
339 suword(&arginfo->ps_nargvstr, argc);
340
341 /* Fill in argument portion of vector table. */
342 for (; argc > 0; --argc) {
343 suword(vectp++, (long)(intptr_t)destp);
344 while (*stringp++ != 0)
345 destp++;
346 destp++;
347 }
348
349 /* A null vector table pointer separates the argp's from the envp's. */
350 suword(vectp++, 0);
351
352 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
353 suword(&arginfo->ps_nenvstr, envc);
354
355 /* Fill in environment portion of vector table. */
356 for (; envc > 0; --envc) {
357 suword(vectp++, (long)(intptr_t)destp);
358 while (*stringp++ != 0)
359 destp++;
360 destp++;
361 }
362
363 /* The end of the vector table is a null pointer. */
364 suword(vectp, 0);
365
366 return (stack_base);
367 }
368
369 static void
370 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
371 {
372 struct thread *td = curthread;
373 struct proc *p = td->td_proc;
374 struct sigacts *psp;
375 struct trapframe *regs;
376 struct l_rt_sigframe *fp, frame;
377 int sig, code;
378 int oonstack;
379
380 sig = ksi->ksi_signo;
381 code = ksi->ksi_code;
382 PROC_LOCK_ASSERT(p, MA_OWNED);
383 psp = p->p_sigacts;
384 mtx_assert(&psp->ps_mtx, MA_OWNED);
385 regs = td->td_frame;
386 oonstack = sigonstack(regs->tf_esp);
387
388 #ifdef DEBUG
389 if (ldebug(rt_sendsig))
390 printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
391 catcher, sig, (void*)mask, code);
392 #endif
393 /* Allocate space for the signal handler context. */
394 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
395 SIGISMEMBER(psp->ps_sigonstack, sig)) {
396 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
397 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
398 } else
399 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
400 mtx_unlock(&psp->ps_mtx);
401
402 /* Build the argument list for the signal handler. */
403 sig = bsd_to_linux_signal(sig);
404
405 bzero(&frame, sizeof(frame));
406
407 frame.sf_handler = catcher;
408 frame.sf_sig = sig;
409 frame.sf_siginfo = &fp->sf_si;
410 frame.sf_ucontext = &fp->sf_sc;
411
412 /* Fill in POSIX parts. */
413 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
414
415 /* Build the signal context to be used by sigreturn. */
416 frame.sf_sc.uc_flags = 0; /* XXX ??? */
417 frame.sf_sc.uc_link = NULL; /* XXX ??? */
418
419 frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
420 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
421 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
422 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
423 PROC_UNLOCK(p);
424
425 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
426
427 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
428 frame.sf_sc.uc_mcontext.sc_gs = rgs();
429 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
430 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
431 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
432 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
433 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
434 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
435 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
436 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp;
437 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
438 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
439 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
440 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
441 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
442 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
443 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
444 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
445 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
446 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
447 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
448
449 #ifdef DEBUG
450 if (ldebug(rt_sendsig))
451 printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
452 frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
453 td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
454 #endif
455
456 if (copyout(&frame, fp, sizeof(frame)) != 0) {
457 /*
458 * Process has trashed its stack; give it an illegal
459 * instruction to halt it in its tracks.
460 */
461 #ifdef DEBUG
462 if (ldebug(rt_sendsig))
463 printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
464 fp, oonstack);
465 #endif
466 PROC_LOCK(p);
467 sigexit(td, SIGILL);
468 }
469
470 /* Build context to run handler in. */
471 regs->tf_esp = (int)fp;
472 regs->tf_eip = linux_rt_sigcode;
473 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
474 regs->tf_cs = _ucodesel;
475 regs->tf_ds = _udatasel;
476 regs->tf_es = _udatasel;
477 regs->tf_fs = _udatasel;
478 regs->tf_ss = _udatasel;
479 PROC_LOCK(p);
480 mtx_lock(&psp->ps_mtx);
481 }
482
483
484 /*
485 * Send an interrupt to process.
486 *
487 * Stack is set up to allow sigcode stored
488 * in u. to call routine, followed by kcall
489 * to sigreturn routine below. After sigreturn
490 * resets the signal mask, the stack, and the
491 * frame pointer, it returns to the user
492 * specified pc, psl.
493 */
494 static void
495 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
496 {
497 struct thread *td = curthread;
498 struct proc *p = td->td_proc;
499 struct sigacts *psp;
500 struct trapframe *regs;
501 struct l_sigframe *fp, frame;
502 l_sigset_t lmask;
503 int sig, code;
504 int oonstack;
505
506 PROC_LOCK_ASSERT(p, MA_OWNED);
507 psp = p->p_sigacts;
508 sig = ksi->ksi_signo;
509 code = ksi->ksi_code;
510 mtx_assert(&psp->ps_mtx, MA_OWNED);
511 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
512 /* Signal handler installed with SA_SIGINFO. */
513 linux_rt_sendsig(catcher, ksi, mask);
514 return;
515 }
516 regs = td->td_frame;
517 oonstack = sigonstack(regs->tf_esp);
518
519 #ifdef DEBUG
520 if (ldebug(sendsig))
521 printf(ARGS(sendsig, "%p, %d, %p, %u"),
522 catcher, sig, (void*)mask, code);
523 #endif
524
525 /* Allocate space for the signal handler context. */
526 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
527 SIGISMEMBER(psp->ps_sigonstack, sig)) {
528 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
529 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
530 } else
531 fp = (struct l_sigframe *)regs->tf_esp - 1;
532 mtx_unlock(&psp->ps_mtx);
533 PROC_UNLOCK(p);
534
535 /* Build the argument list for the signal handler. */
536 sig = bsd_to_linux_signal(sig);
537
538 bzero(&frame, sizeof(frame));
539
540 frame.sf_handler = catcher;
541 frame.sf_sig = sig;
542
543 bsd_to_linux_sigset(mask, &lmask);
544
545 /* Build the signal context to be used by sigreturn. */
546 frame.sf_sc.sc_mask = lmask.__mask;
547 frame.sf_sc.sc_gs = rgs();
548 frame.sf_sc.sc_fs = regs->tf_fs;
549 frame.sf_sc.sc_es = regs->tf_es;
550 frame.sf_sc.sc_ds = regs->tf_ds;
551 frame.sf_sc.sc_edi = regs->tf_edi;
552 frame.sf_sc.sc_esi = regs->tf_esi;
553 frame.sf_sc.sc_ebp = regs->tf_ebp;
554 frame.sf_sc.sc_ebx = regs->tf_ebx;
555 frame.sf_sc.sc_esp = regs->tf_esp;
556 frame.sf_sc.sc_edx = regs->tf_edx;
557 frame.sf_sc.sc_ecx = regs->tf_ecx;
558 frame.sf_sc.sc_eax = regs->tf_eax;
559 frame.sf_sc.sc_eip = regs->tf_eip;
560 frame.sf_sc.sc_cs = regs->tf_cs;
561 frame.sf_sc.sc_eflags = regs->tf_eflags;
562 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
563 frame.sf_sc.sc_ss = regs->tf_ss;
564 frame.sf_sc.sc_err = regs->tf_err;
565 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
566 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
567
568 frame.sf_extramask[0] = lmask.__mask;
569
570 if (copyout(&frame, fp, sizeof(frame)) != 0) {
571 /*
572 * Process has trashed its stack; give it an illegal
573 * instruction to halt it in its tracks.
574 */
575 PROC_LOCK(p);
576 sigexit(td, SIGILL);
577 }
578
579 /* Build context to run handler in. */
580 regs->tf_esp = (int)fp;
581 regs->tf_eip = linux_sigcode;
582 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
583 regs->tf_cs = _ucodesel;
584 regs->tf_ds = _udatasel;
585 regs->tf_es = _udatasel;
586 regs->tf_fs = _udatasel;
587 regs->tf_ss = _udatasel;
588 PROC_LOCK(p);
589 mtx_lock(&psp->ps_mtx);
590 }
591
592 /*
593 * System call to cleanup state after a signal
594 * has been taken. Reset signal mask and
595 * stack state from context left by sendsig (above).
596 * Return to previous pc and psl as specified by
597 * context left by sendsig. Check carefully to
598 * make sure that the user has not modified the
599 * psl to gain improper privileges or to cause
600 * a machine fault.
601 */
602 int
603 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
604 {
605 struct l_sigframe frame;
606 struct trapframe *regs;
607 l_sigset_t lmask;
608 sigset_t bmask;
609 int eflags;
610 ksiginfo_t ksi;
611
612 regs = td->td_frame;
613
614 #ifdef DEBUG
615 if (ldebug(sigreturn))
616 printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
617 #endif
618 /*
619 * The trampoline code hands us the sigframe.
620 * It is unsafe to keep track of it ourselves, in the event that a
621 * program jumps out of a signal handler.
622 */
623 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
624 return (EFAULT);
625
626 /* Check for security violations. */
627 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
628 eflags = frame.sf_sc.sc_eflags;
629 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
630 return (EINVAL);
631
632 /*
633 * Don't allow users to load a valid privileged %cs. Let the
634 * hardware check for invalid selectors, excess privilege in
635 * other selectors, invalid %eip's and invalid %esp's.
636 */
637 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
638 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
639 ksiginfo_init_trap(&ksi);
640 ksi.ksi_signo = SIGBUS;
641 ksi.ksi_code = BUS_OBJERR;
642 ksi.ksi_trapno = T_PROTFLT;
643 ksi.ksi_addr = (void *)regs->tf_eip;
644 trapsignal(td, &ksi);
645 return (EINVAL);
646 }
647
648 lmask.__mask = frame.sf_sc.sc_mask;
649 linux_to_bsd_sigset(&lmask, &bmask);
650 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
651
652 /* Restore signal context. */
653 /* %gs was restored by the trampoline. */
654 regs->tf_fs = frame.sf_sc.sc_fs;
655 regs->tf_es = frame.sf_sc.sc_es;
656 regs->tf_ds = frame.sf_sc.sc_ds;
657 regs->tf_edi = frame.sf_sc.sc_edi;
658 regs->tf_esi = frame.sf_sc.sc_esi;
659 regs->tf_ebp = frame.sf_sc.sc_ebp;
660 regs->tf_ebx = frame.sf_sc.sc_ebx;
661 regs->tf_edx = frame.sf_sc.sc_edx;
662 regs->tf_ecx = frame.sf_sc.sc_ecx;
663 regs->tf_eax = frame.sf_sc.sc_eax;
664 regs->tf_eip = frame.sf_sc.sc_eip;
665 regs->tf_cs = frame.sf_sc.sc_cs;
666 regs->tf_eflags = eflags;
667 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
668 regs->tf_ss = frame.sf_sc.sc_ss;
669
670 return (EJUSTRETURN);
671 }
672
673 /*
674 * System call to cleanup state after a signal
675 * has been taken. Reset signal mask and
676 * stack state from context left by rt_sendsig (above).
677 * Return to previous pc and psl as specified by
678 * context left by sendsig. Check carefully to
679 * make sure that the user has not modified the
680 * psl to gain improper privileges or to cause
681 * a machine fault.
682 */
683 int
684 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
685 {
686 struct l_ucontext uc;
687 struct l_sigcontext *context;
688 sigset_t bmask;
689 l_stack_t *lss;
690 stack_t ss;
691 struct trapframe *regs;
692 int eflags;
693 ksiginfo_t ksi;
694
695 regs = td->td_frame;
696
697 #ifdef DEBUG
698 if (ldebug(rt_sigreturn))
699 printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
700 #endif
701 /*
702 * The trampoline code hands us the ucontext.
703 * It is unsafe to keep track of it ourselves, in the event that a
704 * program jumps out of a signal handler.
705 */
706 if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
707 return (EFAULT);
708
709 context = &uc.uc_mcontext;
710
711 /* Check for security violations. */
712 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
713 eflags = context->sc_eflags;
714 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
715 return (EINVAL);
716
717 /*
718 * Don't allow users to load a valid privileged %cs. Let the
719 * hardware check for invalid selectors, excess privilege in
720 * other selectors, invalid %eip's and invalid %esp's.
721 */
722 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
723 if (!CS_SECURE(context->sc_cs)) {
724 ksiginfo_init_trap(&ksi);
725 ksi.ksi_signo = SIGBUS;
726 ksi.ksi_code = BUS_OBJERR;
727 ksi.ksi_trapno = T_PROTFLT;
728 ksi.ksi_addr = (void *)regs->tf_eip;
729 trapsignal(td, &ksi);
730 return (EINVAL);
731 }
732
733 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
734 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
735
736 /* Restore signal context. */
737 /* %gs was restored by the trampoline. */
738 regs->tf_fs = context->sc_fs;
739 regs->tf_es = context->sc_es;
740 regs->tf_ds = context->sc_ds;
741 regs->tf_edi = context->sc_edi;
742 regs->tf_esi = context->sc_esi;
743 regs->tf_ebp = context->sc_ebp;
744 regs->tf_ebx = context->sc_ebx;
745 regs->tf_edx = context->sc_edx;
746 regs->tf_ecx = context->sc_ecx;
747 regs->tf_eax = context->sc_eax;
748 regs->tf_eip = context->sc_eip;
749 regs->tf_cs = context->sc_cs;
750 regs->tf_eflags = eflags;
751 regs->tf_esp = context->sc_esp_at_signal;
752 regs->tf_ss = context->sc_ss;
753
754 /* Call sigaltstack & ignore results. */
755 lss = &uc.uc_stack;
756 ss.ss_sp = lss->ss_sp;
757 ss.ss_size = lss->ss_size;
758 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
759
760 #ifdef DEBUG
761 if (ldebug(rt_sigreturn))
762 printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
763 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
764 #endif
765 (void)kern_sigaltstack(td, &ss, NULL);
766
767 return (EJUSTRETURN);
768 }
769
770 static int
771 linux_fetch_syscall_args(struct thread *td)
772 {
773 struct proc *p;
774 struct trapframe *frame;
775 struct syscall_args *sa;
776
777 p = td->td_proc;
778 frame = td->td_frame;
779 sa = &td->td_sa;
780
781 sa->code = frame->tf_eax;
782 sa->args[0] = frame->tf_ebx;
783 sa->args[1] = frame->tf_ecx;
784 sa->args[2] = frame->tf_edx;
785 sa->args[3] = frame->tf_esi;
786 sa->args[4] = frame->tf_edi;
787 sa->args[5] = frame->tf_ebp; /* Unconfirmed */
788
789 if (sa->code >= p->p_sysent->sv_size)
790 /* nosys */
791 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
792 else
793 sa->callp = &p->p_sysent->sv_table[sa->code];
794 sa->narg = sa->callp->sy_narg;
795
796 td->td_retval[0] = 0;
797 td->td_retval[1] = frame->tf_edx;
798
799 return (0);
800 }
801
802 /*
803 * exec_setregs may initialize some registers differently than Linux
804 * does, thus potentially confusing Linux binaries. If necessary, we
805 * override the exec_setregs default(s) here.
806 */
807 static void
808 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
809 {
810 struct pcb *pcb = td->td_pcb;
811
812 exec_setregs(td, imgp, stack);
813
814 /* Linux sets %gs to 0, we default to _udatasel. */
815 pcb->pcb_gs = 0;
816 load_gs(0);
817
818 pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
819 }
820
821 static void
822 linux_get_machine(const char **dst)
823 {
824
825 switch (cpu_class) {
826 case CPUCLASS_686:
827 *dst = "i686";
828 break;
829 case CPUCLASS_586:
830 *dst = "i586";
831 break;
832 case CPUCLASS_486:
833 *dst = "i486";
834 break;
835 default:
836 *dst = "i386";
837 }
838 }
839
840 struct sysentvec linux_sysvec = {
841 .sv_size = LINUX_SYS_MAXSYSCALL,
842 .sv_table = linux_sysent,
843 .sv_mask = 0,
844 .sv_errsize = ELAST + 1,
845 .sv_errtbl = linux_errtbl,
846 .sv_transtrap = linux_translate_traps,
847 .sv_fixup = linux_fixup,
848 .sv_sendsig = linux_sendsig,
849 .sv_sigcode = &_binary_linux_locore_o_start,
850 .sv_szsigcode = &linux_szsigcode,
851 .sv_name = "Linux a.out",
852 .sv_coredump = NULL,
853 .sv_imgact_try = linux_exec_imgact_try,
854 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
855 .sv_pagesize = PAGE_SIZE,
856 .sv_minuser = VM_MIN_ADDRESS,
857 .sv_maxuser = VM_MAXUSER_ADDRESS,
858 .sv_usrstack = LINUX_USRSTACK,
859 .sv_psstrings = PS_STRINGS,
860 .sv_stackprot = VM_PROT_ALL,
861 .sv_copyout_strings = exec_copyout_strings,
862 .sv_setregs = linux_exec_setregs,
863 .sv_fixlimit = NULL,
864 .sv_maxssiz = NULL,
865 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
866 .sv_set_syscall_retval = cpu_set_syscall_retval,
867 .sv_fetch_syscall_args = linux_fetch_syscall_args,
868 .sv_syscallnames = NULL,
869 .sv_shared_page_base = LINUX_SHAREDPAGE,
870 .sv_shared_page_len = PAGE_SIZE,
871 .sv_schedtail = linux_schedtail,
872 .sv_thread_detach = linux_thread_detach,
873 .sv_trap = NULL,
874 };
875 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
876
877 struct sysentvec elf_linux_sysvec = {
878 .sv_size = LINUX_SYS_MAXSYSCALL,
879 .sv_table = linux_sysent,
880 .sv_mask = 0,
881 .sv_errsize = ELAST + 1,
882 .sv_errtbl = linux_errtbl,
883 .sv_transtrap = linux_translate_traps,
884 .sv_fixup = linux_fixup_elf,
885 .sv_sendsig = linux_sendsig,
886 .sv_sigcode = &_binary_linux_locore_o_start,
887 .sv_szsigcode = &linux_szsigcode,
888 .sv_name = "Linux ELF",
889 .sv_coredump = elf32_coredump,
890 .sv_imgact_try = linux_exec_imgact_try,
891 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
892 .sv_pagesize = PAGE_SIZE,
893 .sv_minuser = VM_MIN_ADDRESS,
894 .sv_maxuser = VM_MAXUSER_ADDRESS,
895 .sv_usrstack = LINUX_USRSTACK,
896 .sv_psstrings = LINUX_PS_STRINGS,
897 .sv_stackprot = VM_PROT_ALL,
898 .sv_copyout_strings = linux_copyout_strings,
899 .sv_setregs = linux_exec_setregs,
900 .sv_fixlimit = NULL,
901 .sv_maxssiz = NULL,
902 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
903 .sv_set_syscall_retval = cpu_set_syscall_retval,
904 .sv_fetch_syscall_args = linux_fetch_syscall_args,
905 .sv_syscallnames = NULL,
906 .sv_shared_page_base = LINUX_SHAREDPAGE,
907 .sv_shared_page_len = PAGE_SIZE,
908 .sv_schedtail = linux_schedtail,
909 .sv_thread_detach = linux_thread_detach,
910 .sv_trap = NULL,
911 };
912
913 static void
914 linux_vdso_install(void *param)
915 {
916
917 linux_szsigcode = (&_binary_linux_locore_o_end -
918 &_binary_linux_locore_o_start);
919
920 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
921 panic("Linux invalid vdso size\n");
922
923 __elfN(linux_vdso_fixup)(&elf_linux_sysvec);
924
925 linux_shared_page_obj = __elfN(linux_shared_page_init)
926 (&linux_shared_page_mapping);
927
928 __elfN(linux_vdso_reloc)(&elf_linux_sysvec);
929
930 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
931 linux_szsigcode);
932 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
933 }
934 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
935 linux_vdso_install, NULL);
936
937 static void
938 linux_vdso_deinstall(void *param)
939 {
940
941 __elfN(linux_shared_page_fini)(linux_shared_page_obj);
942 }
943 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
944 linux_vdso_deinstall, NULL);
945
946 static char GNU_ABI_VENDOR[] = "GNU";
947 static int GNULINUX_ABI_DESC = 0;
948
949 static bool
950 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
951 {
952 const Elf32_Word *desc;
953 uintptr_t p;
954
955 p = (uintptr_t)(note + 1);
956 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
957
958 desc = (const Elf32_Word *)p;
959 if (desc[0] != GNULINUX_ABI_DESC)
960 return (false);
961
962 /*
963 * For Linux we encode osrel using the Linux convention of
964 * (version << 16) | (major << 8) | (minor)
965 * See macro in linux_mib.h
966 */
967 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
968
969 return (true);
970 }
971
972 static Elf_Brandnote linux_brandnote = {
973 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
974 .hdr.n_descsz = 16, /* XXX at least 16 */
975 .hdr.n_type = 1,
976 .vendor = GNU_ABI_VENDOR,
977 .flags = BN_TRANSLATE_OSREL,
978 .trans_osrel = linux_trans_osrel
979 };
980
981 static Elf32_Brandinfo linux_brand = {
982 .brand = ELFOSABI_LINUX,
983 .machine = EM_386,
984 .compat_3_brand = "Linux",
985 .emul_path = "/compat/linux",
986 .interp_path = "/lib/ld-linux.so.1",
987 .sysvec = &elf_linux_sysvec,
988 .interp_newpath = NULL,
989 .brand_note = &linux_brandnote,
990 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
991 };
992
993 static Elf32_Brandinfo linux_glibc2brand = {
994 .brand = ELFOSABI_LINUX,
995 .machine = EM_386,
996 .compat_3_brand = "Linux",
997 .emul_path = "/compat/linux",
998 .interp_path = "/lib/ld-linux.so.2",
999 .sysvec = &elf_linux_sysvec,
1000 .interp_newpath = NULL,
1001 .brand_note = &linux_brandnote,
1002 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1003 };
1004
1005 static Elf32_Brandinfo linux_muslbrand = {
1006 .brand = ELFOSABI_LINUX,
1007 .machine = EM_386,
1008 .compat_3_brand = "Linux",
1009 .emul_path = "/compat/linux",
1010 .interp_path = "/lib/ld-musl-i386.so.1",
1011 .sysvec = &elf_linux_sysvec,
1012 .interp_newpath = NULL,
1013 .brand_note = &linux_brandnote,
1014 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1015 };
1016
1017 Elf32_Brandinfo *linux_brandlist[] = {
1018 &linux_brand,
1019 &linux_glibc2brand,
1020 &linux_muslbrand,
1021 NULL
1022 };
1023
1024 static int
1025 linux_elf_modevent(module_t mod, int type, void *data)
1026 {
1027 Elf32_Brandinfo **brandinfo;
1028 int error;
1029 struct linux_ioctl_handler **lihp;
1030
1031 error = 0;
1032
1033 switch(type) {
1034 case MOD_LOAD:
1035 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1036 ++brandinfo)
1037 if (elf32_insert_brand_entry(*brandinfo) < 0)
1038 error = EINVAL;
1039 if (error == 0) {
1040 SET_FOREACH(lihp, linux_ioctl_handler_set)
1041 linux_ioctl_register_handler(*lihp);
1042 LIST_INIT(&futex_list);
1043 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1044 linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, linux_proc_exit,
1045 NULL, 1000);
1046 linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_exec,
1047 NULL, 1000);
1048 linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
1049 linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
1050 linux_get_machine(&linux_kplatform);
1051 linux_szplatform = roundup(strlen(linux_kplatform) + 1,
1052 sizeof(char *));
1053 linux_osd_jail_register();
1054 stclohz = (stathz ? stathz : hz);
1055 if (bootverbose)
1056 printf("Linux ELF exec handler installed\n");
1057 } else
1058 printf("cannot insert Linux ELF brand handler\n");
1059 break;
1060 case MOD_UNLOAD:
1061 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1062 ++brandinfo)
1063 if (elf32_brand_inuse(*brandinfo))
1064 error = EBUSY;
1065 if (error == 0) {
1066 for (brandinfo = &linux_brandlist[0];
1067 *brandinfo != NULL; ++brandinfo)
1068 if (elf32_remove_brand_entry(*brandinfo) < 0)
1069 error = EINVAL;
1070 }
1071 if (error == 0) {
1072 SET_FOREACH(lihp, linux_ioctl_handler_set)
1073 linux_ioctl_unregister_handler(*lihp);
1074 mtx_destroy(&futex_mtx);
1075 EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
1076 EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
1077 EVENTHANDLER_DEREGISTER(thread_dtor, linux_thread_dtor_tag);
1078 linux_osd_jail_deregister();
1079 if (bootverbose)
1080 printf("Linux ELF exec handler removed\n");
1081 } else
1082 printf("Could not deinstall ELF interpreter entry\n");
1083 break;
1084 default:
1085 return (EOPNOTSUPP);
1086 }
1087 return (error);
1088 }
1089
1090 static moduledata_t linux_elf_mod = {
1091 "linuxelf",
1092 linux_elf_modevent,
1093 0
1094 };
1095
1096 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1097 FEATURE(linux, "Linux 32bit support");
Cache object: 074c2fa06673dfa25f3cac40716aa5d8
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