2 * Copyright (c) 2004 Tim J. Robbins
3 * Copyright (c) 2003 Peter Wemm
4 * Copyright (c) 2002 Doug Rabson
5 * Copyright (c) 1998-1999 Andrew Gallatin
6 * Copyright (c) 1994-1996 Søren Schmidt
8 * Copyright (c) 2013, 2021 Dmitry Chagin <dchagin@FreeBSD.org>
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer
15 * in this position and unchanged.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #define __ELF_WORD_SIZE 64
39 #include <sys/param.h>
40 #include <sys/systm.h>
42 #include <sys/fcntl.h>
43 #include <sys/imgact.h>
44 #include <sys/imgact_elf.h>
45 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/module.h>
50 #include <sys/mutex.h>
52 #include <sys/resourcevar.h>
53 #include <sys/stddef.h>
54 #include <sys/signalvar.h>
55 #include <sys/syscallsubr.h>
56 #include <sys/sysctl.h>
57 #include <sys/sysent.h>
58 #include <sys/sysproto.h>
59 #include <sys/vnode.h>
60 #include <sys/eventhandler.h>
64 #include <vm/vm_extern.h>
65 #include <vm/vm_map.h>
66 #include <vm/vm_object.h>
67 #include <vm/vm_page.h>
68 #include <vm/vm_param.h>
70 #include <machine/cpu.h>
71 #include <machine/md_var.h>
72 #include <machine/pcb.h>
73 #include <machine/specialreg.h>
74 #include <machine/trap.h>
76 #include <x86/linux/linux_x86.h>
77 #include <amd64/linux/linux.h>
78 #include <amd64/linux/linux_proto.h>
79 #include <compat/linux/linux_emul.h>
80 #include <compat/linux/linux_fork.h>
81 #include <compat/linux/linux_ioctl.h>
82 #include <compat/linux/linux_mib.h>
83 #include <compat/linux/linux_misc.h>
84 #include <compat/linux/linux_signal.h>
85 #include <compat/linux/linux_sysproto.h>
86 #include <compat/linux/linux_util.h>
87 #include <compat/linux/linux_vdso.h>
89 MODULE_VERSION(linux64, 1);
91 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2
92 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \
94 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE)
96 * PAGE_SIZE - the size
97 * of the native SHAREDPAGE
99 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48
100 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \
101 sizeof(struct ps_strings))
103 static int linux_szsigcode;
104 static vm_object_t linux_vdso_obj;
105 static char *linux_vdso_mapping;
106 extern char _binary_linux_vdso_so_o_start;
107 extern char _binary_linux_vdso_so_o_end;
108 static vm_offset_t linux_vdso_base;
110 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
112 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
114 static int linux_copyout_strings(struct image_params *imgp,
115 uintptr_t *stack_base);
116 static int linux_fixup_elf(uintptr_t *stack_base,
117 struct image_params *iparams);
118 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
119 static void linux_vdso_install(const void *param);
120 static void linux_vdso_deinstall(const void *param);
121 static void linux_vdso_reloc(char *mapping, Elf_Addr offset);
122 static void linux_set_syscall_retval(struct thread *td, int error);
123 static int linux_fetch_syscall_args(struct thread *td);
124 static void linux_exec_setregs(struct thread *td, struct image_params *imgp,
126 static void linux_exec_sysvec_init(void *param);
127 static int linux_on_exec_vmspace(struct proc *p,
128 struct image_params *imgp);
129 static void linux_set_fork_retval(struct thread *td);
130 static int linux_vsyscall(struct thread *td);
132 #define LINUX_T_UNKNOWN 255
133 static int _bsd_to_linux_trapcode[] = {
134 LINUX_T_UNKNOWN, /* 0 */
135 6, /* 1 T_PRIVINFLT */
136 LINUX_T_UNKNOWN, /* 2 */
138 LINUX_T_UNKNOWN, /* 4 */
139 LINUX_T_UNKNOWN, /* 5 */
140 16, /* 6 T_ARITHTRAP */
141 254, /* 7 T_ASTFLT */
142 LINUX_T_UNKNOWN, /* 8 */
143 13, /* 9 T_PROTFLT */
144 1, /* 10 T_TRCTRAP */
145 LINUX_T_UNKNOWN, /* 11 */
146 14, /* 12 T_PAGEFLT */
147 LINUX_T_UNKNOWN, /* 13 */
148 17, /* 14 T_ALIGNFLT */
149 LINUX_T_UNKNOWN, /* 15 */
150 LINUX_T_UNKNOWN, /* 16 */
151 LINUX_T_UNKNOWN, /* 17 */
157 8, /* 23 T_DOUBLEFLT */
158 9, /* 24 T_FPOPFLT */
159 10, /* 25 T_TSSFLT */
160 11, /* 26 T_SEGNPFLT */
161 12, /* 27 T_STKFLT */
163 19, /* 29 T_XMMFLT */
164 15 /* 30 T_RESERVED */
166 #define bsd_to_linux_trapcode(code) \
167 ((code)<nitems(_bsd_to_linux_trapcode)? \
168 _bsd_to_linux_trapcode[(code)]: \
171 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
172 LINUX_VDSO_SYM_CHAR(linux_platform);
173 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
174 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
175 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
178 * If FreeBSD & Linux have a difference of opinion about what a trap
179 * means, deal with it here.
184 linux_translate_traps(int signal, int trap_code)
187 if (signal != SIGBUS)
201 linux_fetch_syscall_args(struct thread *td)
204 struct trapframe *frame;
205 struct syscall_args *sa;
208 frame = td->td_frame;
211 sa->args[0] = frame->tf_rdi;
212 sa->args[1] = frame->tf_rsi;
213 sa->args[2] = frame->tf_rdx;
214 sa->args[3] = frame->tf_rcx;
215 sa->args[4] = frame->tf_r8;
216 sa->args[5] = frame->tf_r9;
217 sa->code = frame->tf_rax;
218 sa->original_code = sa->code;
220 if (sa->code >= p->p_sysent->sv_size)
222 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
224 sa->callp = &p->p_sysent->sv_table[sa->code];
226 td->td_retval[0] = 0;
231 linux_set_syscall_retval(struct thread *td, int error)
233 struct trapframe *frame;
235 frame = td->td_frame;
239 frame->tf_rax = td->td_retval[0];
240 frame->tf_r10 = frame->tf_rcx;
245 * Reconstruct pc, we know that 'syscall' is 2 bytes,
246 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
247 * We saved this in tf_err.
250 frame->tf_rip -= frame->tf_err;
251 frame->tf_r10 = frame->tf_rcx;
258 frame->tf_rax = bsd_to_linux_errno(error);
259 frame->tf_r10 = frame->tf_rcx;
264 * Differently from FreeBSD native ABI, on Linux only %rcx
265 * and %r11 values are not preserved across the syscall.
266 * Require full context restore to get all registers except
267 * those two restored at return to usermode.
269 * XXX: Would be great to be able to avoid PCB_FULL_IRET
270 * for the error == 0 case.
272 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
276 linux_set_fork_retval(struct thread *td)
278 struct trapframe *frame = td->td_frame;
284 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
287 Elf_Auxinfo *argarray, *pos;
289 int error, issetugid;
292 args = (Elf64_Auxargs *)imgp->auxargs;
293 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
296 issetugid = p->p_flag & P_SUGID ? 1 : 0;
297 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
298 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
299 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
300 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
301 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
302 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
303 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
304 AUXARGS_ENTRY(pos, AT_BASE, args->base);
305 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
306 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
307 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
308 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
309 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
310 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
311 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
312 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
313 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0);
314 if (imgp->execpathp != 0)
315 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
316 if (args->execfd != -1)
317 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
318 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
319 AUXARGS_ENTRY(pos, AT_NULL, 0);
321 free(imgp->auxargs, M_TEMP);
322 imgp->auxargs = NULL;
323 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
325 error = copyout(argarray, (void *)base,
326 sizeof(*argarray) * LINUX_AT_COUNT);
327 free(argarray, M_TEMP);
332 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
336 base = (Elf64_Addr *)*stack_base;
338 if (suword(base, (uint64_t)imgp->args->argc) == -1)
341 *stack_base = (uintptr_t)base;
346 * Copy strings out to the new process address space, constructing new arg
347 * and env vector tables. Return a pointer to the base so that it can be used
348 * as the initial stack pointer.
351 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
353 int argc, envc, error;
356 uintptr_t destp, ustringp;
357 struct ps_strings *arginfo;
358 char canary[LINUX_AT_RANDOM_LEN];
363 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p);
364 destp = (uintptr_t)arginfo;
366 if (imgp->execpath != NULL && imgp->auxargs != NULL) {
367 execpath_len = strlen(imgp->execpath) + 1;
368 destp -= execpath_len;
369 destp = rounddown2(destp, sizeof(void *));
370 imgp->execpathp = (void *)destp;
371 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
376 /* Prepare the canary for SSP. */
377 arc4rand(canary, sizeof(canary), 0);
378 destp -= roundup(sizeof(canary), sizeof(void *));
379 imgp->canary = (void *)destp;
380 error = copyout(canary, imgp->canary, sizeof(canary));
384 /* Allocate room for the argument and environment strings. */
385 destp -= ARG_MAX - imgp->args->stringspace;
386 destp = rounddown2(destp, sizeof(void *));
391 * Allocate room on the stack for the ELF auxargs
392 * array. It has LINUX_AT_COUNT entries.
394 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo);
395 destp = rounddown2(destp, sizeof(void *));
398 vectp = (char **)destp;
401 * Allocate room for the argv[] and env vectors including the
402 * terminating NULL pointers.
404 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
407 * Starting with 2.24, glibc depends on a 16-byte stack alignment.
408 * One "long argc" will be prepended later.
410 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8);
412 /* vectp also becomes our initial stack base. */
413 *stack_base = (uintptr_t)vectp;
415 stringp = imgp->args->begin_argv;
416 argc = imgp->args->argc;
417 envc = imgp->args->envc;
419 /* Copy out strings - arguments and environment. */
420 error = copyout(stringp, (void *)ustringp,
421 ARG_MAX - imgp->args->stringspace);
425 /* Fill in "ps_strings" struct for ps, w, etc. */
426 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
427 suword(&arginfo->ps_nargvstr, argc) != 0)
430 /* Fill in argument portion of vector table. */
431 for (; argc > 0; --argc) {
432 if (suword(vectp++, ustringp) != 0)
434 while (*stringp++ != 0)
439 /* A null vector table pointer separates the argp's from the envp's. */
440 if (suword(vectp++, 0) != 0)
443 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
444 suword(&arginfo->ps_nenvstr, envc) != 0)
447 /* Fill in environment portion of vector table. */
448 for (; envc > 0; --envc) {
449 if (suword(vectp++, ustringp) != 0)
451 while (*stringp++ != 0)
456 /* The end of the vector table is a null pointer. */
457 if (suword(vectp, 0) != 0)
462 error = imgp->sysent->sv_copyout_auxargs(imgp,
472 * Reset registers to default values on exec.
475 linux_exec_setregs(struct thread *td, struct image_params *imgp,
478 struct trapframe *regs;
480 register_t saved_rflags;
485 if (td->td_proc->p_md.md_ldt != NULL)
490 clear_pcb_flags(pcb, PCB_32BIT);
491 pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
492 set_pcb_flags(pcb, PCB_FULL_IRET);
494 saved_rflags = regs->tf_rflags & PSL_T;
495 bzero((char *)regs, sizeof(struct trapframe));
496 regs->tf_rip = imgp->entry_addr;
497 regs->tf_rsp = stack;
498 regs->tf_rflags = PSL_USER | saved_rflags;
499 regs->tf_ss = _udatasel;
500 regs->tf_cs = _ucodesel;
501 regs->tf_ds = _udatasel;
502 regs->tf_es = _udatasel;
503 regs->tf_fs = _ufssel;
504 regs->tf_gs = _ugssel;
505 regs->tf_flags = TF_HASSEGS;
507 x86_clear_dbregs(pcb);
510 * Drop the FP state if we hold it, so that the process gets a
511 * clean FP state if it uses the FPU again.
517 * Copied from amd64/amd64/machdep.c
519 * XXX fpu state need? don't think so
522 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
525 struct l_ucontext uc;
526 struct l_sigcontext *context;
527 struct trapframe *regs;
528 unsigned long rflags;
533 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
538 context = &uc.uc_mcontext;
539 rflags = context->sc_rflags;
542 * Don't allow users to change privileged or reserved flags.
545 * XXX do allow users to change the privileged flag PSL_RF.
546 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers
547 * should sometimes set it there too. tf_rflags is kept in
548 * the signal context during signal handling and there is no
549 * other place to remember it, so the PSL_RF bit may be
550 * corrupted by the signal handler without us knowing.
551 * Corruption of the PSL_RF bit at worst causes one more or
552 * one less debugger trap, so allowing it is fairly harmless.
554 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
555 uprintf("pid %d comm %s linux mangled rflags %#lx\n",
556 p->p_pid, p->p_comm, rflags);
561 * Don't allow users to load a valid privileged %cs. Let the
562 * hardware check for invalid selectors, excess privilege in
563 * other selectors, invalid %eip's and invalid %esp's.
565 if (!CS_SECURE(context->sc_cs)) {
566 uprintf("pid %d comm %s linux mangled cs %#x\n",
567 p->p_pid, p->p_comm, context->sc_cs);
568 ksiginfo_init_trap(&ksi);
569 ksi.ksi_signo = SIGBUS;
570 ksi.ksi_code = BUS_OBJERR;
571 ksi.ksi_trapno = T_PROTFLT;
572 ksi.ksi_addr = (void *)regs->tf_rip;
573 trapsignal(td, &ksi);
578 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
579 SIG_CANTMASK(td->td_sigmask);
583 regs->tf_rdi = context->sc_rdi;
584 regs->tf_rsi = context->sc_rsi;
585 regs->tf_rdx = context->sc_rdx;
586 regs->tf_rbp = context->sc_rbp;
587 regs->tf_rbx = context->sc_rbx;
588 regs->tf_rcx = context->sc_rcx;
589 regs->tf_rax = context->sc_rax;
590 regs->tf_rip = context->sc_rip;
591 regs->tf_rsp = context->sc_rsp;
592 regs->tf_r8 = context->sc_r8;
593 regs->tf_r9 = context->sc_r9;
594 regs->tf_r10 = context->sc_r10;
595 regs->tf_r11 = context->sc_r11;
596 regs->tf_r12 = context->sc_r12;
597 regs->tf_r13 = context->sc_r13;
598 regs->tf_r14 = context->sc_r14;
599 regs->tf_r15 = context->sc_r15;
600 regs->tf_cs = context->sc_cs;
601 regs->tf_err = context->sc_err;
602 regs->tf_rflags = rflags;
604 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
605 return (EJUSTRETURN);
609 * copied from amd64/amd64/machdep.c
611 * Send an interrupt to process.
614 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
616 struct l_rt_sigframe sf, *sfp;
621 struct trapframe *regs;
627 PROC_LOCK_ASSERT(p, MA_OWNED);
628 sig = ksi->ksi_signo;
630 code = ksi->ksi_code;
631 mtx_assert(&psp->ps_mtx, MA_OWNED);
633 oonstack = sigonstack(regs->tf_rsp);
635 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
636 catcher, sig, mask, code);
638 /* Save user context. */
639 bzero(&sf, sizeof(sf));
640 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask);
641 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask);
643 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
644 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
645 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
646 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
648 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi;
649 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi;
650 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx;
651 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp;
652 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx;
653 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx;
654 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax;
655 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip;
656 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp;
657 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8;
658 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9;
659 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10;
660 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11;
661 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12;
662 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13;
663 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14;
664 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15;
665 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
666 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags;
667 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err;
668 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
669 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
671 /* Allocate space for the signal handler context. */
672 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
673 SIGISMEMBER(psp->ps_sigonstack, sig)) {
674 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
676 sp = (caddr_t)regs->tf_rsp - 128;
677 sp -= sizeof(struct l_rt_sigframe);
678 /* Align to 16 bytes. */
679 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
681 /* Translate the signal. */
682 sig = bsd_to_linux_signal(sig);
684 /* Build the argument list for the signal handler. */
685 regs->tf_rdi = sig; /* arg 1 in %rdi */
687 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
688 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */
690 /* Fill in POSIX parts. */
691 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig);
692 sf.sf_handler = catcher;
694 mtx_unlock(&psp->ps_mtx);
697 /* Copy the sigframe out to the user's stack. */
698 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
699 uprintf("pid %d comm %s has trashed its stack, killing\n",
700 p->p_pid, p->p_comm);
705 regs->tf_rsp = (long)sfp;
706 regs->tf_rip = linux_rt_sigcode;
707 regs->tf_rflags &= ~(PSL_T | PSL_D);
708 regs->tf_cs = _ucodesel;
709 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
711 mtx_lock(&psp->ps_mtx);
714 #define LINUX_VSYSCALL_START (-10UL << 20)
715 #define LINUX_VSYSCALL_SZ 1024
717 const unsigned long linux_vsyscall_vector[] = {
718 LINUX_SYS_gettimeofday,
719 LINUX_SYS_linux_time,
720 LINUX_SYS_linux_getcpu,
724 linux_vsyscall(struct thread *td)
726 struct trapframe *frame;
731 frame = td->td_frame;
733 /* Check %rip for vsyscall area. */
734 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START))
736 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0)
738 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ;
739 if (code >= nitems(linux_vsyscall_vector))
743 * vsyscall called as callq *(%rax), so we must
744 * use return address from %rsp and also fixup %rsp.
746 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr));
750 frame->tf_rip = retqaddr;
751 frame->tf_rax = linux_vsyscall_vector[code];
754 traced = (frame->tf_flags & PSL_T);
756 amd64_syscall(td, traced);
761 struct sysentvec elf_linux_sysvec = {
762 .sv_size = LINUX_SYS_MAXSYSCALL,
763 .sv_table = linux_sysent,
764 .sv_transtrap = linux_translate_traps,
765 .sv_fixup = linux_fixup_elf,
766 .sv_sendsig = linux_rt_sendsig,
767 .sv_sigcode = &_binary_linux_vdso_so_o_start,
768 .sv_szsigcode = &linux_szsigcode,
769 .sv_name = "Linux ELF64",
770 .sv_coredump = elf64_coredump,
771 .sv_elf_core_osabi = ELFOSABI_NONE,
772 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
773 .sv_elf_core_prepare_notes = linux64_prepare_notes,
774 .sv_imgact_try = linux_exec_imgact_try,
775 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
776 .sv_minuser = VM_MIN_ADDRESS,
777 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48,
778 .sv_usrstack = LINUX_USRSTACK_LA48,
779 .sv_psstrings = LINUX_PS_STRINGS_LA48,
780 .sv_psstringssz = sizeof(struct ps_strings),
781 .sv_stackprot = VM_PROT_ALL,
782 .sv_copyout_auxargs = linux_copyout_auxargs,
783 .sv_copyout_strings = linux_copyout_strings,
784 .sv_setregs = linux_exec_setregs,
787 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN |
788 SV_SIG_WAITNDQ | SV_TIMEKEEP,
789 .sv_set_syscall_retval = linux_set_syscall_retval,
790 .sv_fetch_syscall_args = linux_fetch_syscall_args,
791 .sv_syscallnames = NULL,
792 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48,
793 .sv_shared_page_len = PAGE_SIZE,
794 .sv_schedtail = linux_schedtail,
795 .sv_thread_detach = linux_thread_detach,
796 .sv_trap = linux_vsyscall,
797 .sv_onexec = linux_on_exec_vmspace,
798 .sv_onexit = linux_on_exit,
799 .sv_ontdexit = linux_thread_dtor,
800 .sv_setid_allowed = &linux_setid_allowed_query,
801 .sv_set_fork_retval = linux_set_fork_retval,
805 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
809 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base,
810 LINUX_VDSOPAGE_SIZE, imgp);
812 linux_on_exec(p, imgp);
817 * linux_vdso_install() and linux_exec_sysvec_init() must be called
818 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
821 linux_exec_sysvec_init(void *param)
823 l_uintptr_t *ktimekeep_base, *ktsc_selector;
824 struct sysentvec *sv;
828 amd64_lower_shared_page(sv);
829 /* Fill timekeep_base */
830 exec_sysvec_init(sv);
832 tkoff = kern_timekeep_base - linux_vdso_base;
833 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
834 *ktimekeep_base = sv->sv_timekeep_base;
836 tkoff = kern_tsc_selector - linux_vdso_base;
837 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
838 *ktsc_selector = linux_vdso_tsc_selector_idx();
840 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector);
842 tkoff = kern_cpu_selector - linux_vdso_base;
843 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
844 *ktsc_selector = linux_vdso_cpu_selector_idx();
846 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector);
848 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
849 linux_exec_sysvec_init, &elf_linux_sysvec);
852 linux_vdso_install(const void *param)
854 char *vdso_start = &_binary_linux_vdso_so_o_start;
855 char *vdso_end = &_binary_linux_vdso_so_o_end;
857 linux_szsigcode = vdso_end - vdso_start;
858 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE);
860 linux_vdso_base = LINUX_VDSOPAGE_LA48;
861 if (hw_lower_amd64_sharedpage != 0)
862 linux_vdso_base -= PAGE_SIZE;
864 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
866 linux_vdso_obj = __elfN(linux_shared_page_init)
867 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
868 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
870 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
872 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
873 linux_vdso_install, NULL);
876 linux_vdso_deinstall(const void *param)
879 __elfN(linux_shared_page_fini)(linux_vdso_obj,
880 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
882 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
883 linux_vdso_deinstall, NULL);
886 linux_vdso_reloc(char *mapping, Elf_Addr offset)
888 const Elf_Ehdr *ehdr;
889 const Elf_Shdr *shdr;
890 Elf64_Addr *where, val;
891 Elf_Size rtype, symidx;
892 const Elf_Rela *rela;
893 Elf_Addr addr, addend;
900 ehdr = (const Elf_Ehdr *)mapping;
901 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
902 for (i = 0; i < ehdr->e_shnum; i++)
904 switch (shdr[i].sh_type) {
906 printf("Linux x86_64 vDSO: unexpected Rel section\n");
909 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset);
910 relacnt = shdr[i].sh_size / sizeof(*rela);
914 for (j = 0; j < relacnt; j++, rela++) {
915 where = (Elf_Addr *)(mapping + rela->r_offset);
916 addend = rela->r_addend;
917 rtype = ELF_R_TYPE(rela->r_info);
918 symidx = ELF_R_SYM(rela->r_info);
921 case R_X86_64_NONE: /* none */
924 case R_X86_64_RELATIVE: /* B + A */
925 addr = (Elf_Addr)(offset + addend);
930 case R_X86_64_IRELATIVE:
931 printf("Linux x86_64 vDSO: unexpected ifunc relocation, "
932 "symbol index %ld\n", symidx);
935 printf("Linux x86_64 vDSO: unexpected relocation type %ld, "
936 "symbol index %ld\n", rtype, symidx);
941 static char GNULINUX_ABI_VENDOR[] = "GNU";
942 static int GNULINUX_ABI_DESC = 0;
945 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
947 const Elf32_Word *desc;
950 p = (uintptr_t)(note + 1);
951 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
953 desc = (const Elf32_Word *)p;
954 if (desc[0] != GNULINUX_ABI_DESC)
958 * For Linux we encode osrel using the Linux convention of
959 * (version << 16) | (major << 8) | (minor)
960 * See macro in linux_mib.h
962 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
967 static Elf_Brandnote linux64_brandnote = {
968 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR),
971 .vendor = GNULINUX_ABI_VENDOR,
972 .flags = BN_TRANSLATE_OSREL,
973 .trans_osrel = linux_trans_osrel
976 static Elf64_Brandinfo linux_glibc2brand = {
977 .brand = ELFOSABI_LINUX,
978 .machine = EM_X86_64,
979 .compat_3_brand = "Linux",
980 .emul_path = linux_emul_path,
981 .interp_path = "/lib64/ld-linux-x86-64.so.2",
982 .sysvec = &elf_linux_sysvec,
983 .interp_newpath = NULL,
984 .brand_note = &linux64_brandnote,
985 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
988 static Elf64_Brandinfo linux_glibc2brandshort = {
989 .brand = ELFOSABI_LINUX,
990 .machine = EM_X86_64,
991 .compat_3_brand = "Linux",
992 .emul_path = linux_emul_path,
993 .interp_path = "/lib64/ld-linux.so.2",
994 .sysvec = &elf_linux_sysvec,
995 .interp_newpath = NULL,
996 .brand_note = &linux64_brandnote,
997 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
1000 static Elf64_Brandinfo linux_muslbrand = {
1001 .brand = ELFOSABI_LINUX,
1002 .machine = EM_X86_64,
1003 .compat_3_brand = "Linux",
1004 .emul_path = linux_emul_path,
1005 .interp_path = "/lib/ld-musl-x86_64.so.1",
1006 .sysvec = &elf_linux_sysvec,
1007 .interp_newpath = NULL,
1008 .brand_note = &linux64_brandnote,
1009 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE |
1010 LINUX_BI_FUTEX_REQUEUE
1013 Elf64_Brandinfo *linux_brandlist[] = {
1015 &linux_glibc2brandshort,
1021 linux64_elf_modevent(module_t mod, int type, void *data)
1023 Elf64_Brandinfo **brandinfo;
1025 struct linux_ioctl_handler **lihp;
1031 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1033 if (elf64_insert_brand_entry(*brandinfo) < 0)
1036 SET_FOREACH(lihp, linux_ioctl_handler_set)
1037 linux_ioctl_register_handler(*lihp);
1038 stclohz = (stathz ? stathz : hz);
1040 printf("Linux x86-64 ELF exec handler installed\n");
1042 printf("cannot insert Linux x86-64 ELF brand handler\n");
1045 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1047 if (elf64_brand_inuse(*brandinfo))
1050 for (brandinfo = &linux_brandlist[0];
1051 *brandinfo != NULL; ++brandinfo)
1052 if (elf64_remove_brand_entry(*brandinfo) < 0)
1056 SET_FOREACH(lihp, linux_ioctl_handler_set)
1057 linux_ioctl_unregister_handler(*lihp);
1059 printf("Linux x86_64 ELF exec handler removed\n");
1061 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n");
1064 return (EOPNOTSUPP);
1069 static moduledata_t linux64_elf_mod = {
1071 linux64_elf_modevent,
1075 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1076 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
1077 FEATURE(linux64, "Linux 64bit support");