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>
54 #include <vm/vm_extern.h>
55 #include <vm/vm_map.h>
56 #include <vm/vm_object.h>
57 #include <vm/vm_page.h>
58 #include <vm/vm_param.h>
60 #include <machine/cpu.h>
61 #include <machine/cputypes.h>
62 #include <machine/md_var.h>
63 #include <machine/pcb.h>
64 #include <machine/trap.h>
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_ioctl.h>
70 #include <compat/linux/linux_mib.h>
71 #include <compat/linux/linux_misc.h>
72 #include <compat/linux/linux_signal.h>
73 #include <compat/linux/linux_util.h>
74 #include <compat/linux/linux_vdso.h>
76 MODULE_VERSION(linux, 1);
78 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings))
80 static int linux_szsigcode;
81 static vm_object_t linux_shared_page_obj;
82 static char *linux_shared_page_mapping;
83 extern char _binary_linux_locore_o_start;
84 extern char _binary_linux_locore_o_end;
86 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
88 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
90 static int linux_fixup(uintptr_t *stack_base,
91 struct image_params *iparams);
92 static int linux_fixup_elf(uintptr_t *stack_base,
93 struct image_params *iparams);
94 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
95 static void linux_exec_setregs(struct thread *td,
96 struct image_params *imgp, uintptr_t stack);
97 static int linux_copyout_strings(struct image_params *imgp,
98 uintptr_t *stack_base);
99 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
100 static void linux_vdso_install(void *param);
101 static void linux_vdso_deinstall(void *param);
103 static int linux_szplatform;
104 const char *linux_kplatform;
106 #define LINUX_T_UNKNOWN 255
107 static int _bsd_to_linux_trapcode[] = {
108 LINUX_T_UNKNOWN, /* 0 */
109 6, /* 1 T_PRIVINFLT */
110 LINUX_T_UNKNOWN, /* 2 */
112 LINUX_T_UNKNOWN, /* 4 */
113 LINUX_T_UNKNOWN, /* 5 */
114 16, /* 6 T_ARITHTRAP */
115 254, /* 7 T_ASTFLT */
116 LINUX_T_UNKNOWN, /* 8 */
117 13, /* 9 T_PROTFLT */
118 1, /* 10 T_TRCTRAP */
119 LINUX_T_UNKNOWN, /* 11 */
120 14, /* 12 T_PAGEFLT */
121 LINUX_T_UNKNOWN, /* 13 */
122 17, /* 14 T_ALIGNFLT */
123 LINUX_T_UNKNOWN, /* 15 */
124 LINUX_T_UNKNOWN, /* 16 */
125 LINUX_T_UNKNOWN, /* 17 */
131 8, /* 23 T_DOUBLEFLT */
132 9, /* 24 T_FPOPFLT */
133 10, /* 25 T_TSSFLT */
134 11, /* 26 T_SEGNPFLT */
135 12, /* 27 T_STKFLT */
137 19, /* 29 T_XMMFLT */
138 15 /* 30 T_RESERVED */
140 #define bsd_to_linux_trapcode(code) \
141 ((code)<nitems(_bsd_to_linux_trapcode)? \
142 _bsd_to_linux_trapcode[(code)]: \
145 LINUX_VDSO_SYM_INTPTR(linux_sigcode);
146 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
147 LINUX_VDSO_SYM_INTPTR(linux_vsyscall);
150 * If FreeBSD & Linux have a difference of opinion about what a trap
151 * means, deal with it here.
156 linux_translate_traps(int signal, int trap_code)
158 if (signal != SIGBUS)
172 linux_fixup(uintptr_t *stack_base, struct image_params *imgp)
174 register_t *base, *argv, *envp;
176 base = (register_t *)*stack_base;
178 envp = base + (imgp->args->argc + 1);
180 suword(base, (intptr_t)envp);
182 suword(base, (intptr_t)argv);
184 suword(base, imgp->args->argc);
185 *stack_base = (uintptr_t)base;
190 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
194 Elf32_Auxinfo *argarray, *pos;
195 Elf32_Addr *uplatform;
196 struct ps_strings *arginfo;
197 int error, issetugid;
200 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
201 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
202 uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
203 args = (Elf32_Auxargs *)imgp->auxargs;
204 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
207 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
208 imgp->proc->p_sysent->sv_shared_page_base);
209 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall);
210 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
213 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
214 * as it has appeared in the 2.4.0-rc7 first time.
215 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
216 * glibc falls back to the hard-coded CLK_TCK value when aux entry
218 * Also see linux_times() implementation.
220 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
221 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
222 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
223 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
224 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
225 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
226 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
227 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
228 AUXARGS_ENTRY(pos, AT_BASE, args->base);
229 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
230 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
231 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
232 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
233 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
234 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
235 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
236 if (imgp->execpathp != 0)
237 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
238 if (args->execfd != -1)
239 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
240 AUXARGS_ENTRY(pos, AT_NULL, 0);
242 free(imgp->auxargs, M_TEMP);
243 imgp->auxargs = NULL;
244 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
246 error = copyout(argarray, (void *)base,
247 sizeof(*argarray) * LINUX_AT_COUNT);
248 free(argarray, M_TEMP);
253 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
257 base = (register_t *)*stack_base;
259 if (suword(base, (register_t)imgp->args->argc) == -1)
261 *stack_base = (uintptr_t)base;
266 * Copied from kern/kern_exec.c
269 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
271 int argc, envc, error;
274 uintptr_t destp, ustringp;
275 struct ps_strings *arginfo;
276 char canary[LINUX_AT_RANDOM_LEN];
280 /* Calculate string base and vector table pointers. */
282 if (imgp->execpath != NULL && imgp->auxargs != NULL)
283 execpath_len = strlen(imgp->execpath) + 1;
286 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
287 destp = (uintptr_t)arginfo;
289 /* Install LINUX_PLATFORM. */
290 destp -= linux_szplatform;
291 destp = rounddown2(destp, sizeof(void *));
292 error = copyout(linux_kplatform, (void *)destp, linux_szplatform);
296 if (execpath_len != 0) {
297 destp -= execpath_len;
298 destp = rounddown2(destp, sizeof(void *));
299 imgp->execpathp = (void *)destp;
300 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
305 /* Prepare the canary for SSP. */
306 arc4rand(canary, sizeof(canary), 0);
307 destp -= roundup(sizeof(canary), sizeof(void *));
308 imgp->canary = (void *)destp;
309 error = copyout(canary, imgp->canary, sizeof(canary));
313 /* Allocate room for the argument and environment strings. */
314 destp -= ARG_MAX - imgp->args->stringspace;
315 destp = rounddown2(destp, sizeof(void *));
320 * Allocate room on the stack for the ELF auxargs
321 * array. It has LINUX_AT_COUNT entries.
323 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo);
324 destp = rounddown2(destp, sizeof(void *));
327 vectp = (char **)destp;
330 * Allocate room for the argv[] and env vectors including the
331 * terminating NULL pointers.
333 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
335 /* vectp also becomes our initial stack base. */
336 *stack_base = (uintptr_t)vectp;
338 stringp = imgp->args->begin_argv;
339 argc = imgp->args->argc;
340 envc = imgp->args->envc;
342 /* Copy out strings - arguments and environment. */
343 error = copyout(stringp, (void *)ustringp,
344 ARG_MAX - imgp->args->stringspace);
348 /* Fill in "ps_strings" struct for ps, w, etc. */
349 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
350 suword(&arginfo->ps_nargvstr, argc) != 0)
353 /* Fill in argument portion of vector table. */
354 for (; argc > 0; --argc) {
355 if (suword(vectp++, ustringp) != 0)
357 while (*stringp++ != 0)
362 /* A null vector table pointer separates the argp's from the envp's. */
363 if (suword(vectp++, 0) != 0)
366 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
367 suword(&arginfo->ps_nenvstr, envc) != 0)
370 /* Fill in environment portion of vector table. */
371 for (; envc > 0; --envc) {
372 if (suword(vectp++, ustringp) != 0)
374 while (*stringp++ != 0)
379 /* The end of the vector table is a null pointer. */
380 if (suword(vectp, 0) != 0)
385 error = imgp->sysent->sv_copyout_auxargs(imgp,
395 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
397 struct thread *td = curthread;
398 struct proc *p = td->td_proc;
400 struct trapframe *regs;
401 struct l_rt_sigframe *fp, frame;
405 sig = ksi->ksi_signo;
406 code = ksi->ksi_code;
407 PROC_LOCK_ASSERT(p, MA_OWNED);
409 mtx_assert(&psp->ps_mtx, MA_OWNED);
411 oonstack = sigonstack(regs->tf_esp);
413 /* Allocate space for the signal handler context. */
414 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
415 SIGISMEMBER(psp->ps_sigonstack, sig)) {
416 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
417 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
419 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
420 mtx_unlock(&psp->ps_mtx);
422 /* Build the argument list for the signal handler. */
423 sig = bsd_to_linux_signal(sig);
425 bzero(&frame, sizeof(frame));
427 frame.sf_handler = catcher;
429 frame.sf_siginfo = &fp->sf_si;
430 frame.sf_ucontext = &fp->sf_sc;
432 /* Fill in POSIX parts. */
433 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
435 /* Build the signal context to be used by sigreturn. */
436 frame.sf_sc.uc_flags = 0; /* XXX ??? */
437 frame.sf_sc.uc_link = NULL; /* XXX ??? */
439 frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
440 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
441 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
442 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
445 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
447 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
448 frame.sf_sc.uc_mcontext.sc_gs = rgs();
449 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
450 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
451 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
452 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
453 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
454 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
455 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
456 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp;
457 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
458 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
459 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
460 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
461 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
462 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
463 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
464 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
465 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
466 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
467 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
469 if (copyout(&frame, fp, sizeof(frame)) != 0) {
471 * Process has trashed its stack; give it an illegal
472 * instruction to halt it in its tracks.
478 /* Build context to run handler in. */
479 regs->tf_esp = (int)fp;
480 regs->tf_eip = linux_rt_sigcode;
481 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
482 regs->tf_cs = _ucodesel;
483 regs->tf_ds = _udatasel;
484 regs->tf_es = _udatasel;
485 regs->tf_fs = _udatasel;
486 regs->tf_ss = _udatasel;
488 mtx_lock(&psp->ps_mtx);
492 * Send an interrupt to process.
494 * Stack is set up to allow sigcode stored
495 * in u. to call routine, followed by kcall
496 * to sigreturn routine below. After sigreturn
497 * resets the signal mask, the stack, and the
498 * frame pointer, it returns to the user
502 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
504 struct thread *td = curthread;
505 struct proc *p = td->td_proc;
507 struct trapframe *regs;
508 struct l_sigframe *fp, frame;
513 PROC_LOCK_ASSERT(p, MA_OWNED);
515 sig = ksi->ksi_signo;
516 code = ksi->ksi_code;
517 mtx_assert(&psp->ps_mtx, MA_OWNED);
518 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
519 /* Signal handler installed with SA_SIGINFO. */
520 linux_rt_sendsig(catcher, ksi, mask);
524 oonstack = sigonstack(regs->tf_esp);
526 /* Allocate space for the signal handler context. */
527 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
528 SIGISMEMBER(psp->ps_sigonstack, sig)) {
529 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
530 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
532 fp = (struct l_sigframe *)regs->tf_esp - 1;
533 mtx_unlock(&psp->ps_mtx);
536 /* Build the argument list for the signal handler. */
537 sig = bsd_to_linux_signal(sig);
539 bzero(&frame, sizeof(frame));
541 frame.sf_handler = catcher;
544 bsd_to_linux_sigset(mask, &lmask);
546 /* Build the signal context to be used by sigreturn. */
547 frame.sf_sc.sc_mask = lmask.__mask;
548 frame.sf_sc.sc_gs = rgs();
549 frame.sf_sc.sc_fs = regs->tf_fs;
550 frame.sf_sc.sc_es = regs->tf_es;
551 frame.sf_sc.sc_ds = regs->tf_ds;
552 frame.sf_sc.sc_edi = regs->tf_edi;
553 frame.sf_sc.sc_esi = regs->tf_esi;
554 frame.sf_sc.sc_ebp = regs->tf_ebp;
555 frame.sf_sc.sc_ebx = regs->tf_ebx;
556 frame.sf_sc.sc_esp = regs->tf_esp;
557 frame.sf_sc.sc_edx = regs->tf_edx;
558 frame.sf_sc.sc_ecx = regs->tf_ecx;
559 frame.sf_sc.sc_eax = regs->tf_eax;
560 frame.sf_sc.sc_eip = regs->tf_eip;
561 frame.sf_sc.sc_cs = regs->tf_cs;
562 frame.sf_sc.sc_eflags = regs->tf_eflags;
563 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
564 frame.sf_sc.sc_ss = regs->tf_ss;
565 frame.sf_sc.sc_err = regs->tf_err;
566 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
567 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
569 frame.sf_extramask[0] = lmask.__mask;
571 if (copyout(&frame, fp, sizeof(frame)) != 0) {
573 * Process has trashed its stack; give it an illegal
574 * instruction to halt it in its tracks.
580 /* Build context to run handler in. */
581 regs->tf_esp = (int)fp;
582 regs->tf_eip = linux_sigcode;
583 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
584 regs->tf_cs = _ucodesel;
585 regs->tf_ds = _udatasel;
586 regs->tf_es = _udatasel;
587 regs->tf_fs = _udatasel;
588 regs->tf_ss = _udatasel;
590 mtx_lock(&psp->ps_mtx);
594 * System call to cleanup state after a signal
595 * has been taken. Reset signal mask and
596 * stack state from context left by sendsig (above).
597 * Return to previous pc and psl as specified by
598 * context left by sendsig. Check carefully to
599 * make sure that the user has not modified the
600 * psl to gain improper privileges or to cause
604 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
606 struct l_sigframe frame;
607 struct trapframe *regs;
616 * The trampoline code hands us the sigframe.
617 * It is unsafe to keep track of it ourselves, in the event that a
618 * program jumps out of a signal handler.
620 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
623 /* Check for security violations. */
624 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
625 eflags = frame.sf_sc.sc_eflags;
626 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
630 * Don't allow users to load a valid privileged %cs. Let the
631 * hardware check for invalid selectors, excess privilege in
632 * other selectors, invalid %eip's and invalid %esp's.
634 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
635 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
636 ksiginfo_init_trap(&ksi);
637 ksi.ksi_signo = SIGBUS;
638 ksi.ksi_code = BUS_OBJERR;
639 ksi.ksi_trapno = T_PROTFLT;
640 ksi.ksi_addr = (void *)regs->tf_eip;
641 trapsignal(td, &ksi);
645 lmask.__mask = frame.sf_sc.sc_mask;
646 linux_to_bsd_sigset(&lmask, &bmask);
647 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
649 /* Restore signal context. */
650 /* %gs was restored by the trampoline. */
651 regs->tf_fs = frame.sf_sc.sc_fs;
652 regs->tf_es = frame.sf_sc.sc_es;
653 regs->tf_ds = frame.sf_sc.sc_ds;
654 regs->tf_edi = frame.sf_sc.sc_edi;
655 regs->tf_esi = frame.sf_sc.sc_esi;
656 regs->tf_ebp = frame.sf_sc.sc_ebp;
657 regs->tf_ebx = frame.sf_sc.sc_ebx;
658 regs->tf_edx = frame.sf_sc.sc_edx;
659 regs->tf_ecx = frame.sf_sc.sc_ecx;
660 regs->tf_eax = frame.sf_sc.sc_eax;
661 regs->tf_eip = frame.sf_sc.sc_eip;
662 regs->tf_cs = frame.sf_sc.sc_cs;
663 regs->tf_eflags = eflags;
664 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
665 regs->tf_ss = frame.sf_sc.sc_ss;
667 return (EJUSTRETURN);
671 * System call to cleanup state after a signal
672 * has been taken. Reset signal mask and
673 * stack state from context left by rt_sendsig (above).
674 * Return to previous pc and psl as specified by
675 * context left by sendsig. Check carefully to
676 * make sure that the user has not modified the
677 * psl to gain improper privileges or to cause
681 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
683 struct l_ucontext uc;
684 struct l_sigcontext *context;
688 struct trapframe *regs;
695 * The trampoline code hands us the ucontext.
696 * It is unsafe to keep track of it ourselves, in the event that a
697 * program jumps out of a signal handler.
699 if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
702 context = &uc.uc_mcontext;
704 /* Check for security violations. */
705 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
706 eflags = context->sc_eflags;
707 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
711 * Don't allow users to load a valid privileged %cs. Let the
712 * hardware check for invalid selectors, excess privilege in
713 * other selectors, invalid %eip's and invalid %esp's.
715 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
716 if (!CS_SECURE(context->sc_cs)) {
717 ksiginfo_init_trap(&ksi);
718 ksi.ksi_signo = SIGBUS;
719 ksi.ksi_code = BUS_OBJERR;
720 ksi.ksi_trapno = T_PROTFLT;
721 ksi.ksi_addr = (void *)regs->tf_eip;
722 trapsignal(td, &ksi);
726 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
727 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
729 /* Restore signal context. */
730 /* %gs was restored by the trampoline. */
731 regs->tf_fs = context->sc_fs;
732 regs->tf_es = context->sc_es;
733 regs->tf_ds = context->sc_ds;
734 regs->tf_edi = context->sc_edi;
735 regs->tf_esi = context->sc_esi;
736 regs->tf_ebp = context->sc_ebp;
737 regs->tf_ebx = context->sc_ebx;
738 regs->tf_edx = context->sc_edx;
739 regs->tf_ecx = context->sc_ecx;
740 regs->tf_eax = context->sc_eax;
741 regs->tf_eip = context->sc_eip;
742 regs->tf_cs = context->sc_cs;
743 regs->tf_eflags = eflags;
744 regs->tf_esp = context->sc_esp_at_signal;
745 regs->tf_ss = context->sc_ss;
747 /* Call sigaltstack & ignore results. */
749 ss.ss_sp = lss->ss_sp;
750 ss.ss_size = lss->ss_size;
751 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
753 (void)kern_sigaltstack(td, &ss, NULL);
755 return (EJUSTRETURN);
759 linux_fetch_syscall_args(struct thread *td)
762 struct trapframe *frame;
763 struct syscall_args *sa;
766 frame = td->td_frame;
769 sa->code = frame->tf_eax;
770 sa->args[0] = frame->tf_ebx;
771 sa->args[1] = frame->tf_ecx;
772 sa->args[2] = frame->tf_edx;
773 sa->args[3] = frame->tf_esi;
774 sa->args[4] = frame->tf_edi;
775 sa->args[5] = frame->tf_ebp; /* Unconfirmed */
777 if (sa->code >= p->p_sysent->sv_size)
779 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
781 sa->callp = &p->p_sysent->sv_table[sa->code];
783 td->td_retval[0] = 0;
784 td->td_retval[1] = frame->tf_edx;
790 linux_set_syscall_retval(struct thread *td, int error)
792 struct trapframe *frame = td->td_frame;
794 cpu_set_syscall_retval(td, error);
796 if (__predict_false(error != 0)) {
797 if (error != ERESTART && error != EJUSTRETURN)
798 frame->tf_eax = bsd_to_linux_errno(error);
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.
808 linux_exec_setregs(struct thread *td, struct image_params *imgp,
811 struct pcb *pcb = td->td_pcb;
813 exec_setregs(td, imgp, stack);
815 /* Linux sets %gs to 0, we default to _udatasel. */
819 pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
823 linux_get_machine(const char **dst)
841 struct sysentvec linux_sysvec = {
842 .sv_size = LINUX_SYS_MAXSYSCALL,
843 .sv_table = linux_sysent,
844 .sv_transtrap = linux_translate_traps,
845 .sv_fixup = linux_fixup,
846 .sv_sendsig = linux_sendsig,
847 .sv_sigcode = &_binary_linux_locore_o_start,
848 .sv_szsigcode = &linux_szsigcode,
849 .sv_name = "Linux a.out",
851 .sv_imgact_try = linux_exec_imgact_try,
852 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
853 .sv_minuser = VM_MIN_ADDRESS,
854 .sv_maxuser = VM_MAXUSER_ADDRESS,
855 .sv_usrstack = LINUX_USRSTACK,
856 .sv_psstrings = PS_STRINGS,
857 .sv_stackprot = VM_PROT_ALL,
858 .sv_copyout_strings = exec_copyout_strings,
859 .sv_setregs = linux_exec_setregs,
862 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
863 .sv_set_syscall_retval = linux_set_syscall_retval,
864 .sv_fetch_syscall_args = linux_fetch_syscall_args,
865 .sv_syscallnames = NULL,
866 .sv_shared_page_base = LINUX_SHAREDPAGE,
867 .sv_shared_page_len = PAGE_SIZE,
868 .sv_schedtail = linux_schedtail,
869 .sv_thread_detach = linux_thread_detach,
871 .sv_onexec = linux_on_exec,
872 .sv_onexit = linux_on_exit,
873 .sv_ontdexit = linux_thread_dtor,
875 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
877 struct sysentvec elf_linux_sysvec = {
878 .sv_size = LINUX_SYS_MAXSYSCALL,
879 .sv_table = linux_sysent,
880 .sv_transtrap = linux_translate_traps,
881 .sv_fixup = linux_fixup_elf,
882 .sv_sendsig = linux_sendsig,
883 .sv_sigcode = &_binary_linux_locore_o_start,
884 .sv_szsigcode = &linux_szsigcode,
885 .sv_name = "Linux ELF32",
886 .sv_coredump = elf32_coredump,
887 .sv_imgact_try = linux_exec_imgact_try,
888 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
889 .sv_minuser = VM_MIN_ADDRESS,
890 .sv_maxuser = VM_MAXUSER_ADDRESS,
891 .sv_usrstack = LINUX_USRSTACK,
892 .sv_psstrings = LINUX_PS_STRINGS,
893 .sv_stackprot = VM_PROT_ALL,
894 .sv_copyout_auxargs = linux_copyout_auxargs,
895 .sv_copyout_strings = linux_copyout_strings,
896 .sv_setregs = linux_exec_setregs,
899 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
900 .sv_set_syscall_retval = linux_set_syscall_retval,
901 .sv_fetch_syscall_args = linux_fetch_syscall_args,
902 .sv_syscallnames = NULL,
903 .sv_shared_page_base = LINUX_SHAREDPAGE,
904 .sv_shared_page_len = PAGE_SIZE,
905 .sv_schedtail = linux_schedtail,
906 .sv_thread_detach = linux_thread_detach,
908 .sv_onexec = linux_on_exec,
909 .sv_onexit = linux_on_exit,
910 .sv_ontdexit = linux_thread_dtor,
914 linux_vdso_install(void *param)
917 linux_szsigcode = (&_binary_linux_locore_o_end -
918 &_binary_linux_locore_o_start);
920 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
921 panic("Linux invalid vdso size\n");
923 __elfN(linux_vdso_fixup)(&elf_linux_sysvec);
925 linux_shared_page_obj = __elfN(linux_shared_page_init)
926 (&linux_shared_page_mapping);
928 __elfN(linux_vdso_reloc)(&elf_linux_sysvec);
930 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
932 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
934 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
935 linux_vdso_install, NULL);
938 linux_vdso_deinstall(void *param)
941 __elfN(linux_shared_page_fini)(linux_shared_page_obj,
942 linux_shared_page_mapping);
944 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
945 linux_vdso_deinstall, NULL);
947 static char GNU_ABI_VENDOR[] = "GNU";
948 static int GNULINUX_ABI_DESC = 0;
951 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
953 const Elf32_Word *desc;
956 p = (uintptr_t)(note + 1);
957 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
959 desc = (const Elf32_Word *)p;
960 if (desc[0] != GNULINUX_ABI_DESC)
964 * For Linux we encode osrel using the Linux convention of
965 * (version << 16) | (major << 8) | (minor)
966 * See macro in linux_mib.h
968 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
973 static Elf_Brandnote linux_brandnote = {
974 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
975 .hdr.n_descsz = 16, /* XXX at least 16 */
977 .vendor = GNU_ABI_VENDOR,
978 .flags = BN_TRANSLATE_OSREL,
979 .trans_osrel = linux_trans_osrel
982 static Elf32_Brandinfo linux_brand = {
983 .brand = ELFOSABI_LINUX,
985 .compat_3_brand = "Linux",
986 .emul_path = linux_emul_path,
987 .interp_path = "/lib/ld-linux.so.1",
988 .sysvec = &elf_linux_sysvec,
989 .interp_newpath = NULL,
990 .brand_note = &linux_brandnote,
991 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
994 static Elf32_Brandinfo linux_glibc2brand = {
995 .brand = ELFOSABI_LINUX,
997 .compat_3_brand = "Linux",
998 .emul_path = linux_emul_path,
999 .interp_path = "/lib/ld-linux.so.2",
1000 .sysvec = &elf_linux_sysvec,
1001 .interp_newpath = NULL,
1002 .brand_note = &linux_brandnote,
1003 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1006 static Elf32_Brandinfo linux_muslbrand = {
1007 .brand = ELFOSABI_LINUX,
1009 .compat_3_brand = "Linux",
1010 .emul_path = linux_emul_path,
1011 .interp_path = "/lib/ld-musl-i386.so.1",
1012 .sysvec = &elf_linux_sysvec,
1013 .interp_newpath = NULL,
1014 .brand_note = &linux_brandnote,
1015 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1018 Elf32_Brandinfo *linux_brandlist[] = {
1026 linux_elf_modevent(module_t mod, int type, void *data)
1028 Elf32_Brandinfo **brandinfo;
1030 struct linux_ioctl_handler **lihp;
1036 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1038 if (elf32_insert_brand_entry(*brandinfo) < 0)
1041 SET_FOREACH(lihp, linux_ioctl_handler_set)
1042 linux_ioctl_register_handler(*lihp);
1043 LIST_INIT(&futex_list);
1044 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1045 linux_get_machine(&linux_kplatform);
1046 linux_szplatform = roundup(strlen(linux_kplatform) + 1,
1048 linux_dev_shm_create();
1049 linux_osd_jail_register();
1050 stclohz = (stathz ? stathz : hz);
1052 printf("Linux ELF exec handler installed\n");
1054 printf("cannot insert Linux ELF brand handler\n");
1057 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1059 if (elf32_brand_inuse(*brandinfo))
1062 for (brandinfo = &linux_brandlist[0];
1063 *brandinfo != NULL; ++brandinfo)
1064 if (elf32_remove_brand_entry(*brandinfo) < 0)
1068 SET_FOREACH(lihp, linux_ioctl_handler_set)
1069 linux_ioctl_unregister_handler(*lihp);
1070 mtx_destroy(&futex_mtx);
1071 linux_dev_shm_destroy();
1072 linux_osd_jail_deregister();
1074 printf("Linux ELF exec handler removed\n");
1076 printf("Could not deinstall ELF interpreter entry\n");
1079 return (EOPNOTSUPP);
1084 static moduledata_t linux_elf_mod = {
1090 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1091 FEATURE(linux, "Linux 32bit support");