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);
177 * If FreeBSD & Linux have a difference of opinion about what a trap
178 * means, deal with it here.
183 linux_translate_traps(int signal, int trap_code)
186 if (signal != SIGBUS)
200 linux_fetch_syscall_args(struct thread *td)
203 struct trapframe *frame;
204 struct syscall_args *sa;
207 frame = td->td_frame;
210 sa->args[0] = frame->tf_rdi;
211 sa->args[1] = frame->tf_rsi;
212 sa->args[2] = frame->tf_rdx;
213 sa->args[3] = frame->tf_rcx;
214 sa->args[4] = frame->tf_r8;
215 sa->args[5] = frame->tf_r9;
216 sa->code = frame->tf_rax;
217 sa->original_code = sa->code;
219 if (sa->code >= p->p_sysent->sv_size)
221 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
223 sa->callp = &p->p_sysent->sv_table[sa->code];
225 td->td_retval[0] = 0;
230 linux_set_syscall_retval(struct thread *td, int error)
232 struct trapframe *frame;
234 frame = td->td_frame;
238 frame->tf_rax = td->td_retval[0];
239 frame->tf_r10 = frame->tf_rcx;
244 * Reconstruct pc, we know that 'syscall' is 2 bytes,
245 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
246 * We saved this in tf_err.
249 frame->tf_rip -= frame->tf_err;
250 frame->tf_r10 = frame->tf_rcx;
257 frame->tf_rax = bsd_to_linux_errno(error);
258 frame->tf_r10 = frame->tf_rcx;
263 * Differently from FreeBSD native ABI, on Linux only %rcx
264 * and %r11 values are not preserved across the syscall.
265 * Require full context restore to get all registers except
266 * those two restored at return to usermode.
268 * XXX: Would be great to be able to avoid PCB_FULL_IRET
269 * for the error == 0 case.
271 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
275 linux_set_fork_retval(struct thread *td)
277 struct trapframe *frame = td->td_frame;
283 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
286 Elf_Auxinfo *argarray, *pos;
288 int error, issetugid;
291 args = (Elf64_Auxargs *)imgp->auxargs;
292 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
295 issetugid = p->p_flag & P_SUGID ? 1 : 0;
296 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
297 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
298 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
299 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
300 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
301 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
302 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
303 AUXARGS_ENTRY(pos, AT_BASE, args->base);
304 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
305 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
306 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
307 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
308 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
309 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
310 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
311 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
312 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0);
313 if (imgp->execpathp != 0)
314 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
315 if (args->execfd != -1)
316 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
317 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
318 AUXARGS_ENTRY(pos, AT_NULL, 0);
320 free(imgp->auxargs, M_TEMP);
321 imgp->auxargs = NULL;
322 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
324 error = copyout(argarray, (void *)base,
325 sizeof(*argarray) * LINUX_AT_COUNT);
326 free(argarray, M_TEMP);
331 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
335 base = (Elf64_Addr *)*stack_base;
337 if (suword(base, (uint64_t)imgp->args->argc) == -1)
340 *stack_base = (uintptr_t)base;
345 * Copy strings out to the new process address space, constructing new arg
346 * and env vector tables. Return a pointer to the base so that it can be used
347 * as the initial stack pointer.
350 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
352 int argc, envc, error;
355 uintptr_t destp, ustringp;
356 struct ps_strings *arginfo;
357 char canary[LINUX_AT_RANDOM_LEN];
361 /* Calculate string base and vector table pointers. */
362 if (imgp->execpath != NULL && imgp->auxargs != NULL)
363 execpath_len = strlen(imgp->execpath) + 1;
368 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
369 destp = (uintptr_t)arginfo;
371 if (execpath_len != 0) {
372 destp -= execpath_len;
373 destp = rounddown2(destp, sizeof(void *));
374 imgp->execpathp = (void *)destp;
375 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
380 /* Prepare the canary for SSP. */
381 arc4rand(canary, sizeof(canary), 0);
382 destp -= roundup(sizeof(canary), sizeof(void *));
383 imgp->canary = (void *)destp;
384 error = copyout(canary, imgp->canary, sizeof(canary));
388 /* Allocate room for the argument and environment strings. */
389 destp -= ARG_MAX - imgp->args->stringspace;
390 destp = rounddown2(destp, sizeof(void *));
395 * Allocate room on the stack for the ELF auxargs
396 * array. It has LINUX_AT_COUNT entries.
398 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo);
399 destp = rounddown2(destp, sizeof(void *));
402 vectp = (char **)destp;
405 * Allocate room for the argv[] and env vectors including the
406 * terminating NULL pointers.
408 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
411 * Starting with 2.24, glibc depends on a 16-byte stack alignment.
412 * One "long argc" will be prepended later.
414 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8);
416 /* vectp also becomes our initial stack base. */
417 *stack_base = (uintptr_t)vectp;
419 stringp = imgp->args->begin_argv;
420 argc = imgp->args->argc;
421 envc = imgp->args->envc;
423 /* Copy out strings - arguments and environment. */
424 error = copyout(stringp, (void *)ustringp,
425 ARG_MAX - imgp->args->stringspace);
429 /* Fill in "ps_strings" struct for ps, w, etc. */
430 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
431 suword(&arginfo->ps_nargvstr, argc) != 0)
434 /* Fill in argument portion of vector table. */
435 for (; argc > 0; --argc) {
436 if (suword(vectp++, ustringp) != 0)
438 while (*stringp++ != 0)
443 /* A null vector table pointer separates the argp's from the envp's. */
444 if (suword(vectp++, 0) != 0)
447 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
448 suword(&arginfo->ps_nenvstr, envc) != 0)
451 /* Fill in environment portion of vector table. */
452 for (; envc > 0; --envc) {
453 if (suword(vectp++, ustringp) != 0)
455 while (*stringp++ != 0)
460 /* The end of the vector table is a null pointer. */
461 if (suword(vectp, 0) != 0)
466 error = imgp->sysent->sv_copyout_auxargs(imgp,
476 * Reset registers to default values on exec.
479 linux_exec_setregs(struct thread *td, struct image_params *imgp,
482 struct trapframe *regs;
484 register_t saved_rflags;
489 if (td->td_proc->p_md.md_ldt != NULL)
494 clear_pcb_flags(pcb, PCB_32BIT);
495 pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
496 set_pcb_flags(pcb, PCB_FULL_IRET);
498 saved_rflags = regs->tf_rflags & PSL_T;
499 bzero((char *)regs, sizeof(struct trapframe));
500 regs->tf_rip = imgp->entry_addr;
501 regs->tf_rsp = stack;
502 regs->tf_rflags = PSL_USER | saved_rflags;
503 regs->tf_ss = _udatasel;
504 regs->tf_cs = _ucodesel;
505 regs->tf_ds = _udatasel;
506 regs->tf_es = _udatasel;
507 regs->tf_fs = _ufssel;
508 regs->tf_gs = _ugssel;
509 regs->tf_flags = TF_HASSEGS;
511 x86_clear_dbregs(pcb);
514 * Drop the FP state if we hold it, so that the process gets a
515 * clean FP state if it uses the FPU again.
521 * Copied from amd64/amd64/machdep.c
523 * XXX fpu state need? don't think so
526 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
529 struct l_ucontext uc;
530 struct l_sigcontext *context;
531 struct trapframe *regs;
532 unsigned long rflags;
537 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
542 context = &uc.uc_mcontext;
543 rflags = context->sc_rflags;
546 * Don't allow users to change privileged or reserved flags.
549 * XXX do allow users to change the privileged flag PSL_RF.
550 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers
551 * should sometimes set it there too. tf_rflags is kept in
552 * the signal context during signal handling and there is no
553 * other place to remember it, so the PSL_RF bit may be
554 * corrupted by the signal handler without us knowing.
555 * Corruption of the PSL_RF bit at worst causes one more or
556 * one less debugger trap, so allowing it is fairly harmless.
559 #define RFLAG_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
560 if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
561 printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags);
566 * Don't allow users to load a valid privileged %cs. Let the
567 * hardware check for invalid selectors, excess privilege in
568 * other selectors, invalid %eip's and invalid %esp's.
570 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
571 if (!CS_SECURE(context->sc_cs)) {
572 printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs);
573 ksiginfo_init_trap(&ksi);
574 ksi.ksi_signo = SIGBUS;
575 ksi.ksi_code = BUS_OBJERR;
576 ksi.ksi_trapno = T_PROTFLT;
577 ksi.ksi_addr = (void *)regs->tf_rip;
578 trapsignal(td, &ksi);
583 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
584 SIG_CANTMASK(td->td_sigmask);
588 regs->tf_rdi = context->sc_rdi;
589 regs->tf_rsi = context->sc_rsi;
590 regs->tf_rdx = context->sc_rdx;
591 regs->tf_rbp = context->sc_rbp;
592 regs->tf_rbx = context->sc_rbx;
593 regs->tf_rcx = context->sc_rcx;
594 regs->tf_rax = context->sc_rax;
595 regs->tf_rip = context->sc_rip;
596 regs->tf_rsp = context->sc_rsp;
597 regs->tf_r8 = context->sc_r8;
598 regs->tf_r9 = context->sc_r9;
599 regs->tf_r10 = context->sc_r10;
600 regs->tf_r11 = context->sc_r11;
601 regs->tf_r12 = context->sc_r12;
602 regs->tf_r13 = context->sc_r13;
603 regs->tf_r14 = context->sc_r14;
604 regs->tf_r15 = context->sc_r15;
605 regs->tf_cs = context->sc_cs;
606 regs->tf_err = context->sc_err;
607 regs->tf_rflags = rflags;
609 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
610 return (EJUSTRETURN);
614 * copied from amd64/amd64/machdep.c
616 * Send an interrupt to process.
619 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
621 struct l_rt_sigframe sf, *sfp;
626 struct trapframe *regs;
632 PROC_LOCK_ASSERT(p, MA_OWNED);
633 sig = ksi->ksi_signo;
635 code = ksi->ksi_code;
636 mtx_assert(&psp->ps_mtx, MA_OWNED);
638 oonstack = sigonstack(regs->tf_rsp);
640 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
641 catcher, sig, mask, code);
643 /* Save user context. */
644 bzero(&sf, sizeof(sf));
645 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask);
646 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask);
648 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
649 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
650 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
651 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
653 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi;
654 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi;
655 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx;
656 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp;
657 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx;
658 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx;
659 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax;
660 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip;
661 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp;
662 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8;
663 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9;
664 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10;
665 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11;
666 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12;
667 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13;
668 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14;
669 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15;
670 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
671 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags;
672 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err;
673 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
674 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
676 /* Allocate space for the signal handler context. */
677 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
678 SIGISMEMBER(psp->ps_sigonstack, sig)) {
679 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size -
680 sizeof(struct l_rt_sigframe);
682 sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128;
683 /* Align to 16 bytes. */
684 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
686 /* Translate the signal. */
687 sig = bsd_to_linux_signal(sig);
689 /* Build the argument list for the signal handler. */
690 regs->tf_rdi = sig; /* arg 1 in %rdi */
692 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
693 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */
695 /* Fill in POSIX parts. */
696 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig);
697 sf.sf_handler = catcher;
699 mtx_unlock(&psp->ps_mtx);
702 /* Copy the sigframe out to the user's stack. */
703 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
708 regs->tf_rsp = (long)sfp;
709 regs->tf_rip = linux_rt_sigcode;
710 regs->tf_rflags &= ~(PSL_T | PSL_D);
711 regs->tf_cs = _ucodesel;
712 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
714 mtx_lock(&psp->ps_mtx);
717 #define LINUX_VSYSCALL_START (-10UL << 20)
718 #define LINUX_VSYSCALL_SZ 1024
720 const unsigned long linux_vsyscall_vector[] = {
721 LINUX_SYS_gettimeofday,
722 LINUX_SYS_linux_time,
723 LINUX_SYS_linux_getcpu,
727 linux_vsyscall(struct thread *td)
729 struct trapframe *frame;
734 frame = td->td_frame;
736 /* Check %rip for vsyscall area. */
737 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START))
739 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0)
741 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ;
742 if (code >= nitems(linux_vsyscall_vector))
746 * vsyscall called as callq *(%rax), so we must
747 * use return address from %rsp and also fixup %rsp.
749 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr));
753 frame->tf_rip = retqaddr;
754 frame->tf_rax = linux_vsyscall_vector[code];
757 traced = (frame->tf_flags & PSL_T);
759 amd64_syscall(td, traced);
764 struct sysentvec elf_linux_sysvec = {
765 .sv_size = LINUX_SYS_MAXSYSCALL,
766 .sv_table = linux_sysent,
767 .sv_transtrap = linux_translate_traps,
768 .sv_fixup = linux_fixup_elf,
769 .sv_sendsig = linux_rt_sendsig,
770 .sv_sigcode = &_binary_linux_vdso_so_o_start,
771 .sv_szsigcode = &linux_szsigcode,
772 .sv_name = "Linux ELF64",
773 .sv_coredump = elf64_coredump,
774 .sv_elf_core_osabi = ELFOSABI_NONE,
775 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
776 .sv_elf_core_prepare_notes = linux64_prepare_notes,
777 .sv_imgact_try = linux_exec_imgact_try,
778 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
779 .sv_minuser = VM_MIN_ADDRESS,
780 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48,
781 .sv_usrstack = LINUX_USRSTACK_LA48,
782 .sv_psstrings = LINUX_PS_STRINGS_LA48,
783 .sv_stackprot = VM_PROT_ALL,
784 .sv_copyout_auxargs = linux_copyout_auxargs,
785 .sv_copyout_strings = linux_copyout_strings,
786 .sv_setregs = linux_exec_setregs,
789 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN |
790 SV_SIG_WAITNDQ | SV_TIMEKEEP,
791 .sv_set_syscall_retval = linux_set_syscall_retval,
792 .sv_fetch_syscall_args = linux_fetch_syscall_args,
793 .sv_syscallnames = NULL,
794 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48,
795 .sv_shared_page_len = PAGE_SIZE,
796 .sv_schedtail = linux_schedtail,
797 .sv_thread_detach = linux_thread_detach,
798 .sv_trap = linux_vsyscall,
799 .sv_onexec = linux_on_exec_vmspace,
800 .sv_onexit = linux_on_exit,
801 .sv_ontdexit = linux_thread_dtor,
802 .sv_setid_allowed = &linux_setid_allowed_query,
803 .sv_set_fork_retval = linux_set_fork_retval,
807 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
811 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base,
812 LINUX_VDSOPAGE_SIZE, imgp);
814 linux_on_exec(p, imgp);
819 * linux_vdso_install() and linux_exec_sysvec_init() must be called
820 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
823 linux_exec_sysvec_init(void *param)
825 l_uintptr_t *ktimekeep_base, *ktsc_selector;
826 struct sysentvec *sv;
830 amd64_lower_shared_page(sv);
831 /* Fill timekeep_base */
832 exec_sysvec_init(sv);
834 tkoff = kern_timekeep_base - linux_vdso_base;
835 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
836 *ktimekeep_base = sv->sv_timekeep_base;
838 tkoff = kern_tsc_selector - linux_vdso_base;
839 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
840 *ktsc_selector = linux_vdso_tsc_selector_idx();
842 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector);
844 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
845 linux_exec_sysvec_init, &elf_linux_sysvec);
848 linux_vdso_install(const void *param)
850 char *vdso_start = &_binary_linux_vdso_so_o_start;
851 char *vdso_end = &_binary_linux_vdso_so_o_end;
853 linux_szsigcode = vdso_end - vdso_start;
854 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE);
856 linux_vdso_base = LINUX_VDSOPAGE_LA48;
857 if (hw_lower_amd64_sharedpage != 0)
858 linux_vdso_base -= PAGE_SIZE;
860 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
862 linux_vdso_obj = __elfN(linux_shared_page_init)
863 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
864 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
866 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
868 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
869 linux_vdso_install, NULL);
872 linux_vdso_deinstall(const void *param)
875 __elfN(linux_shared_page_fini)(linux_vdso_obj,
876 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
878 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
879 linux_vdso_deinstall, NULL);
882 linux_vdso_reloc(char *mapping, Elf_Addr offset)
884 const Elf_Ehdr *ehdr;
885 const Elf_Shdr *shdr;
886 Elf64_Addr *where, val;
887 Elf_Size rtype, symidx;
888 const Elf_Rela *rela;
889 Elf_Addr addr, addend;
896 ehdr = (const Elf_Ehdr *)mapping;
897 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
898 for (i = 0; i < ehdr->e_shnum; i++)
900 switch (shdr[i].sh_type) {
902 printf("Linux x86_64 vDSO: unexpected Rel section\n");
905 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset);
906 relacnt = shdr[i].sh_size / sizeof(*rela);
910 for (j = 0; j < relacnt; j++, rela++) {
911 where = (Elf_Addr *)(mapping + rela->r_offset);
912 addend = rela->r_addend;
913 rtype = ELF_R_TYPE(rela->r_info);
914 symidx = ELF_R_SYM(rela->r_info);
917 case R_X86_64_NONE: /* none */
920 case R_X86_64_RELATIVE: /* B + A */
921 addr = (Elf_Addr)(offset + addend);
926 case R_X86_64_IRELATIVE:
927 printf("Linux x86_64 vDSO: unexpected ifunc relocation, "
928 "symbol index %ld\n", symidx);
931 printf("Linux x86_64 vDSO: unexpected relocation type %ld, "
932 "symbol index %ld\n", rtype, symidx);
937 static char GNULINUX_ABI_VENDOR[] = "GNU";
938 static int GNULINUX_ABI_DESC = 0;
941 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
943 const Elf32_Word *desc;
946 p = (uintptr_t)(note + 1);
947 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
949 desc = (const Elf32_Word *)p;
950 if (desc[0] != GNULINUX_ABI_DESC)
954 * For Linux we encode osrel using the Linux convention of
955 * (version << 16) | (major << 8) | (minor)
956 * See macro in linux_mib.h
958 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
963 static Elf_Brandnote linux64_brandnote = {
964 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR),
967 .vendor = GNULINUX_ABI_VENDOR,
968 .flags = BN_TRANSLATE_OSREL,
969 .trans_osrel = linux_trans_osrel
972 static Elf64_Brandinfo linux_glibc2brand = {
973 .brand = ELFOSABI_LINUX,
974 .machine = EM_X86_64,
975 .compat_3_brand = "Linux",
976 .emul_path = linux_emul_path,
977 .interp_path = "/lib64/ld-linux-x86-64.so.2",
978 .sysvec = &elf_linux_sysvec,
979 .interp_newpath = NULL,
980 .brand_note = &linux64_brandnote,
981 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
984 static Elf64_Brandinfo linux_glibc2brandshort = {
985 .brand = ELFOSABI_LINUX,
986 .machine = EM_X86_64,
987 .compat_3_brand = "Linux",
988 .emul_path = linux_emul_path,
989 .interp_path = "/lib64/ld-linux.so.2",
990 .sysvec = &elf_linux_sysvec,
991 .interp_newpath = NULL,
992 .brand_note = &linux64_brandnote,
993 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
996 static Elf64_Brandinfo linux_muslbrand = {
997 .brand = ELFOSABI_LINUX,
998 .machine = EM_X86_64,
999 .compat_3_brand = "Linux",
1000 .emul_path = linux_emul_path,
1001 .interp_path = "/lib/ld-musl-x86_64.so.1",
1002 .sysvec = &elf_linux_sysvec,
1003 .interp_newpath = NULL,
1004 .brand_note = &linux64_brandnote,
1005 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE |
1006 LINUX_BI_FUTEX_REQUEUE
1009 Elf64_Brandinfo *linux_brandlist[] = {
1011 &linux_glibc2brandshort,
1017 linux64_elf_modevent(module_t mod, int type, void *data)
1019 Elf64_Brandinfo **brandinfo;
1021 struct linux_ioctl_handler **lihp;
1027 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1029 if (elf64_insert_brand_entry(*brandinfo) < 0)
1032 SET_FOREACH(lihp, linux_ioctl_handler_set)
1033 linux_ioctl_register_handler(*lihp);
1034 stclohz = (stathz ? stathz : hz);
1036 printf("Linux x86-64 ELF exec handler installed\n");
1038 printf("cannot insert Linux x86-64 ELF brand handler\n");
1041 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
1043 if (elf64_brand_inuse(*brandinfo))
1046 for (brandinfo = &linux_brandlist[0];
1047 *brandinfo != NULL; ++brandinfo)
1048 if (elf64_remove_brand_entry(*brandinfo) < 0)
1052 SET_FOREACH(lihp, linux_ioctl_handler_set)
1053 linux_ioctl_unregister_handler(*lihp);
1055 printf("Linux x86_64 ELF exec handler removed\n");
1057 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n");
1060 return (EOPNOTSUPP);
1065 static moduledata_t linux64_elf_mod = {
1067 linux64_elf_modevent,
1071 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
1072 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
1073 FEATURE(linux64, "Linux 64bit support");