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freebsd/sys/i386/linux/linux_sysvec.c

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/*-
* 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 withough 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.
*
* $Id: linux_sysvec.c,v 1.13 1997/04/01 08:39:07 bde Exp $
*/
/* XXX we use functions that might not exist. */
#define COMPAT_43 1
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <sys/lock.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_pager.h>
#include <vm/vm_extern.h>
#include <sys/user.h>
#include <sys/exec.h>
#include <sys/kernel.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <machine/reg.h>
#include <machine/specialreg.h>
#include <machine/psl.h>
#include <machine/sysarch.h>
#include <machine/md_var.h>
#include <i386/linux/linux.h>
#include <i386/linux/linux_proto.h>
int linux_fixup __P((int **stack_base, struct image_params *iparams));
int elf_linux_fixup __P((int **stack_base, struct image_params *iparams));
void linux_prepsyscall __P((struct trapframe *tf, int *args, u_int *code, caddr_t *params));
void linux_sendsig __P((sig_t catcher, int sig, int mask, u_long code));
static void linux_elf_init __P((void *dummy));
/*
* Linux syscalls return negative errno's, we do positive and map them
*/
int bsd_to_linux_errno[ELAST] = {
-0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
-116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
-6,
};
int bsd_to_linux_signal[NSIG] = {
0, LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT,
LINUX_SIGILL, LINUX_SIGTRAP, LINUX_SIGABRT, 0,
LINUX_SIGFPE, LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV,
0, LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM,
LINUX_SIGURG, LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT,
LINUX_SIGCHLD, LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO,
LINUX_SIGXCPU, LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF,
LINUX_SIGWINCH, 0, LINUX_SIGUSR1, LINUX_SIGUSR2
};
int linux_to_bsd_signal[LINUX_NSIG] = {
0, SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGEMT,
SIGFPE, SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM,
SIGBUS, SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGIO,
SIGXCPU, SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH, SIGURG, SIGURG, 0
};
int linux_fixup(int **stack_base, struct image_params *imgp)
{
int *argv, *envp;
argv = *stack_base;
envp = *stack_base + (imgp->argc + 1);
(*stack_base)--;
**stack_base = (int)envp;
(*stack_base)--;
**stack_base = (int)argv;
(*stack_base)--;
**stack_base = (int)imgp->argc;
return 0;
}
int elf_linux_fixup(int **stack_base, struct image_params *imgp)
{
Elf32_Auxargs *args = (Elf32_Auxargs *)imgp->auxargs;
int *pos;
pos = *stack_base + (imgp->argc + imgp->envc + 2);
if (args->trace) {
AUXARGS_ENTRY(pos, AT_DEBUG, 1);
}
if (args->execfd != -1) {
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
}
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_FLAGS, args->flags);
AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
AUXARGS_ENTRY(pos, AT_BASE, args->base);
AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_cred->p_ruid);
AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_cred->p_svuid);
AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_cred->p_rgid);
AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_cred->p_svgid);
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
(*stack_base)--;
**stack_base = (int)imgp->argc;
return 0;
}
extern int _ucodesel, _udatasel;
/*
* 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.
*/
void
linux_sendsig(sig_t catcher, int sig, int mask, u_long code)
{
register struct proc *p = curproc;
register struct trapframe *regs;
struct linux_sigframe *fp, frame;
struct sigacts *psp = p->p_sigacts;
int oonstack;
regs = p->p_md.md_regs;
oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
#ifdef DEBUG
printf("Linux-emul(%d): linux_sendsig(%8x, %d, %d, %ld)\n",
p->p_pid, catcher, sig, mask, code);
#endif
/*
* Allocate space for the signal handler context.
*/
if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
(psp->ps_sigonstack & sigmask(sig))) {
fp = (struct linux_sigframe *)(psp->ps_sigstk.ss_sp +
psp->ps_sigstk.ss_size - sizeof(struct linux_sigframe));
psp->ps_sigstk.ss_flags |= SS_ONSTACK;
} else {
fp = (struct linux_sigframe *)regs->tf_esp - 1;
}
/*
* grow() will return FALSE if the fp will not fit inside the stack
* and the stack can not be grown. useracc will return FALSE
* if access is denied.
*/
if ((grow(p, (int)fp) == FALSE) ||
(useracc((caddr_t)fp, sizeof (struct linux_sigframe), B_WRITE) == FALSE)) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
SIGACTION(p, SIGILL) = SIG_DFL;
sig = sigmask(SIGILL);
p->p_sigignore &= ~sig;
p->p_sigcatch &= ~sig;
p->p_sigmask &= ~sig;
psignal(p, SIGILL);
return;
}
/*
* Build the argument list for the signal handler.
*/
if (p->p_sysent->sv_sigtbl) {
if (sig < p->p_sysent->sv_sigsize)
sig = p->p_sysent->sv_sigtbl[sig];
else
sig = p->p_sysent->sv_sigsize + 1;
}
frame.sf_handler = catcher;
frame.sf_sig = sig;
/*
* Build the signal context to be used by sigreturn.
*/
frame.sf_sc.sc_mask = mask;
__asm("movl %%gs,%w0" : "=r" (frame.sf_sc.sc_gs));
__asm("movl %%fs,%w0" : "=r" (frame.sf_sc.sc_fs));
frame.sf_sc.sc_es = regs->tf_es;
frame.sf_sc.sc_ds = regs->tf_ds;
frame.sf_sc.sc_edi = regs->tf_edi;
frame.sf_sc.sc_esi = regs->tf_esi;
frame.sf_sc.sc_ebp = regs->tf_ebp;
frame.sf_sc.sc_ebx = regs->tf_ebx;
frame.sf_sc.sc_edx = regs->tf_edx;
frame.sf_sc.sc_ecx = regs->tf_ecx;
frame.sf_sc.sc_eax = regs->tf_eax;
frame.sf_sc.sc_eip = regs->tf_eip;
frame.sf_sc.sc_cs = regs->tf_cs;
frame.sf_sc.sc_eflags = regs->tf_eflags;
frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
frame.sf_sc.sc_ss = regs->tf_ss;
frame.sf_sc.sc_err = regs->tf_err;
frame.sf_sc.sc_trapno = code; /* XXX ???? */
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
sigexit(p, SIGILL);
/* NOTREACHED */
}
/*
* Build context to run handler in.
*/
regs->tf_esp = (int)fp;
regs->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
regs->tf_eflags &= ~PSL_VM;
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_ss = _udatasel;
}
/*
* 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(p, args, retval)
struct proc *p;
struct linux_sigreturn_args *args;
int *retval;
{
struct linux_sigcontext *scp, context;
register struct trapframe *regs;
int eflags;
regs = p->p_md.md_regs;
#ifdef DEBUG
printf("Linux-emul(%d): linux_sigreturn(%8x)\n", p->p_pid, args->scp);
#endif
/*
* The trampoline code hands us the context.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
scp = args->scp;
if (copyin((caddr_t)scp, &context, sizeof(*scp)) != 0)
return (EFAULT);
/*
* Check for security violations.
*/
#define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
eflags = context.sc_eflags;
/*
* XXX do allow users to change the privileged flag PSL_RF. The
* cpu sets PSL_RF in tf_eflags for faults. Debuggers should
* sometimes set it there too. tf_eflags 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.
*/
if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
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)) {
trapsignal(p, SIGBUS, T_PROTFLT);
return(EINVAL);
}
p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
p->p_sigmask = context.sc_mask &~
(sigmask(SIGKILL)|sigmask(SIGCONT)|sigmask(SIGSTOP));
/*
* Restore signal context.
*/
/* %fs and %gs were restored by the trampoline. */
regs->tf_es = context.sc_es;
regs->tf_ds = context.sc_ds;
regs->tf_edi = context.sc_edi;
regs->tf_esi = context.sc_esi;
regs->tf_ebp = context.sc_ebp;
regs->tf_ebx = context.sc_ebx;
regs->tf_edx = context.sc_edx;
regs->tf_ecx = context.sc_ecx;
regs->tf_eax = context.sc_eax;
regs->tf_eip = context.sc_eip;
regs->tf_cs = context.sc_cs;
regs->tf_eflags = eflags;
regs->tf_esp = context.sc_esp_at_signal;
regs->tf_ss = context.sc_ss;
return (EJUSTRETURN);
}
void
linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params)
{
args[0] = tf->tf_ebx;
args[1] = tf->tf_ecx;
args[2] = tf->tf_edx;
args[3] = tf->tf_esi;
args[4] = tf->tf_edi;
*params = NULL; /* no copyin */
}
struct sysentvec linux_sysvec = {
LINUX_SYS_MAXSYSCALL,
linux_sysent,
0xff,
NSIG,
bsd_to_linux_signal,
ELAST,
bsd_to_linux_errno,
linux_fixup,
linux_sendsig,
linux_sigcode,
&linux_szsigcode,
linux_prepsyscall,
"Linux a.out"
};
struct sysentvec elf_linux_sysvec = {
LINUX_SYS_MAXSYSCALL,
linux_sysent,
0xff,
NSIG,
bsd_to_linux_signal,
ELAST,
bsd_to_linux_errno,
elf_linux_fixup,
linux_sendsig,
linux_sigcode,
&linux_szsigcode,
linux_prepsyscall,
"Linux ELF"
};
/*
* Installed either via SYSINIT() or via LKM stubs.
*/
Elf32_Brandinfo linux_brand = {
"Linux",
"/compat/linux",
"/lib/ld-linux.so.1",
&elf_linux_sysvec
};
#ifndef LKM
/*
* XXX: this is WRONG, it needs to be SI_SUB_EXEC, but this is just at the
* "proof of concept" stage and will be fixed shortly
*/
static void
linux_elf_init(dummy)
void *dummy;
{
if (elf_insert_brand_entry(&linux_brand) < 0)
printf("cannot insert Linux elf brand handler\n");
else if (bootverbose)
printf("Linux-ELF exec handler installed\n");
}
SYSINIT(linuxelf, SI_SUB_VFS, SI_ORDER_ANY, linux_elf_init, NULL);
#endif
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