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linux32_sysvec.c
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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("$FreeBSD$");
#ifndef COMPAT_FREEBSD32
#error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
#endif
#define __ELF_WORD_SIZE 32
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/stddef.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <vm/pmap.h>
#include <vm/vm.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/specialreg.h>
#include <machine/trap.h>
#include <x86/linux/linux_x86.h>
#include <amd64/linux32/linux.h>
#include <amd64/linux32/linux32_proto.h>
#include <compat/linux/linux_elf.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_fork.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_util.h>
#include <compat/linux/linux_vdso.h>
#include <x86/linux/linux_x86_sigframe.h>
MODULE_VERSION(linux, 1);
#define LINUX32_MAXUSER ((1ul << 32) - PAGE_SIZE)
#define LINUX32_VDSOPAGE_SIZE PAGE_SIZE * 2
#define LINUX32_VDSOPAGE (LINUX32_MAXUSER - LINUX32_VDSOPAGE_SIZE)
#define LINUX32_SHAREDPAGE (LINUX32_VDSOPAGE - PAGE_SIZE)
/*
* PAGE_SIZE - the size
* of the native SHAREDPAGE
*/
#define LINUX32_USRSTACK LINUX32_SHAREDPAGE
static int linux_szsigcode;
static vm_object_t linux_vdso_obj;
static char *linux_vdso_mapping;
extern char _binary_linux32_vdso_so_o_start;
extern char _binary_linux32_vdso_so_o_end;
static vm_offset_t linux_vdso_base;
extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL];
extern const char *linux32_syscallnames[];
SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
static int linux_copyout_strings(struct image_params *imgp,
uintptr_t *stack_base);
static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
static void linux_exec_setregs(struct thread *td,
struct image_params *imgp, uintptr_t stack);
static void linux_exec_sysvec_init(void *param);
static int linux_on_exec_vmspace(struct proc *p,
struct image_params *imgp);
static void linux32_fixlimit(struct rlimit *rl, int which);
static void linux_vdso_install(const void *param);
static void linux_vdso_deinstall(const void *param);
static void linux_vdso_reloc(char *mapping, Elf_Addr offset);
static void linux32_set_fork_retval(struct thread *td);
static void linux32_set_syscall_retval(struct thread *td, int error);
struct linux32_ps_strings {
u_int32_t ps_argvstr; /* first of 0 or more argument strings */
u_int ps_nargvstr; /* the number of argument strings */
u_int32_t ps_envstr; /* first of 0 or more environment strings */
u_int ps_nenvstr; /* the number of environment strings */
};
#define LINUX32_PS_STRINGS (LINUX32_USRSTACK - \
sizeof(struct linux32_ps_strings))
LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall);
LINUX_VDSO_SYM_INTPTR(linux32_vdso_sigcode);
LINUX_VDSO_SYM_INTPTR(linux32_vdso_rt_sigcode);
LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
LINUX_VDSO_SYM_CHAR(linux_platform);
void
linux32_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos)
{
AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO, __kernel_vsyscall);
AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base);
AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature);
AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, 0);
AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform));
}
static void
linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
struct sigacts *psp;
struct trapframe *regs;
struct l_rt_sigframe *fp, frame;
int oonstack;
int sig;
int code;
sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno);
code = ksi->ksi_code;
PROC_LOCK_ASSERT(p, MA_OWNED);
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
/* Allocate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
} else
fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
mtx_unlock(&psp->ps_mtx);
/* Build the argument list for the signal handler. */
sig = bsd_to_linux_signal(sig);
bzero(&frame, sizeof(frame));
frame.sf_sig = sig;
frame.sf_siginfo = PTROUT(&fp->sf_si);
frame.sf_ucontext = PTROUT(&fp->sf_uc);
/* Fill in POSIX parts. */
siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig);
/*
* Build the signal context to be used by sigreturn and libgcc unwind.
*/
frame.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
PROC_UNLOCK(p);
bsd_to_linux_sigset(mask, &frame.sf_uc.uc_sigmask);
frame.sf_uc.uc_mcontext.sc_mask = frame.sf_uc.uc_sigmask.__mask;
frame.sf_uc.uc_mcontext.sc_edi = regs->tf_rdi;
frame.sf_uc.uc_mcontext.sc_esi = regs->tf_rsi;
frame.sf_uc.uc_mcontext.sc_ebp = regs->tf_rbp;
frame.sf_uc.uc_mcontext.sc_ebx = regs->tf_rbx;
frame.sf_uc.uc_mcontext.sc_esp = regs->tf_rsp;
frame.sf_uc.uc_mcontext.sc_edx = regs->tf_rdx;
frame.sf_uc.uc_mcontext.sc_ecx = regs->tf_rcx;
frame.sf_uc.uc_mcontext.sc_eax = regs->tf_rax;
frame.sf_uc.uc_mcontext.sc_eip = regs->tf_rip;
frame.sf_uc.uc_mcontext.sc_cs = regs->tf_cs;
frame.sf_uc.uc_mcontext.sc_gs = regs->tf_gs;
frame.sf_uc.uc_mcontext.sc_fs = regs->tf_fs;
frame.sf_uc.uc_mcontext.sc_es = regs->tf_es;
frame.sf_uc.uc_mcontext.sc_ds = regs->tf_ds;
frame.sf_uc.uc_mcontext.sc_eflags = regs->tf_rflags;
frame.sf_uc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
frame.sf_uc.uc_mcontext.sc_ss = regs->tf_ss;
frame.sf_uc.uc_mcontext.sc_err = regs->tf_err;
frame.sf_uc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
frame.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
PROC_LOCK(p);
sigexit(td, SIGILL);
}
/* Build context to run handler in. */
regs->tf_rsp = PTROUT(fp);
regs->tf_rip = linux32_vdso_rt_sigcode;
regs->tf_rdi = PTROUT(catcher);
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
/*
* Send an interrupt to process.
*
* Stack is set up to allow sigcode stored
* in u. to call routine, followed by kcall
* to sigreturn routine below. After sigreturn
* resets the signal mask, the stack, and the
* frame pointer, it returns to the user
* specified pc, psl.
*/
static void
linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
struct sigacts *psp;
struct trapframe *regs;
struct l_sigframe *fp, frame;
l_sigset_t lmask;
int oonstack;
int sig, code;
sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno);
code = ksi->ksi_code;
PROC_LOCK_ASSERT(p, MA_OWNED);
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
if (SIGISMEMBER(psp->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
linux_rt_sendsig(catcher, ksi, mask);
return;
}
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
/* Allocate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(struct l_sigframe));
} else
fp = (struct l_sigframe *)regs->tf_rsp - 1;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(p);
/* Build the argument list for the signal handler. */
sig = bsd_to_linux_signal(sig);
bzero(&frame, sizeof(frame));
frame.sf_sig = sig;
frame.sf_sigmask = *mask;
bsd_to_linux_sigset(mask, &lmask);
/* Build the signal context to be used by sigreturn. */
frame.sf_sc.sc_mask = lmask.__mask;
frame.sf_sc.sc_gs = regs->tf_gs;
frame.sf_sc.sc_fs = regs->tf_fs;
frame.sf_sc.sc_es = regs->tf_es;
frame.sf_sc.sc_ds = regs->tf_ds;
frame.sf_sc.sc_edi = regs->tf_rdi;
frame.sf_sc.sc_esi = regs->tf_rsi;
frame.sf_sc.sc_ebp = regs->tf_rbp;
frame.sf_sc.sc_ebx = regs->tf_rbx;
frame.sf_sc.sc_esp = regs->tf_rsp;
frame.sf_sc.sc_edx = regs->tf_rdx;
frame.sf_sc.sc_ecx = regs->tf_rcx;
frame.sf_sc.sc_eax = regs->tf_rax;
frame.sf_sc.sc_eip = regs->tf_rip;
frame.sf_sc.sc_cs = regs->tf_cs;
frame.sf_sc.sc_eflags = regs->tf_rflags;
frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
frame.sf_sc.sc_ss = regs->tf_ss;
frame.sf_sc.sc_err = regs->tf_err;
frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
PROC_LOCK(p);
sigexit(td, SIGILL);
}
/* Build context to run handler in. */
regs->tf_rsp = PTROUT(fp);
regs->tf_rip = linux32_vdso_sigcode;
regs->tf_rdi = PTROUT(catcher);
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
/*
* System call to cleanup state after a signal
* has been taken. Reset signal mask and
* stack state from context left by sendsig (above).
* Return to previous pc and psl as specified by
* context left by sendsig. Check carefully to
* make sure that the user has not modified the
* psl to gain improper privileges or to cause
* a machine fault.
*/
int
linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
{
struct l_sigframe frame;
struct trapframe *regs;
int eflags;
ksiginfo_t ksi;
regs = td->td_frame;
/*
* The trampoline code hands us the sigframe.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
return (EFAULT);
/* Check for security violations. */
eflags = frame.sf_sc.sc_eflags;
if (!EFL_SECURE(eflags, regs->tf_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.
*/
if (!CS_SECURE(frame.sf_sc.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);
}
kern_sigprocmask(td, SIG_SETMASK, &frame.sf_sigmask, NULL, 0);
/* Restore signal context. */
regs->tf_rdi = frame.sf_sc.sc_edi;
regs->tf_rsi = frame.sf_sc.sc_esi;
regs->tf_rbp = frame.sf_sc.sc_ebp;
regs->tf_rbx = frame.sf_sc.sc_ebx;
regs->tf_rdx = frame.sf_sc.sc_edx;
regs->tf_rcx = frame.sf_sc.sc_ecx;
regs->tf_rax = frame.sf_sc.sc_eax;
regs->tf_rip = frame.sf_sc.sc_eip;
regs->tf_cs = frame.sf_sc.sc_cs;
regs->tf_ds = frame.sf_sc.sc_ds;
regs->tf_es = frame.sf_sc.sc_es;
regs->tf_fs = frame.sf_sc.sc_fs;
regs->tf_gs = frame.sf_sc.sc_gs;
regs->tf_rflags = eflags;
regs->tf_rsp = frame.sf_sc.sc_esp_at_signal;
regs->tf_ss = frame.sf_sc.sc_ss;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
/*
* System call to cleanup state after a signal
* has been taken. Reset signal mask and
* stack state from context left by rt_sendsig (above).
* Return to previous pc and psl as specified by
* context left by sendsig. Check carefully to
* make sure that the user has not modified the
* psl to gain improper privileges or to cause
* a machine fault.
*/
int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
struct l_ucontext uc;
struct l_sigcontext *context;
sigset_t bmask;
l_stack_t *lss;
stack_t ss;
struct trapframe *regs;
int eflags;
ksiginfo_t ksi;
regs = td->td_frame;
/*
* The trampoline code hands us the ucontext.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
return (EFAULT);
context = &uc.uc_mcontext;
/* Check for security violations. */
eflags = context->sc_eflags;
if (!EFL_SECURE(eflags, regs->tf_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.
*/
if (!CS_SECURE(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);
}
linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
/*
* Restore signal context
*/
regs->tf_gs = context->sc_gs;
regs->tf_fs = context->sc_fs;
regs->tf_es = context->sc_es;
regs->tf_ds = context->sc_ds;
regs->tf_rdi = context->sc_edi;
regs->tf_rsi = context->sc_esi;
regs->tf_rbp = context->sc_ebp;
regs->tf_rbx = context->sc_ebx;
regs->tf_rdx = context->sc_edx;
regs->tf_rcx = context->sc_ecx;
regs->tf_rax = context->sc_eax;
regs->tf_rip = context->sc_eip;
regs->tf_cs = context->sc_cs;
regs->tf_rflags = eflags;
regs->tf_rsp = context->sc_esp_at_signal;
regs->tf_ss = context->sc_ss;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
/*
* call sigaltstack & ignore results..
*/
lss = &uc.uc_stack;
ss.ss_sp = PTRIN(lss->ss_sp);
ss.ss_size = lss->ss_size;
ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
(void)kern_sigaltstack(td, &ss, NULL);
return (EJUSTRETURN);
}
static int
linux32_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_rbx;
sa->args[1] = frame->tf_rcx;
sa->args[2] = frame->tf_rdx;
sa->args[3] = frame->tf_rsi;
sa->args[4] = frame->tf_rdi;
sa->args[5] = frame->tf_rbp; /* Unconfirmed */
sa->code = frame->tf_rax;
sa->original_code = sa->code;
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;
td->td_retval[1] = frame->tf_rdx;
return (0);
}
static void
linux32_set_syscall_retval(struct thread *td, int error)
{
struct trapframe *frame = td->td_frame;
cpu_set_syscall_retval(td, error);
if (__predict_false(error != 0)) {
if (error != ERESTART && error != EJUSTRETURN)
frame->tf_rax = bsd_to_linux_errno(error);
}
}
static void
linux32_set_fork_retval(struct thread *td)
{
struct trapframe *frame = td->td_frame;
frame->tf_rax = 0;
}
/*
* Clear registers on exec
* XXX copied from ia32_signal.c.
*/
static void
linux_exec_setregs(struct thread *td, struct image_params *imgp,
uintptr_t stack)
{
struct trapframe *regs = td->td_frame;
struct pcb *pcb = td->td_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);
critical_enter();
wrmsr(MSR_FSBASE, 0);
wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */
pcb->pcb_fsbase = 0;
pcb->pcb_gsbase = 0;
critical_exit();
pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
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_gs = _ugssel;
regs->tf_fs = _ufssel;
regs->tf_es = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_ss = _udatasel;
regs->tf_flags = TF_HASSEGS;
regs->tf_cs = _ucode32sel;
regs->tf_rbx = (register_t)imgp->ps_strings;
x86_clear_dbregs(pcb);
fpstate_drop(td);
/* Do full restore on return so that we can change to a different %cs */
set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
}
/*
* XXX copied from ia32_sysvec.c.
*/
static int
linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
{
int argc, envc, error;
u_int32_t *vectp;
char *stringp;
uintptr_t destp, ustringp;
struct linux32_ps_strings *arginfo;
char canary[LINUX_AT_RANDOM_LEN];
size_t execpath_len;
arginfo = (struct linux32_ps_strings *)PROC_PS_STRINGS(imgp->proc);
destp = (uintptr_t)arginfo;
if (imgp->execpath != NULL && imgp->auxargs != NULL) {
execpath_len = strlen(imgp->execpath) + 1;
destp -= execpath_len;
destp = rounddown2(destp, sizeof(uint32_t));
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(uint32_t));
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(uint32_t));
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(Elf32_Auxinfo);
destp = rounddown2(destp, sizeof(uint32_t));
}
vectp = (uint32_t *)destp;
/*
* Allocate room for the argv[] and env vectors including the
* terminating NULL pointers.
*/
vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
/* 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 (suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp) != 0 ||
suword32(&arginfo->ps_nargvstr, argc) != 0)
return (EFAULT);
/* Fill in argument portion of vector table. */
for (; argc > 0; --argc) {
if (suword32(vectp++, ustringp) != 0)
return (EFAULT);
while (*stringp++ != 0)
ustringp++;
ustringp++;
}
/* A null vector table pointer separates the argp's from the envp's. */
if (suword32(vectp++, 0) != 0)
return (EFAULT);
if (suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp) != 0 ||
suword32(&arginfo->ps_nenvstr, envc) != 0)
return (EFAULT);
/* Fill in environment portion of vector table. */
for (; envc > 0; --envc) {
if (suword32(vectp++, ustringp) != 0)
return (EFAULT);
while (*stringp++ != 0)
ustringp++;
ustringp++;
}
/* The end of the vector table is a null pointer. */
if (suword32(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);
}
static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"32-bit Linux emulation");
static u_long linux32_maxdsiz = LINUX32_MAXDSIZ;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
&linux32_maxdsiz, 0, "");
static u_long linux32_maxssiz = LINUX32_MAXSSIZ;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
&linux32_maxssiz, 0, "");
static u_long linux32_maxvmem = LINUX32_MAXVMEM;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
&linux32_maxvmem, 0, "");
bool linux32_emulate_i386 = false;
SYSCTL_BOOL(_compat_linux32, OID_AUTO, emulate_i386, CTLFLAG_RWTUN,
&linux32_emulate_i386, 0, "Emulate the real i386");
static void
linux32_fixlimit(struct rlimit *rl, int which)
{
switch (which) {
case RLIMIT_DATA:
if (linux32_maxdsiz != 0) {
if (rl->rlim_cur > linux32_maxdsiz)
rl->rlim_cur = linux32_maxdsiz;
if (rl->rlim_max > linux32_maxdsiz)
rl->rlim_max = linux32_maxdsiz;
}
break;
case RLIMIT_STACK:
if (linux32_maxssiz != 0) {
if (rl->rlim_cur > linux32_maxssiz)
rl->rlim_cur = linux32_maxssiz;
if (rl->rlim_max > linux32_maxssiz)
rl->rlim_max = linux32_maxssiz;
}
break;
case RLIMIT_VMEM:
if (linux32_maxvmem != 0) {
if (rl->rlim_cur > linux32_maxvmem)
rl->rlim_cur = linux32_maxvmem;
if (rl->rlim_max > linux32_maxvmem)
rl->rlim_max = linux32_maxvmem;
}
break;
}
}
struct sysentvec elf_linux_sysvec = {
.sv_size = LINUX32_SYS_MAXSYSCALL,
.sv_table = linux32_sysent,
.sv_fixup = elf32_freebsd_fixup,
.sv_sendsig = linux_sendsig,
.sv_sigcode = &_binary_linux32_vdso_so_o_start,
.sv_szsigcode = &linux_szsigcode,
.sv_name = "Linux ELF32",
.sv_coredump = elf32_coredump,
.sv_elf_core_osabi = ELFOSABI_NONE,
.sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
.sv_elf_core_prepare_notes = linux32_prepare_notes,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_minuser = VM_MIN_ADDRESS,
.sv_maxuser = LINUX32_MAXUSER,
.sv_usrstack = LINUX32_USRSTACK,
.sv_psstrings = LINUX32_PS_STRINGS,
.sv_psstringssz = sizeof(struct linux32_ps_strings),
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_auxargs = __linuxN(copyout_auxargs),
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = linux32_fixlimit,
.sv_maxssiz = &linux32_maxssiz,
.sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP |
SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP,
.sv_set_syscall_retval = linux32_set_syscall_retval,
.sv_fetch_syscall_args = linux32_fetch_syscall_args,
.sv_syscallnames = linux32_syscallnames,
.sv_shared_page_base = LINUX32_SHAREDPAGE,
.sv_shared_page_len = PAGE_SIZE,
.sv_schedtail = linux_schedtail,
.sv_thread_detach = linux_thread_detach,
.sv_trap = NULL,
.sv_hwcap = NULL,
.sv_hwcap2 = NULL,
.sv_onexec = linux_on_exec_vmspace,
.sv_onexit = linux_on_exit,
.sv_ontdexit = linux_thread_dtor,
.sv_setid_allowed = &linux_setid_allowed_query,
.sv_set_fork_retval = linux32_set_fork_retval,
};
static int
linux_on_exec_vmspace(struct proc *p, struct image_params *imgp)
{
int error;
error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base,
LINUX32_VDSOPAGE_SIZE, imgp);
if (error == 0)
error = linux_on_exec(p, imgp);
return (error);
}
/*
* linux_vdso_install() and linux_exec_sysvec_init() must be called
* after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY).
*/
static void
linux_exec_sysvec_init(void *param)
{
l_uintptr_t *ktimekeep_base, *ktsc_selector;
struct sysentvec *sv;
ptrdiff_t tkoff;
sv = param;
/* Fill timekeep_base */
exec_sysvec_init(sv);
tkoff = kern_timekeep_base - linux_vdso_base;
ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
*ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset;
tkoff = kern_tsc_selector - linux_vdso_base;
ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
*ktsc_selector = linux_vdso_tsc_selector_idx();
if (bootverbose)
printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector);
tkoff = kern_cpu_selector - linux_vdso_base;
ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
*ktsc_selector = linux_vdso_cpu_selector_idx();
if (bootverbose)
printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector);
}
SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
linux_exec_sysvec_init, &elf_linux_sysvec);
static void
linux_vdso_install(const void *param)
{
char *vdso_start = &_binary_linux32_vdso_so_o_start;
char *vdso_end = &_binary_linux32_vdso_so_o_end;
linux_szsigcode = vdso_end - vdso_start;
MPASS(linux_szsigcode <= LINUX32_VDSOPAGE_SIZE);
linux_vdso_base = LINUX32_VDSOPAGE;
__elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base);
linux_vdso_obj = __elfN(linux_shared_page_init)
(&linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE);
bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode);
linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base);
}
SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST,
linux_vdso_install, NULL);
static void
linux_vdso_deinstall(const void *param)
{
__elfN(linux_shared_page_fini)(linux_vdso_obj,
linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE);
}
SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
linux_vdso_deinstall, NULL);
static void
linux_vdso_reloc(char *mapping, Elf_Addr offset)
{
const Elf_Shdr *shdr;
const Elf_Rel *rel;
const Elf_Ehdr *ehdr;
Elf32_Addr *where;
Elf_Size rtype, symidx;
Elf32_Addr addr, addend;
int i, relcnt;
MPASS(offset != 0);
relcnt = 0;
ehdr = (const Elf_Ehdr *)mapping;
shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff);
for (i = 0; i < ehdr->e_shnum; i++)
{
switch (shdr[i].sh_type) {
case SHT_REL:
rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset);
relcnt = shdr[i].sh_size / sizeof(*rel);
break;
case SHT_RELA:
printf("Linux i386 vDSO: unexpected Rela section\n");
break;
}
}
for (i = 0; i < relcnt; i++, rel++) {
where = (Elf32_Addr *)(mapping + rel->r_offset);
addend = *where;
rtype = ELF_R_TYPE(rel->r_info);
symidx = ELF_R_SYM(rel->r_info);
switch (rtype) {
case R_386_NONE: /* none */
break;
case R_386_RELATIVE: /* B + A */
addr = (Elf32_Addr)PTROUT(offset + addend);
if (*where != addr)
*where = addr;
break;
case R_386_IRELATIVE:
printf("Linux i386 vDSO: unexpected ifunc relocation, "
"symbol index %ld\n", (intmax_t)symidx);
break;
default:
printf("Linux i386 vDSO: unexpected relocation type %ld, "
"symbol index %ld\n", (intmax_t)rtype, (intmax_t)symidx);
}
}
}
static Elf_Brandnote linux32_brandnote = {
.hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
.hdr.n_descsz = 16, /* XXX at least 16 */
.hdr.n_type = 1,
.vendor = GNU_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = linux_trans_osrel
};
static Elf32_Brandinfo linux_brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_386,
.compat_3_brand = "Linux",
.interp_path = "/lib/ld-linux.so.1",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux32_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
static Elf32_Brandinfo linux_glibc2brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_386,
.compat_3_brand = "Linux",
.interp_path = "/lib/ld-linux.so.2",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux32_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
static Elf32_Brandinfo linux_muslbrand = {
.brand = ELFOSABI_LINUX,
.machine = EM_386,
.compat_3_brand = "Linux",
.interp_path = "/lib/ld-musl-i386.so.1",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux32_brandnote,