freebsd-dev/sys/i386/svr4/svr4_machdep.c
Konstantin Belousov 22eca0bf45 Since version 4.3, gcc changed its behaviour concerning the i386/amd64
ABI and the direction flag, that is it now assumes that the direction
flag is cleared at the entry of a function and it doesn't clear once
more if needed. This new behaviour conforms to the i386/amd64 ABI.

Modify the signal handler frame setup code to clear the DF {e,r}flags
bit on the amd64/i386 for the signal handlers.

jhb@ noted that it might break old apps if they assumed DF == 1 would be
preserved in the signal handlers, but that such apps should be rare and
that older versions of gcc would not generate such apps.

Submitted by:	Aurelien Jarno <aurelien aurel32 net>
PR:	121422
Reviewed by:	jhb
MFC after:	2 weeks
2008-03-13 10:54:38 +00:00

612 lines
15 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/filedesc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signal.h>
#include <sys/signalvar.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 <vm/vm.h>
#include <vm/pmap.h>
#include <compat/svr4/svr4.h>
#include <compat/svr4/svr4_types.h>
#include <compat/svr4/svr4_signal.h>
#include <i386/svr4/svr4_machdep.h>
#include <compat/svr4/svr4_ucontext.h>
#include <compat/svr4/svr4_proto.h>
#include <compat/svr4/svr4_util.h>
#undef sigcode
#undef szsigcode
extern int svr4_szsigcode;
extern char svr4_sigcode[];
extern int _udatasel, _ucodesel;
static void svr4_getsiginfo(union svr4_siginfo *, int, u_long, caddr_t);
#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(td, epp, stack)
struct thread *td;
struct exec_package *epp;
u_long stack;
{
register struct pcb *pcb = td->td_pcb;
pcb->pcb_savefpu.sv_env.en_cw = __SVR4_NPXCW__;
setregs(td, epp, stack, 0UL);
}
#endif /* __NetBSD__ */
void
svr4_getcontext(td, uc, mask, oonstack)
struct thread *td;
struct svr4_ucontext *uc;
sigset_t *mask;
int oonstack;
{
struct proc *p = td->td_proc;
struct trapframe *tf = td->td_frame;
svr4_greg_t *r = uc->uc_mcontext.greg;
struct svr4_sigaltstack *s = &uc->uc_stack;
#if defined(DONE_MORE_SIGALTSTACK_WORK)
struct sigacts *psp;
struct sigaltstack *sf;
#endif
PROC_LOCK(p);
#if defined(DONE_MORE_SIGALTSTACK_WORK)
psp = p->p_sigacts;
sf = &p->p_sigstk;
#endif
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(td);
} else
#endif
{
#if defined(__NetBSD__)
__asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
__asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
#else
r[SVR4_X86_GS] = rgs();
r[SVR4_X86_FS] = tf->tf_fs;
#endif
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 defined(DONE_MORE_SIGALTSTACK_WORK)
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
PROC_UNLOCK(p);
/*
* Set the signal mask
*/
bsd_to_svr4_sigset(mask, &uc->uc_sigmask);
/*
* Set the flags
*/
uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
}
/*
* Set to ucontext specified. 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(td, uc)
struct thread *td;
struct svr4_ucontext *uc;
{
#if defined(DONE_MORE_SIGALTSTACK_WORK)
struct sigacts *psp;
#endif
struct proc *p = td->td_proc;
register struct trapframe *tf;
svr4_greg_t *r = uc->uc_mcontext.greg;
struct svr4_sigaltstack *s = &uc->uc_stack;
struct sigaltstack *sf;
sigset_t mask;
PROC_LOCK(p);
#if defined(DONE_MORE_SIGALTSTACK_WORK)
psp = p->p_sigacts;
#endif
sf = &td->td_sigstk;
/*
* 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) {
PROC_UNLOCK(p);
return 0;
}
DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
tf = td->td_frame;
/*
* Restore register context.
*/
#ifdef VM86
#warning "VM86 doesn't work yet, please don't try to use it."
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(td, 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])) {
PROC_UNLOCK(p);
return (EINVAL);
}
#if defined(__NetBSD__)
/* %fs and %gs were restored by the trampoline. */
#else
/* %gs was restored by the trampoline. */
tf->tf_fs = r[SVR4_X86_FS];
#endif
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) {
#if defined(DEBUG_SVR4)
{
int i;
for (i = 0; i < 4; i++)
DPRINTF(("\tuc_sigmask[%d] = %lx\n", i,
uc->uc_sigmask.bits[i]));
}
#endif
svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
SIG_CANTMASK(mask);
td->td_sigmask = mask;
signotify(td);
}
PROC_UNLOCK(p);
return 0; /*EJUSTRETURN;*/
}
static void
svr4_getsiginfo(si, sig, code, addr)
union svr4_siginfo *si;
int sig;
u_long code;
caddr_t addr;
{
si->svr4_si_signo = bsd_to_svr4_sig[sig];
si->svr4_si_errno = 0;
si->svr4_si_addr = addr;
switch (code) {
case T_PRIVINFLT:
si->svr4_si_code = SVR4_ILL_PRVOPC;
si->svr4_si_trap = SVR4_T_PRIVINFLT;
break;
case T_BPTFLT:
si->svr4_si_code = SVR4_TRAP_BRKPT;
si->svr4_si_trap = SVR4_T_BPTFLT;
break;
case T_ARITHTRAP:
si->svr4_si_code = SVR4_FPE_INTOVF;
si->svr4_si_trap = SVR4_T_DIVIDE;
break;
case T_PROTFLT:
si->svr4_si_code = SVR4_SEGV_ACCERR;
si->svr4_si_trap = SVR4_T_PROTFLT;
break;
case T_TRCTRAP:
si->svr4_si_code = SVR4_TRAP_TRACE;
si->svr4_si_trap = SVR4_T_TRCTRAP;
break;
case T_PAGEFLT:
si->svr4_si_code = SVR4_SEGV_ACCERR;
si->svr4_si_trap = SVR4_T_PAGEFLT;
break;
case T_ALIGNFLT:
si->svr4_si_code = SVR4_BUS_ADRALN;
si->svr4_si_trap = SVR4_T_ALIGNFLT;
break;
case T_DIVIDE:
si->svr4_si_code = SVR4_FPE_FLTDIV;
si->svr4_si_trap = SVR4_T_DIVIDE;
break;
case T_OFLOW:
si->svr4_si_code = SVR4_FPE_FLTOVF;
si->svr4_si_trap = SVR4_T_DIVIDE;
break;
case T_BOUND:
si->svr4_si_code = SVR4_FPE_FLTSUB;
si->svr4_si_trap = SVR4_T_BOUND;
break;
case T_DNA:
si->svr4_si_code = SVR4_FPE_FLTINV;
si->svr4_si_trap = SVR4_T_DNA;
break;
case T_FPOPFLT:
si->svr4_si_code = SVR4_FPE_FLTINV;
si->svr4_si_trap = SVR4_T_FPOPFLT;
break;
case T_SEGNPFLT:
si->svr4_si_code = SVR4_SEGV_MAPERR;
si->svr4_si_trap = SVR4_T_SEGNPFLT;
break;
case T_STKFLT:
si->svr4_si_code = SVR4_ILL_BADSTK;
si->svr4_si_trap = SVR4_T_STKFLT;
break;
default:
si->svr4_si_code = 0;
si->svr4_si_trap = 0;
#if defined(DEBUG_SVR4)
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, ksi, mask)
sig_t catcher;
ksiginfo_t *ksi;
sigset_t *mask;
{
register struct thread *td = curthread;
struct proc *p = td->td_proc;
register struct trapframe *tf;
struct svr4_sigframe *fp, frame;
struct sigacts *psp;
int oonstack;
int sig;
int code;
PROC_LOCK_ASSERT(p, MA_OWNED);
sig = ksi->ksi_signo;
#if defined(DEBUG_SVR4)
printf("svr4_sendsig(%d)\n", sig);
#endif
code = ksi->ksi_trapno; /* use trap No. */
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
tf = td->td_frame;
oonstack = sigonstack(tf->tf_esp);
/*
* Allocate space for the signal handler context.
*/
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct svr4_sigframe *)(td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(struct svr4_sigframe));
td->td_sigstk.ss_flags |= SS_ONSTACK;
} else {
fp = (struct svr4_sigframe *)tf->tf_esp - 1;
}
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(p);
/*
* 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(td, &frame.sf_uc, mask, oonstack);
#if defined(DEBUG_SVR4)
printf("obtained ucontext\n");
#endif
svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
#if defined(DEBUG_SVR4)
printf("obtained siginfo\n");
#endif
frame.sf_signum = frame.sf_si.svr4_si_signo;
frame.sf_sip = &fp->sf_si;
frame.sf_ucp = &fp->sf_uc;
frame.sf_handler = catcher;
#if defined(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.
*/
PROC_LOCK(p);
sigexit(td, 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|PSL_D);
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_eflags &= ~(PSL_T | PSL_D);
tf->tf_cs = _ucodesel;
tf->tf_ds = _udatasel;
tf->tf_es = _udatasel;
tf->tf_fs = _udatasel;
load_gs(_udatasel);
tf->tf_ss = _udatasel;
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
#endif
}
int
svr4_sys_sysarch(td, v)
struct thread *td;
struct svr4_sys_sysarch_args *v;
{
struct svr4_sys_sysarch_args *uap = v;
#if 0 /* USER_LDT */
#if defined(__NetBSD__)
caddr_t sg = stackgap_init(p->p_emul);
#else
caddr_t sg = stackgap_init();
#endif
int error;
#endif
switch (uap->op) {
case SVR4_SYSARCH_FPHW:
return 0;
case SVR4_SYSARCH_DSCR:
#if 0 /* USER_LDT */
#warning "USER_LDT doesn't work - are you sure you want this?"
{
struct i386_set_ldt_args sa, *sap;
struct sys_sysarch_args ua;
struct svr4_ssd ssd;
union descriptor bsd;
if ((error = copyin(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;
}
ua.op = I386_SET_LDT;
ua.parms = (char *) sap;
if ((error = copyout(&bsd, sa.desc, sizeof(bsd))) != 0) {
printf("Cannot copyout desc\n");
return error;
}
return sys_sysarch(td, &ua, retval);
}
#endif
default:
printf("svr4_sysarch(%d), a1 %p\n", uap->op,
uap->a1);
return 0;
}
}