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 #define __ELF_WORD_SIZE 64
36 #include <sys/param.h>
38 #include <sys/imgact.h>
39 #include <sys/imgact_elf.h>
40 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/module.h>
45 #include <sys/mutex.h>
47 #include <sys/stddef.h>
48 #include <sys/syscallsubr.h>
49 #include <sys/sysctl.h>
50 #include <sys/sysent.h>
54 #include <vm/vm_map.h>
55 #include <vm/vm_page.h>
57 #include <machine/cpu.h>
58 #include <machine/md_var.h>
59 #include <machine/pcb.h>
60 #include <machine/specialreg.h>
61 #include <machine/trap.h>
63 #include <x86/linux/linux_x86.h>
64 #include <amd64/linux/linux.h>
65 #include <amd64/linux/linux_proto.h>
66 #include <compat/linux/linux_elf.h>
67 #include <compat/linux/linux_emul.h>
68 #include <compat/linux/linux_fork.h>
69 #include <compat/linux/linux_ioctl.h>
70 #include <compat/linux/linux_mib.h>
71 #include <compat/linux/linux_misc.h>
72 #include <compat/linux/linux_signal.h>
73 #include <compat/linux/linux_sysproto.h>
74 #include <compat/linux/linux_util.h>
75 #include <compat/linux/linux_vdso.h>
77 #include <x86/linux/linux_x86_sigframe.h>
79 _Static_assert(sizeof(struct l_fpstate) ==
80 sizeof(__typeof(((mcontext_t *)0)->mc_fpstate)),
81 "fxsave area size incorrect");
83 MODULE_VERSION(linux64, 1);
85 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2
86 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \
88 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE)
90 * PAGE_SIZE - the size
91 * of the native SHAREDPAGE
93 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48
94 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \
95 sizeof(struct ps_strings))
97 static int linux_szsigcode;
98 static vm_object_t linux_vdso_obj;
99 static char *linux_vdso_mapping;
100 extern char _binary_linux_vdso_so_o_start;
101 extern char _binary_linux_vdso_so_o_end;
102 static vm_offset_t linux_vdso_base;
104 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
105 extern const char *linux_syscallnames[];
107 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
109 static void linux_vdso_install(const void *param);
110 static void linux_vdso_deinstall(const void *param);
111 static void linux_vdso_reloc(char *mapping, Elf_Addr offset);
112 static void linux_set_syscall_retval(struct thread *td, int error);
113 static int linux_fetch_syscall_args(struct thread *td);
114 static void linux_exec_setregs(struct thread *td, struct image_params *imgp,
116 static void linux_exec_sysvec_init(void *param);
117 static int linux_on_exec_vmspace(struct proc *p,
118 struct image_params *imgp);
119 static void linux_set_fork_retval(struct thread *td);
120 static int linux_vsyscall(struct thread *td);
122 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
123 LINUX_VDSO_SYM_CHAR(linux_platform);
124 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
125 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
126 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
129 * According to the Intel x86 ISA 64-bit syscall
130 * saves %rip to %rcx and rflags to %r11. Registers on syscall entry:
131 * %rax system call number
132 * %rcx return address
141 * Then FreeBSD fast_syscall() move registers:
142 * %rcx -> trapframe.tf_rip
143 * %r10 -> trapframe.tf_rcx
146 linux_fetch_syscall_args(struct thread *td)
149 struct trapframe *frame;
150 struct syscall_args *sa;
153 frame = td->td_frame;
156 sa->args[0] = frame->tf_rdi;
157 sa->args[1] = frame->tf_rsi;
158 sa->args[2] = frame->tf_rdx;
159 sa->args[3] = frame->tf_rcx;
160 sa->args[4] = frame->tf_r8;
161 sa->args[5] = frame->tf_r9;
162 sa->code = frame->tf_rax;
163 sa->original_code = sa->code;
165 if (sa->code >= p->p_sysent->sv_size)
167 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
169 sa->callp = &p->p_sysent->sv_table[sa->code];
171 /* Restore r10 earlier to avoid doing this multiply times. */
172 frame->tf_r10 = frame->tf_rcx;
173 /* Restore %rcx for machine context. */
174 frame->tf_rcx = frame->tf_rip;
176 td->td_retval[0] = 0;
181 linux_set_syscall_retval(struct thread *td, int error)
183 struct trapframe *frame;
185 frame = td->td_frame;
189 frame->tf_rax = td->td_retval[0];
194 * Reconstruct pc, we know that 'syscall' is 2 bytes,
195 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
196 * We saved this in tf_err.
199 frame->tf_rip -= frame->tf_err;
206 frame->tf_rax = bsd_to_linux_errno(error);
211 * Differently from FreeBSD native ABI, on Linux only %rcx
212 * and %r11 values are not preserved across the syscall.
213 * Require full context restore to get all registers except
214 * those two restored at return to usermode.
216 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
220 linux_set_fork_retval(struct thread *td)
222 struct trapframe *frame = td->td_frame;
228 linux64_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos)
231 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
232 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature);
233 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2());
234 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform));
238 * Reset registers to default values on exec.
241 linux_exec_setregs(struct thread *td, struct image_params *imgp,
244 struct trapframe *regs;
246 register_t saved_rflags;
251 if (td->td_proc->p_md.md_ldt != NULL)
256 clear_pcb_flags(pcb, PCB_32BIT);
257 pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
258 set_pcb_flags(pcb, PCB_FULL_IRET);
260 saved_rflags = regs->tf_rflags & PSL_T;
261 bzero((char *)regs, sizeof(struct trapframe));
262 regs->tf_rip = imgp->entry_addr;
263 regs->tf_rsp = stack;
264 regs->tf_rflags = PSL_USER | saved_rflags;
265 regs->tf_ss = _udatasel;
266 regs->tf_cs = _ucodesel;
267 regs->tf_ds = _udatasel;
268 regs->tf_es = _udatasel;
269 regs->tf_fs = _ufssel;
270 regs->tf_gs = _ugssel;
271 regs->tf_flags = TF_HASSEGS;
273 x86_clear_dbregs(pcb);
276 * Drop the FP state if we hold it, so that the process gets a
277 * clean FP state if it uses the FPU again.
283 linux_fxrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc)
285 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0];
288 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate));
291 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad));
292 return (set_fpcontext(td, mcp, NULL, 0));
296 linux_xrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc)
298 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0];
305 mcp->mc_xfpustate_len = cpu_max_ext_state_size - sizeof(struct savefpu);
307 /* Legacy region of an xsave area. */
308 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate));
311 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad));
313 /* Extended region of an xsave area. */
314 sc->sc_fpstate += sizeof(mcp->mc_fpstate);
315 xfpustate = (char *)fpu_save_area_alloc();
316 error = copyin(PTRIN(sc->sc_fpstate), xfpustate, mcp->mc_xfpustate_len);
318 fpu_save_area_free((struct savefpu *)xfpustate);
319 uprintf("pid %d (%s): linux xrstor failed\n", p->p_pid,
324 /* Linux specific end of xsave area marker. */
325 sc->sc_fpstate += mcp->mc_xfpustate_len;
326 error = copyin(PTRIN(sc->sc_fpstate), &magic2, LINUX_FP_XSTATE_MAGIC2_SIZE);
327 if (error != 0 || magic2 != LINUX_FP_XSTATE_MAGIC2) {
328 fpu_save_area_free((struct savefpu *)xfpustate);
329 uprintf("pid %d (%s): sigreturn magic2 0x%x error %d\n",
330 p->p_pid, td->td_name, magic2, error);
334 error = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
335 fpu_save_area_free((struct savefpu *)xfpustate);
337 uprintf("pid %d (%s): sigreturn set_fpcontext error %d\n",
338 p->p_pid, td->td_name, error);
344 linux_copyin_fpstate(struct thread *td, struct l_ucontext *uc)
348 bzero(&mc, sizeof(mc));
349 mc.mc_ownedfp = _MC_FPOWNED_FPU;
350 mc.mc_fpformat = _MC_FPFMT_XMM;
352 if ((uc->uc_flags & LINUX_UC_FP_XSTATE) != 0)
353 return (linux_xrstor(td, &mc, &uc->uc_mcontext));
355 return (linux_fxrstor(td, &mc, &uc->uc_mcontext));
359 * Copied from amd64/amd64/machdep.c
362 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
365 struct l_rt_sigframe sf;
366 struct l_sigcontext *context;
367 struct trapframe *regs;
368 unsigned long rflags;
374 error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf));
379 context = &sf.sf_uc.uc_mcontext;
380 rflags = context->sc_rflags;
383 * Don't allow users to change privileged or reserved flags.
386 * XXX do allow users to change the privileged flag PSL_RF.
387 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers
388 * should sometimes set it there too. tf_rflags is kept in
389 * the signal context during signal handling and there is no
390 * other place to remember it, so the PSL_RF bit may be
391 * corrupted by the signal handler without us knowing.
392 * Corruption of the PSL_RF bit at worst causes one more or
393 * one less debugger trap, so allowing it is fairly harmless.
395 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
396 uprintf("pid %d comm %s linux mangled rflags %#lx\n",
397 p->p_pid, p->p_comm, rflags);
402 * Don't allow users to load a valid privileged %cs. Let the
403 * hardware check for invalid selectors, excess privilege in
404 * other selectors, invalid %eip's and invalid %esp's.
406 if (!CS_SECURE(context->sc_cs)) {
407 uprintf("pid %d comm %s linux mangled cs %#x\n",
408 p->p_pid, p->p_comm, context->sc_cs);
409 ksiginfo_init_trap(&ksi);
410 ksi.ksi_signo = SIGBUS;
411 ksi.ksi_code = BUS_OBJERR;
412 ksi.ksi_trapno = T_PROTFLT;
413 ksi.ksi_addr = (void *)regs->tf_rip;
414 trapsignal(td, &ksi);
418 linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask);
419 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
421 regs->tf_rdi = context->sc_rdi;
422 regs->tf_rsi = context->sc_rsi;
423 regs->tf_rdx = context->sc_rdx;
424 regs->tf_rbp = context->sc_rbp;
425 regs->tf_rbx = context->sc_rbx;
426 regs->tf_rcx = context->sc_rcx;
427 regs->tf_rax = context->sc_rax;
428 regs->tf_rip = context->sc_rip;
429 regs->tf_rsp = context->sc_rsp;
430 regs->tf_r8 = context->sc_r8;
431 regs->tf_r9 = context->sc_r9;
432 regs->tf_r10 = context->sc_r10;
433 regs->tf_r11 = context->sc_r11;
434 regs->tf_r12 = context->sc_r12;
435 regs->tf_r13 = context->sc_r13;
436 regs->tf_r14 = context->sc_r14;
437 regs->tf_r15 = context->sc_r15;
438 regs->tf_cs = context->sc_cs;
439 regs->tf_err = context->sc_err;
440 regs->tf_rflags = rflags;
442 error = linux_copyin_fpstate(td, &sf.sf_uc);
444 uprintf("pid %d comm %s linux can't restore fpu state %d\n",
445 p->p_pid, p->p_comm, error);
449 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
450 return (EJUSTRETURN);
454 linux_fxsave(mcontext_t *mcp, void *ufp)
456 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0];
458 bzero(&fx->reserved2[0], sizeof(fx->reserved2));
459 return (copyout(fx, ufp, sizeof(*fx)));
463 linux_xsave(mcontext_t *mcp, char *xfpusave, char *ufp)
465 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0];
469 /* Legacy region of an xsave area. */
470 fx->sw_reserved.magic1 = LINUX_FP_XSTATE_MAGIC1;
471 fx->sw_reserved.xstate_size = mcp->mc_xfpustate_len + sizeof(*fx);
472 fx->sw_reserved.extended_size = fx->sw_reserved.xstate_size +
473 LINUX_FP_XSTATE_MAGIC2_SIZE;
474 fx->sw_reserved.xfeatures = xsave_mask;
476 error = copyout(fx, ufp, sizeof(*fx));
481 /* Extended region of an xsave area. */
482 error = copyout(xfpusave, ufp, mcp->mc_xfpustate_len);
486 /* Linux specific end of xsave area marker. */
487 ufp += mcp->mc_xfpustate_len;
488 magic2 = LINUX_FP_XSTATE_MAGIC2;
489 return (copyout(&magic2, ufp, LINUX_FP_XSTATE_MAGIC2_SIZE));
493 linux_copyout_fpstate(struct thread *td, struct l_ucontext *uc, char **sp)
500 get_fpcontext(td, &mc, &xfpusave, &xfpusave_len);
501 KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present"));
503 /* Room for fxsave area. */
504 ufp -= sizeof(struct l_fpstate);
505 if (xfpusave != NULL) {
506 /* Room for xsave area. */
507 ufp -= (xfpusave_len + LINUX_FP_XSTATE_MAGIC2_SIZE);
508 uc->uc_flags |= LINUX_UC_FP_XSTATE;
510 *sp = ufp = (char *)((unsigned long)ufp & ~0x3Ful);
512 if (xfpusave != NULL)
513 return (linux_xsave(&mc, xfpusave, ufp));
515 return (linux_fxsave(&mc, ufp));
519 * copied from amd64/amd64/machdep.c
521 * Send an interrupt to process.
524 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
526 struct l_rt_sigframe sf, *sfp;
531 struct trapframe *regs;
533 int oonstack, issiginfo;
537 PROC_LOCK_ASSERT(p, MA_OWNED);
538 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno);
540 issiginfo = SIGISMEMBER(psp->ps_siginfo, sig);
541 code = ksi->ksi_code;
542 mtx_assert(&psp->ps_mtx, MA_OWNED);
544 oonstack = sigonstack(regs->tf_rsp);
546 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
547 catcher, sig, mask, code);
549 bzero(&sf, sizeof(sf));
550 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
551 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
552 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
553 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
555 /* Allocate space for the signal handler context. */
556 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
557 SIGISMEMBER(psp->ps_sigonstack, sig)) {
558 sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
560 sp = (char *)regs->tf_rsp - 128;
562 mtx_unlock(&psp->ps_mtx);
565 if (linux_copyout_fpstate(td, &sf.sf_uc, &sp) != 0) {
566 uprintf("pid %d comm %s linux can't save fpu state, killing\n",
567 p->p_pid, p->p_comm);
571 sf.sf_uc.uc_mcontext.sc_fpstate = (register_t)sp;
573 /* Make room, keeping the stack aligned. */
574 sp -= sizeof(struct l_rt_sigframe);
575 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
577 /* Save user context. */
578 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask);
579 sf.sf_uc.uc_mcontext.sc_mask = sf.sf_uc.uc_sigmask;
580 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi;
581 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi;
582 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx;
583 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp;
584 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx;
585 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx;
586 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax;
587 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip;
588 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp;
589 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8;
590 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9;
591 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10;
592 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11;
593 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12;
594 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13;
595 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14;
596 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15;
597 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs;
598 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags;
599 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err;
600 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
601 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
603 /* Translate the signal. */
604 sig = bsd_to_linux_signal(sig);
605 /* Fill in POSIX parts. */
606 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig);
608 /* Copy the sigframe out to the user's stack. */
609 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
610 uprintf("pid %d comm %s has trashed its stack, killing\n",
611 p->p_pid, p->p_comm);
617 /* Build the argument list for the signal handler. */
618 regs->tf_rdi = sig; /* arg 1 in %rdi */
621 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
622 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */
627 regs->tf_rcx = (register_t)catcher;
628 regs->tf_rsp = (long)sfp;
629 regs->tf_rip = linux_rt_sigcode;
630 regs->tf_rflags &= ~(PSL_T | PSL_D);
631 regs->tf_cs = _ucodesel;
632 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
634 mtx_lock(&psp->ps_mtx);
637 #define LINUX_VSYSCALL_START (-10UL << 20)
638 #define LINUX_VSYSCALL_SZ 1024
640 const unsigned long linux_vsyscall_vector[] = {
641 LINUX_SYS_gettimeofday,
642 LINUX_SYS_linux_time,
643 LINUX_SYS_linux_getcpu,
647 linux_vsyscall(struct thread *td)
649 struct trapframe *frame;
654 frame = td->td_frame;
656 /* Check %rip for vsyscall area. */
657 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START))
659 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0)
661 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ;
662 if (code >= nitems(linux_vsyscall_vector))
666 * vsyscall called as callq *(%rax), so we must
667 * use return address from %rsp and also fixup %rsp.
669 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr));
673 frame->tf_rip = retqaddr;
674 frame->tf_rax = linux_vsyscall_vector[code];
677 traced = (frame->tf_flags & PSL_T);
679 amd64_syscall(td, traced);
684 struct sysentvec elf_linux_sysvec = {
685 .sv_size = LINUX_SYS_MAXSYSCALL,
686 .sv_table = linux_sysent,
687 .sv_fixup = __elfN(freebsd_fixup),
688 .sv_sendsig = linux_rt_sendsig,
689 .sv_sigcode = &_binary_linux_vdso_so_o_start,
690 .sv_szsigcode = &linux_szsigcode,
691 .sv_name = "Linux ELF64",
692 .sv_coredump = elf64_coredump,
693 .sv_elf_core_osabi = ELFOSABI_NONE,
694 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
695 .sv_elf_core_prepare_notes = linux64_prepare_notes,
696 .sv_minsigstksz = LINUX_MINSIGSTKSZ,
697 .sv_minuser = VM_MIN_ADDRESS,
698 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48,
699 .sv_usrstack = LINUX_USRSTACK_LA48,
700 .sv_psstrings = LINUX_PS_STRINGS_LA48,
701 .sv_psstringssz = sizeof(struct ps_strings),
702 .sv_stackprot = VM_PROT_ALL,
703 .sv_copyout_auxargs = __linuxN(copyout_auxargs),
704 .sv_copyout_strings = __linuxN(copyout_strings),
705 .sv_setregs = linux_exec_setregs,
708 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN |
709 SV_SIG_WAITNDQ | SV_TIMEKEEP,
710 .sv_set_syscall_retval = linux_set_syscall_retval,
711 .sv_fetch_syscall_args = linux_fetch_syscall_args,
712 .sv_syscallnames = linux_syscallnames,
713 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48,
714 .sv_shared_page_len = PAGE_SIZE,
715 .sv_schedtail = linux_schedtail,
716 .sv_thread_detach = linux_thread_detach,
717 .sv_trap = linux_vsyscall,
720 .sv_onexec = linux_on_exec_vmspace,
721 .sv_onexit = linux_on_exit,
722 .sv_ontdexit = linux_thread_dtor,
723 .sv_setid_allowed = &linux_setid_allowed_query,
724 .sv_set_fork_retval = linux_set_fork_retval,
728 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
732 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base,
733 LINUX_VDSOPAGE_SIZE, imgp);
735 error = linux_on_exec(p, imgp);
740 * linux_vdso_install() and linux_exec_sysvec_init() must be called
741 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
744 linux_exec_sysvec_init(void *param)
746 l_uintptr_t *ktimekeep_base, *ktsc_selector;
747 struct sysentvec *sv;
751 amd64_lower_shared_page(sv);
752 /* Fill timekeep_base */
753 exec_sysvec_init(sv);
755 tkoff = kern_timekeep_base - linux_vdso_base;
756 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
757 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset;
759 tkoff = kern_tsc_selector - linux_vdso_base;
760 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
761 *ktsc_selector = linux_vdso_tsc_selector_idx();
763 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector);
765 tkoff = kern_cpu_selector - linux_vdso_base;
766 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
767 *ktsc_selector = linux_vdso_cpu_selector_idx();
769 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector);
771 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
772 linux_exec_sysvec_init, &elf_linux_sysvec);
775 linux_vdso_install(const void *param)
777 char *vdso_start = &_binary_linux_vdso_so_o_start;
778 char *vdso_end = &_binary_linux_vdso_so_o_end;
780 linux_szsigcode = vdso_end - vdso_start;
781 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE);
783 linux_vdso_base = LINUX_VDSOPAGE_LA48;
784 if (hw_lower_amd64_sharedpage != 0)
785 linux_vdso_base -= PAGE_SIZE;
787 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
789 linux_vdso_obj = __elfN(linux_shared_page_init)
790 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
791 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
793 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
795 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
796 linux_vdso_install, NULL);
799 linux_vdso_deinstall(const void *param)
802 __elfN(linux_shared_page_fini)(linux_vdso_obj,
803 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE);
805 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
806 linux_vdso_deinstall, NULL);
809 linux_vdso_reloc(char *mapping, Elf_Addr offset)
811 const Elf_Ehdr *ehdr;
812 const Elf_Shdr *shdr;
813 Elf64_Addr *where, val;
814 Elf_Size rtype, symidx;
815 const Elf_Rela *rela;
816 Elf_Addr addr, addend;
823 ehdr = (const Elf_Ehdr *)mapping;
824 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
825 for (i = 0; i < ehdr->e_shnum; i++)
827 switch (shdr[i].sh_type) {
829 printf("Linux x86_64 vDSO: unexpected Rel section\n");
832 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset);
833 relacnt = shdr[i].sh_size / sizeof(*rela);
837 for (j = 0; j < relacnt; j++, rela++) {
838 where = (Elf_Addr *)(mapping + rela->r_offset);
839 addend = rela->r_addend;
840 rtype = ELF_R_TYPE(rela->r_info);
841 symidx = ELF_R_SYM(rela->r_info);
844 case R_X86_64_NONE: /* none */
847 case R_X86_64_RELATIVE: /* B + A */
848 addr = (Elf_Addr)(offset + addend);
853 case R_X86_64_IRELATIVE:
854 printf("Linux x86_64 vDSO: unexpected ifunc relocation, "
855 "symbol index %ld\n", symidx);
858 printf("Linux x86_64 vDSO: unexpected relocation type %ld, "
859 "symbol index %ld\n", rtype, symidx);
864 static Elf_Brandnote linux64_brandnote = {
865 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
868 .vendor = GNU_ABI_VENDOR,
869 .flags = BN_TRANSLATE_OSREL,
870 .trans_osrel = linux_trans_osrel
873 static Elf64_Brandinfo linux_glibc2brand = {
874 .brand = ELFOSABI_LINUX,
875 .machine = EM_X86_64,
876 .compat_3_brand = "Linux",
877 .interp_path = "/lib64/ld-linux-x86-64.so.2",
878 .sysvec = &elf_linux_sysvec,
879 .interp_newpath = NULL,
880 .brand_note = &linux64_brandnote,
881 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
884 static Elf64_Brandinfo linux_glibc2brandshort = {
885 .brand = ELFOSABI_LINUX,
886 .machine = EM_X86_64,
887 .compat_3_brand = "Linux",
888 .interp_path = "/lib64/ld-linux.so.2",
889 .sysvec = &elf_linux_sysvec,
890 .interp_newpath = NULL,
891 .brand_note = &linux64_brandnote,
892 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
895 static Elf64_Brandinfo linux_muslbrand = {
896 .brand = ELFOSABI_LINUX,
897 .machine = EM_X86_64,
898 .compat_3_brand = "Linux",
899 .interp_path = "/lib/ld-musl-x86_64.so.1",
900 .sysvec = &elf_linux_sysvec,
901 .interp_newpath = NULL,
902 .brand_note = &linux64_brandnote,
903 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE |
904 LINUX_BI_FUTEX_REQUEUE
907 Elf64_Brandinfo *linux_brandlist[] = {
909 &linux_glibc2brandshort,
915 linux64_elf_modevent(module_t mod, int type, void *data)
917 Elf64_Brandinfo **brandinfo;
919 struct linux_ioctl_handler **lihp;
925 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
927 if (elf64_insert_brand_entry(*brandinfo) < 0)
930 SET_FOREACH(lihp, linux_ioctl_handler_set)
931 linux_ioctl_register_handler(*lihp);
932 stclohz = (stathz ? stathz : hz);
934 printf("Linux x86-64 ELF exec handler installed\n");
936 printf("cannot insert Linux x86-64 ELF brand handler\n");
939 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
941 if (elf64_brand_inuse(*brandinfo))
944 for (brandinfo = &linux_brandlist[0];
945 *brandinfo != NULL; ++brandinfo)
946 if (elf64_remove_brand_entry(*brandinfo) < 0)
950 SET_FOREACH(lihp, linux_ioctl_handler_set)
951 linux_ioctl_unregister_handler(*lihp);
953 printf("Linux x86_64 ELF exec handler removed\n");
955 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n");
963 static moduledata_t linux64_elf_mod = {
965 linux64_elf_modevent,
969 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
970 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
971 FEATURE(linux64, "Linux 64bit support");