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/stddef.h>
46 #include <sys/signalvar.h>
47 #include <sys/syscallsubr.h>
48 #include <sys/sysctl.h>
49 #include <sys/sysent.h>
50 #include <sys/sysproto.h>
51 #include <sys/vnode.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 <x86/linux/linux_x86.h>
68 #include <i386/linux/linux.h>
69 #include <i386/linux/linux_proto.h>
70 #include <compat/linux/linux_emul.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 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2
81 #define LINUX_VDSOPAGE (VM_MAXUSER_ADDRESS - LINUX_VDSOPAGE_SIZE)
82 #define LINUX_SHAREDPAGE (LINUX_VDSOPAGE - PAGE_SIZE)
84 * PAGE_SIZE - the size
85 * of the native SHAREDPAGE
87 #define LINUX_USRSTACK LINUX_SHAREDPAGE
88 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings))
90 static int linux_szsigcode;
91 static vm_object_t linux_vdso_obj;
92 static char *linux_vdso_mapping;
93 extern char _binary_linux_vdso_so_o_start;
94 extern char _binary_linux_vdso_so_o_end;
95 static vm_offset_t linux_vdso_base;
97 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
99 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
101 static int linux_fixup(uintptr_t *stack_base,
102 struct image_params *iparams);
103 static int linux_fixup_elf(uintptr_t *stack_base,
104 struct image_params *iparams);
105 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
106 static void linux_exec_setregs(struct thread *td,
107 struct image_params *imgp, uintptr_t stack);
108 static void linux_exec_sysvec_init(void *param);
109 static int linux_on_exec_vmspace(struct proc *p,
110 struct image_params *imgp);
111 static int linux_copyout_strings(struct image_params *imgp,
112 uintptr_t *stack_base);
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)
209 Elf32_Auxinfo *argarray, *pos;
210 struct ps_strings *arginfo;
211 int error, issetugid;
214 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
215 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p);
216 args = (Elf32_Auxargs *)imgp->auxargs;
217 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
220 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
221 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, __kernel_vsyscall);
222 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
225 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
226 * as it has appeared in the 2.4.0-rc7 first time.
227 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
228 * glibc falls back to the hard-coded CLK_TCK value when aux entry
230 * Also see linux_times() implementation.
232 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
233 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
234 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
235 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
236 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
237 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
238 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
239 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
240 AUXARGS_ENTRY(pos, AT_BASE, args->base);
241 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
242 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
243 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
244 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
245 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
246 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
247 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
248 if (imgp->execpathp != 0)
249 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
250 if (args->execfd != -1)
251 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
252 AUXARGS_ENTRY(pos, AT_NULL, 0);
254 free(imgp->auxargs, M_TEMP);
255 imgp->auxargs = NULL;
256 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
258 error = copyout(argarray, (void *)base,
259 sizeof(*argarray) * LINUX_AT_COUNT);
260 free(argarray, M_TEMP);
265 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
269 base = (register_t *)*stack_base;
271 if (suword(base, (register_t)imgp->args->argc) == -1)
273 *stack_base = (uintptr_t)base;
278 * Copied from kern/kern_exec.c
281 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
283 int argc, envc, error;
286 uintptr_t destp, ustringp;
287 struct ps_strings *arginfo;
288 char canary[LINUX_AT_RANDOM_LEN];
293 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p);
294 destp = (uintptr_t)arginfo;
296 if (imgp->execpath != NULL && imgp->auxargs != NULL) {
297 execpath_len = strlen(imgp->execpath) + 1;
298 destp -= execpath_len;
299 destp = rounddown2(destp, sizeof(void *));
300 imgp->execpathp = (void *)destp;
301 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
306 /* Prepare the canary for SSP. */
307 arc4rand(canary, sizeof(canary), 0);
308 destp -= roundup(sizeof(canary), sizeof(void *));
309 imgp->canary = (void *)destp;
310 error = copyout(canary, imgp->canary, sizeof(canary));
314 /* Allocate room for the argument and environment strings. */
315 destp -= ARG_MAX - imgp->args->stringspace;
316 destp = rounddown2(destp, sizeof(void *));
321 * Allocate room on the stack for the ELF auxargs
322 * array. It has LINUX_AT_COUNT entries.
324 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo);
325 destp = rounddown2(destp, sizeof(void *));
328 vectp = (char **)destp;
331 * Allocate room for the argv[] and env vectors including the
332 * terminating NULL pointers.
334 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
336 /* vectp also becomes our initial stack base. */
337 *stack_base = (uintptr_t)vectp;
339 stringp = imgp->args->begin_argv;
340 argc = imgp->args->argc;
341 envc = imgp->args->envc;
343 /* Copy out strings - arguments and environment. */
344 error = copyout(stringp, (void *)ustringp,
345 ARG_MAX - imgp->args->stringspace);
349 /* Fill in "ps_strings" struct for ps, w, etc. */
350 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
351 suword(&arginfo->ps_nargvstr, argc) != 0)
354 /* Fill in argument portion of vector table. */
355 for (; argc > 0; --argc) {
356 if (suword(vectp++, ustringp) != 0)
358 while (*stringp++ != 0)
363 /* A null vector table pointer separates the argp's from the envp's. */
364 if (suword(vectp++, 0) != 0)
367 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
368 suword(&arginfo->ps_nenvstr, envc) != 0)
371 /* Fill in environment portion of vector table. */
372 for (; envc > 0; --envc) {
373 if (suword(vectp++, ustringp) != 0)
375 while (*stringp++ != 0)
380 /* The end of the vector table is a null pointer. */
381 if (suword(vectp, 0) != 0)
386 error = imgp->sysent->sv_copyout_auxargs(imgp,
396 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
398 struct thread *td = curthread;
399 struct proc *p = td->td_proc;
401 struct trapframe *regs;
402 struct l_rt_sigframe *fp, frame;
406 sig = ksi->ksi_signo;
407 code = ksi->ksi_code;
408 PROC_LOCK_ASSERT(p, MA_OWNED);
410 mtx_assert(&psp->ps_mtx, MA_OWNED);
412 oonstack = sigonstack(regs->tf_esp);
414 /* Allocate space for the signal handler context. */
415 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
416 SIGISMEMBER(psp->ps_sigonstack, sig)) {
417 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
418 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
420 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
421 mtx_unlock(&psp->ps_mtx);
423 /* Build the argument list for the signal handler. */
424 sig = bsd_to_linux_signal(sig);
426 bzero(&frame, sizeof(frame));
428 frame.sf_handler = catcher;
430 frame.sf_siginfo = &fp->sf_si;
431 frame.sf_ucontext = &fp->sf_sc;
433 /* Fill in POSIX parts. */
434 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig);
436 /* Build the signal context to be used by sigreturn. */
437 frame.sf_sc.uc_flags = 0; /* XXX ??? */
438 frame.sf_sc.uc_link = NULL; /* XXX ??? */
440 frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp;
441 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
442 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
443 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
446 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
448 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
449 frame.sf_sc.uc_mcontext.sc_gs = rgs();
450 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
451 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
452 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
453 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
454 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
455 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
456 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
457 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp;
458 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
459 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
460 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
461 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
462 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
463 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
464 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
465 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
466 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
467 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
468 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
470 if (copyout(&frame, fp, sizeof(frame)) != 0) {
472 * Process has trashed its stack; give it an illegal
473 * instruction to halt it in its tracks.
479 /* Build context to run handler in. */
480 regs->tf_esp = (int)fp;
481 regs->tf_eip = __kernel_rt_sigreturn;
482 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
483 regs->tf_cs = _ucodesel;
484 regs->tf_ds = _udatasel;
485 regs->tf_es = _udatasel;
486 regs->tf_fs = _udatasel;
487 regs->tf_ss = _udatasel;
489 mtx_lock(&psp->ps_mtx);
493 * Send an interrupt to process.
495 * Stack is set up to allow sigcode stored
496 * in u. to call routine, followed by kcall
497 * to sigreturn routine below. After sigreturn
498 * resets the signal mask, the stack, and the
499 * frame pointer, it returns to the user
503 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
505 struct thread *td = curthread;
506 struct proc *p = td->td_proc;
508 struct trapframe *regs;
509 struct l_sigframe *fp, frame;
514 PROC_LOCK_ASSERT(p, MA_OWNED);
516 sig = ksi->ksi_signo;
517 code = ksi->ksi_code;
518 mtx_assert(&psp->ps_mtx, MA_OWNED);
519 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
520 /* Signal handler installed with SA_SIGINFO. */
521 linux_rt_sendsig(catcher, ksi, mask);
525 oonstack = sigonstack(regs->tf_esp);
527 /* Allocate space for the signal handler context. */
528 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
529 SIGISMEMBER(psp->ps_sigonstack, sig)) {
530 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
531 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
533 fp = (struct l_sigframe *)regs->tf_esp - 1;
534 mtx_unlock(&psp->ps_mtx);
537 /* Build the argument list for the signal handler. */
538 sig = bsd_to_linux_signal(sig);
540 bzero(&frame, sizeof(frame));
542 frame.sf_handler = catcher;
545 bsd_to_linux_sigset(mask, &lmask);
547 /* Build the signal context to be used by sigreturn. */
548 frame.sf_sc.sc_mask = lmask.__mask;
549 frame.sf_sc.sc_gs = rgs();
550 frame.sf_sc.sc_fs = regs->tf_fs;
551 frame.sf_sc.sc_es = regs->tf_es;
552 frame.sf_sc.sc_ds = regs->tf_ds;
553 frame.sf_sc.sc_edi = regs->tf_edi;
554 frame.sf_sc.sc_esi = regs->tf_esi;
555 frame.sf_sc.sc_ebp = regs->tf_ebp;
556 frame.sf_sc.sc_ebx = regs->tf_ebx;
557 frame.sf_sc.sc_esp = regs->tf_esp;
558 frame.sf_sc.sc_edx = regs->tf_edx;
559 frame.sf_sc.sc_ecx = regs->tf_ecx;
560 frame.sf_sc.sc_eax = regs->tf_eax;
561 frame.sf_sc.sc_eip = regs->tf_eip;
562 frame.sf_sc.sc_cs = regs->tf_cs;
563 frame.sf_sc.sc_eflags = regs->tf_eflags;
564 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
565 frame.sf_sc.sc_ss = regs->tf_ss;
566 frame.sf_sc.sc_err = regs->tf_err;
567 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
568 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
570 frame.sf_extramask[0] = lmask.__mask;
572 if (copyout(&frame, fp, sizeof(frame)) != 0) {
574 * Process has trashed its stack; give it an illegal
575 * instruction to halt it in its tracks.
581 /* Build context to run handler in. */
582 regs->tf_esp = (int)fp;
583 regs->tf_eip = __kernel_sigreturn;
584 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
585 regs->tf_cs = _ucodesel;
586 regs->tf_ds = _udatasel;
587 regs->tf_es = _udatasel;
588 regs->tf_fs = _udatasel;
589 regs->tf_ss = _udatasel;
591 mtx_lock(&psp->ps_mtx);
595 * System call to cleanup state after a signal
596 * has been taken. Reset signal mask and
597 * stack state from context left by sendsig (above).
598 * Return to previous pc and psl as specified by
599 * context left by sendsig. Check carefully to
600 * make sure that the user has not modified the
601 * psl to gain improper privileges or to cause
605 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
607 struct l_sigframe frame;
608 struct trapframe *regs;
617 * The trampoline code hands us the sigframe.
618 * It is unsafe to keep track of it ourselves, in the event that a
619 * program jumps out of a signal handler.
621 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
624 /* Check for security violations. */
625 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
626 eflags = frame.sf_sc.sc_eflags;
627 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
631 * Don't allow users to load a valid privileged %cs. Let the
632 * hardware check for invalid selectors, excess privilege in
633 * other selectors, invalid %eip's and invalid %esp's.
635 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
636 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
637 ksiginfo_init_trap(&ksi);
638 ksi.ksi_signo = SIGBUS;
639 ksi.ksi_code = BUS_OBJERR;
640 ksi.ksi_trapno = T_PROTFLT;
641 ksi.ksi_addr = (void *)regs->tf_eip;
642 trapsignal(td, &ksi);
646 lmask.__mask = frame.sf_sc.sc_mask;
647 linux_to_bsd_sigset(&lmask, &bmask);
648 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
650 /* Restore signal context. */
651 /* %gs was restored by the trampoline. */
652 regs->tf_fs = frame.sf_sc.sc_fs;
653 regs->tf_es = frame.sf_sc.sc_es;
654 regs->tf_ds = frame.sf_sc.sc_ds;
655 regs->tf_edi = frame.sf_sc.sc_edi;
656 regs->tf_esi = frame.sf_sc.sc_esi;
657 regs->tf_ebp = frame.sf_sc.sc_ebp;
658 regs->tf_ebx = frame.sf_sc.sc_ebx;
659 regs->tf_edx = frame.sf_sc.sc_edx;
660 regs->tf_ecx = frame.sf_sc.sc_ecx;
661 regs->tf_eax = frame.sf_sc.sc_eax;
662 regs->tf_eip = frame.sf_sc.sc_eip;
663 regs->tf_cs = frame.sf_sc.sc_cs;
664 regs->tf_eflags = eflags;
665 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
666 regs->tf_ss = frame.sf_sc.sc_ss;
668 return (EJUSTRETURN);
672 * System call to cleanup state after a signal
673 * has been taken. Reset signal mask and
674 * stack state from context left by rt_sendsig (above).
675 * Return to previous pc and psl as specified by
676 * context left by sendsig. Check carefully to
677 * make sure that the user has not modified the
678 * psl to gain improper privileges or to cause
682 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
684 struct l_ucontext uc;
685 struct l_sigcontext *context;
689 struct trapframe *regs;
696 * The trampoline code hands us the ucontext.
697 * It is unsafe to keep track of it ourselves, in the event that a
698 * program jumps out of a signal handler.
700 if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
703 context = &uc.uc_mcontext;
705 /* Check for security violations. */
706 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
707 eflags = context->sc_eflags;
708 if (!EFLAGS_SECURE(eflags, regs->tf_eflags))
712 * Don't allow users to load a valid privileged %cs. Let the
713 * hardware check for invalid selectors, excess privilege in
714 * other selectors, invalid %eip's and invalid %esp's.
716 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
717 if (!CS_SECURE(context->sc_cs)) {
718 ksiginfo_init_trap(&ksi);
719 ksi.ksi_signo = SIGBUS;
720 ksi.ksi_code = BUS_OBJERR;
721 ksi.ksi_trapno = T_PROTFLT;
722 ksi.ksi_addr = (void *)regs->tf_eip;
723 trapsignal(td, &ksi);
727 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
728 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
730 /* Restore signal context. */
731 /* %gs was restored by the trampoline. */
732 regs->tf_fs = context->sc_fs;
733 regs->tf_es = context->sc_es;
734 regs->tf_ds = context->sc_ds;
735 regs->tf_edi = context->sc_edi;
736 regs->tf_esi = context->sc_esi;
737 regs->tf_ebp = context->sc_ebp;
738 regs->tf_ebx = context->sc_ebx;
739 regs->tf_edx = context->sc_edx;
740 regs->tf_ecx = context->sc_ecx;
741 regs->tf_eax = context->sc_eax;
742 regs->tf_eip = context->sc_eip;
743 regs->tf_cs = context->sc_cs;
744 regs->tf_eflags = eflags;
745 regs->tf_esp = context->sc_esp_at_signal;
746 regs->tf_ss = context->sc_ss;
748 /* Call sigaltstack & ignore results. */
750 ss.ss_sp = lss->ss_sp;
751 ss.ss_size = lss->ss_size;
752 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
754 (void)kern_sigaltstack(td, &ss, NULL);
756 return (EJUSTRETURN);
760 linux_fetch_syscall_args(struct thread *td)
763 struct trapframe *frame;
764 struct syscall_args *sa;
767 frame = td->td_frame;
770 sa->code = frame->tf_eax;
771 sa->args[0] = frame->tf_ebx;
772 sa->args[1] = frame->tf_ecx;
773 sa->args[2] = frame->tf_edx;
774 sa->args[3] = frame->tf_esi;
775 sa->args[4] = frame->tf_edi;
776 sa->args[5] = frame->tf_ebp; /* Unconfirmed */
778 if (sa->code >= p->p_sysent->sv_size)
780 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
782 sa->callp = &p->p_sysent->sv_table[sa->code];
784 td->td_retval[0] = 0;
785 td->td_retval[1] = frame->tf_edx;
791 linux_set_syscall_retval(struct thread *td, int error)
793 struct trapframe *frame = td->td_frame;
795 cpu_set_syscall_retval(td, error);
797 if (__predict_false(error != 0)) {
798 if (error != ERESTART && error != EJUSTRETURN)
799 frame->tf_eax = bsd_to_linux_errno(error);
804 * exec_setregs may initialize some registers differently than Linux
805 * does, thus potentially confusing Linux binaries. If necessary, we
806 * override the exec_setregs default(s) here.
809 linux_exec_setregs(struct thread *td, struct image_params *imgp,
812 struct pcb *pcb = td->td_pcb;
814 exec_setregs(td, imgp, stack);
816 /* Linux sets %gs to 0, we default to _udatasel. */
820 pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
823 struct sysentvec linux_sysvec = {
824 .sv_size = LINUX_SYS_MAXSYSCALL,
825 .sv_table = linux_sysent,
826 .sv_transtrap = linux_translate_traps,
827 .sv_fixup = linux_fixup,
828 .sv_sendsig = linux_sendsig,
829 .sv_sigcode = &_binary_linux_vdso_so_o_start,
830 .sv_szsigcode = &linux_szsigcode,
831 .sv_name = "Linux a.out",
833 .sv_imgact_try = linux_exec_imgact_try,
834 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
835 .sv_minuser = VM_MIN_ADDRESS,
836 .sv_maxuser = VM_MAXUSER_ADDRESS,
837 .sv_usrstack = LINUX_USRSTACK,
838 .sv_psstrings = PS_STRINGS,
839 .sv_psstringssz = sizeof(struct ps_strings),
840 .sv_stackprot = VM_PROT_ALL,
841 .sv_copyout_strings = exec_copyout_strings,
842 .sv_setregs = linux_exec_setregs,
845 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32 |
846 SV_SIG_DISCIGN | SV_SIG_WAITNDQ,
847 .sv_set_syscall_retval = linux_set_syscall_retval,
848 .sv_fetch_syscall_args = linux_fetch_syscall_args,
849 .sv_syscallnames = NULL,
850 .sv_schedtail = linux_schedtail,
851 .sv_thread_detach = linux_thread_detach,
853 .sv_onexec = linux_on_exec_vmspace,
854 .sv_onexit = linux_on_exit,
855 .sv_ontdexit = linux_thread_dtor,
856 .sv_setid_allowed = &linux_setid_allowed_query,
858 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
860 struct sysentvec elf_linux_sysvec = {
861 .sv_size = LINUX_SYS_MAXSYSCALL,
862 .sv_table = linux_sysent,
863 .sv_transtrap = linux_translate_traps,
864 .sv_fixup = linux_fixup_elf,
865 .sv_sendsig = linux_sendsig,
866 .sv_sigcode = &_binary_linux_vdso_so_o_start,
867 .sv_szsigcode = &linux_szsigcode,
868 .sv_name = "Linux ELF32",
869 .sv_coredump = elf32_coredump,
870 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
871 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
872 .sv_elf_core_prepare_notes = elf32_prepare_notes,
873 .sv_imgact_try = linux_exec_imgact_try,
874 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
875 .sv_minuser = VM_MIN_ADDRESS,
876 .sv_maxuser = VM_MAXUSER_ADDRESS,
877 .sv_usrstack = LINUX_USRSTACK,
878 .sv_psstrings = LINUX_PS_STRINGS,
879 .sv_psstringssz = sizeof(struct ps_strings),
880 .sv_stackprot = VM_PROT_ALL,
881 .sv_copyout_auxargs = linux_copyout_auxargs,
882 .sv_copyout_strings = linux_copyout_strings,
883 .sv_setregs = linux_exec_setregs,
886 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP |
887 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP,
888 .sv_set_syscall_retval = linux_set_syscall_retval,
889 .sv_fetch_syscall_args = linux_fetch_syscall_args,
890 .sv_syscallnames = NULL,
891 .sv_shared_page_base = LINUX_SHAREDPAGE,
892 .sv_shared_page_len = PAGE_SIZE,
893 .sv_schedtail = linux_schedtail,
894 .sv_thread_detach = linux_thread_detach,
896 .sv_onexec = linux_on_exec_vmspace,
897 .sv_onexit = linux_on_exit,
898 .sv_ontdexit = linux_thread_dtor,
899 .sv_setid_allowed = &linux_setid_allowed_query,
903 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
907 if (SV_PROC_FLAG(p, SV_SHP) != 0)
908 error = linux_map_vdso(p, linux_vdso_obj,
909 linux_vdso_base, LINUX_VDSOPAGE_SIZE, imgp);
911 linux_on_exec(p, imgp);
916 * linux_vdso_install() and linux_exec_sysvec_init() must be called
917 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
920 linux_exec_sysvec_init(void *param)
922 l_uintptr_t *ktimekeep_base, *ktsc_selector;
923 struct sysentvec *sv;
927 /* Fill timekeep_base */
928 exec_sysvec_init(sv);
930 tkoff = kern_timekeep_base - linux_vdso_base;
931 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
932 *ktimekeep_base = sv->sv_timekeep_base;
934 tkoff = kern_tsc_selector - linux_vdso_base;
935 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
936 *ktsc_selector = linux_vdso_tsc_selector_idx();
938 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector);
940 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
941 linux_exec_sysvec_init, &elf_linux_sysvec);
944 linux_vdso_install(const void *param)
946 char *vdso_start = &_binary_linux_vdso_so_o_start;
947 char *vdso_end = &_binary_linux_vdso_so_o_end;
949 linux_szsigcode = vdso_end - vdso_start;
950 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE);
952 linux_vdso_base = LINUX_VDSOPAGE;
954 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
956 linux_vdso_obj = __elfN(linux_shared_page_init)
957 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
958 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
960 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
962 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
963 linux_vdso_install, NULL);
966 linux_vdso_deinstall(const void *param)
969 __elfN(linux_shared_page_fini)(linux_vdso_obj,
970 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
972 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
973 linux_vdso_deinstall, NULL);
976 linux_vdso_reloc(char *mapping, Elf_Addr offset)
978 const Elf_Shdr *shdr;
980 const Elf_Ehdr *ehdr;
982 Elf_Size rtype, symidx;
983 Elf_Addr addr, addend;
989 ehdr = (const Elf_Ehdr *)mapping;
990 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
991 for (i = 0; i < ehdr->e_shnum; i++)
993 switch (shdr[i].sh_type) {
995 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset);
996 relcnt = shdr[i].sh_size / sizeof(*rel);
999 printf("Linux i386 vDSO: unexpected Rela section\n");
1004 for (i = 0; i < relcnt; i++, rel++) {
1005 where = (Elf_Addr *)(mapping + rel->r_offset);
1007 rtype = ELF_R_TYPE(rel->r_info);
1008 symidx = ELF_R_SYM(rel->r_info);
1011 case R_386_NONE: /* none */
1014 case R_386_RELATIVE: /* B + A */
1015 addr = (Elf_Addr)PTROUT(offset + addend);
1020 case R_386_IRELATIVE:
1021 printf("Linux i386 vDSO: unexpected ifunc relocation, "
1022 "symbol index %d\n", symidx);
1025 printf("Linux i386 vDSO: unexpected relocation type %d, "
1026 "symbol index %d\n", rtype, symidx);
1031 static char GNU_ABI_VENDOR[] = "GNU";
1032 static int GNULINUX_ABI_DESC = 0;
1035 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
1037 const Elf32_Word *desc;
1040 p = (uintptr_t)(note + 1);
1041 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1043 desc = (const Elf32_Word *)p;
1044 if (desc[0] != GNULINUX_ABI_DESC)
1048 * For Linux we encode osrel using the Linux convention of
1049 * (version << 16) | (major << 8) | (minor)
1050 * See macro in linux_mib.h
1052 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
1057 static Elf_Brandnote linux_brandnote = {
1058 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
1059 .hdr.n_descsz = 16, /* XXX at least 16 */
1061 .vendor = GNU_ABI_VENDOR,
1062 .flags = BN_TRANSLATE_OSREL,
1063 .trans_osrel = linux_trans_osrel
1066 static Elf32_Brandinfo linux_brand = {
1067 .brand = ELFOSABI_LINUX,
1069 .compat_3_brand = "Linux",
1070 .emul_path = linux_emul_path,
1071 .interp_path = "/lib/ld-linux.so.1",
1072 .sysvec = &elf_linux_sysvec,
1073 .interp_newpath = NULL,
1074 .brand_note = &linux_brandnote,
1075 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1078 static Elf32_Brandinfo linux_glibc2brand = {
1079 .brand = ELFOSABI_LINUX,
1081 .compat_3_brand = "Linux",
1082 .emul_path = linux_emul_path,
1083 .interp_path = "/lib/ld-linux.so.2",
1084 .sysvec = &elf_linux_sysvec,
1085 .interp_newpath = NULL,
1086 .brand_note = &linux_brandnote,
1087 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1090 static Elf32_Brandinfo linux_muslbrand = {
1091 .brand = ELFOSABI_LINUX,
1093 .compat_3_brand = "Linux",
1094 .emul_path = linux_emul_path,
1095 .interp_path = "/lib/ld-musl-i386.so.1",
1096 .sysvec = &elf_linux_sysvec,
1097 .interp_newpath = NULL,
1098 .brand_note = &linux_brandnote,
1099 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1102 Elf32_Brandinfo *linux_brandlist[] = {
1110 linux_elf_modevent(module_t mod, int type, void *data)
1112 Elf32_Brandinfo **brandinfo;
1114 struct linux_ioctl_handler **lihp;
1120 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1122 if (elf32_insert_brand_entry(*brandinfo) < 0)
1125 SET_FOREACH(lihp, linux_ioctl_handler_set)
1126 linux_ioctl_register_handler(*lihp);
1127 LIST_INIT(&futex_list);
1128 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1129 linux_dev_shm_create();
1130 linux_osd_jail_register();
1131 stclohz = (stathz ? stathz : hz);
1133 printf("Linux ELF exec handler installed\n");
1135 printf("cannot insert Linux ELF brand handler\n");
1138 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1140 if (elf32_brand_inuse(*brandinfo))
1143 for (brandinfo = &linux_brandlist[0];
1144 *brandinfo != NULL; ++brandinfo)
1145 if (elf32_remove_brand_entry(*brandinfo) < 0)
1149 SET_FOREACH(lihp, linux_ioctl_handler_set)
1150 linux_ioctl_unregister_handler(*lihp);
1151 mtx_destroy(&futex_mtx);
1152 linux_dev_shm_destroy();
1153 linux_osd_jail_deregister();
1155 printf("Linux ELF exec handler removed\n");
1157 printf("Could not deinstall ELF interpreter entry\n");
1160 return (EOPNOTSUPP);
1165 static moduledata_t linux_elf_mod = {
1171 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1172 FEATURE(linux, "Linux 32bit support");
1175 * linux_vdso_install() and linux_exec_sysvec_init() must be called
1176 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).