2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1994-1996 Søren Schmidt
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.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>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.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>
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>
61 #include <machine/cpu.h>
62 #include <machine/cputypes.h>
63 #include <machine/md_var.h>
64 #include <machine/pcb.h>
65 #include <machine/trap.h>
67 #include <i386/linux/linux.h>
68 #include <i386/linux/linux_proto.h>
69 #include <compat/linux/linux_emul.h>
70 #include <compat/linux/linux_futex.h>
71 #include <compat/linux/linux_ioctl.h>
72 #include <compat/linux/linux_mib.h>
73 #include <compat/linux/linux_misc.h>
74 #include <compat/linux/linux_signal.h>
75 #include <compat/linux/linux_util.h>
76 #include <compat/linux/linux_vdso.h>
78 MODULE_VERSION(linux, 1);
80 #if BYTE_ORDER == LITTLE_ENDIAN
81 #define SHELLMAGIC 0x2123 /* #! */
83 #define SHELLMAGIC 0x2321
87 SYSCTL_PROC(_compat_linux, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
88 linux_sysctl_debug, "A", "Linux debugging control");
92 * Allow the sendsig functions to use the ldebug() facility even though they
93 * are not syscalls themselves. Map them to syscall 0. This is slightly less
94 * bogus than using ldebug(sigreturn).
96 #define LINUX_SYS_linux_rt_sendsig 0
97 #define LINUX_SYS_linux_sendsig 0
99 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings))
101 static int linux_szsigcode;
102 static vm_object_t linux_shared_page_obj;
103 static char *linux_shared_page_mapping;
104 extern char _binary_linux_locore_o_start;
105 extern char _binary_linux_locore_o_end;
107 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
109 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
111 static int linux_fixup(register_t **stack_base,
112 struct image_params *iparams);
113 static int linux_fixup_elf(register_t **stack_base,
114 struct image_params *iparams);
115 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
116 static int linux_exec_imgact_try(struct image_params *iparams);
117 static void linux_exec_setregs(struct thread *td,
118 struct image_params *imgp, u_long stack);
119 static register_t *linux_copyout_strings(struct image_params *imgp);
120 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
121 static void linux_vdso_install(void *param);
122 static void linux_vdso_deinstall(void *param);
124 static int linux_szplatform;
125 const char *linux_kplatform;
127 static eventhandler_tag linux_exit_tag;
128 static eventhandler_tag linux_exec_tag;
129 static eventhandler_tag linux_thread_dtor_tag;
131 #define LINUX_T_UNKNOWN 255
132 static int _bsd_to_linux_trapcode[] = {
133 LINUX_T_UNKNOWN, /* 0 */
134 6, /* 1 T_PRIVINFLT */
135 LINUX_T_UNKNOWN, /* 2 */
137 LINUX_T_UNKNOWN, /* 4 */
138 LINUX_T_UNKNOWN, /* 5 */
139 16, /* 6 T_ARITHTRAP */
140 254, /* 7 T_ASTFLT */
141 LINUX_T_UNKNOWN, /* 8 */
142 13, /* 9 T_PROTFLT */
143 1, /* 10 T_TRCTRAP */
144 LINUX_T_UNKNOWN, /* 11 */
145 14, /* 12 T_PAGEFLT */
146 LINUX_T_UNKNOWN, /* 13 */
147 17, /* 14 T_ALIGNFLT */
148 LINUX_T_UNKNOWN, /* 15 */
149 LINUX_T_UNKNOWN, /* 16 */
150 LINUX_T_UNKNOWN, /* 17 */
156 8, /* 23 T_DOUBLEFLT */
157 9, /* 24 T_FPOPFLT */
158 10, /* 25 T_TSSFLT */
159 11, /* 26 T_SEGNPFLT */
160 12, /* 27 T_STKFLT */
162 19, /* 29 T_XMMFLT */
163 15 /* 30 T_RESERVED */
165 #define bsd_to_linux_trapcode(code) \
166 ((code)<nitems(_bsd_to_linux_trapcode)? \
167 _bsd_to_linux_trapcode[(code)]: \
170 LINUX_VDSO_SYM_INTPTR(linux_sigcode);
171 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
172 LINUX_VDSO_SYM_INTPTR(linux_vsyscall);
175 * If FreeBSD & Linux have a difference of opinion about what a trap
176 * means, deal with it here.
181 linux_translate_traps(int signal, int trap_code)
183 if (signal != SIGBUS)
197 linux_fixup(register_t **stack_base, struct image_params *imgp)
199 register_t *argv, *envp;
202 envp = *stack_base + (imgp->args->argc + 1);
204 suword(*stack_base, (intptr_t)(void *)envp);
206 suword(*stack_base, (intptr_t)(void *)argv);
208 suword(*stack_base, imgp->args->argc);
213 linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
217 Elf32_Addr *uplatform;
218 struct ps_strings *arginfo;
222 KASSERT(curthread->td_proc == imgp->proc,
223 ("unsafe linux_fixup_elf(), should be curproc"));
226 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
227 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
228 uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
229 args = (Elf32_Auxargs *)imgp->auxargs;
230 pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
232 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
233 imgp->proc->p_sysent->sv_shared_page_base);
234 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall);
235 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
238 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
239 * as it has appeared in the 2.4.0-rc7 first time.
240 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
241 * glibc falls back to the hard-coded CLK_TCK value when aux entry
243 * Also see linux_times() implementation.
245 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
246 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
247 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
248 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
249 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
250 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
251 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
252 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
253 AUXARGS_ENTRY(pos, AT_BASE, args->base);
254 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
255 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
256 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
257 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
258 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
259 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
260 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary);
261 if (imgp->execpathp != 0)
262 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp);
263 if (args->execfd != -1)
264 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
265 AUXARGS_ENTRY(pos, AT_NULL, 0);
267 free(imgp->auxargs, M_TEMP);
268 imgp->auxargs = NULL;
271 suword(*stack_base, (register_t)imgp->args->argc);
276 * Copied from kern/kern_exec.c
279 linux_copyout_strings(struct image_params *imgp)
283 char *stringp, *destp;
284 register_t *stack_base;
285 struct ps_strings *arginfo;
286 char canary[LINUX_AT_RANDOM_LEN];
290 /* Calculate string base and vector table pointers. */
292 if (imgp->execpath != NULL && imgp->auxargs != NULL)
293 execpath_len = strlen(imgp->execpath) + 1;
296 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
297 destp = (caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform -
298 roundup(sizeof(canary), sizeof(char *)) -
299 roundup(execpath_len, sizeof(char *)) -
300 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
302 /* Install LINUX_PLATFORM. */
303 copyout(linux_kplatform, ((caddr_t)arginfo - linux_szplatform),
306 if (execpath_len != 0) {
307 imgp->execpathp = (uintptr_t)arginfo -
308 linux_szplatform - execpath_len;
309 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
312 /* Prepare the canary for SSP. */
313 arc4rand(canary, sizeof(canary), 0);
314 imgp->canary = (uintptr_t)arginfo - linux_szplatform -
315 roundup(execpath_len, sizeof(char *)) -
316 roundup(sizeof(canary), sizeof(char *));
317 copyout(canary, (void *)imgp->canary, sizeof(canary));
319 /* If we have a valid auxargs ptr, prepare some room on the stack. */
322 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
323 * lower compatibility.
325 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
326 (LINUX_AT_COUNT * 2);
328 * The '+ 2' is for the null pointers at the end of each of
329 * the arg and env vector sets,and imgp->auxarg_size is room
330 * for argument of Runtime loader.
332 vectp = (char **)(destp - (imgp->args->argc +
333 imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
336 * The '+ 2' is for the null pointers at the end of each of
337 * the arg and env vector sets
339 vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
343 /* vectp also becomes our initial stack base. */
344 stack_base = (register_t *)vectp;
346 stringp = imgp->args->begin_argv;
347 argc = imgp->args->argc;
348 envc = imgp->args->envc;
350 /* Copy out strings - arguments and environment. */
351 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
353 /* Fill in "ps_strings" struct for ps, w, etc. */
354 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
355 suword(&arginfo->ps_nargvstr, argc);
357 /* Fill in argument portion of vector table. */
358 for (; argc > 0; --argc) {
359 suword(vectp++, (long)(intptr_t)destp);
360 while (*stringp++ != 0)
365 /* A null vector table pointer separates the argp's from the envp's. */
368 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
369 suword(&arginfo->ps_nenvstr, envc);
371 /* Fill in environment portion of vector table. */
372 for (; envc > 0; --envc) {
373 suword(vectp++, (long)(intptr_t)destp);
374 while (*stringp++ != 0)
379 /* The end of the vector table is a null pointer. */
386 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
388 struct thread *td = curthread;
389 struct proc *p = td->td_proc;
391 struct trapframe *regs;
392 struct l_rt_sigframe *fp, frame;
396 sig = ksi->ksi_signo;
397 code = ksi->ksi_code;
398 PROC_LOCK_ASSERT(p, MA_OWNED);
400 mtx_assert(&psp->ps_mtx, MA_OWNED);
402 oonstack = sigonstack(regs->tf_esp);
405 if (ldebug(rt_sendsig))
406 printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
407 catcher, sig, (void*)mask, code);
409 /* Allocate space for the signal handler context. */
410 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
411 SIGISMEMBER(psp->ps_sigonstack, sig)) {
412 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
413 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
415 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
416 mtx_unlock(&psp->ps_mtx);
418 /* Build the argument list for the signal handler. */
419 sig = bsd_to_linux_signal(sig);
421 bzero(&frame, sizeof(frame));
423 frame.sf_handler = catcher;
425 frame.sf_siginfo = &fp->sf_si;
426 frame.sf_ucontext = &fp->sf_sc;
428 /* Fill in POSIX parts. */
429 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
431 /* Build the signal context to be used by sigreturn. */
432 frame.sf_sc.uc_flags = 0; /* XXX ??? */
433 frame.sf_sc.uc_link = NULL; /* XXX ??? */
435 frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
436 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
437 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
438 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
441 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
443 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
444 frame.sf_sc.uc_mcontext.sc_gs = rgs();
445 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
446 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
447 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
448 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
449 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
450 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
451 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
452 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp;
453 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
454 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
455 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
456 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
457 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
458 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
459 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
460 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
461 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
462 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
463 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
466 if (ldebug(rt_sendsig))
467 printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
468 frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
469 td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
472 if (copyout(&frame, fp, sizeof(frame)) != 0) {
474 * Process has trashed its stack; give it an illegal
475 * instruction to halt it in its tracks.
478 if (ldebug(rt_sendsig))
479 printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
486 /* Build context to run handler in. */
487 regs->tf_esp = (int)fp;
488 regs->tf_eip = linux_rt_sigcode;
489 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
490 regs->tf_cs = _ucodesel;
491 regs->tf_ds = _udatasel;
492 regs->tf_es = _udatasel;
493 regs->tf_fs = _udatasel;
494 regs->tf_ss = _udatasel;
496 mtx_lock(&psp->ps_mtx);
501 * Send an interrupt to process.
503 * Stack is set up to allow sigcode stored
504 * in u. to call routine, followed by kcall
505 * to sigreturn routine below. After sigreturn
506 * resets the signal mask, the stack, and the
507 * frame pointer, it returns to the user
511 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
513 struct thread *td = curthread;
514 struct proc *p = td->td_proc;
516 struct trapframe *regs;
517 struct l_sigframe *fp, frame;
522 PROC_LOCK_ASSERT(p, MA_OWNED);
524 sig = ksi->ksi_signo;
525 code = ksi->ksi_code;
526 mtx_assert(&psp->ps_mtx, MA_OWNED);
527 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
528 /* Signal handler installed with SA_SIGINFO. */
529 linux_rt_sendsig(catcher, ksi, mask);
533 oonstack = sigonstack(regs->tf_esp);
537 printf(ARGS(sendsig, "%p, %d, %p, %u"),
538 catcher, sig, (void*)mask, code);
541 /* Allocate space for the signal handler context. */
542 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
543 SIGISMEMBER(psp->ps_sigonstack, sig)) {
544 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
545 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
547 fp = (struct l_sigframe *)regs->tf_esp - 1;
548 mtx_unlock(&psp->ps_mtx);
551 /* Build the argument list for the signal handler. */
552 sig = bsd_to_linux_signal(sig);
554 bzero(&frame, sizeof(frame));
556 frame.sf_handler = catcher;
559 bsd_to_linux_sigset(mask, &lmask);
561 /* Build the signal context to be used by sigreturn. */
562 frame.sf_sc.sc_mask = lmask.__mask;
563 frame.sf_sc.sc_gs = rgs();
564 frame.sf_sc.sc_fs = regs->tf_fs;
565 frame.sf_sc.sc_es = regs->tf_es;
566 frame.sf_sc.sc_ds = regs->tf_ds;
567 frame.sf_sc.sc_edi = regs->tf_edi;
568 frame.sf_sc.sc_esi = regs->tf_esi;
569 frame.sf_sc.sc_ebp = regs->tf_ebp;
570 frame.sf_sc.sc_ebx = regs->tf_ebx;
571 frame.sf_sc.sc_esp = regs->tf_esp;
572 frame.sf_sc.sc_edx = regs->tf_edx;
573 frame.sf_sc.sc_ecx = regs->tf_ecx;
574 frame.sf_sc.sc_eax = regs->tf_eax;
575 frame.sf_sc.sc_eip = regs->tf_eip;
576 frame.sf_sc.sc_cs = regs->tf_cs;
577 frame.sf_sc.sc_eflags = regs->tf_eflags;
578 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
579 frame.sf_sc.sc_ss = regs->tf_ss;
580 frame.sf_sc.sc_err = regs->tf_err;
581 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
582 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
584 frame.sf_extramask[0] = lmask.__mask;
586 if (copyout(&frame, fp, sizeof(frame)) != 0) {
588 * Process has trashed its stack; give it an illegal
589 * instruction to halt it in its tracks.
595 /* Build context to run handler in. */
596 regs->tf_esp = (int)fp;
597 regs->tf_eip = linux_sigcode;
598 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
599 regs->tf_cs = _ucodesel;
600 regs->tf_ds = _udatasel;
601 regs->tf_es = _udatasel;
602 regs->tf_fs = _udatasel;
603 regs->tf_ss = _udatasel;
605 mtx_lock(&psp->ps_mtx);
609 * System call to cleanup state after a signal
610 * has been taken. Reset signal mask and
611 * stack state from context left by sendsig (above).
612 * Return to previous pc and psl as specified by
613 * context left by sendsig. Check carefully to
614 * make sure that the user has not modified the
615 * psl to gain improper privileges or to cause
619 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
621 struct l_sigframe frame;
622 struct trapframe *regs;
631 if (ldebug(sigreturn))
632 printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
635 * The trampoline code hands us the sigframe.
636 * It is unsafe to keep track of it ourselves, in the event that a
637 * program jumps out of a signal handler.
639 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
642 /* Check for security violations. */
643 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
644 eflags = frame.sf_sc.sc_eflags;
645 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
649 * Don't allow users to load a valid privileged %cs. Let the
650 * hardware check for invalid selectors, excess privilege in
651 * other selectors, invalid %eip's and invalid %esp's.
653 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
654 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
655 ksiginfo_init_trap(&ksi);
656 ksi.ksi_signo = SIGBUS;
657 ksi.ksi_code = BUS_OBJERR;
658 ksi.ksi_trapno = T_PROTFLT;
659 ksi.ksi_addr = (void *)regs->tf_eip;
660 trapsignal(td, &ksi);
664 lmask.__mask = frame.sf_sc.sc_mask;
665 linux_to_bsd_sigset(&lmask, &bmask);
666 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
668 /* Restore signal context. */
669 /* %gs was restored by the trampoline. */
670 regs->tf_fs = frame.sf_sc.sc_fs;
671 regs->tf_es = frame.sf_sc.sc_es;
672 regs->tf_ds = frame.sf_sc.sc_ds;
673 regs->tf_edi = frame.sf_sc.sc_edi;
674 regs->tf_esi = frame.sf_sc.sc_esi;
675 regs->tf_ebp = frame.sf_sc.sc_ebp;
676 regs->tf_ebx = frame.sf_sc.sc_ebx;
677 regs->tf_edx = frame.sf_sc.sc_edx;
678 regs->tf_ecx = frame.sf_sc.sc_ecx;
679 regs->tf_eax = frame.sf_sc.sc_eax;
680 regs->tf_eip = frame.sf_sc.sc_eip;
681 regs->tf_cs = frame.sf_sc.sc_cs;
682 regs->tf_eflags = eflags;
683 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
684 regs->tf_ss = frame.sf_sc.sc_ss;
686 return (EJUSTRETURN);
690 * System call to cleanup state after a signal
691 * has been taken. Reset signal mask and
692 * stack state from context left by rt_sendsig (above).
693 * Return to previous pc and psl as specified by
694 * context left by sendsig. Check carefully to
695 * make sure that the user has not modified the
696 * psl to gain improper privileges or to cause
700 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
702 struct l_ucontext uc;
703 struct l_sigcontext *context;
707 struct trapframe *regs;
714 if (ldebug(rt_sigreturn))
715 printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
718 * The trampoline code hands us the ucontext.
719 * It is unsafe to keep track of it ourselves, in the event that a
720 * program jumps out of a signal handler.
722 if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
725 context = &uc.uc_mcontext;
727 /* Check for security violations. */
728 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
729 eflags = context->sc_eflags;
730 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
734 * Don't allow users to load a valid privileged %cs. Let the
735 * hardware check for invalid selectors, excess privilege in
736 * other selectors, invalid %eip's and invalid %esp's.
738 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
739 if (!CS_SECURE(context->sc_cs)) {
740 ksiginfo_init_trap(&ksi);
741 ksi.ksi_signo = SIGBUS;
742 ksi.ksi_code = BUS_OBJERR;
743 ksi.ksi_trapno = T_PROTFLT;
744 ksi.ksi_addr = (void *)regs->tf_eip;
745 trapsignal(td, &ksi);
749 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
750 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
752 /* Restore signal context. */
753 /* %gs was restored by the trampoline. */
754 regs->tf_fs = context->sc_fs;
755 regs->tf_es = context->sc_es;
756 regs->tf_ds = context->sc_ds;
757 regs->tf_edi = context->sc_edi;
758 regs->tf_esi = context->sc_esi;
759 regs->tf_ebp = context->sc_ebp;
760 regs->tf_ebx = context->sc_ebx;
761 regs->tf_edx = context->sc_edx;
762 regs->tf_ecx = context->sc_ecx;
763 regs->tf_eax = context->sc_eax;
764 regs->tf_eip = context->sc_eip;
765 regs->tf_cs = context->sc_cs;
766 regs->tf_eflags = eflags;
767 regs->tf_esp = context->sc_esp_at_signal;
768 regs->tf_ss = context->sc_ss;
770 /* Call sigaltstack & ignore results. */
772 ss.ss_sp = lss->ss_sp;
773 ss.ss_size = lss->ss_size;
774 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
777 if (ldebug(rt_sigreturn))
778 printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
779 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
781 (void)kern_sigaltstack(td, &ss, NULL);
783 return (EJUSTRETURN);
787 linux_fetch_syscall_args(struct thread *td)
790 struct trapframe *frame;
791 struct syscall_args *sa;
794 frame = td->td_frame;
797 sa->code = frame->tf_eax;
798 sa->args[0] = frame->tf_ebx;
799 sa->args[1] = frame->tf_ecx;
800 sa->args[2] = frame->tf_edx;
801 sa->args[3] = frame->tf_esi;
802 sa->args[4] = frame->tf_edi;
803 sa->args[5] = frame->tf_ebp; /* Unconfirmed */
805 if (sa->code >= p->p_sysent->sv_size)
807 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
809 sa->callp = &p->p_sysent->sv_table[sa->code];
810 sa->narg = sa->callp->sy_narg;
812 td->td_retval[0] = 0;
813 td->td_retval[1] = frame->tf_edx;
819 * If a Linux binary is exec'ing something, try this image activator
820 * first. We override standard shell script execution in order to
821 * be able to modify the interpreter path. We only do this if a Linux
822 * binary is doing the exec, so we do not create an EXEC module for it.
825 linux_exec_imgact_try(struct image_params *imgp)
827 const char *head = (const char *)imgp->image_header;
832 * The interpreter for shell scripts run from a Linux binary needs
833 * to be located in /compat/linux if possible in order to recursively
834 * maintain Linux path emulation.
836 if (((const short *)head)[0] == SHELLMAGIC) {
838 * Run our normal shell image activator. If it succeeds then
839 * attempt to use the alternate path for the interpreter. If
840 * an alternate path is found, use our stringspace to store it.
842 if ((error = exec_shell_imgact(imgp)) == 0) {
843 linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
844 imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0,
847 imgp->args->fname_buf =
848 imgp->interpreter_name = rpath;
855 * exec_setregs may initialize some registers differently than Linux
856 * does, thus potentially confusing Linux binaries. If necessary, we
857 * override the exec_setregs default(s) here.
860 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
862 struct pcb *pcb = td->td_pcb;
864 exec_setregs(td, imgp, stack);
866 /* Linux sets %gs to 0, we default to _udatasel. */
870 pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
874 linux_get_machine(const char **dst)
892 struct sysentvec linux_sysvec = {
893 .sv_size = LINUX_SYS_MAXSYSCALL,
894 .sv_table = linux_sysent,
896 .sv_errsize = ELAST + 1,
897 .sv_errtbl = linux_errtbl,
898 .sv_transtrap = linux_translate_traps,
899 .sv_fixup = linux_fixup,
900 .sv_sendsig = linux_sendsig,
901 .sv_sigcode = &_binary_linux_locore_o_start,
902 .sv_szsigcode = &linux_szsigcode,
903 .sv_name = "Linux a.out",
905 .sv_imgact_try = linux_exec_imgact_try,
906 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
907 .sv_pagesize = PAGE_SIZE,
908 .sv_minuser = VM_MIN_ADDRESS,
909 .sv_maxuser = VM_MAXUSER_ADDRESS,
910 .sv_usrstack = LINUX_USRSTACK,
911 .sv_psstrings = PS_STRINGS,
912 .sv_stackprot = VM_PROT_ALL,
913 .sv_copyout_strings = exec_copyout_strings,
914 .sv_setregs = linux_exec_setregs,
917 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
918 .sv_set_syscall_retval = cpu_set_syscall_retval,
919 .sv_fetch_syscall_args = linux_fetch_syscall_args,
920 .sv_syscallnames = NULL,
921 .sv_shared_page_base = LINUX_SHAREDPAGE,
922 .sv_shared_page_len = PAGE_SIZE,
923 .sv_schedtail = linux_schedtail,
924 .sv_thread_detach = linux_thread_detach,
927 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
929 struct sysentvec elf_linux_sysvec = {
930 .sv_size = LINUX_SYS_MAXSYSCALL,
931 .sv_table = linux_sysent,
933 .sv_errsize = ELAST + 1,
934 .sv_errtbl = linux_errtbl,
935 .sv_transtrap = linux_translate_traps,
936 .sv_fixup = linux_fixup_elf,
937 .sv_sendsig = linux_sendsig,
938 .sv_sigcode = &_binary_linux_locore_o_start,
939 .sv_szsigcode = &linux_szsigcode,
940 .sv_name = "Linux ELF",
941 .sv_coredump = elf32_coredump,
942 .sv_imgact_try = linux_exec_imgact_try,
943 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
944 .sv_pagesize = PAGE_SIZE,
945 .sv_minuser = VM_MIN_ADDRESS,
946 .sv_maxuser = VM_MAXUSER_ADDRESS,
947 .sv_usrstack = LINUX_USRSTACK,
948 .sv_psstrings = LINUX_PS_STRINGS,
949 .sv_stackprot = VM_PROT_ALL,
950 .sv_copyout_strings = linux_copyout_strings,
951 .sv_setregs = linux_exec_setregs,
954 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
955 .sv_set_syscall_retval = cpu_set_syscall_retval,
956 .sv_fetch_syscall_args = linux_fetch_syscall_args,
957 .sv_syscallnames = NULL,
958 .sv_shared_page_base = LINUX_SHAREDPAGE,
959 .sv_shared_page_len = PAGE_SIZE,
960 .sv_schedtail = linux_schedtail,
961 .sv_thread_detach = linux_thread_detach,
966 linux_vdso_install(void *param)
969 linux_szsigcode = (&_binary_linux_locore_o_end -
970 &_binary_linux_locore_o_start);
972 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
973 panic("Linux invalid vdso size\n");
975 __elfN(linux_vdso_fixup)(&elf_linux_sysvec);
977 linux_shared_page_obj = __elfN(linux_shared_page_init)
978 (&linux_shared_page_mapping);
980 __elfN(linux_vdso_reloc)(&elf_linux_sysvec);
982 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
984 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
986 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
987 linux_vdso_install, NULL);
990 linux_vdso_deinstall(void *param)
993 __elfN(linux_shared_page_fini)(linux_shared_page_obj);
995 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
996 linux_vdso_deinstall, NULL);
998 static char GNU_ABI_VENDOR[] = "GNU";
999 static int GNULINUX_ABI_DESC = 0;
1002 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
1004 const Elf32_Word *desc;
1007 p = (uintptr_t)(note + 1);
1008 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1010 desc = (const Elf32_Word *)p;
1011 if (desc[0] != GNULINUX_ABI_DESC)
1015 * For Linux we encode osrel as follows (see linux_mib.c):
1016 * VVVMMMIII (version, major, minor), see linux_mib.c.
1018 *osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
1023 static Elf_Brandnote linux_brandnote = {
1024 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
1025 .hdr.n_descsz = 16, /* XXX at least 16 */
1027 .vendor = GNU_ABI_VENDOR,
1028 .flags = BN_TRANSLATE_OSREL,
1029 .trans_osrel = linux_trans_osrel
1032 static Elf32_Brandinfo linux_brand = {
1033 .brand = ELFOSABI_LINUX,
1035 .compat_3_brand = "Linux",
1036 .emul_path = "/compat/linux",
1037 .interp_path = "/lib/ld-linux.so.1",
1038 .sysvec = &elf_linux_sysvec,
1039 .interp_newpath = NULL,
1040 .brand_note = &linux_brandnote,
1041 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1044 static Elf32_Brandinfo linux_glibc2brand = {
1045 .brand = ELFOSABI_LINUX,
1047 .compat_3_brand = "Linux",
1048 .emul_path = "/compat/linux",
1049 .interp_path = "/lib/ld-linux.so.2",
1050 .sysvec = &elf_linux_sysvec,
1051 .interp_newpath = NULL,
1052 .brand_note = &linux_brandnote,
1053 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1056 static Elf32_Brandinfo linux_muslbrand = {
1057 .brand = ELFOSABI_LINUX,
1059 .compat_3_brand = "Linux",
1060 .emul_path = "/compat/linux",
1061 .interp_path = "/lib/ld-musl-i386.so.1",
1062 .sysvec = &elf_linux_sysvec,
1063 .interp_newpath = NULL,
1064 .brand_note = &linux_brandnote,
1065 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1068 Elf32_Brandinfo *linux_brandlist[] = {
1076 linux_elf_modevent(module_t mod, int type, void *data)
1078 Elf32_Brandinfo **brandinfo;
1080 struct linux_ioctl_handler **lihp;
1086 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1088 if (elf32_insert_brand_entry(*brandinfo) < 0)
1091 SET_FOREACH(lihp, linux_ioctl_handler_set)
1092 linux_ioctl_register_handler(*lihp);
1093 LIST_INIT(&futex_list);
1094 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1095 linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, linux_proc_exit,
1097 linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_exec,
1099 linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
1100 linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
1101 linux_get_machine(&linux_kplatform);
1102 linux_szplatform = roundup(strlen(linux_kplatform) + 1,
1104 linux_osd_jail_register();
1105 stclohz = (stathz ? stathz : hz);
1107 printf("Linux ELF exec handler installed\n");
1109 printf("cannot insert Linux ELF brand handler\n");
1112 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1114 if (elf32_brand_inuse(*brandinfo))
1117 for (brandinfo = &linux_brandlist[0];
1118 *brandinfo != NULL; ++brandinfo)
1119 if (elf32_remove_brand_entry(*brandinfo) < 0)
1123 SET_FOREACH(lihp, linux_ioctl_handler_set)
1124 linux_ioctl_unregister_handler(*lihp);
1125 mtx_destroy(&futex_mtx);
1126 EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
1127 EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
1128 EVENTHANDLER_DEREGISTER(thread_dtor, linux_thread_dtor_tag);
1129 linux_osd_jail_deregister();
1131 printf("Linux ELF exec handler removed\n");
1133 printf("Could not deinstall ELF interpreter entry\n");
1136 return (EOPNOTSUPP);
1141 static moduledata_t linux_elf_mod = {
1147 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1148 FEATURE(linux, "Linux 32bit support");