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freebsd-skq/sys/amd64/linux/linux_sysvec.c
Edward Tomasz Napierala ca6e1fa3ce linux: adjust ordering of Linux auxv and add dummy AT_HWCAP2 
This should be a no-op; the purpose of this is to reduce
a spurious difference between Linuxulator and Linux, to make
debugging core dumps slightly easier.

Note that AT_HWCAP2 we pass to Linux binaries is always 0,
instead of being equal to 'cpu_feature2'.  This matches what
I've observed under Ubuntu Focal VM.

Reviewed By:	chuck, dchagin
Sponsored By:	EPSRC
Differential Revision:	https://reviews.freebsd.org/D29609
2021-04-13 13:14:30 +01:00

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/*-
* Copyright (c) 2013 Dmitry Chagin
* Copyright (c) 2004 Tim J. Robbins
* Copyright (c) 2003 Peter Wemm
* Copyright (c) 2002 Doug Rabson
* Copyright (c) 1998-1999 Andrew Gallatin
* Copyright (c) 1994-1996 Søren Schmidt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define __ELF_WORD_SIZE 64
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/vnode.h>
#include <sys/eventhandler.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_param.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/specialreg.h>
#include <machine/trap.h>
#include <amd64/linux/linux.h>
#include <amd64/linux/linux_proto.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_ioctl.h>
#include <compat/linux/linux_mib.h>
#include <compat/linux/linux_misc.h>
#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_sysproto.h>
#include <compat/linux/linux_util.h>
#include <compat/linux/linux_vdso.h>
MODULE_VERSION(linux64, 1);
const char *linux_kplatform;
static int linux_szsigcode;
static vm_object_t linux_shared_page_obj;
static char *linux_shared_page_mapping;
extern char _binary_linux_locore_o_start;
extern char _binary_linux_locore_o_end;
extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
static int linux_copyout_strings(struct image_params *imgp,
uintptr_t *stack_base);
static int linux_fixup_elf(uintptr_t *stack_base,
struct image_params *iparams);
static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
static void linux_vdso_install(void *param);
static void linux_vdso_deinstall(void *param);
static void linux_set_syscall_retval(struct thread *td, int error);
static int linux_fetch_syscall_args(struct thread *td);
static void linux_exec_setregs(struct thread *td, struct image_params *imgp,
uintptr_t stack);
static int linux_vsyscall(struct thread *td);
#define LINUX_T_UNKNOWN 255
static int _bsd_to_linux_trapcode[] = {
LINUX_T_UNKNOWN, /* 0 */
6, /* 1 T_PRIVINFLT */
LINUX_T_UNKNOWN, /* 2 */
3, /* 3 T_BPTFLT */
LINUX_T_UNKNOWN, /* 4 */
LINUX_T_UNKNOWN, /* 5 */
16, /* 6 T_ARITHTRAP */
254, /* 7 T_ASTFLT */
LINUX_T_UNKNOWN, /* 8 */
13, /* 9 T_PROTFLT */
1, /* 10 T_TRCTRAP */
LINUX_T_UNKNOWN, /* 11 */
14, /* 12 T_PAGEFLT */
LINUX_T_UNKNOWN, /* 13 */
17, /* 14 T_ALIGNFLT */
LINUX_T_UNKNOWN, /* 15 */
LINUX_T_UNKNOWN, /* 16 */
LINUX_T_UNKNOWN, /* 17 */
0, /* 18 T_DIVIDE */
2, /* 19 T_NMI */
4, /* 20 T_OFLOW */
5, /* 21 T_BOUND */
7, /* 22 T_DNA */
8, /* 23 T_DOUBLEFLT */
9, /* 24 T_FPOPFLT */
10, /* 25 T_TSSFLT */
11, /* 26 T_SEGNPFLT */
12, /* 27 T_STKFLT */
18, /* 28 T_MCHK */
19, /* 29 T_XMMFLT */
15 /* 30 T_RESERVED */
};
#define bsd_to_linux_trapcode(code) \
((code)<nitems(_bsd_to_linux_trapcode)? \
_bsd_to_linux_trapcode[(code)]: \
LINUX_T_UNKNOWN)
LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
LINUX_VDSO_SYM_CHAR(linux_platform);
/*
* If FreeBSD & Linux have a difference of opinion about what a trap
* means, deal with it here.
*
* MPSAFE
*/
static int
linux_translate_traps(int signal, int trap_code)
{
if (signal != SIGBUS)
return (signal);
switch (trap_code) {
case T_PROTFLT:
case T_TSSFLT:
case T_DOUBLEFLT:
case T_PAGEFLT:
return (SIGSEGV);
default:
return (signal);
}
}
static int
linux_fetch_syscall_args(struct thread *td)
{
struct proc *p;
struct trapframe *frame;
struct syscall_args *sa;
p = td->td_proc;
frame = td->td_frame;
sa = &td->td_sa;
sa->args[0] = frame->tf_rdi;
sa->args[1] = frame->tf_rsi;
sa->args[2] = frame->tf_rdx;
sa->args[3] = frame->tf_rcx;
sa->args[4] = frame->tf_r8;
sa->args[5] = frame->tf_r9;
sa->code = frame->tf_rax;
if (sa->code >= p->p_sysent->sv_size)
/* nosys */
sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
else
sa->callp = &p->p_sysent->sv_table[sa->code];
td->td_retval[0] = 0;
return (0);
}
static void
linux_set_syscall_retval(struct thread *td, int error)
{
struct trapframe *frame;
frame = td->td_frame;
switch (error) {
case 0:
frame->tf_rax = td->td_retval[0];
frame->tf_r10 = frame->tf_rcx;
break;
case ERESTART:
/*
* Reconstruct pc, we know that 'syscall' is 2 bytes,
* lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
* We saved this in tf_err.
*
*/
frame->tf_rip -= frame->tf_err;
frame->tf_r10 = frame->tf_rcx;
break;
case EJUSTRETURN:
break;
default:
frame->tf_rax = bsd_to_linux_errno(error);
frame->tf_r10 = frame->tf_rcx;
break;
}
/*
* Differently from FreeBSD native ABI, on Linux only %rcx
* and %r11 values are not preserved across the syscall.
* Require full context restore to get all registers except
* those two restored at return to usermode.
*
* XXX: Would be great to be able to avoid PCB_FULL_IRET
* for the error == 0 case.
*/
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
}
static int
linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
{
Elf_Auxargs *args;
Elf_Auxinfo *argarray, *pos;
struct proc *p;
int error, issetugid;
p = imgp->proc;
args = (Elf64_Auxargs *)imgp->auxargs;
argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
issetugid = p->p_flag & P_SUGID ? 1 : 0;
AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
imgp->proc->p_sysent->sv_shared_page_base);
AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
AUXARGS_ENTRY(pos, AT_BASE, args->base);
AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0);
if (imgp->execpathp != 0)
AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
if (args->execfd != -1)
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
error = copyout(argarray, (void *)base,
sizeof(*argarray) * LINUX_AT_COUNT);
free(argarray, M_TEMP);
return (error);
}
static int
linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp)
{
Elf_Addr *base;
base = (Elf64_Addr *)*stack_base;
base--;
if (suword(base, (uint64_t)imgp->args->argc) == -1)
return (EFAULT);
*stack_base = (uintptr_t)base;
return (0);
}
/*
* Copy strings out to the new process address space, constructing new arg
* and env vector tables. Return a pointer to the base so that it can be used
* as the initial stack pointer.
*/
static int
linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
{
int argc, envc, error;
char **vectp;
char *stringp;
uintptr_t destp, ustringp;
struct ps_strings *arginfo;
char canary[LINUX_AT_RANDOM_LEN];
size_t execpath_len;
struct proc *p;
/* Calculate string base and vector table pointers. */
if (imgp->execpath != NULL && imgp->auxargs != NULL)
execpath_len = strlen(imgp->execpath) + 1;
else
execpath_len = 0;
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
destp = (uintptr_t)arginfo;
if (execpath_len != 0) {
destp -= execpath_len;
destp = rounddown2(destp, sizeof(void *));
imgp->execpathp = (void *)destp;
error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
if (error != 0)
return (error);
}
/* Prepare the canary for SSP. */
arc4rand(canary, sizeof(canary), 0);
destp -= roundup(sizeof(canary), sizeof(void *));
imgp->canary = (void *)destp;
error = copyout(canary, imgp->canary, sizeof(canary));
if (error != 0)
return (error);
/* Allocate room for the argument and environment strings. */
destp -= ARG_MAX - imgp->args->stringspace;
destp = rounddown2(destp, sizeof(void *));
ustringp = destp;
if (imgp->auxargs) {
/*
* Allocate room on the stack for the ELF auxargs
* array. It has LINUX_AT_COUNT entries.
*/
destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo);
destp = rounddown2(destp, sizeof(void *));
}
vectp = (char **)destp;
/*
* Allocate room for the argv[] and env vectors including the
* terminating NULL pointers.
*/
vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
/*
* Starting with 2.24, glibc depends on a 16-byte stack alignment.
* One "long argc" will be prepended later.
*/
vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8);
/* vectp also becomes our initial stack base. */
*stack_base = (uintptr_t)vectp;
stringp = imgp->args->begin_argv;
argc = imgp->args->argc;
envc = imgp->args->envc;
/* Copy out strings - arguments and environment. */
error = copyout(stringp, (void *)ustringp,
ARG_MAX - imgp->args->stringspace);
if (error != 0)
return (error);
/* Fill in "ps_strings" struct for ps, w, etc. */
if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
suword(&arginfo->ps_nargvstr, argc) != 0)
return (EFAULT);
/* Fill in argument portion of vector table. */
for (; argc > 0; --argc) {
if (suword(vectp++, ustringp) != 0)
return (EFAULT);
while (*stringp++ != 0)
ustringp++;
ustringp++;
}
/* A null vector table pointer separates the argp's from the envp's. */
if (suword(vectp++, 0) != 0)
return (EFAULT);
if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
suword(&arginfo->ps_nenvstr, envc) != 0)
return (EFAULT);
/* Fill in environment portion of vector table. */
for (; envc > 0; --envc) {
if (suword(vectp++, ustringp) != 0)
return (EFAULT);
while (*stringp++ != 0)
ustringp++;
ustringp++;
}
/* The end of the vector table is a null pointer. */
if (suword(vectp, 0) != 0)
return (EFAULT);
if (imgp->auxargs) {
vectp++;
error = imgp->sysent->sv_copyout_auxargs(imgp,
(uintptr_t)vectp);
if (error != 0)
return (error);
}
return (0);
}
/*
* Reset registers to default values on exec.
*/
static void
linux_exec_setregs(struct thread *td, struct image_params *imgp,
uintptr_t stack)
{
struct trapframe *regs;
struct pcb *pcb;
register_t saved_rflags;
regs = td->td_frame;
pcb = td->td_pcb;
if (td->td_proc->p_md.md_ldt != NULL)
user_ldt_free(td);
pcb->pcb_fsbase = 0;
pcb->pcb_gsbase = 0;
clear_pcb_flags(pcb, PCB_32BIT);
pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
set_pcb_flags(pcb, PCB_FULL_IRET);
saved_rflags = regs->tf_rflags & PSL_T;
bzero((char *)regs, sizeof(struct trapframe));
regs->tf_rip = imgp->entry_addr;
regs->tf_rsp = stack;
regs->tf_rflags = PSL_USER | saved_rflags;
regs->tf_ss = _udatasel;
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
x86_clear_dbregs(pcb);
/*
* Drop the FP state if we hold it, so that the process gets a
* clean FP state if it uses the FPU again.
*/
fpstate_drop(td);
}
/*
* Copied from amd64/amd64/machdep.c
*
* XXX fpu state need? don't think so
*/
int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
struct proc *p;
struct l_ucontext uc;
struct l_sigcontext *context;
struct trapframe *regs;
unsigned long rflags;
int error;
ksiginfo_t ksi;
regs = td->td_frame;
error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
if (error != 0)
return (error);
p = td->td_proc;
context = &uc.uc_mcontext;
rflags = context->sc_rflags;
/*
* Don't allow users to change privileged or reserved flags.
*/
/*
* XXX do allow users to change the privileged flag PSL_RF.
* The cpu sets PSL_RF in tf_rflags for faults. Debuggers
* should sometimes set it there too. tf_rflags is kept in
* the signal context during signal handling and there is no
* other place to remember it, so the PSL_RF bit may be
* corrupted by the signal handler without us knowing.
* Corruption of the PSL_RF bit at worst causes one more or
* one less debugger trap, so allowing it is fairly harmless.
*/
#define RFLAG_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags);
return (EINVAL);
}
/*
* Don't allow users to load a valid privileged %cs. Let the
* hardware check for invalid selectors, excess privilege in
* other selectors, invalid %eip's and invalid %esp's.
*/
#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
if (!CS_SECURE(context->sc_cs)) {
printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_OBJERR;
ksi.ksi_trapno = T_PROTFLT;
ksi.ksi_addr = (void *)regs->tf_rip;
trapsignal(td, &ksi);
return (EINVAL);
}
PROC_LOCK(p);
linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask);
SIG_CANTMASK(td->td_sigmask);
signotify(td);
PROC_UNLOCK(p);
regs->tf_rdi = context->sc_rdi;
regs->tf_rsi = context->sc_rsi;
regs->tf_rdx = context->sc_rdx;
regs->tf_rbp = context->sc_rbp;
regs->tf_rbx = context->sc_rbx;
regs->tf_rcx = context->sc_rcx;
regs->tf_rax = context->sc_rax;
regs->tf_rip = context->sc_rip;
regs->tf_rsp = context->sc_rsp;
regs->tf_r8 = context->sc_r8;
regs->tf_r9 = context->sc_r9;
regs->tf_r10 = context->sc_r10;
regs->tf_r11 = context->sc_r11;
regs->tf_r12 = context->sc_r12;
regs->tf_r13 = context->sc_r13;
regs->tf_r14 = context->sc_r14;
regs->tf_r15 = context->sc_r15;
regs->tf_cs = context->sc_cs;
regs->tf_err = context->sc_err;
regs->tf_rflags = rflags;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
/*
* copied from amd64/amd64/machdep.c
*
* Send an interrupt to process.
*/
static void
linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct l_rt_sigframe sf, *sfp;
struct proc *p;
struct thread *td;
struct sigacts *psp;
caddr_t sp;
struct trapframe *regs;
int sig, code;
int oonstack;
td = curthread;
p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
sig = ksi->ksi_signo;
psp = p->p_sigacts;
code = ksi->ksi_code;
mtx_assert(&psp->ps_mtx, MA_OWNED);
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u",
catcher, sig, mask, code);
/* Allocate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size -
sizeof(struct l_rt_sigframe);
} else
sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128;
/* Align to 16 bytes. */
sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul);
mtx_unlock(&psp->ps_mtx);
/* Translate the signal. */
sig = bsd_to_linux_signal(sig);
/* Save user context. */
bzero(&sf, sizeof(sf));
bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask);
bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask);
sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
PROC_UNLOCK(p);
sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi;
sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi;
sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx;
sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp;
sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx;
sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx;
sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax;
sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip;
sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp;
sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8;
sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9;
sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10;
sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11;
sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12;
sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13;
sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14;
sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15;
sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags;
sf.sf_sc.uc_mcontext.sc_err = regs->tf_err;
sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr;
/* Build the argument list for the signal handler. */
regs->tf_rdi = sig; /* arg 1 in %rdi */
regs->tf_rax = 0;
regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */
sf.sf_handler = catcher;
/* Fill in POSIX parts. */
ksiginfo_to_lsiginfo(ksi, &sf.sf_si, sig);
/* Copy the sigframe out to the user's stack. */
if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
PROC_LOCK(p);
sigexit(td, SIGILL);
}
regs->tf_rsp = (long)sfp;
regs->tf_rip = linux_rt_sigcode;
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucodesel;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
#define LINUX_VSYSCALL_START (-10UL << 20)
#define LINUX_VSYSCALL_SZ 1024
const unsigned long linux_vsyscall_vector[] = {
LINUX_SYS_gettimeofday,
LINUX_SYS_linux_time,
LINUX_SYS_linux_getcpu,
};
static int
linux_vsyscall(struct thread *td)
{
struct trapframe *frame;
uint64_t retqaddr;
int code, traced;
int error;
frame = td->td_frame;
/* Check %rip for vsyscall area. */
if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START))
return (EINVAL);
if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0)
return (EINVAL);
code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ;
if (code >= nitems(linux_vsyscall_vector))
return (EINVAL);
/*
* vsyscall called as callq *(%rax), so we must
* use return address from %rsp and also fixup %rsp.
*/
error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr));
if (error)
return (error);
frame->tf_rip = retqaddr;
frame->tf_rax = linux_vsyscall_vector[code];
frame->tf_rsp += 8;
traced = (frame->tf_flags & PSL_T);
amd64_syscall(td, traced);
return (0);
}
struct sysentvec elf_linux_sysvec = {
.sv_size = LINUX_SYS_MAXSYSCALL,
.sv_table = linux_sysent,
.sv_transtrap = linux_translate_traps,
.sv_fixup = linux_fixup_elf,
.sv_sendsig = linux_rt_sendsig,
.sv_sigcode = &_binary_linux_locore_o_start,
.sv_szsigcode = &linux_szsigcode,
.sv_name = "Linux ELF64",
.sv_coredump = elf64_coredump,
.sv_imgact_try = linux_exec_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_minuser = VM_MIN_ADDRESS,
.sv_maxuser = VM_MAXUSER_ADDRESS_LA48,
.sv_usrstack = USRSTACK_LA48,
.sv_psstrings = PS_STRINGS_LA48,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_auxargs = linux_copyout_auxargs,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP,
.sv_set_syscall_retval = linux_set_syscall_retval,
.sv_fetch_syscall_args = linux_fetch_syscall_args,
.sv_syscallnames = NULL,
.sv_shared_page_base = SHAREDPAGE_LA48,
.sv_shared_page_len = PAGE_SIZE,
.sv_schedtail = linux_schedtail,
.sv_thread_detach = linux_thread_detach,
.sv_trap = linux_vsyscall,
.sv_onexec = linux_on_exec,
.sv_onexit = linux_on_exit,
.sv_ontdexit = linux_thread_dtor,
};
static void
linux_vdso_install(void *param)
{
amd64_lower_shared_page(&elf_linux_sysvec);
linux_szsigcode = (&_binary_linux_locore_o_end -
&_binary_linux_locore_o_start);
if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
panic("Linux invalid vdso size\n");
__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
linux_shared_page_obj = __elfN(linux_shared_page_init)
(&linux_shared_page_mapping);
__elfN(linux_vdso_reloc)(&elf_linux_sysvec);
bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
linux_szsigcode);
elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
linux_kplatform = linux_shared_page_mapping +
(linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
}
SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
linux_vdso_install, NULL);
static void
linux_vdso_deinstall(void *param)
{
__elfN(linux_shared_page_fini)(linux_shared_page_obj,
linux_shared_page_mapping);
}
SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
linux_vdso_deinstall, NULL);
static char GNULINUX_ABI_VENDOR[] = "GNU";
static int GNULINUX_ABI_DESC = 0;
static bool
linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
{
const Elf32_Word *desc;
uintptr_t p;
p = (uintptr_t)(note + 1);
p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
desc = (const Elf32_Word *)p;
if (desc[0] != GNULINUX_ABI_DESC)
return (false);
/*
* For Linux we encode osrel using the Linux convention of
* (version << 16) | (major << 8) | (minor)
* See macro in linux_mib.h
*/
*osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
return (true);
}
static Elf_Brandnote linux64_brandnote = {
.hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR),
.hdr.n_descsz = 16,
.hdr.n_type = 1,
.vendor = GNULINUX_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = linux_trans_osrel
};
static Elf64_Brandinfo linux_glibc2brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_X86_64,
.compat_3_brand = "Linux",
.emul_path = linux_emul_path,
.interp_path = "/lib64/ld-linux-x86-64.so.2",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux64_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
static Elf64_Brandinfo linux_glibc2brandshort = {
.brand = ELFOSABI_LINUX,
.machine = EM_X86_64,
.compat_3_brand = "Linux",
.emul_path = linux_emul_path,
.interp_path = "/lib64/ld-linux.so.2",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux64_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
static Elf64_Brandinfo linux_muslbrand = {
.brand = ELFOSABI_LINUX,
.machine = EM_X86_64,
.compat_3_brand = "Linux",
.emul_path = linux_emul_path,
.interp_path = "/lib/ld-musl-x86_64.so.1",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux64_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
Elf64_Brandinfo *linux_brandlist[] = {
&linux_glibc2brand,
&linux_glibc2brandshort,
&linux_muslbrand,
NULL
};
static int
linux64_elf_modevent(module_t mod, int type, void *data)
{
Elf64_Brandinfo **brandinfo;
int error;
struct linux_ioctl_handler **lihp;
error = 0;
switch(type) {
case MOD_LOAD:
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf64_insert_brand_entry(*brandinfo) < 0)
error = EINVAL;
if (error == 0) {
SET_FOREACH(lihp, linux_ioctl_handler_set)
linux_ioctl_register_handler(*lihp);
stclohz = (stathz ? stathz : hz);
if (bootverbose)
printf("Linux x86-64 ELF exec handler installed\n");
} else
printf("cannot insert Linux x86-64 ELF brand handler\n");
break;
case MOD_UNLOAD:
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf64_brand_inuse(*brandinfo))
error = EBUSY;
if (error == 0) {
for (brandinfo = &linux_brandlist[0];
*brandinfo != NULL; ++brandinfo)
if (elf64_remove_brand_entry(*brandinfo) < 0)
error = EINVAL;
}
if (error == 0) {
SET_FOREACH(lihp, linux_ioctl_handler_set)
linux_ioctl_unregister_handler(*lihp);
if (bootverbose)
printf("Linux ELF exec handler removed\n");
} else
printf("Could not deinstall ELF interpreter entry\n");
break;
default:
return (EOPNOTSUPP);
}
return (error);
}
static moduledata_t linux64_elf_mod = {
"linux64elf",
linux64_elf_modevent,
0
};
DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1);
FEATURE(linux64, "Linux 64bit support");
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