2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2004 Tim J. Robbins
5 * Copyright (c) 2003 Peter Wemm
6 * Copyright (c) 2002 Doug Rabson
7 * Copyright (c) 1998-1999 Andrew Gallatin
8 * Copyright (c) 1994-1996 Søren Schmidt
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer
16 * in this position and unchanged.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 #include "opt_compat.h"
39 #ifndef COMPAT_FREEBSD32
40 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
43 #define __ELF_WORD_SIZE 32
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/fcntl.h>
49 #include <sys/imgact.h>
50 #include <sys/imgact_elf.h>
51 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/module.h>
55 #include <sys/mutex.h>
57 #include <sys/resourcevar.h>
58 #include <sys/signalvar.h>
59 #include <sys/syscallsubr.h>
60 #include <sys/sysctl.h>
61 #include <sys/sysent.h>
62 #include <sys/sysproto.h>
63 #include <sys/vnode.h>
64 #include <sys/eventhandler.h>
68 #include <vm/vm_extern.h>
69 #include <vm/vm_map.h>
70 #include <vm/vm_object.h>
71 #include <vm/vm_page.h>
72 #include <vm/vm_param.h>
74 #include <machine/cpu.h>
75 #include <machine/md_var.h>
76 #include <machine/pcb.h>
77 #include <machine/specialreg.h>
78 #include <machine/trap.h>
80 #include <amd64/linux32/linux.h>
81 #include <amd64/linux32/linux32_proto.h>
82 #include <compat/linux/linux_emul.h>
83 #include <compat/linux/linux_futex.h>
84 #include <compat/linux/linux_ioctl.h>
85 #include <compat/linux/linux_mib.h>
86 #include <compat/linux/linux_misc.h>
87 #include <compat/linux/linux_signal.h>
88 #include <compat/linux/linux_util.h>
89 #include <compat/linux/linux_vdso.h>
91 MODULE_VERSION(linux, 1);
93 #define AUXARGS_ENTRY_32(pos, id, val) \
95 suword32(pos++, id); \
96 suword32(pos++, val); \
99 #if BYTE_ORDER == LITTLE_ENDIAN
100 #define SHELLMAGIC 0x2123 /* #! */
102 #define SHELLMAGIC 0x2321
106 * Allow the sendsig functions to use the ldebug() facility even though they
107 * are not syscalls themselves. Map them to syscall 0. This is slightly less
108 * bogus than using ldebug(sigreturn).
110 #define LINUX32_SYS_linux_rt_sendsig 0
111 #define LINUX32_SYS_linux_sendsig 0
113 const char *linux_kplatform;
114 static int linux_szsigcode;
115 static vm_object_t linux_shared_page_obj;
116 static char *linux_shared_page_mapping;
117 extern char _binary_linux32_locore_o_start;
118 extern char _binary_linux32_locore_o_end;
120 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL];
122 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
124 static int linux_fixup_elf(register_t **stack_base,
125 struct image_params *iparams);
126 static register_t *linux_copyout_strings(struct image_params *imgp);
127 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
128 static int linux_exec_imgact_try(struct image_params *iparams);
129 static void linux_exec_setregs(struct thread *td,
130 struct image_params *imgp, u_long stack);
131 static void linux32_fixlimit(struct rlimit *rl, int which);
132 static bool linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
133 static void linux_vdso_install(void *param);
134 static void linux_vdso_deinstall(void *param);
136 #define LINUX_T_UNKNOWN 255
137 static int _bsd_to_linux_trapcode[] = {
138 LINUX_T_UNKNOWN, /* 0 */
139 6, /* 1 T_PRIVINFLT */
140 LINUX_T_UNKNOWN, /* 2 */
142 LINUX_T_UNKNOWN, /* 4 */
143 LINUX_T_UNKNOWN, /* 5 */
144 16, /* 6 T_ARITHTRAP */
145 254, /* 7 T_ASTFLT */
146 LINUX_T_UNKNOWN, /* 8 */
147 13, /* 9 T_PROTFLT */
148 1, /* 10 T_TRCTRAP */
149 LINUX_T_UNKNOWN, /* 11 */
150 14, /* 12 T_PAGEFLT */
151 LINUX_T_UNKNOWN, /* 13 */
152 17, /* 14 T_ALIGNFLT */
153 LINUX_T_UNKNOWN, /* 15 */
154 LINUX_T_UNKNOWN, /* 16 */
155 LINUX_T_UNKNOWN, /* 17 */
161 8, /* 23 T_DOUBLEFLT */
162 9, /* 24 T_FPOPFLT */
163 10, /* 25 T_TSSFLT */
164 11, /* 26 T_SEGNPFLT */
165 12, /* 27 T_STKFLT */
167 19, /* 29 T_XMMFLT */
168 15 /* 30 T_RESERVED */
170 #define bsd_to_linux_trapcode(code) \
171 ((code)<nitems(_bsd_to_linux_trapcode)? \
172 _bsd_to_linux_trapcode[(code)]: \
175 struct linux32_ps_strings {
176 u_int32_t ps_argvstr; /* first of 0 or more argument strings */
177 u_int ps_nargvstr; /* the number of argument strings */
178 u_int32_t ps_envstr; /* first of 0 or more environment strings */
179 u_int ps_nenvstr; /* the number of environment strings */
182 LINUX_VDSO_SYM_INTPTR(linux32_sigcode);
183 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode);
184 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall);
185 LINUX_VDSO_SYM_CHAR(linux_platform);
188 * If FreeBSD & Linux have a difference of opinion about what a trap
189 * means, deal with it here.
194 linux_translate_traps(int signal, int trap_code)
196 if (signal != SIGBUS)
210 linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
215 struct linux32_ps_strings *arginfo;
218 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
220 KASSERT(curthread->td_proc == imgp->proc,
221 ("unsafe linux_fixup_elf(), should be curproc"));
222 base = (Elf32_Addr *)*stack_base;
223 args = (Elf32_Auxargs *)imgp->auxargs;
224 pos = base + (imgp->args->argc + imgp->args->envc + 2);
226 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
227 AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO_EHDR,
228 imgp->proc->p_sysent->sv_shared_page_base);
229 AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
230 AUXARGS_ENTRY_32(pos, LINUX_AT_HWCAP, cpu_feature);
233 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
234 * as it has appeared in the 2.4.0-rc7 first time.
235 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
236 * glibc falls back to the hard-coded CLK_TCK value when aux entry
238 * Also see linux_times() implementation.
240 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
241 AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz);
242 AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr);
243 AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent);
244 AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum);
245 AUXARGS_ENTRY_32(pos, AT_PAGESZ, args->pagesz);
246 AUXARGS_ENTRY_32(pos, AT_FLAGS, args->flags);
247 AUXARGS_ENTRY_32(pos, AT_ENTRY, args->entry);
248 AUXARGS_ENTRY_32(pos, AT_BASE, args->base);
249 AUXARGS_ENTRY_32(pos, LINUX_AT_SECURE, issetugid);
250 AUXARGS_ENTRY_32(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
251 AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
252 AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
253 AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
254 AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
255 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary));
256 if (imgp->execpathp != 0)
257 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp));
258 if (args->execfd != -1)
259 AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd);
260 AUXARGS_ENTRY_32(pos, AT_NULL, 0);
262 free(imgp->auxargs, M_TEMP);
263 imgp->auxargs = NULL;
266 suword32(base, (uint32_t)imgp->args->argc);
267 *stack_base = (register_t *)base;
272 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
274 struct thread *td = curthread;
275 struct proc *p = td->td_proc;
277 struct trapframe *regs;
278 struct l_rt_sigframe *fp, frame;
283 sig = ksi->ksi_signo;
284 code = ksi->ksi_code;
285 PROC_LOCK_ASSERT(p, MA_OWNED);
287 mtx_assert(&psp->ps_mtx, MA_OWNED);
289 oonstack = sigonstack(regs->tf_rsp);
292 if (ldebug(rt_sendsig))
293 printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
294 catcher, sig, (void*)mask, code);
296 /* Allocate space for the signal handler context. */
297 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
298 SIGISMEMBER(psp->ps_sigonstack, sig)) {
299 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
300 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
302 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
303 mtx_unlock(&psp->ps_mtx);
305 /* Build the argument list for the signal handler. */
306 sig = bsd_to_linux_signal(sig);
308 bzero(&frame, sizeof(frame));
310 frame.sf_handler = PTROUT(catcher);
312 frame.sf_siginfo = PTROUT(&fp->sf_si);
313 frame.sf_ucontext = PTROUT(&fp->sf_sc);
315 /* Fill in POSIX parts. */
316 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
319 * Build the signal context to be used by sigreturn and libgcc unwind.
321 frame.sf_sc.uc_flags = 0; /* XXX ??? */
322 frame.sf_sc.uc_link = 0; /* XXX ??? */
324 frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
325 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
326 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
327 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
330 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
332 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask;
333 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_rdi;
334 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_rsi;
335 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_rbp;
336 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_rbx;
337 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_rsp;
338 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_rdx;
339 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_rcx;
340 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_rax;
341 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_rip;
342 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
343 frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs;
344 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
345 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
346 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
347 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags;
348 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
349 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
350 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
351 frame.sf_sc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
352 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
355 if (ldebug(rt_sendsig))
356 printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
357 frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
358 td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
361 if (copyout(&frame, fp, sizeof(frame)) != 0) {
363 * Process has trashed its stack; give it an illegal
364 * instruction to halt it in its tracks.
367 if (ldebug(rt_sendsig))
368 printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
375 /* Build context to run handler in. */
376 regs->tf_rsp = PTROUT(fp);
377 regs->tf_rip = linux32_rt_sigcode;
378 regs->tf_rflags &= ~(PSL_T | PSL_D);
379 regs->tf_cs = _ucode32sel;
380 regs->tf_ss = _udatasel;
381 regs->tf_ds = _udatasel;
382 regs->tf_es = _udatasel;
383 regs->tf_fs = _ufssel;
384 regs->tf_gs = _ugssel;
385 regs->tf_flags = TF_HASSEGS;
386 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
388 mtx_lock(&psp->ps_mtx);
393 * Send an interrupt to process.
395 * Stack is set up to allow sigcode stored
396 * in u. to call routine, followed by kcall
397 * to sigreturn routine below. After sigreturn
398 * resets the signal mask, the stack, and the
399 * frame pointer, it returns to the user
403 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
405 struct thread *td = curthread;
406 struct proc *p = td->td_proc;
408 struct trapframe *regs;
409 struct l_sigframe *fp, frame;
414 sig = ksi->ksi_signo;
415 code = ksi->ksi_code;
416 PROC_LOCK_ASSERT(p, MA_OWNED);
418 mtx_assert(&psp->ps_mtx, MA_OWNED);
419 if (SIGISMEMBER(psp->ps_siginfo, sig)) {
420 /* Signal handler installed with SA_SIGINFO. */
421 linux_rt_sendsig(catcher, ksi, mask);
426 oonstack = sigonstack(regs->tf_rsp);
430 printf(ARGS(sendsig, "%p, %d, %p, %u"),
431 catcher, sig, (void*)mask, code);
434 /* Allocate space for the signal handler context. */
435 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
436 SIGISMEMBER(psp->ps_sigonstack, sig)) {
437 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
438 td->td_sigstk.ss_size - sizeof(struct l_sigframe));
440 fp = (struct l_sigframe *)regs->tf_rsp - 1;
441 mtx_unlock(&psp->ps_mtx);
444 /* Build the argument list for the signal handler. */
445 sig = bsd_to_linux_signal(sig);
447 bzero(&frame, sizeof(frame));
449 frame.sf_handler = PTROUT(catcher);
452 bsd_to_linux_sigset(mask, &lmask);
454 /* Build the signal context to be used by sigreturn. */
455 frame.sf_sc.sc_mask = lmask.__mask;
456 frame.sf_sc.sc_gs = regs->tf_gs;
457 frame.sf_sc.sc_fs = regs->tf_fs;
458 frame.sf_sc.sc_es = regs->tf_es;
459 frame.sf_sc.sc_ds = regs->tf_ds;
460 frame.sf_sc.sc_edi = regs->tf_rdi;
461 frame.sf_sc.sc_esi = regs->tf_rsi;
462 frame.sf_sc.sc_ebp = regs->tf_rbp;
463 frame.sf_sc.sc_ebx = regs->tf_rbx;
464 frame.sf_sc.sc_esp = regs->tf_rsp;
465 frame.sf_sc.sc_edx = regs->tf_rdx;
466 frame.sf_sc.sc_ecx = regs->tf_rcx;
467 frame.sf_sc.sc_eax = regs->tf_rax;
468 frame.sf_sc.sc_eip = regs->tf_rip;
469 frame.sf_sc.sc_cs = regs->tf_cs;
470 frame.sf_sc.sc_eflags = regs->tf_rflags;
471 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
472 frame.sf_sc.sc_ss = regs->tf_ss;
473 frame.sf_sc.sc_err = regs->tf_err;
474 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
475 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
477 frame.sf_extramask[0] = lmask.__mask;
479 if (copyout(&frame, fp, sizeof(frame)) != 0) {
481 * Process has trashed its stack; give it an illegal
482 * instruction to halt it in its tracks.
488 /* Build context to run handler in. */
489 regs->tf_rsp = PTROUT(fp);
490 regs->tf_rip = linux32_sigcode;
491 regs->tf_rflags &= ~(PSL_T | PSL_D);
492 regs->tf_cs = _ucode32sel;
493 regs->tf_ss = _udatasel;
494 regs->tf_ds = _udatasel;
495 regs->tf_es = _udatasel;
496 regs->tf_fs = _ufssel;
497 regs->tf_gs = _ugssel;
498 regs->tf_flags = TF_HASSEGS;
499 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
501 mtx_lock(&psp->ps_mtx);
505 * System call to cleanup state after a signal
506 * has been taken. Reset signal mask and
507 * stack state from context left by sendsig (above).
508 * Return to previous pc and psl as specified by
509 * context left by sendsig. Check carefully to
510 * make sure that the user has not modified the
511 * psl to gain improper privileges or to cause
515 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
517 struct l_sigframe frame;
518 struct trapframe *regs;
527 if (ldebug(sigreturn))
528 printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
531 * The trampoline code hands us the sigframe.
532 * It is unsafe to keep track of it ourselves, in the event that a
533 * program jumps out of a signal handler.
535 if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
538 /* Check for security violations. */
539 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
540 eflags = frame.sf_sc.sc_eflags;
541 if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
545 * Don't allow users to load a valid privileged %cs. Let the
546 * hardware check for invalid selectors, excess privilege in
547 * other selectors, invalid %eip's and invalid %esp's.
549 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
550 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
551 ksiginfo_init_trap(&ksi);
552 ksi.ksi_signo = SIGBUS;
553 ksi.ksi_code = BUS_OBJERR;
554 ksi.ksi_trapno = T_PROTFLT;
555 ksi.ksi_addr = (void *)regs->tf_rip;
556 trapsignal(td, &ksi);
560 lmask.__mask = frame.sf_sc.sc_mask;
561 lmask.__mask = frame.sf_extramask[0];
562 linux_to_bsd_sigset(&lmask, &bmask);
563 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
565 /* Restore signal context. */
566 regs->tf_rdi = frame.sf_sc.sc_edi;
567 regs->tf_rsi = frame.sf_sc.sc_esi;
568 regs->tf_rbp = frame.sf_sc.sc_ebp;
569 regs->tf_rbx = frame.sf_sc.sc_ebx;
570 regs->tf_rdx = frame.sf_sc.sc_edx;
571 regs->tf_rcx = frame.sf_sc.sc_ecx;
572 regs->tf_rax = frame.sf_sc.sc_eax;
573 regs->tf_rip = frame.sf_sc.sc_eip;
574 regs->tf_cs = frame.sf_sc.sc_cs;
575 regs->tf_ds = frame.sf_sc.sc_ds;
576 regs->tf_es = frame.sf_sc.sc_es;
577 regs->tf_fs = frame.sf_sc.sc_fs;
578 regs->tf_gs = frame.sf_sc.sc_gs;
579 regs->tf_rflags = eflags;
580 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal;
581 regs->tf_ss = frame.sf_sc.sc_ss;
582 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
584 return (EJUSTRETURN);
588 * System call to cleanup state after a signal
589 * has been taken. Reset signal mask and
590 * stack state from context left by rt_sendsig (above).
591 * Return to previous pc and psl as specified by
592 * context left by sendsig. Check carefully to
593 * make sure that the user has not modified the
594 * psl to gain improper privileges or to cause
598 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
600 struct l_ucontext uc;
601 struct l_sigcontext *context;
605 struct trapframe *regs;
612 if (ldebug(rt_sigreturn))
613 printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
616 * The trampoline code hands us the ucontext.
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->ucp, &uc, sizeof(uc)) != 0)
623 context = &uc.uc_mcontext;
625 /* Check for security violations. */
626 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
627 eflags = context->sc_eflags;
628 if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
632 * Don't allow users to load a valid privileged %cs. Let the
633 * hardware check for invalid selectors, excess privilege in
634 * other selectors, invalid %eip's and invalid %esp's.
636 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
637 if (!CS_SECURE(context->sc_cs)) {
638 ksiginfo_init_trap(&ksi);
639 ksi.ksi_signo = SIGBUS;
640 ksi.ksi_code = BUS_OBJERR;
641 ksi.ksi_trapno = T_PROTFLT;
642 ksi.ksi_addr = (void *)regs->tf_rip;
643 trapsignal(td, &ksi);
647 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
648 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
651 * Restore signal context
653 regs->tf_gs = context->sc_gs;
654 regs->tf_fs = context->sc_fs;
655 regs->tf_es = context->sc_es;
656 regs->tf_ds = context->sc_ds;
657 regs->tf_rdi = context->sc_edi;
658 regs->tf_rsi = context->sc_esi;
659 regs->tf_rbp = context->sc_ebp;
660 regs->tf_rbx = context->sc_ebx;
661 regs->tf_rdx = context->sc_edx;
662 regs->tf_rcx = context->sc_ecx;
663 regs->tf_rax = context->sc_eax;
664 regs->tf_rip = context->sc_eip;
665 regs->tf_cs = context->sc_cs;
666 regs->tf_rflags = eflags;
667 regs->tf_rsp = context->sc_esp_at_signal;
668 regs->tf_ss = context->sc_ss;
669 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
672 * call sigaltstack & ignore results..
675 ss.ss_sp = PTRIN(lss->ss_sp);
676 ss.ss_size = lss->ss_size;
677 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
680 if (ldebug(rt_sigreturn))
681 printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
682 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
684 (void)kern_sigaltstack(td, &ss, NULL);
686 return (EJUSTRETURN);
690 linux32_fetch_syscall_args(struct thread *td)
693 struct trapframe *frame;
694 struct syscall_args *sa;
697 frame = td->td_frame;
700 sa->args[0] = frame->tf_rbx;
701 sa->args[1] = frame->tf_rcx;
702 sa->args[2] = frame->tf_rdx;
703 sa->args[3] = frame->tf_rsi;
704 sa->args[4] = frame->tf_rdi;
705 sa->args[5] = frame->tf_rbp; /* Unconfirmed */
706 sa->code = frame->tf_rax;
708 if (sa->code >= p->p_sysent->sv_size)
710 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
712 sa->callp = &p->p_sysent->sv_table[sa->code];
713 sa->narg = sa->callp->sy_narg;
715 td->td_retval[0] = 0;
716 td->td_retval[1] = frame->tf_rdx;
722 * If a Linux binary is exec'ing something, try this image activator
723 * first. We override standard shell script execution in order to
724 * be able to modify the interpreter path. We only do this if a Linux
725 * binary is doing the exec, so we do not create an EXEC module for it.
728 linux_exec_imgact_try(struct image_params *imgp)
730 const char *head = (const char *)imgp->image_header;
735 * The interpreter for shell scripts run from a Linux binary needs
736 * to be located in /compat/linux if possible in order to recursively
737 * maintain Linux path emulation.
739 if (((const short *)head)[0] == SHELLMAGIC) {
741 * Run our normal shell image activator. If it succeeds then
742 * attempt to use the alternate path for the interpreter. If
743 * an alternate path is found, use our stringspace to store it.
745 if ((error = exec_shell_imgact(imgp)) == 0) {
746 linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
747 imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0,
750 imgp->args->fname_buf =
751 imgp->interpreter_name = rpath;
758 * Clear registers on exec
759 * XXX copied from ia32_signal.c.
762 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
764 struct trapframe *regs = td->td_frame;
765 struct pcb *pcb = td->td_pcb;
767 if (td->td_proc->p_md.md_ldt != NULL)
771 wrmsr(MSR_FSBASE, 0);
772 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */
776 pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
778 bzero((char *)regs, sizeof(struct trapframe));
779 regs->tf_rip = imgp->entry_addr;
780 regs->tf_rsp = stack;
781 regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
782 regs->tf_gs = _ugssel;
783 regs->tf_fs = _ufssel;
784 regs->tf_es = _udatasel;
785 regs->tf_ds = _udatasel;
786 regs->tf_ss = _udatasel;
787 regs->tf_flags = TF_HASSEGS;
788 regs->tf_cs = _ucode32sel;
789 regs->tf_rbx = imgp->ps_strings;
793 /* Do full restore on return so that we can change to a different %cs */
794 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
798 * XXX copied from ia32_sysvec.c.
801 linux_copyout_strings(struct image_params *imgp)
805 char *stringp, *destp;
806 u_int32_t *stack_base;
807 struct linux32_ps_strings *arginfo;
808 char canary[LINUX_AT_RANDOM_LEN];
811 /* Calculate string base and vector table pointers. */
812 if (imgp->execpath != NULL && imgp->auxargs != NULL)
813 execpath_len = strlen(imgp->execpath) + 1;
817 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
818 destp = (caddr_t)arginfo - SPARE_USRSPACE -
819 roundup(sizeof(canary), sizeof(char *)) -
820 roundup(execpath_len, sizeof(char *)) -
821 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
823 if (execpath_len != 0) {
824 imgp->execpathp = (uintptr_t)arginfo - execpath_len;
825 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
828 /* Prepare the canary for SSP. */
829 arc4rand(canary, sizeof(canary), 0);
830 imgp->canary = (uintptr_t)arginfo -
831 roundup(execpath_len, sizeof(char *)) -
832 roundup(sizeof(canary), sizeof(char *));
833 copyout(canary, (void *)imgp->canary, sizeof(canary));
835 /* If we have a valid auxargs ptr, prepare some room on the stack. */
838 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
839 * lower compatibility.
841 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
842 (LINUX_AT_COUNT * 2);
844 * The '+ 2' is for the null pointers at the end of each of
845 * the arg and env vector sets,and imgp->auxarg_size is room
846 * for argument of Runtime loader.
848 vectp = (u_int32_t *) (destp - (imgp->args->argc +
849 imgp->args->envc + 2 + imgp->auxarg_size) *
854 * The '+ 2' is for the null pointers at the end of each of
855 * the arg and env vector sets
857 vectp = (u_int32_t *)(destp - (imgp->args->argc +
858 imgp->args->envc + 2) * sizeof(u_int32_t));
860 /* vectp also becomes our initial stack base. */
863 stringp = imgp->args->begin_argv;
864 argc = imgp->args->argc;
865 envc = imgp->args->envc;
866 /* Copy out strings - arguments and environment. */
867 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
869 /* Fill in "ps_strings" struct for ps, w, etc. */
870 suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp);
871 suword32(&arginfo->ps_nargvstr, argc);
873 /* Fill in argument portion of vector table. */
874 for (; argc > 0; --argc) {
875 suword32(vectp++, (uint32_t)(intptr_t)destp);
876 while (*stringp++ != 0)
881 /* A null vector table pointer separates the argp's from the envp's. */
882 suword32(vectp++, 0);
884 suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp);
885 suword32(&arginfo->ps_nenvstr, envc);
887 /* Fill in environment portion of vector table. */
888 for (; envc > 0; --envc) {
889 suword32(vectp++, (uint32_t)(intptr_t)destp);
890 while (*stringp++ != 0)
895 /* The end of the vector table is a null pointer. */
898 return ((register_t *)stack_base);
901 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0,
902 "32-bit Linux emulation");
904 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ;
905 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
906 &linux32_maxdsiz, 0, "");
907 static u_long linux32_maxssiz = LINUX32_MAXSSIZ;
908 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
909 &linux32_maxssiz, 0, "");
910 static u_long linux32_maxvmem = LINUX32_MAXVMEM;
911 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
912 &linux32_maxvmem, 0, "");
915 SYSCTL_PROC(_compat_linux32, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
916 linux_sysctl_debug, "A", "Linux debugging control");
920 linux32_fixlimit(struct rlimit *rl, int which)
925 if (linux32_maxdsiz != 0) {
926 if (rl->rlim_cur > linux32_maxdsiz)
927 rl->rlim_cur = linux32_maxdsiz;
928 if (rl->rlim_max > linux32_maxdsiz)
929 rl->rlim_max = linux32_maxdsiz;
933 if (linux32_maxssiz != 0) {
934 if (rl->rlim_cur > linux32_maxssiz)
935 rl->rlim_cur = linux32_maxssiz;
936 if (rl->rlim_max > linux32_maxssiz)
937 rl->rlim_max = linux32_maxssiz;
941 if (linux32_maxvmem != 0) {
942 if (rl->rlim_cur > linux32_maxvmem)
943 rl->rlim_cur = linux32_maxvmem;
944 if (rl->rlim_max > linux32_maxvmem)
945 rl->rlim_max = linux32_maxvmem;
951 struct sysentvec elf_linux_sysvec = {
952 .sv_size = LINUX32_SYS_MAXSYSCALL,
953 .sv_table = linux32_sysent,
955 .sv_errsize = ELAST + 1,
956 .sv_errtbl = linux_errtbl,
957 .sv_transtrap = linux_translate_traps,
958 .sv_fixup = linux_fixup_elf,
959 .sv_sendsig = linux_sendsig,
960 .sv_sigcode = &_binary_linux32_locore_o_start,
961 .sv_szsigcode = &linux_szsigcode,
962 .sv_name = "Linux ELF32",
963 .sv_coredump = elf32_coredump,
964 .sv_imgact_try = linux_exec_imgact_try,
965 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
966 .sv_pagesize = PAGE_SIZE,
967 .sv_minuser = VM_MIN_ADDRESS,
968 .sv_maxuser = LINUX32_MAXUSER,
969 .sv_usrstack = LINUX32_USRSTACK,
970 .sv_psstrings = LINUX32_PS_STRINGS,
971 .sv_stackprot = VM_PROT_ALL,
972 .sv_copyout_strings = linux_copyout_strings,
973 .sv_setregs = linux_exec_setregs,
974 .sv_fixlimit = linux32_fixlimit,
975 .sv_maxssiz = &linux32_maxssiz,
976 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP,
977 .sv_set_syscall_retval = cpu_set_syscall_retval,
978 .sv_fetch_syscall_args = linux32_fetch_syscall_args,
979 .sv_syscallnames = NULL,
980 .sv_shared_page_base = LINUX32_SHAREDPAGE,
981 .sv_shared_page_len = PAGE_SIZE,
982 .sv_schedtail = linux_schedtail,
983 .sv_thread_detach = linux_thread_detach,
988 linux_vdso_install(void *param)
991 linux_szsigcode = (&_binary_linux32_locore_o_end -
992 &_binary_linux32_locore_o_start);
994 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
995 panic("Linux invalid vdso size\n");
997 __elfN(linux_vdso_fixup)(&elf_linux_sysvec);
999 linux_shared_page_obj = __elfN(linux_shared_page_init)
1000 (&linux_shared_page_mapping);
1002 __elfN(linux_vdso_reloc)(&elf_linux_sysvec);
1004 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
1006 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
1008 linux_kplatform = linux_shared_page_mapping +
1009 (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
1011 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
1012 linux_vdso_install, NULL);
1015 linux_vdso_deinstall(void *param)
1018 __elfN(linux_shared_page_fini)(linux_shared_page_obj);
1020 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
1021 linux_vdso_deinstall, NULL);
1023 static char GNU_ABI_VENDOR[] = "GNU";
1024 static int GNULINUX_ABI_DESC = 0;
1027 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
1029 const Elf32_Word *desc;
1032 p = (uintptr_t)(note + 1);
1033 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1035 desc = (const Elf32_Word *)p;
1036 if (desc[0] != GNULINUX_ABI_DESC)
1040 * For Linux we encode osrel as follows (see linux_mib.c):
1041 * VVVMMMIII (version, major, minor), see linux_mib.c.
1043 *osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
1048 static Elf_Brandnote linux32_brandnote = {
1049 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
1050 .hdr.n_descsz = 16, /* XXX at least 16 */
1052 .vendor = GNU_ABI_VENDOR,
1053 .flags = BN_TRANSLATE_OSREL,
1054 .trans_osrel = linux32_trans_osrel
1057 static Elf32_Brandinfo linux_brand = {
1058 .brand = ELFOSABI_LINUX,
1060 .compat_3_brand = "Linux",
1061 .emul_path = "/compat/linux",
1062 .interp_path = "/lib/ld-linux.so.1",
1063 .sysvec = &elf_linux_sysvec,
1064 .interp_newpath = NULL,
1065 .brand_note = &linux32_brandnote,
1066 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1069 static Elf32_Brandinfo linux_glibc2brand = {
1070 .brand = ELFOSABI_LINUX,
1072 .compat_3_brand = "Linux",
1073 .emul_path = "/compat/linux",
1074 .interp_path = "/lib/ld-linux.so.2",
1075 .sysvec = &elf_linux_sysvec,
1076 .interp_newpath = NULL,
1077 .brand_note = &linux32_brandnote,
1078 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1081 static Elf32_Brandinfo linux_muslbrand = {
1082 .brand = ELFOSABI_LINUX,
1084 .compat_3_brand = "Linux",
1085 .emul_path = "/compat/linux",
1086 .interp_path = "/lib/ld-musl-i386.so.1",
1087 .sysvec = &elf_linux_sysvec,
1088 .interp_newpath = NULL,
1089 .brand_note = &linux32_brandnote,
1090 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1093 Elf32_Brandinfo *linux_brandlist[] = {
1101 linux_elf_modevent(module_t mod, int type, void *data)
1103 Elf32_Brandinfo **brandinfo;
1105 struct linux_ioctl_handler **lihp;
1111 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1113 if (elf32_insert_brand_entry(*brandinfo) < 0)
1116 SET_FOREACH(lihp, linux_ioctl_handler_set)
1117 linux_ioctl_register_handler(*lihp);
1118 LIST_INIT(&futex_list);
1119 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
1120 stclohz = (stathz ? stathz : hz);
1122 printf("Linux ELF exec handler installed\n");
1124 printf("cannot insert Linux ELF brand handler\n");
1127 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1129 if (elf32_brand_inuse(*brandinfo))
1132 for (brandinfo = &linux_brandlist[0];
1133 *brandinfo != NULL; ++brandinfo)
1134 if (elf32_remove_brand_entry(*brandinfo) < 0)
1138 SET_FOREACH(lihp, linux_ioctl_handler_set)
1139 linux_ioctl_unregister_handler(*lihp);
1140 mtx_destroy(&futex_mtx);
1142 printf("Linux ELF exec handler removed\n");
1144 printf("Could not deinstall ELF interpreter entry\n");
1147 return (EOPNOTSUPP);
1152 static moduledata_t linux_elf_mod = {
1158 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1159 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1);
1160 FEATURE(linux, "Linux 32bit support");