freebsd-dev/sys/arm64/linux/linux_sysvec.c
Brooks Davis b24e6ac8b7 Convert canary, execpathp, and pagesizes to pointers.
Use AUXARGS_ENTRY_PTR to export these pointers.  This is a followup to
r359987 and r359988.

Reviewed by:	jhb
Obtained from:	CheriBSD
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D24446
2020-04-16 21:53:17 +00:00

567 lines
16 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1994-1996 Søren Schmidt
* Copyright (c) 2018 Turing Robotic Industries Inc.
*
* 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.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cdefs.h>
#include <sys/elf.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <vm/vm_param.h>
#include <arm64/linux/linux.h>
#include <arm64/linux/linux_proto.h>
#include <compat/linux/linux_dtrace.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_util.h>
#include <compat/linux/linux_vdso.h>
MODULE_VERSION(linux64elf, 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_elf_fixup(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(const void *param);
static void linux_vdso_deinstall(const 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);
/* DTrace init */
LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
/* DTrace probes */
LIN_SDT_PROBE_DEFINE2(sysvec, linux_translate_traps, todo, "int", "int");
LIN_SDT_PROBE_DEFINE0(sysvec, linux_exec_setregs, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_copyout_auxargs, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_elf_fixup, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sigreturn, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sendsig, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_vsyscall, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_vdso_install, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_vdso_deinstall, todo);
/* LINUXTODO: do we have traps to translate? */
static int
linux_translate_traps(int signal, int trap_code)
{
LIN_SDT_PROBE2(sysvec, linux_translate_traps, todo, signal, trap_code);
return (signal);
}
LINUX_VDSO_SYM_CHAR(linux_platform);
static int
linux_fetch_syscall_args(struct thread *td)
{
struct proc *p;
struct syscall_args *sa;
register_t *ap;
p = td->td_proc;
ap = td->td_frame->tf_x;
sa = &td->td_sa;
sa->code = td->td_frame->tf_x[8];
/* LINUXTODO: generic syscall? */
if (sa->code >= p->p_sysent->sv_size)
sa->callp = &p->p_sysent->sv_table[0];
else
sa->callp = &p->p_sysent->sv_table[sa->code];
sa->narg = sa->callp->sy_narg;
if (sa->narg > 8)
panic("ARM64TODO: Could we have more than 8 args?");
memcpy(sa->args, ap, 8 * sizeof(register_t));
td->td_retval[0] = 0;
return (0);
}
static void
linux_set_syscall_retval(struct thread *td, int error)
{
td->td_retval[1] = td->td_frame->tf_x[1];
cpu_set_syscall_retval(td, error);
}
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;
LIN_SDT_PROBE0(sysvec, linux_copyout_auxargs, todo);
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);
#if 0 /* LINUXTODO: implement arm64 LINUX_AT_HWCAP */
AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
#endif
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_PAGESZ, args->pagesz);
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);
#if 0 /* LINUXTODO: implement arm64 LINUX_AT_PLATFORM */
AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
#endif
AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
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, 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_elf_fixup(uintptr_t *stack_base, struct image_params *imgp)
{
LIN_SDT_PROBE0(sysvec, linux_elf_fixup, todo);
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.
* LINUXTODO: deduplicate against other linuxulator archs
*/
static int
linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
{
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;
int argc, envc, error;
/* 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 up to LINUX_AT_COUNT entries.
*/
destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo);
destp = rounddown2(destp, sizeof(void *));
}
vectp = (char **)destp;
/*
* Allocate room for argc and the argv[] and env vectors including the
* terminating NULL pointers.
*/
vectp -= 1 + imgp->args->argc + 1 + imgp->args->envc + 1;
vectp = (char **)STACKALIGN(vectp);
/* 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);
if (suword(vectp++, 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 = td->td_frame;
/* LINUXTODO: validate */
LIN_SDT_PROBE0(sysvec, linux_exec_setregs, todo);
memset(regs, 0, sizeof(*regs));
/* glibc start.S registers function pointer in x0 with atexit. */
regs->tf_sp = stack;
#if 0 /* LINUXTODO: See if this is used. */
regs->tf_lr = imgp->entry_addr;
#else
regs->tf_lr = 0xffffffffffffffff;
#endif
regs->tf_elr = imgp->entry_addr;
}
int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
/* LINUXTODO: implement */
LIN_SDT_PROBE0(sysvec, linux_rt_sigreturn, todo);
return (EDOOFUS);
}
static void
linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
/* LINUXTODO: implement */
LIN_SDT_PROBE0(sysvec, linux_rt_sendsig, todo);
}
static int
linux_vsyscall(struct thread *td)
{
/* LINUXTODO: implement */
LIN_SDT_PROBE0(sysvec, linux_vsyscall, todo);
return (EDOOFUS);
}
struct sysentvec elf_linux_sysvec = {
.sv_size = LINUX_SYS_MAXSYSCALL,
.sv_table = linux_sysent,
.sv_errsize = ELAST + 1,
.sv_errtbl = linux_errtbl,
.sv_transtrap = linux_translate_traps,
.sv_fixup = linux_elf_fixup,
.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,
.sv_usrstack = USRSTACK,
.sv_psstrings = PS_STRINGS, /* XXX */
.sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
.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,
.sv_shared_page_len = PAGE_SIZE,
.sv_schedtail = linux_schedtail,
.sv_thread_detach = linux_thread_detach,
.sv_trap = linux_vsyscall,
};
static void
linux_vdso_install(const void *param)
{
linux_szsigcode = (&_binary_linux_locore_o_end -
&_binary_linux_locore_o_start);
if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
panic("invalid Linux 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);
memcpy(linux_shared_page_mapping, elf_linux_sysvec.sv_sigcode,
linux_szsigcode);
elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
printf("LINUXTODO: %s: fix linux_kplatform\n", __func__);
#if 0
linux_kplatform = linux_shared_page_mapping +
(linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
#else
linux_kplatform = "arm64";
#endif
}
SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
linux_vdso_install, NULL);
static void
linux_vdso_deinstall(const void *param)
{
LIN_SDT_PROBE0(sysvec, linux_vdso_deinstall, todo);
__elfN(linux_shared_page_fini)(linux_shared_page_obj);
}
SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
linux_vdso_deinstall, NULL);
static char GNU_ABI_VENDOR[] = "GNU";
static int GNU_ABI_LINUX = 0;
/* LINUXTODO: deduplicate */
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] != GNU_ABI_LINUX)
return (false);
*osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
return (true);
}
static Elf_Brandnote linux64_brandnote = {
.hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
.hdr.n_descsz = 16,
.hdr.n_type = 1,
.vendor = GNU_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = linux_trans_osrel
};
static Elf64_Brandinfo linux_glibc2brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_AARCH64,
.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
};
Elf64_Brandinfo *linux_brandlist[] = {
&linux_glibc2brand,
NULL
};
static int
linux64_elf_modevent(module_t mod, int type, void *data)
{
Elf64_Brandinfo **brandinfo;
struct linux_ioctl_handler**lihp;
int error;
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 arm64 ELF exec handler installed\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, "AArch64 Linux 64bit support");