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>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
43 #include <sys/stddef.h>
44 #include <sys/signalvar.h>
45 #include <sys/syscallsubr.h>
46 #include <sys/sysctl.h>
47 #include <sys/sysent.h>
48 #include <sys/sysproto.h>
49 #include <sys/vnode.h>
53 #include <vm/vm_extern.h>
54 #include <vm/vm_map.h>
55 #include <vm/vm_object.h>
56 #include <vm/vm_page.h>
57 #include <vm/vm_param.h>
59 #include <machine/cpu.h>
60 #include <machine/cputypes.h>
61 #include <machine/md_var.h>
62 #include <machine/pcb.h>
63 #include <machine/trap.h>
65 #include <x86/linux/linux_x86.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_fork.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>
77 MODULE_VERSION(linux, 1);
79 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2
80 #define LINUX_VDSOPAGE (VM_MAXUSER_ADDRESS - LINUX_VDSOPAGE_SIZE)
81 #define LINUX_SHAREDPAGE (LINUX_VDSOPAGE - PAGE_SIZE)
83 * PAGE_SIZE - the size
84 * of the native SHAREDPAGE
86 #define LINUX_USRSTACK LINUX_SHAREDPAGE
87 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings))
89 static int linux_szsigcode;
90 static vm_object_t linux_vdso_obj;
91 static char *linux_vdso_mapping;
92 extern char _binary_linux_vdso_so_o_start;
93 extern char _binary_linux_vdso_so_o_end;
94 static vm_offset_t linux_vdso_base;
96 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
98 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
100 static int linux_fixup(uintptr_t *stack_base,
101 struct image_params *iparams);
102 static int linux_fixup_elf(uintptr_t *stack_base,
103 struct image_params *iparams);
104 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
105 static void linux_exec_setregs(struct thread *td,
106 struct image_params *imgp, uintptr_t stack);
107 static void linux_exec_sysvec_init(void *param);
108 static int linux_on_exec_vmspace(struct proc *p,
109 struct image_params *imgp);
110 static int linux_copyout_strings(struct image_params *imgp,
111 uintptr_t *stack_base);
112 static void linux_set_fork_retval(struct thread *td);
113 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
114 static void linux_vdso_install(const void *param);
115 static void linux_vdso_deinstall(const void *param);
116 static void linux_vdso_reloc(char *mapping, Elf_Addr offset);
118 #define LINUX_T_UNKNOWN 255
119 static int _bsd_to_linux_trapcode[] = {
120 LINUX_T_UNKNOWN, /* 0 */
121 6, /* 1 T_PRIVINFLT */
122 LINUX_T_UNKNOWN, /* 2 */
124 LINUX_T_UNKNOWN, /* 4 */
125 LINUX_T_UNKNOWN, /* 5 */
126 16, /* 6 T_ARITHTRAP */
127 254, /* 7 T_ASTFLT */
128 LINUX_T_UNKNOWN, /* 8 */
129 13, /* 9 T_PROTFLT */
130 1, /* 10 T_TRCTRAP */
131 LINUX_T_UNKNOWN, /* 11 */
132 14, /* 12 T_PAGEFLT */
133 LINUX_T_UNKNOWN, /* 13 */
134 17, /* 14 T_ALIGNFLT */
135 LINUX_T_UNKNOWN, /* 15 */
136 LINUX_T_UNKNOWN, /* 16 */
137 LINUX_T_UNKNOWN, /* 17 */
143 8, /* 23 T_DOUBLEFLT */
144 9, /* 24 T_FPOPFLT */
145 10, /* 25 T_TSSFLT */
146 11, /* 26 T_SEGNPFLT */
147 12, /* 27 T_STKFLT */
149 19, /* 29 T_XMMFLT */
150 15 /* 30 T_RESERVED */
152 #define bsd_to_linux_trapcode(code) \
153 ((code)<nitems(_bsd_to_linux_trapcode)? \
154 _bsd_to_linux_trapcode[(code)]: \
157 LINUX_VDSO_SYM_CHAR(linux_platform);
158 LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall);
159 LINUX_VDSO_SYM_INTPTR(__kernel_sigreturn);
160 LINUX_VDSO_SYM_INTPTR(__kernel_rt_sigreturn);
161 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
162 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
165 * If FreeBSD & Linux have a difference of opinion about what a trap
166 * means, deal with it here.
171 linux_translate_traps(int signal, int trap_code)
173 if (signal != SIGBUS)
187 linux_fixup(uintptr_t *stack_base, struct image_params *imgp)
189 register_t *base, *argv, *envp;
191 base = (register_t *)*stack_base;
193 envp = base + (imgp->args->argc + 1);
195 suword(base, (intptr_t)envp);
197 suword(base, (intptr_t)argv);
199 suword(base, imgp->args->argc);
200 *stack_base = (uintptr_t)base;
205 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
208 Elf32_Auxinfo *argarray, *pos;
209 int error, issetugid;
211 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
212 args = (Elf32_Auxargs *)imgp->auxargs;
213 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
216 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
217 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, __kernel_vsyscall);
218 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
221 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
222 * as it has appeared in the 2.4.0-rc7 first time.
223 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
224 * glibc falls back to the hard-coded CLK_TCK value when aux entry
226 * Also see linux_times() implementation.
228 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
229 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
230 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
231 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
232 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
233 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
234 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
235 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
236 AUXARGS_ENTRY(pos, AT_BASE, args->base);
237 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
238 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
239 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
240 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
241 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
242 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
243 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
244 if (imgp->execpathp != 0)
245 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
246 if (args->execfd != -1)
247 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
248 AUXARGS_ENTRY(pos, AT_NULL, 0);
250 free(imgp->auxargs, M_TEMP);
251 imgp->auxargs = NULL;
252 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
254 error = copyout(argarray, (void *)base,
255 sizeof(*argarray) * LINUX_AT_COUNT);
256 free(argarray, M_TEMP);
261 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
265 base = (register_t *)*stack_base;
267 if (suword(base, (register_t)imgp->args->argc) == -1)
269 *stack_base = (uintptr_t)base;
274 * Copied from kern/kern_exec.c
277 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
279 int argc, envc, error;
282 uintptr_t destp, ustringp;
283 struct ps_strings *arginfo;
284 char canary[LINUX_AT_RANDOM_LEN];
289 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p);
290 destp = (uintptr_t)arginfo;
292 if (imgp->execpath != NULL && imgp->auxargs != NULL) {
293 execpath_len = strlen(imgp->execpath) + 1;
294 destp -= execpath_len;
295 destp = rounddown2(destp, sizeof(void *));
296 imgp->execpathp = (void *)destp;
297 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
302 /* Prepare the canary for SSP. */
303 arc4rand(canary, sizeof(canary), 0);
304 destp -= roundup(sizeof(canary), sizeof(void *));
305 imgp->canary = (void *)destp;
306 error = copyout(canary, imgp->canary, sizeof(canary));
310 /* Allocate room for the argument and environment strings. */
311 destp -= ARG_MAX - imgp->args->stringspace;
312 destp = rounddown2(destp, sizeof(void *));
317 * Allocate room on the stack for the ELF auxargs
318 * array. It has LINUX_AT_COUNT entries.
320 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo);
321 destp = rounddown2(destp, sizeof(void *));
324 vectp = (char **)destp;
327 * Allocate room for the argv[] and env vectors including the
328 * terminating NULL pointers.
330 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
332 /* vectp also becomes our initial stack base. */
333 *stack_base = (uintptr_t)vectp;
335 stringp = imgp->args->begin_argv;
336 argc = imgp->args->argc;
337 envc = imgp->args->envc;
339 /* Copy out strings - arguments and environment. */
340 error = copyout(stringp, (void *)ustringp,
341 ARG_MAX - imgp->args->stringspace);
345 /* Fill in "ps_strings" struct for ps, w, etc. */
346 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
347 suword(&arginfo->ps_nargvstr, argc) != 0)
350 /* Fill in argument portion of vector table. */
351 for (; argc > 0; --argc) {
352 if (suword(vectp++, ustringp) != 0)
354 while (*stringp++ != 0)
359 /* A null vector table pointer separates the argp's from the envp's. */
360 if (suword(vectp++, 0) != 0)
363 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
364 suword(&arginfo->ps_nenvstr, envc) != 0)
367 /* Fill in environment portion of vector table. */
368 for (; envc > 0; --envc) {
369 if (suword(vectp++, ustringp) != 0)
371 while (*stringp++ != 0)
376 /* The end of the vector table is a null pointer. */
377 if (suword(vectp, 0) != 0)
382 error = imgp->sysent->sv_copyout_auxargs(imgp,
392 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
394 struct thread *td = curthread;
395 struct proc *p = td->td_proc;
397 struct trapframe *regs;
398 struct l_rt_sigframe *fp, frame;
402 sig = ksi->ksi_signo;
403 code = ksi->ksi_code;
404 PROC_LOCK_ASSERT(p, MA_OWNED);
406 mtx_assert(&psp->ps_mtx, MA_OWNED);
408 oonstack = sigonstack(regs->tf_esp);
410 /* Allocate space for the signal handler context. */
411 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
412 SIGISMEMBER(psp->ps_sigonstack, sig)) {
413 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
414 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
416 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
417 mtx_unlock(&psp->ps_mtx);
419 /* Build the argument list for the signal handler. */
420 sig = bsd_to_linux_signal(sig);
422 bzero(&frame, sizeof(frame));
424 frame.sf_handler = catcher;
426 frame.sf_siginfo = &fp->sf_si;
427 frame.sf_ucontext = &fp->sf_sc;
429 /* Fill in POSIX parts. */
430 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig);
432 /* Build the signal context to be used by sigreturn. */
433 frame.sf_sc.uc_flags = 0; /* XXX ??? */
434 frame.sf_sc.uc_link = NULL; /* XXX ??? */
436 frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
437 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
438 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
439 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
442 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
444 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
445 frame.sf_sc.uc_mcontext.sc_gs = rgs();
446 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
447 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
448 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
449 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
450 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
451 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
452 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
453 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp;
454 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
455 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
456 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
457 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
458 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
459 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
460 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
461 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
462 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
463 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
464 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
466 if (copyout(&frame, fp, sizeof(frame)) != 0) {
468 * Process has trashed its stack; give it an illegal
469 * instruction to halt it in its tracks.
475 /* Build context to run handler in. */
476 regs->tf_esp = (int)fp;
477 regs->tf_eip = __kernel_rt_sigreturn;
478 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
479 regs->tf_cs = _ucodesel;
480 regs->tf_ds = _udatasel;
481 regs->tf_es = _udatasel;
482 regs->tf_fs = _udatasel;
483 regs->tf_ss = _udatasel;
485 mtx_lock(&psp->ps_mtx);
489 * Send an interrupt to process.
491 * Stack is set up to allow sigcode stored
492 * in u. to call routine, followed by kcall
493 * to sigreturn routine below. After sigreturn
494 * resets the signal mask, the stack, and the
495 * frame pointer, it returns to the user
499 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
501 struct thread *td = curthread;
502 struct proc *p = td->td_proc;
504 struct trapframe *regs;
505 struct l_sigframe *fp, frame;
510 PROC_LOCK_ASSERT(p, MA_OWNED);
512 sig = ksi->ksi_signo;
513 mtx_assert(&psp->ps_mtx, MA_OWNED);
514 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
515 /* Signal handler installed with SA_SIGINFO. */
516 linux_rt_sendsig(catcher, ksi, mask);
520 oonstack = sigonstack(regs->tf_esp);
522 /* Allocate space for the signal handler context. */
523 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
524 SIGISMEMBER(psp->ps_sigonstack, sig)) {
525 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
526 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
528 fp = (struct l_sigframe *)regs->tf_esp - 1;
529 mtx_unlock(&psp->ps_mtx);
532 /* Build the argument list for the signal handler. */
533 sig = bsd_to_linux_signal(sig);
535 bzero(&frame, sizeof(frame));
537 frame.sf_handler = catcher;
540 bsd_to_linux_sigset(mask, &lmask);
542 /* Build the signal context to be used by sigreturn. */
543 frame.sf_sc.sc_mask = lmask.__mask;
544 frame.sf_sc.sc_gs = rgs();
545 frame.sf_sc.sc_fs = regs->tf_fs;
546 frame.sf_sc.sc_es = regs->tf_es;
547 frame.sf_sc.sc_ds = regs->tf_ds;
548 frame.sf_sc.sc_edi = regs->tf_edi;
549 frame.sf_sc.sc_esi = regs->tf_esi;
550 frame.sf_sc.sc_ebp = regs->tf_ebp;
551 frame.sf_sc.sc_ebx = regs->tf_ebx;
552 frame.sf_sc.sc_esp = regs->tf_esp;
553 frame.sf_sc.sc_edx = regs->tf_edx;
554 frame.sf_sc.sc_ecx = regs->tf_ecx;
555 frame.sf_sc.sc_eax = regs->tf_eax;
556 frame.sf_sc.sc_eip = regs->tf_eip;
557 frame.sf_sc.sc_cs = regs->tf_cs;
558 frame.sf_sc.sc_eflags = regs->tf_eflags;
559 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
560 frame.sf_sc.sc_ss = regs->tf_ss;
561 frame.sf_sc.sc_err = regs->tf_err;
562 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
563 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
565 frame.sf_extramask[0] = lmask.__mask;
567 if (copyout(&frame, fp, sizeof(frame)) != 0) {
569 * Process has trashed its stack; give it an illegal
570 * instruction to halt it in its tracks.
576 /* Build context to run handler in. */
577 regs->tf_esp = (int)fp;
578 regs->tf_eip = __kernel_sigreturn;
579 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
580 regs->tf_cs = _ucodesel;
581 regs->tf_ds = _udatasel;
582 regs->tf_es = _udatasel;
583 regs->tf_fs = _udatasel;
584 regs->tf_ss = _udatasel;
586 mtx_lock(&psp->ps_mtx);
590 * System call to cleanup state after a signal
591 * has been taken. Reset signal mask and
592 * stack state from context left by sendsig (above).
593 * Return to previous pc and psl as specified by
594 * context left by sendsig. Check carefully to
595 * make sure that the user has not modified the
596 * psl to gain improper privileges or to cause
600 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
602 struct l_sigframe frame;
603 struct trapframe *regs;
612 * The trampoline code hands us the sigframe.
613 * It is unsafe to keep track of it ourselves, in the event that a
614 * program jumps out of a signal handler.
616 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
619 /* Check for security violations. */
620 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
621 eflags = frame.sf_sc.sc_eflags;
622 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
626 * Don't allow users to load a valid privileged %cs. Let the
627 * hardware check for invalid selectors, excess privilege in
628 * other selectors, invalid %eip's and invalid %esp's.
630 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
631 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
632 ksiginfo_init_trap(&ksi);
633 ksi.ksi_signo = SIGBUS;
634 ksi.ksi_code = BUS_OBJERR;
635 ksi.ksi_trapno = T_PROTFLT;
636 ksi.ksi_addr = (void *)regs->tf_eip;
637 trapsignal(td, &ksi);
641 lmask.__mask = frame.sf_sc.sc_mask;
642 linux_to_bsd_sigset(&lmask, &bmask);
643 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
645 /* Restore signal context. */
646 /* %gs was restored by the trampoline. */
647 regs->tf_fs = frame.sf_sc.sc_fs;
648 regs->tf_es = frame.sf_sc.sc_es;
649 regs->tf_ds = frame.sf_sc.sc_ds;
650 regs->tf_edi = frame.sf_sc.sc_edi;
651 regs->tf_esi = frame.sf_sc.sc_esi;
652 regs->tf_ebp = frame.sf_sc.sc_ebp;
653 regs->tf_ebx = frame.sf_sc.sc_ebx;
654 regs->tf_edx = frame.sf_sc.sc_edx;
655 regs->tf_ecx = frame.sf_sc.sc_ecx;
656 regs->tf_eax = frame.sf_sc.sc_eax;
657 regs->tf_eip = frame.sf_sc.sc_eip;
658 regs->tf_cs = frame.sf_sc.sc_cs;
659 regs->tf_eflags = eflags;
660 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
661 regs->tf_ss = frame.sf_sc.sc_ss;
663 return (EJUSTRETURN);
667 * System call to cleanup state after a signal
668 * has been taken. Reset signal mask and
669 * stack state from context left by rt_sendsig (above).
670 * Return to previous pc and psl as specified by
671 * context left by sendsig. Check carefully to
672 * make sure that the user has not modified the
673 * psl to gain improper privileges or to cause
677 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
679 struct l_ucontext uc;
680 struct l_sigcontext *context;
684 struct trapframe *regs;
691 * The trampoline code hands us the ucontext.
692 * It is unsafe to keep track of it ourselves, in the event that a
693 * program jumps out of a signal handler.
695 if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
698 context = &uc.uc_mcontext;
700 /* Check for security violations. */
701 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
702 eflags = context->sc_eflags;
703 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
707 * Don't allow users to load a valid privileged %cs. Let the
708 * hardware check for invalid selectors, excess privilege in
709 * other selectors, invalid %eip's and invalid %esp's.
711 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
712 if (!CS_SECURE(context->sc_cs)) {
713 ksiginfo_init_trap(&ksi);
714 ksi.ksi_signo = SIGBUS;
715 ksi.ksi_code = BUS_OBJERR;
716 ksi.ksi_trapno = T_PROTFLT;
717 ksi.ksi_addr = (void *)regs->tf_eip;
718 trapsignal(td, &ksi);
722 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
723 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
725 /* Restore signal context. */
726 /* %gs was restored by the trampoline. */
727 regs->tf_fs = context->sc_fs;
728 regs->tf_es = context->sc_es;
729 regs->tf_ds = context->sc_ds;
730 regs->tf_edi = context->sc_edi;
731 regs->tf_esi = context->sc_esi;
732 regs->tf_ebp = context->sc_ebp;
733 regs->tf_ebx = context->sc_ebx;
734 regs->tf_edx = context->sc_edx;
735 regs->tf_ecx = context->sc_ecx;
736 regs->tf_eax = context->sc_eax;
737 regs->tf_eip = context->sc_eip;
738 regs->tf_cs = context->sc_cs;
739 regs->tf_eflags = eflags;
740 regs->tf_esp = context->sc_esp_at_signal;
741 regs->tf_ss = context->sc_ss;
743 /* Call sigaltstack & ignore results. */
745 ss.ss_sp = PTRIN(lss->ss_sp);
746 ss.ss_size = lss->ss_size;
747 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
749 (void)kern_sigaltstack(td, &ss, NULL);
751 return (EJUSTRETURN);
755 linux_fetch_syscall_args(struct thread *td)
758 struct trapframe *frame;
759 struct syscall_args *sa;
762 frame = td->td_frame;
765 sa->code = frame->tf_eax;
766 sa->original_code = sa->code;
767 sa->args[0] = frame->tf_ebx;
768 sa->args[1] = frame->tf_ecx;
769 sa->args[2] = frame->tf_edx;
770 sa->args[3] = frame->tf_esi;
771 sa->args[4] = frame->tf_edi;
772 sa->args[5] = frame->tf_ebp; /* Unconfirmed */
774 if (sa->code >= p->p_sysent->sv_size)
776 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
778 sa->callp = &p->p_sysent->sv_table[sa->code];
780 td->td_retval[0] = 0;
781 td->td_retval[1] = frame->tf_edx;
787 linux_set_syscall_retval(struct thread *td, int error)
789 struct trapframe *frame = td->td_frame;
791 cpu_set_syscall_retval(td, error);
793 if (__predict_false(error != 0)) {
794 if (error != ERESTART && error != EJUSTRETURN)
795 frame->tf_eax = bsd_to_linux_errno(error);
800 linux_set_fork_retval(struct thread *td)
802 struct trapframe *frame = td->td_frame;
808 * exec_setregs may initialize some registers differently than Linux
809 * does, thus potentially confusing Linux binaries. If necessary, we
810 * override the exec_setregs default(s) here.
813 linux_exec_setregs(struct thread *td, struct image_params *imgp,
816 struct pcb *pcb = td->td_pcb;
818 exec_setregs(td, imgp, stack);
820 /* Linux sets %gs to 0, we default to _udatasel. */
824 pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
827 struct sysentvec linux_sysvec = {
828 .sv_size = LINUX_SYS_MAXSYSCALL,
829 .sv_table = linux_sysent,
830 .sv_transtrap = linux_translate_traps,
831 .sv_fixup = linux_fixup,
832 .sv_sendsig = linux_sendsig,
833 .sv_sigcode = &_binary_linux_vdso_so_o_start,
834 .sv_szsigcode = &linux_szsigcode,
835 .sv_name = "Linux a.out",
837 .sv_imgact_try = linux_exec_imgact_try,
838 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
839 .sv_minuser = VM_MIN_ADDRESS,
840 .sv_maxuser = VM_MAXUSER_ADDRESS,
841 .sv_usrstack = LINUX_USRSTACK,
842 .sv_psstrings = PS_STRINGS,
843 .sv_psstringssz = sizeof(struct ps_strings),
844 .sv_stackprot = VM_PROT_ALL,
845 .sv_copyout_strings = exec_copyout_strings,
846 .sv_setregs = linux_exec_setregs,
849 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32 |
850 SV_SIG_DISCIGN | SV_SIG_WAITNDQ,
851 .sv_set_syscall_retval = linux_set_syscall_retval,
852 .sv_fetch_syscall_args = linux_fetch_syscall_args,
853 .sv_syscallnames = NULL,
854 .sv_schedtail = linux_schedtail,
855 .sv_thread_detach = linux_thread_detach,
857 .sv_onexec = linux_on_exec_vmspace,
858 .sv_onexit = linux_on_exit,
859 .sv_ontdexit = linux_thread_dtor,
860 .sv_setid_allowed = &linux_setid_allowed_query,
861 .sv_set_fork_retval = linux_set_fork_retval,
863 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
865 struct sysentvec elf_linux_sysvec = {
866 .sv_size = LINUX_SYS_MAXSYSCALL,
867 .sv_table = linux_sysent,
868 .sv_transtrap = linux_translate_traps,
869 .sv_fixup = linux_fixup_elf,
870 .sv_sendsig = linux_sendsig,
871 .sv_sigcode = &_binary_linux_vdso_so_o_start,
872 .sv_szsigcode = &linux_szsigcode,
873 .sv_name = "Linux ELF32",
874 .sv_coredump = elf32_coredump,
875 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
876 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
877 .sv_elf_core_prepare_notes = elf32_prepare_notes,
878 .sv_imgact_try = linux_exec_imgact_try,
879 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
880 .sv_minuser = VM_MIN_ADDRESS,
881 .sv_maxuser = VM_MAXUSER_ADDRESS,
882 .sv_usrstack = LINUX_USRSTACK,
883 .sv_psstrings = LINUX_PS_STRINGS,
884 .sv_psstringssz = sizeof(struct ps_strings),
885 .sv_stackprot = VM_PROT_ALL,
886 .sv_copyout_auxargs = linux_copyout_auxargs,
887 .sv_copyout_strings = linux_copyout_strings,
888 .sv_setregs = linux_exec_setregs,
891 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP |
892 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP,
893 .sv_set_syscall_retval = linux_set_syscall_retval,
894 .sv_fetch_syscall_args = linux_fetch_syscall_args,
895 .sv_syscallnames = NULL,
896 .sv_shared_page_base = LINUX_SHAREDPAGE,
897 .sv_shared_page_len = PAGE_SIZE,
898 .sv_schedtail = linux_schedtail,
899 .sv_thread_detach = linux_thread_detach,
901 .sv_onexec = linux_on_exec_vmspace,
902 .sv_onexit = linux_on_exit,
903 .sv_ontdexit = linux_thread_dtor,
904 .sv_setid_allowed = &linux_setid_allowed_query,
905 .sv_set_fork_retval = linux_set_fork_retval,
909 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
913 if (SV_PROC_FLAG(p, SV_SHP) != 0)
914 error = linux_map_vdso(p, linux_vdso_obj,
915 linux_vdso_base, LINUX_VDSOPAGE_SIZE, imgp);
917 linux_on_exec(p, imgp);
922 * linux_vdso_install() and linux_exec_sysvec_init() must be called
923 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
926 linux_exec_sysvec_init(void *param)
928 l_uintptr_t *ktimekeep_base, *ktsc_selector;
929 struct sysentvec *sv;
933 /* Fill timekeep_base */
934 exec_sysvec_init(sv);
936 tkoff = kern_timekeep_base - linux_vdso_base;
937 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
938 *ktimekeep_base = sv->sv_timekeep_base;
940 tkoff = kern_tsc_selector - linux_vdso_base;
941 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
942 *ktsc_selector = linux_vdso_tsc_selector_idx();
944 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector);
946 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
947 linux_exec_sysvec_init, &elf_linux_sysvec);
950 linux_vdso_install(const void *param)
952 char *vdso_start = &_binary_linux_vdso_so_o_start;
953 char *vdso_end = &_binary_linux_vdso_so_o_end;
955 linux_szsigcode = vdso_end - vdso_start;
956 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE);
958 linux_vdso_base = LINUX_VDSOPAGE;
960 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
962 linux_vdso_obj = __elfN(linux_shared_page_init)
963 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
964 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
966 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
968 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
969 linux_vdso_install, NULL);
972 linux_vdso_deinstall(const void *param)
975 __elfN(linux_shared_page_fini)(linux_vdso_obj,
976 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
978 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
979 linux_vdso_deinstall, NULL);
982 linux_vdso_reloc(char *mapping, Elf_Addr offset)
984 const Elf_Shdr *shdr;
986 const Elf_Ehdr *ehdr;
988 Elf_Size rtype, symidx;
989 Elf_Addr addr, addend;
995 ehdr = (const Elf_Ehdr *)mapping;
996 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
997 for (i = 0; i < ehdr->e_shnum; i++)
999 switch (shdr[i].sh_type) {
1001 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset);
1002 relcnt = shdr[i].sh_size / sizeof(*rel);
1005 printf("Linux i386 vDSO: unexpected Rela section\n");
1010 for (i = 0; i < relcnt; i++, rel++) {
1011 where = (Elf_Addr *)(mapping + rel->r_offset);
1013 rtype = ELF_R_TYPE(rel->r_info);
1014 symidx = ELF_R_SYM(rel->r_info);
1017 case R_386_NONE: /* none */
1020 case R_386_RELATIVE: /* B + A */
1021 addr = (Elf_Addr)PTROUT(offset + addend);
1026 case R_386_IRELATIVE:
1027 printf("Linux i386 vDSO: unexpected ifunc relocation, "
1028 "symbol index %d\n", symidx);
1031 printf("Linux i386 vDSO: unexpected relocation type %d, "
1032 "symbol index %d\n", rtype, symidx);
1037 static char GNU_ABI_VENDOR[] = "GNU";
1038 static int GNULINUX_ABI_DESC = 0;
1041 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
1043 const Elf32_Word *desc;
1046 p = (uintptr_t)(note + 1);
1047 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1049 desc = (const Elf32_Word *)p;
1050 if (desc[0] != GNULINUX_ABI_DESC)
1054 * For Linux we encode osrel using the Linux convention of
1055 * (version << 16) | (major << 8) | (minor)
1056 * See macro in linux_mib.h
1058 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
1063 static Elf_Brandnote linux_brandnote = {
1064 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
1065 .hdr.n_descsz = 16, /* XXX at least 16 */
1067 .vendor = GNU_ABI_VENDOR,
1068 .flags = BN_TRANSLATE_OSREL,
1069 .trans_osrel = linux_trans_osrel
1072 static Elf32_Brandinfo linux_brand = {
1073 .brand = ELFOSABI_LINUX,
1075 .compat_3_brand = "Linux",
1076 .emul_path = linux_emul_path,
1077 .interp_path = "/lib/ld-linux.so.1",
1078 .sysvec = &elf_linux_sysvec,
1079 .interp_newpath = NULL,
1080 .brand_note = &linux_brandnote,
1081 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1084 static Elf32_Brandinfo linux_glibc2brand = {
1085 .brand = ELFOSABI_LINUX,
1087 .compat_3_brand = "Linux",
1088 .emul_path = linux_emul_path,
1089 .interp_path = "/lib/ld-linux.so.2",
1090 .sysvec = &elf_linux_sysvec,
1091 .interp_newpath = NULL,
1092 .brand_note = &linux_brandnote,
1093 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1096 static Elf32_Brandinfo linux_muslbrand = {
1097 .brand = ELFOSABI_LINUX,
1099 .compat_3_brand = "Linux",
1100 .emul_path = linux_emul_path,
1101 .interp_path = "/lib/ld-musl-i386.so.1",
1102 .sysvec = &elf_linux_sysvec,
1103 .interp_newpath = NULL,
1104 .brand_note = &linux_brandnote,
1105 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE |
1106 LINUX_BI_FUTEX_REQUEUE
1109 Elf32_Brandinfo *linux_brandlist[] = {
1117 linux_elf_modevent(module_t mod, int type, void *data)
1119 Elf32_Brandinfo **brandinfo;
1121 struct linux_ioctl_handler **lihp;
1127 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1129 if (elf32_insert_brand_entry(*brandinfo) < 0)
1132 SET_FOREACH(lihp, linux_ioctl_handler_set)
1133 linux_ioctl_register_handler(*lihp);
1134 linux_dev_shm_create();
1135 linux_osd_jail_register();
1136 stclohz = (stathz ? stathz : hz);
1138 printf("Linux ELF exec handler installed\n");
1140 printf("cannot insert Linux ELF brand handler\n");
1143 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1145 if (elf32_brand_inuse(*brandinfo))
1148 for (brandinfo = &linux_brandlist[0];
1149 *brandinfo != NULL; ++brandinfo)
1150 if (elf32_remove_brand_entry(*brandinfo) < 0)
1154 SET_FOREACH(lihp, linux_ioctl_handler_set)
1155 linux_ioctl_unregister_handler(*lihp);
1156 linux_dev_shm_destroy();
1157 linux_osd_jail_deregister();
1159 printf("Linux ELF exec handler removed\n");
1161 printf("Could not deinstall ELF interpreter entry\n");
1164 return (EOPNOTSUPP);
1169 static moduledata_t linux_elf_mod = {
1175 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1176 FEATURE(linux, "Linux 32bit support");