freebsd-skq/sys/i386/svr4/svr4_machdep.c
John Polstra 4fe88fe637 Restore support for executing BSD/OS binaries on the i386 by passing
the address of the ps_strings structure to the process via %ebx.
For other kinds of binaries, %ebx is still zeroed as before.

Submitted by:	Thomas Stephens <tas@stephens.org>
Reviewed by:	jdp
1999-04-03 22:20:03 +00:00

544 lines
13 KiB
C

/*
* Copyright (c) 1998 Mark Newton
* Copyright (c) 1994 Christos Zoulas
* 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.
* 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/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/exec.h>
#include <sys/lock.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_prot.h>
#include <vm/vm_extern.h>
#include <sys/user.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/signal.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/sysproto.h>
#include <sys/elf32.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/specialreg.h>
#include <machine/sysarch.h>
#include <machine/vm86.h>
#include <machine/vmparam.h>
#include <svr4/svr4.h>
#include <svr4/svr4_types.h>
#include <svr4/svr4_signal.h>
#include <i386/svr4/svr4_machdep.h>
#include <svr4/svr4_ucontext.h>
#include <svr4/svr4_proto.h>
#include <svr4/svr4_util.h>
#include <svr4/svr4_exec.h>
#undef sigcode
#undef szsigcode
extern int svr4_szsigcode;
extern char svr4_sigcode[];
extern int _udatasel, _ucodesel;
static void svr4_getsiginfo __P((union svr4_siginfo *, int, u_long, caddr_t));
extern int bsd_to_svr4_sig[];
#if !defined(__NetBSD__)
/* taken from /sys/arch/i386/include/psl.h on NetBSD-1.3 */
# define PSL_MBZ 0xffc08028
# define PSL_USERSTATIC (PSL_USER | PSL_MBZ | PSL_IOPL | PSL_NT | PSL_VM | PSL_VIF | PSL_VIP)
# define USERMODE(c, f) (ISPL(c) == SEL_UPL)
#endif
#if defined(__NetBSD__)
void
svr4_setregs(p, epp, stack)
struct proc *p;
struct exec_package *epp;
u_long stack;
{
register struct pcb *pcb = &p->p_addr->u_pcb;
pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
setregs(p, epp, stack, 0UL);
}
#endif /* __NetBSD__ */
void
svr4_getcontext(p, uc, mask, oonstack)
struct proc *p;
struct svr4_ucontext *uc;
int mask, oonstack;
{
struct trapframe *tf = p->p_md.md_regs;
struct sigacts *psp = p->p_sigacts;
svr4_greg_t *r = uc->uc_mcontext.greg;
struct svr4_sigaltstack *s = &uc->uc_stack;
struct sigaltstack *sf = &psp->ps_sigstk;
memset(uc, 0, sizeof(struct svr4_ucontext));
uc->uc_link = p->p_emuldata;
/*
* Set the general purpose registers
*/
#ifdef VM86
if (tf->tf_eflags & PSL_VM) {
r[SVR4_X86_GS] = tf->tf_vm86_gs;
r[SVR4_X86_FS] = tf->tf_vm86_fs;
r[SVR4_X86_ES] = tf->tf_vm86_es;
r[SVR4_X86_DS] = tf->tf_vm86_ds;
r[SVR4_X86_EFL] = get_vflags(p);
} else
#endif
{
__asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
__asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
r[SVR4_X86_ES] = tf->tf_es;
r[SVR4_X86_DS] = tf->tf_ds;
r[SVR4_X86_EFL] = tf->tf_eflags;
}
r[SVR4_X86_EDI] = tf->tf_edi;
r[SVR4_X86_ESI] = tf->tf_esi;
r[SVR4_X86_EBP] = tf->tf_ebp;
r[SVR4_X86_ESP] = tf->tf_esp;
r[SVR4_X86_EBX] = tf->tf_ebx;
r[SVR4_X86_EDX] = tf->tf_edx;
r[SVR4_X86_ECX] = tf->tf_ecx;
r[SVR4_X86_EAX] = tf->tf_eax;
r[SVR4_X86_TRAPNO] = tf->tf_trapno;
r[SVR4_X86_ERR] = tf->tf_err;
r[SVR4_X86_EIP] = tf->tf_eip;
r[SVR4_X86_CS] = tf->tf_cs;
r[SVR4_X86_UESP] = 0;
r[SVR4_X86_SS] = tf->tf_ss;
/*
* Set the signal stack
*/
#if 0
bsd_to_svr4_sigaltstack(sf, s);
#else
s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
s->ss_size = 16384;
s->ss_flags = 0;
#endif
/*
* Set the signal mask
*/
bsd_to_svr4_sigset(&mask, &uc->uc_sigmask);
/*
* Set the flags
*/
uc->uc_flags = SVR4_UC_STACK|SVR4_UC_SIGMASK|SVR4_UC_CPU;
}
/*
* Set to ucontext specified.
* has been taken. Reset signal mask and
* stack state from context.
* 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
svr4_setcontext(p, uc)
struct proc *p;
struct svr4_ucontext *uc;
{
struct sigacts *psp = p->p_sigacts;
register struct trapframe *tf;
svr4_greg_t *r = uc->uc_mcontext.greg;
struct svr4_sigaltstack *s = &uc->uc_stack;
struct sigaltstack *sf = &psp->ps_sigstk;
int mask;
/*
* XXX:
* Should we check the value of flags to determine what to restore?
* What to do with uc_link?
* What to do with floating point stuff?
* Should we bother with the rest of the registers that we
* set to 0 right now?
*/
if ((uc->uc_flags & SVR4_UC_CPU) == 0)
return 0;
tf = p->p_md.md_regs;
/*
* Restore register context.
*/
#ifdef VM86
if (r[SVR4_X86_EFL] & PSL_VM) {
tf->tf_vm86_gs = r[SVR4_X86_GS];
tf->tf_vm86_fs = r[SVR4_X86_FS];
tf->tf_vm86_es = r[SVR4_X86_ES];
tf->tf_vm86_ds = r[SVR4_X86_DS];
set_vflags(p, r[SVR4_X86_EFL]);
} else
#endif
{
/*
* Check for security violations. If we're returning to
* protected mode, the CPU will validate the segment registers
* automatically and generate a trap on violations. We handle
* the trap, rather than doing all of the checking here.
*/
if (((r[SVR4_X86_EFL] ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
!USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL]))
return (EINVAL);
/* %fs and %gs were restored by the trampoline. */
tf->tf_es = r[SVR4_X86_ES];
tf->tf_ds = r[SVR4_X86_DS];
tf->tf_eflags = r[SVR4_X86_EFL];
}
tf->tf_edi = r[SVR4_X86_EDI];
tf->tf_esi = r[SVR4_X86_ESI];
tf->tf_ebp = r[SVR4_X86_EBP];
tf->tf_ebx = r[SVR4_X86_EBX];
tf->tf_edx = r[SVR4_X86_EDX];
tf->tf_ecx = r[SVR4_X86_ECX];
tf->tf_eax = r[SVR4_X86_EAX];
tf->tf_trapno = r[SVR4_X86_TRAPNO];
tf->tf_err = r[SVR4_X86_ERR];
tf->tf_eip = r[SVR4_X86_EIP];
tf->tf_cs = r[SVR4_X86_CS];
tf->tf_ss = r[SVR4_X86_SS];
tf->tf_esp = r[SVR4_X86_ESP];
p->p_emuldata = uc->uc_link;
/*
* restore signal stack
*/
if (uc->uc_flags & SVR4_UC_STACK) {
svr4_to_bsd_sigaltstack(s, sf);
}
/*
* restore signal mask
*/
if (uc->uc_flags & SVR4_UC_SIGMASK) {
svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
p->p_sigmask = mask & ~sigcantmask;
}
return 0; /*EJUSTRETURN;*/
}
static void
svr4_getsiginfo(si, sig, code, addr)
union svr4_siginfo *si;
int sig;
u_long code;
caddr_t addr;
{
si->si_signo = bsd_to_svr4_sig[sig];
si->si_errno = 0;
si->si_addr = addr;
switch (code) {
case T_PRIVINFLT:
si->si_code = SVR4_ILL_PRVOPC;
si->si_trap = SVR4_T_PRIVINFLT;
break;
case T_BPTFLT:
si->si_code = SVR4_TRAP_BRKPT;
si->si_trap = SVR4_T_BPTFLT;
break;
case T_ARITHTRAP:
si->si_code = SVR4_FPE_INTOVF;
si->si_trap = SVR4_T_DIVIDE;
break;
case T_PROTFLT:
si->si_code = SVR4_SEGV_ACCERR;
si->si_trap = SVR4_T_PROTFLT;
break;
case T_TRCTRAP:
si->si_code = SVR4_TRAP_TRACE;
si->si_trap = SVR4_T_TRCTRAP;
break;
case T_PAGEFLT:
si->si_code = SVR4_SEGV_ACCERR;
si->si_trap = SVR4_T_PAGEFLT;
break;
case T_ALIGNFLT:
si->si_code = SVR4_BUS_ADRALN;
si->si_trap = SVR4_T_ALIGNFLT;
break;
case T_DIVIDE:
si->si_code = SVR4_FPE_FLTDIV;
si->si_trap = SVR4_T_DIVIDE;
break;
case T_OFLOW:
si->si_code = SVR4_FPE_FLTOVF;
si->si_trap = SVR4_T_DIVIDE;
break;
case T_BOUND:
si->si_code = SVR4_FPE_FLTSUB;
si->si_trap = SVR4_T_BOUND;
break;
case T_DNA:
si->si_code = SVR4_FPE_FLTINV;
si->si_trap = SVR4_T_DNA;
break;
case T_FPOPFLT:
si->si_code = SVR4_FPE_FLTINV;
si->si_trap = SVR4_T_FPOPFLT;
break;
case T_SEGNPFLT:
si->si_code = SVR4_SEGV_MAPERR;
si->si_trap = SVR4_T_SEGNPFLT;
break;
case T_STKFLT:
si->si_code = SVR4_ILL_BADSTK;
si->si_trap = SVR4_T_STKFLT;
break;
default:
si->si_code = 0;
si->si_trap = 0;
#ifdef DIAGNOSTIC
printf("sig %d code %ld\n", sig, code);
panic("svr4_getsiginfo");
#endif
break;
}
}
/*
* Send an interrupt to process.
*
* Stack is set up to allow sigcode stored
* in u. to call routine. After the handler is
* done svr4 will call setcontext for us
* with the user context we just set up, and we
* will return to the user pc, psl.
*/
void
svr4_sendsig(catcher, sig, mask, code)
sig_t catcher;
int sig, mask;
u_long code;
{
register struct proc *p = curproc;
register struct trapframe *tf;
struct svr4_sigframe *fp, frame;
struct sigacts *psp = p->p_sigacts;
int oonstack;
tf = p->p_md.md_regs;
oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
/*
* Allocate space for the signal handler context.
*/
if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
(psp->ps_sigonstack & sigmask(sig))) {
fp = (struct svr4_sigframe *)((caddr_t)psp->ps_sigstk.ss_sp +
psp->ps_sigstk.ss_size - sizeof(struct svr4_sigframe));
psp->ps_sigstk.ss_flags |= SS_ONSTACK;
} else {
fp = (struct svr4_sigframe *)tf->tf_esp - 1;
}
/*
* Build the argument list for the signal handler.
* Notes:
* - we always build the whole argument list, even when we
* don't need to [when SA_SIGINFO is not set, we don't need
* to pass all sf_si and sf_uc]
* - we don't pass the correct signal address [we need to
* modify many kernel files to enable that]
*/
svr4_getcontext(p, &frame.sf_uc, mask, oonstack);
DPRINTF(("obtained ucontext\n"));
svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
DPRINTF(("obtained siginfo\n"));
frame.sf_signum = frame.sf_si.si_signo;
frame.sf_sip = &fp->sf_si;
frame.sf_ucp = &fp->sf_uc;
frame.sf_handler = catcher;
#ifdef DEBUG_SVR4
printf("sig = %d, sip %p, ucp = %p, handler = %p\n",
frame.sf_signum, frame.sf_sip, frame.sf_ucp, frame.sf_handler);
#endif
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 */
}
#if defined(__NetBSD__)
/*
* Build context to run handler in.
*/
tf->tf_es = GSEL(GUSERLDT_SEL, SEL_UPL);
tf->tf_ds = GSEL(GUSERLDT_SEL, SEL_UPL);
tf->tf_eip = (int)(((char *)PS_STRINGS) -
svr4_szsigcode);
tf->tf_cs = GSEL(GUSERLDT_SEL, SEL_UPL);
tf->tf_eflags &= ~(PSL_T|PSL_VM|PSL_AC);
tf->tf_esp = (int)fp;
tf->tf_ss = GSEL(GUSERLDT_SEL, SEL_UPL);
#else
tf->tf_esp = (int)fp;
tf->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
tf->tf_cs = _ucodesel;
tf->tf_ds = _udatasel;
tf->tf_es = _udatasel;
tf->tf_ss = _udatasel;
#endif
}
int
svr4_sys_sysarch(p, v)
struct proc *p;
struct svr4_sys_sysarch_args *v;
{
struct svr4_sys_sysarch_args *uap = v;
#ifdef USER_LDT
caddr_t sg = stackgap_init(p->p_emul);
int error;
#endif
switch (uap->op) {
case SVR4_SYSARCH_FPHW:
return 0;
case SVR4_SYSARCH_DSCR:
#ifdef USER_LDT
{
struct i386_set_ldt_args sa, *sap;
struct sys_sysarch_args ua;
struct svr4_ssd ssd;
union descriptor bsd;
if ((error = copyin(SCARG(uap, a1), &ssd,
sizeof(ssd))) != 0) {
printf("Cannot copy arg1\n");
return error;
}
printf("s=%x, b=%x, l=%x, a1=%x a2=%x\n",
ssd.selector, ssd.base, ssd.limit,
ssd.access1, ssd.access2);
/* We can only set ldt's for now. */
if (!ISLDT(ssd.selector)) {
printf("Not an ldt\n");
return EPERM;
}
/* Oh, well we don't cleanup either */
if (ssd.access1 == 0)
return 0;
bsd.sd.sd_lobase = ssd.base & 0xffffff;
bsd.sd.sd_hibase = (ssd.base >> 24) & 0xff;
bsd.sd.sd_lolimit = ssd.limit & 0xffff;
bsd.sd.sd_hilimit = (ssd.limit >> 16) & 0xf;
bsd.sd.sd_type = ssd.access1 & 0x1f;
bsd.sd.sd_dpl = (ssd.access1 >> 5) & 0x3;
bsd.sd.sd_p = (ssd.access1 >> 7) & 0x1;
bsd.sd.sd_xx = ssd.access2 & 0x3;
bsd.sd.sd_def32 = (ssd.access2 >> 2) & 0x1;
bsd.sd.sd_gran = (ssd.access2 >> 3)& 0x1;
sa.start = IDXSEL(ssd.selector);
sa.desc = stackgap_alloc(&sg, sizeof(union descriptor));
sa.num = 1;
sap = stackgap_alloc(&sg,
sizeof(struct i386_set_ldt_args));
if ((error = copyout(&sa, sap, sizeof(sa))) != 0) {
printf("Cannot copyout args\n");
return error;
}
SCARG(&ua, op) = I386_SET_LDT;
SCARG(&ua, parms) = (char *) sap;
if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
printf("Cannot copyout desc\n");
return error;
}
return sys_sysarch(p, &ua, retval);
}
#endif
default:
printf("svr4_sysarch(%d), a1 %p\n", uap->op,
uap->a1);
return 0;
}
}