Add a per-signal flag to mark handlers registered with osigaction, so we

can provide the correct context to each signal handler.

Fix broken sigsuspend(): don't use p_oldsigmask as a flag, use SAS_OLDMASK
as we did before the linuxthreads support merge (submitted by bde).

Move ps_sigstk from to p_sigacts to the main proc structure since signal
stack should not be shared among threads.

Move SAS_OLDMASK and SAS_ALTSTACK flags from sigacts::ps_flags to proc::p_flag.
Move PS_NOCLDSTOP and PS_NOCLDWAIT flags from proc::p_flag to procsig::ps_flag.

Reviewed by:	marcel, jdp, bde

31 files changed, 346 insertions, 377 deletions

diff --git a/sys/alpha/alpha/machdep.c b/sys/alpha/alpha/machdep.c
index ce72dce..38aaee8 100644
--- a/sys/alpha/alpha/machdep.c
+++ b/sys/alpha/alpha/machdep.c
@@ -1172,7 +1172,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack, fsize, rndfsize;
 
 	frame = p->p_md.md_tf;
-	oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
+	oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 	fsize = sizeof ksi;
 	rndfsize = ((fsize + 15) / 16) * 16;
 
@@ -1183,11 +1183,11 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	 * will fail if the process has not already allocated
 	 * the space with a `brk'.
 	 */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sip = (osiginfo_t *)((caddr_t)psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - rndfsize);
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sip = (osiginfo_t *)((caddr_t)p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - rndfsize);
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else
 		sip = (osiginfo_t *)(alpha_pal_rdusp() - rndfsize);
 
@@ -1265,29 +1265,26 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 void
 sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 {
-	struct proc *p;
+	struct proc *p = curproc;
 	struct trapframe *frame;
-	struct sigacts *psp;
+	struct sigacts *psp = p->p_sigacts;
 	struct sigframe sf, *sfp;
-	int onstack, rndfsize;
+	int oonstack, rndfsize;
 
-	p = curproc;
-
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
+	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
 
 	frame = p->p_md.md_tf;
-	psp = p->p_sigacts;
-	onstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 	rndfsize = ((sizeof(sf) + 15) / 16) * 16;
 
 	/* save user context */
 	bzero(&sf, sizeof(struct sigframe));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = psp->ps_sigstk;
-	sf.sf_uc.uc_mcontext.mc_onstack = onstack;
+	sf.sf_uc.uc_stack = p->p_sigstk;
+	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
 
 	fill_regs(p, (struct reg *)sf.sf_uc.uc_mcontext.mc_regs);
 	sf.sf_uc.uc_mcontext.mc_regs[R_SP] = alpha_pal_rdusp();
@@ -1308,11 +1305,11 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	 * will fail if the process has not already allocated
 	 * the space with a `brk'.
 	 */
-	if ((psp->ps_flags & SAS_ALTSTACK) != 0 && !onstack &&
+	if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe *)((caddr_t)psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - rndfsize);
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sfp = (struct sigframe *)((caddr_t)p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - rndfsize);
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else
 		sfp = (struct sigframe *)(alpha_pal_rdusp() - rndfsize);
 
@@ -1438,20 +1435,16 @@ osigreturn(struct proc *p,
 	 * Restore the user-supplied information
 	 */
 	if (ksc.sc_onstack)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	/*
 	 * longjmp is still implemented by calling osigreturn. The new
 	 * sigmask is stored in sc_reserved, sc_mask is only used for
 	 * backward compatibility.
 	 */
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
-		OSIG2SIG(ksc.sc_mask, p->p_sigmask);
-	}
-	else
-		p->p_sigmask = *((sigset_t *)(&ksc.sc_reserved[0]));
+	SIGSETOLD(p->p_sigmask, ksc.sc_mask);
 	SIG_CANTMASK(p->p_sigmask);
 
 	set_regs(p, (struct reg *)ksc.sc_regs);
@@ -1480,11 +1473,10 @@ sigreturn(struct proc *p,
 	struct pcb *pcb;
 	unsigned long val;
 
-	ucp = uap->sigcntxp;
-
-	if ((p->p_flag & P_NEWSIGSET) == 0)
-		return (osigreturn(p, (struct osigreturn_args *)uap));
+	if (((struct osigcontext*)uap->sigcntxp)->sc_regs[R_ZERO] == 0xACEDBADE)
+		return osigreturn(p, (struct osigreturn_args *)uap);
 
+	ucp = uap->sigcntxp;
 	pcb = &p->p_addr->u_pcb;
 
 #ifdef DEBUG
@@ -1514,9 +1506,9 @@ sigreturn(struct proc *p,
 	alpha_pal_wrusp(uc.uc_mcontext.mc_regs[R_SP]);
 
 	if (uc.uc_mcontext.mc_onstack & 1)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	p->p_sigmask = uc.uc_sigmask;
 	SIG_CANTMASK(p->p_sigmask);
diff --git a/sys/alpha/linux/linux_sysvec.c b/sys/alpha/linux/linux_sysvec.c
index ecaa359..d282439 100644
--- a/sys/alpha/linux/linux_sysvec.c
+++ b/sys/alpha/linux/linux_sysvec.c
@@ -198,7 +198,7 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
+	oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 
 #ifdef DEBUG
 	printf("Linux-emul(%ld): linux_sendsig(%p, %d, %p, %lu)\n",
@@ -207,11 +207,11 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/*
 	 * Allocate space for the signal handler context.
 	 */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, 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;
+		fp = (struct linux_sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct linux_sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else {
 		fp = (struct linux_sigframe *)regs->tf_esp - 1;
 	}
@@ -287,6 +287,7 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
 	regs->tf_fs = _udatasel;
+	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
 
@@ -354,12 +355,9 @@ linux_sigreturn(p, args)
 		return(EINVAL);
 	}
 
-	p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
-	SIGEMPTYSET(p->p_sigmask);
-	p->p_sigmask.__bits[0] = context.sc_mask;
-	SIGDELSET(p->p_sigmask, SIGKILL);
-	SIGDELSET(p->p_sigmask, SIGCONT);
-	SIGDELSET(p->p_sigmask, SIGSTOP);
+	p->p_sigstk.ss_flags &= ~SS_ONSTACK;
+	SIGSETOLD(p->p_sigmask, context.sc_mask);
+	SIG_CANTMASK(p->p_sigmask);
 
 	/*
 	 * Restore signal context.
diff --git a/sys/amd64/amd64/genassym.c b/sys/amd64/amd64/genassym.c
index b95a9a7..d137b12 100644
--- a/sys/amd64/amd64/genassym.c
+++ b/sys/amd64/amd64/genassym.c
@@ -148,8 +148,18 @@ main()
 	printf("#define\tTF_EFLAGS %#x\n", OS(trapframe, tf_eflags));
 
 	printf("#define\tSIGF_HANDLER %#x\n", OS(sigframe, sf_ahu.sf_handler));
+	printf("#define\tSIGF_SC %#x\n", OS(osigframe, sf_siginfo.si_sc));
 	printf("#define\tSIGF_UC %#x\n", OS(sigframe, sf_uc));
 
+	printf("#define\tSC_PS %#x\n", OS(osigcontext, sc_ps));
+	printf("#define\tSC_FS %#x\n", OS(osigcontext, sc_fs));
+	printf("#define\tSC_GS %#x\n", OS(osigcontext, sc_gs));
+	printf("#define\tSC_TRAPNO %#x\n", OS(osigcontext, sc_trapno));
+
+	printf("#define\tUC_EFLAGS %#x\n",
+	    OS(__ucontext, uc_mcontext.mc_eflags));
+	printf("#define\tUC_GS %#x\n", OS(__ucontext, uc_mcontext.mc_gs));
+
 	printf("#define\tB_READ %#x\n", B_READ);
 	printf("#define\tENOENT %d\n", ENOENT);
 	printf("#define\tEFAULT %d\n", EFAULT);
diff --git a/sys/amd64/amd64/locore.S b/sys/amd64/amd64/locore.S
index a1b6ff7..2abcc80 100644
--- a/sys/amd64/amd64/locore.S
+++ b/sys/amd64/amd64/locore.S
@@ -417,19 +417,39 @@ NON_GPROF_ENTRY(sigcode)
 	call	SIGF_HANDLER(%esp)		/* call signal handler */
 	lea	SIGF_UC(%esp),%eax		/* get ucontext_t */
 	pushl	%eax
-	movl	$SYS_osigreturn,%eax
+	testl	$PSL_VM,UC_EFLAGS(%eax)
+	jne	9f
+	movl	UC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$SYS_sigreturn,%eax
 	pushl	%eax				/* junk to fake return addr. */
 	int	$0x80				/* enter kernel with args */
-						/* on stack */
-1:
-	jmp	1b
+0:	jmp	0b
+
+	ALIGN_TEXT
+_osigcode:
+	call	SIGF_HANDLER(%esp)		/* call signal handler */
+	lea	SIGF_SC(%esp),%eax		/* get sigcontext */
+	pushl	%eax
+	testl	$PSL_VM,SC_PS(%eax)
+	jne	9f
+	movl	SC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$0x01d516,SC_TRAPNO(%eax)	/* magic: 0ldSiG */
+	movl	$SYS_sigreturn,%eax
+	pushl	%eax				/* junk to fake return addr. */
+	int	$0x80				/* enter kernel with args */
+0:	jmp	0b
+
 	ALIGN_TEXT
 _esigcode:
 
 	.data
-	.globl	_szsigcode
+	.globl	_szsigcode, _oszsigcode
 _szsigcode:
 	.long	_esigcode-_sigcode
+_oszsigcode:
+	.long	_esigcode-_osigcode
 	.text
 
 /**********************************************************************
diff --git a/sys/amd64/amd64/locore.s b/sys/amd64/amd64/locore.s
index a1b6ff7..2abcc80 100644
--- a/sys/amd64/amd64/locore.s
+++ b/sys/amd64/amd64/locore.s
@@ -417,19 +417,39 @@ NON_GPROF_ENTRY(sigcode)
 	call	SIGF_HANDLER(%esp)		/* call signal handler */
 	lea	SIGF_UC(%esp),%eax		/* get ucontext_t */
 	pushl	%eax
-	movl	$SYS_osigreturn,%eax
+	testl	$PSL_VM,UC_EFLAGS(%eax)
+	jne	9f
+	movl	UC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$SYS_sigreturn,%eax
 	pushl	%eax				/* junk to fake return addr. */
 	int	$0x80				/* enter kernel with args */
-						/* on stack */
-1:
-	jmp	1b
+0:	jmp	0b
+
+	ALIGN_TEXT
+_osigcode:
+	call	SIGF_HANDLER(%esp)		/* call signal handler */
+	lea	SIGF_SC(%esp),%eax		/* get sigcontext */
+	pushl	%eax
+	testl	$PSL_VM,SC_PS(%eax)
+	jne	9f
+	movl	SC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$0x01d516,SC_TRAPNO(%eax)	/* magic: 0ldSiG */
+	movl	$SYS_sigreturn,%eax
+	pushl	%eax				/* junk to fake return addr. */
+	int	$0x80				/* enter kernel with args */
+0:	jmp	0b
+
 	ALIGN_TEXT
 _esigcode:
 
 	.data
-	.globl	_szsigcode
+	.globl	_szsigcode, _oszsigcode
 _szsigcode:
 	.long	_esigcode-_sigcode
+_oszsigcode:
+	.long	_esigcode-_osigcode
 	.text
 
 /**********************************************************************
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index a682098..0bc5838 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -483,14 +483,14 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* Allocate and validate space for the signal handler context. */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct osigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct osigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		fp = (struct osigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct osigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		fp = (struct osigframe *)regs->tf_esp - 1;
@@ -594,7 +594,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	}
 
 	regs->tf_esp = (int)fp;
-	regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	regs->tf_eip = PS_STRINGS - oszsigcode;
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
@@ -610,37 +610,34 @@ sendsig(catcher, sig, mask, code)
 	sigset_t *mask;
 	u_long code;
 {
-	struct proc *p;
+	struct proc *p = curproc;
 	struct trapframe *regs;
-	struct sigacts *psp;
+	struct sigacts *psp = p->p_sigacts;
 	struct sigframe sf, *sfp;
-	int onstack;
-
-	p = curproc;
+	int oonstack;
 
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
+	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
 
 	regs = p->p_md.md_regs;
-	psp = p->p_sigacts;
-	onstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* save user context */
 	bzero(&sf, sizeof(struct sigframe));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = psp->ps_sigstk;
-	sf.sf_uc.uc_mcontext.mc_onstack = onstack;
+	sf.sf_uc.uc_stack = p->p_sigstk;
+	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(struct trapframe));
 
 	/* Allocate and validate space for the signal handler context. */
-        if ((psp->ps_flags & SAS_ALTSTACK) != 0 && !onstack &&
+        if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct sigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sfp = (struct sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		sfp = (struct sigframe *)regs->tf_esp - 1;
@@ -770,9 +767,6 @@ osigreturn(p, uap)
 	register struct trapframe *regs = p->p_md.md_regs;
 	int eflags;
 
-	if ((p->p_flag & P_NEWSIGSET) != 0)
-		return sigreturn(p, (struct sigreturn_args *)uap);
-
 	scp = uap->sigcntxp;
 
 	if (useracc((caddr_t)scp, sizeof (struct osigcontext), B_WRITE) == 0)
@@ -841,10 +835,6 @@ osigreturn(p, uap)
 		regs->tf_ds = scp->sc_ds;
 		regs->tf_es = scp->sc_es;
 		regs->tf_fs = scp->sc_fs;
-		if (load_gs_param(scp->sc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	/* restore scratch registers */
@@ -859,11 +849,11 @@ osigreturn(p, uap)
 	regs->tf_isp = scp->sc_isp;
 
 	if (scp->sc_onstack & 01)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
-	OSIG2SIG(scp->sc_mask, p->p_sigmask);
+	SIGSETOLD(p->p_sigmask, scp->sc_mask);
 	SIG_CANTMASK(p->p_sigmask);
 	regs->tf_ebp = scp->sc_fp;
 	regs->tf_esp = scp->sc_sp;
@@ -883,7 +873,8 @@ sigreturn(p, uap)
 	ucontext_t *ucp;
 	int cs, eflags;
 
-	p->p_flag |= P_NEWSIGSET;
+	if (((struct osigcontext *)uap->sigcntxp)->sc_trapno == 0x01d516)
+		return osigreturn(p, (struct osigreturn_args *)uap);
 
 	regs = p->p_md.md_regs;
 	ucp = uap->sigcntxp;
@@ -956,16 +947,12 @@ sigreturn(p, uap)
 			return(EINVAL);
 		}
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(struct trapframe));
-		if (load_gs_param(ucp->uc_mcontext.mc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	p->p_sigmask = ucp->uc_sigmask;
 	SIG_CANTMASK(p->p_sigmask);
diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S
index 6a6e9fc..ae99af9 100644
--- a/sys/amd64/amd64/support.S
+++ b/sys/amd64/amd64/support.S
@@ -1586,21 +1586,6 @@ ENTRY(load_cr4)
 	movl	%eax,%cr4
 	ret
 
-/* int load_gs_param(caddr_t gs) */
-ENTRY(load_gs_param)
-	movl	_curpcb,%ecx
-	movl	$load_gs_param_fault,PCB_ONFAULT(%ecx)
-	movl	4(%esp),%eax
-	movl	%eax,%gs
-	xor	%eax,%eax
-	movl	%eax,PCB_ONFAULT(%ecx)
-	ret
-load_gs_param_fault:
-	movl	_curpcb,%ecx
-	movl	$0,PCB_ONFAULT(%ecx)
-	movl	$EFAULT,%eax
-	ret
-
 /*****************************************************************************/
 /* setjump, longjump                                                         */
 /*****************************************************************************/
diff --git a/sys/amd64/amd64/support.s b/sys/amd64/amd64/support.s
index 6a6e9fc..ae99af9 100644
--- a/sys/amd64/amd64/support.s
+++ b/sys/amd64/amd64/support.s
@@ -1586,21 +1586,6 @@ ENTRY(load_cr4)
 	movl	%eax,%cr4
 	ret
 
-/* int load_gs_param(caddr_t gs) */
-ENTRY(load_gs_param)
-	movl	_curpcb,%ecx
-	movl	$load_gs_param_fault,PCB_ONFAULT(%ecx)
-	movl	4(%esp),%eax
-	movl	%eax,%gs
-	xor	%eax,%eax
-	movl	%eax,PCB_ONFAULT(%ecx)
-	ret
-load_gs_param_fault:
-	movl	_curpcb,%ecx
-	movl	$0,PCB_ONFAULT(%ecx)
-	movl	$EFAULT,%eax
-	ret
-
 /*****************************************************************************/
 /* setjump, longjump                                                         */
 /*****************************************************************************/
diff --git a/sys/amd64/include/md_var.h b/sys/amd64/include/md_var.h
index d9a43fa..e0bc65a 100644
--- a/sys/amd64/include/md_var.h
+++ b/sys/amd64/include/md_var.h
@@ -58,7 +58,7 @@ extern	void	(*netisrs[32]) __P((void));
 extern	int	nfs_diskless_valid;
 extern	void	(*ovbcopy_vector) __P((const void *from, void *to, size_t len));
 extern	char	sigcode[];
-extern	int	szsigcode;
+extern	int	szsigcode, oszsigcode;
 
 typedef void alias_for_inthand_t __P((u_int cs, u_int ef, u_int esp, u_int ss));
 struct	proc;
@@ -91,7 +91,6 @@ int	i586_copyout __P((const void *kaddr, void *udaddr, size_t len));
 void	i686_pagezero __P((void *addr));
 int	is_physical_memory __P((vm_offset_t addr));
 u_long	kvtop __P((void *addr));
-int	load_gs_param __P((u_int sel));
 void	setidt __P((int idx, alias_for_inthand_t *func, int typ, int dpl,
 		    int selec));
 void	swi_vm __P((void));
diff --git a/sys/amd64/include/ucontext.h b/sys/amd64/include/ucontext.h
index 6397a31..c0a3aa8 100644
--- a/sys/amd64/include/ucontext.h
+++ b/sys/amd64/include/ucontext.h
@@ -31,8 +31,6 @@
 #ifndef _MACHINE_UCONTEXT_H_
 #define	_MACHINE_UCONTEXT_H_
 
-#include <machine/frame.h>
-
 typedef struct __mcontext {
 	/*
 	 * The first 20 fields must match the definition of
diff --git a/sys/compat/svr4/svr4_signal.c b/sys/compat/svr4/svr4_signal.c
index 5b8838c..791e9f2 100644
--- a/sys/compat/svr4/svr4_signal.c
+++ b/sys/compat/svr4/svr4_signal.c
@@ -602,7 +602,7 @@ svr4_sys_context(p, uap)
 	case 0:
 		DPRINTF(("getcontext(%p)\n", uap->uc));
 		svr4_getcontext(p, &uc, &p->p_sigmask,
-		    p->p_sigacts->ps_sigstk.ss_flags & SS_ONSTACK);
+		    p->p_sigstk.ss_flags & SS_ONSTACK);
 		return copyout(&uc, uap->uc, sizeof(uc));
 
 	case 1: 
diff --git a/sys/i386/i386/genassym.c b/sys/i386/i386/genassym.c
index b95a9a7..d137b12 100644
--- a/sys/i386/i386/genassym.c
+++ b/sys/i386/i386/genassym.c
@@ -148,8 +148,18 @@ main()
 	printf("#define\tTF_EFLAGS %#x\n", OS(trapframe, tf_eflags));
 
 	printf("#define\tSIGF_HANDLER %#x\n", OS(sigframe, sf_ahu.sf_handler));
+	printf("#define\tSIGF_SC %#x\n", OS(osigframe, sf_siginfo.si_sc));
 	printf("#define\tSIGF_UC %#x\n", OS(sigframe, sf_uc));
 
+	printf("#define\tSC_PS %#x\n", OS(osigcontext, sc_ps));
+	printf("#define\tSC_FS %#x\n", OS(osigcontext, sc_fs));
+	printf("#define\tSC_GS %#x\n", OS(osigcontext, sc_gs));
+	printf("#define\tSC_TRAPNO %#x\n", OS(osigcontext, sc_trapno));
+
+	printf("#define\tUC_EFLAGS %#x\n",
+	    OS(__ucontext, uc_mcontext.mc_eflags));
+	printf("#define\tUC_GS %#x\n", OS(__ucontext, uc_mcontext.mc_gs));
+
 	printf("#define\tB_READ %#x\n", B_READ);
 	printf("#define\tENOENT %d\n", ENOENT);
 	printf("#define\tEFAULT %d\n", EFAULT);
diff --git a/sys/i386/i386/locore.s b/sys/i386/i386/locore.s
index a1b6ff7..2abcc80 100644
--- a/sys/i386/i386/locore.s
+++ b/sys/i386/i386/locore.s
@@ -417,19 +417,39 @@ NON_GPROF_ENTRY(sigcode)
 	call	SIGF_HANDLER(%esp)		/* call signal handler */
 	lea	SIGF_UC(%esp),%eax		/* get ucontext_t */
 	pushl	%eax
-	movl	$SYS_osigreturn,%eax
+	testl	$PSL_VM,UC_EFLAGS(%eax)
+	jne	9f
+	movl	UC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$SYS_sigreturn,%eax
 	pushl	%eax				/* junk to fake return addr. */
 	int	$0x80				/* enter kernel with args */
-						/* on stack */
-1:
-	jmp	1b
+0:	jmp	0b
+
+	ALIGN_TEXT
+_osigcode:
+	call	SIGF_HANDLER(%esp)		/* call signal handler */
+	lea	SIGF_SC(%esp),%eax		/* get sigcontext */
+	pushl	%eax
+	testl	$PSL_VM,SC_PS(%eax)
+	jne	9f
+	movl	SC_GS(%eax),%gs			/* restore %gs */
+9:
+	movl	$0x01d516,SC_TRAPNO(%eax)	/* magic: 0ldSiG */
+	movl	$SYS_sigreturn,%eax
+	pushl	%eax				/* junk to fake return addr. */
+	int	$0x80				/* enter kernel with args */
+0:	jmp	0b
+
 	ALIGN_TEXT
 _esigcode:
 
 	.data
-	.globl	_szsigcode
+	.globl	_szsigcode, _oszsigcode
 _szsigcode:
 	.long	_esigcode-_sigcode
+_oszsigcode:
+	.long	_esigcode-_osigcode
 	.text
 
 /**********************************************************************
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index a682098..0bc5838 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -483,14 +483,14 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* Allocate and validate space for the signal handler context. */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct osigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct osigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		fp = (struct osigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct osigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		fp = (struct osigframe *)regs->tf_esp - 1;
@@ -594,7 +594,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	}
 
 	regs->tf_esp = (int)fp;
-	regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	regs->tf_eip = PS_STRINGS - oszsigcode;
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
@@ -610,37 +610,34 @@ sendsig(catcher, sig, mask, code)
 	sigset_t *mask;
 	u_long code;
 {
-	struct proc *p;
+	struct proc *p = curproc;
 	struct trapframe *regs;
-	struct sigacts *psp;
+	struct sigacts *psp = p->p_sigacts;
 	struct sigframe sf, *sfp;
-	int onstack;
-
-	p = curproc;
+	int oonstack;
 
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
+	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
 
 	regs = p->p_md.md_regs;
-	psp = p->p_sigacts;
-	onstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* save user context */
 	bzero(&sf, sizeof(struct sigframe));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = psp->ps_sigstk;
-	sf.sf_uc.uc_mcontext.mc_onstack = onstack;
+	sf.sf_uc.uc_stack = p->p_sigstk;
+	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(struct trapframe));
 
 	/* Allocate and validate space for the signal handler context. */
-        if ((psp->ps_flags & SAS_ALTSTACK) != 0 && !onstack &&
+        if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct sigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sfp = (struct sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		sfp = (struct sigframe *)regs->tf_esp - 1;
@@ -770,9 +767,6 @@ osigreturn(p, uap)
 	register struct trapframe *regs = p->p_md.md_regs;
 	int eflags;
 
-	if ((p->p_flag & P_NEWSIGSET) != 0)
-		return sigreturn(p, (struct sigreturn_args *)uap);
-
 	scp = uap->sigcntxp;
 
 	if (useracc((caddr_t)scp, sizeof (struct osigcontext), B_WRITE) == 0)
@@ -841,10 +835,6 @@ osigreturn(p, uap)
 		regs->tf_ds = scp->sc_ds;
 		regs->tf_es = scp->sc_es;
 		regs->tf_fs = scp->sc_fs;
-		if (load_gs_param(scp->sc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	/* restore scratch registers */
@@ -859,11 +849,11 @@ osigreturn(p, uap)
 	regs->tf_isp = scp->sc_isp;
 
 	if (scp->sc_onstack & 01)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
-	OSIG2SIG(scp->sc_mask, p->p_sigmask);
+	SIGSETOLD(p->p_sigmask, scp->sc_mask);
 	SIG_CANTMASK(p->p_sigmask);
 	regs->tf_ebp = scp->sc_fp;
 	regs->tf_esp = scp->sc_sp;
@@ -883,7 +873,8 @@ sigreturn(p, uap)
 	ucontext_t *ucp;
 	int cs, eflags;
 
-	p->p_flag |= P_NEWSIGSET;
+	if (((struct osigcontext *)uap->sigcntxp)->sc_trapno == 0x01d516)
+		return osigreturn(p, (struct osigreturn_args *)uap);
 
 	regs = p->p_md.md_regs;
 	ucp = uap->sigcntxp;
@@ -956,16 +947,12 @@ sigreturn(p, uap)
 			return(EINVAL);
 		}
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(struct trapframe));
-		if (load_gs_param(ucp->uc_mcontext.mc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	p->p_sigmask = ucp->uc_sigmask;
 	SIG_CANTMASK(p->p_sigmask);
diff --git a/sys/i386/i386/support.s b/sys/i386/i386/support.s
index 6a6e9fc..ae99af9 100644
--- a/sys/i386/i386/support.s
+++ b/sys/i386/i386/support.s
@@ -1586,21 +1586,6 @@ ENTRY(load_cr4)
 	movl	%eax,%cr4
 	ret
 
-/* int load_gs_param(caddr_t gs) */
-ENTRY(load_gs_param)
-	movl	_curpcb,%ecx
-	movl	$load_gs_param_fault,PCB_ONFAULT(%ecx)
-	movl	4(%esp),%eax
-	movl	%eax,%gs
-	xor	%eax,%eax
-	movl	%eax,PCB_ONFAULT(%ecx)
-	ret
-load_gs_param_fault:
-	movl	_curpcb,%ecx
-	movl	$0,PCB_ONFAULT(%ecx)
-	movl	$EFAULT,%eax
-	ret
-
 /*****************************************************************************/
 /* setjump, longjump                                                         */
 /*****************************************************************************/
diff --git a/sys/i386/include/asnames.h b/sys/i386/include/asnames.h
index 930c227..8ab8dc7 100644
--- a/sys/i386/include/asnames.h
+++ b/sys/i386/include/asnames.h
@@ -258,6 +258,7 @@
 #define _normalize_nuo			normalize_nuo
 #define _npx_intr			npx_intr
 #define _npxsave			npxsave
+#define _oszsigcode			oszsigcode
 #define _ovbcopy_vector			ovbcopy_vector
 #define _panic				panic
 #define _pc98_system_parameter		pc98_system_parameter
diff --git a/sys/i386/include/md_var.h b/sys/i386/include/md_var.h
index d9a43fa..e0bc65a 100644
--- a/sys/i386/include/md_var.h
+++ b/sys/i386/include/md_var.h
@@ -58,7 +58,7 @@ extern	void	(*netisrs[32]) __P((void));
 extern	int	nfs_diskless_valid;
 extern	void	(*ovbcopy_vector) __P((const void *from, void *to, size_t len));
 extern	char	sigcode[];
-extern	int	szsigcode;
+extern	int	szsigcode, oszsigcode;
 
 typedef void alias_for_inthand_t __P((u_int cs, u_int ef, u_int esp, u_int ss));
 struct	proc;
@@ -91,7 +91,6 @@ int	i586_copyout __P((const void *kaddr, void *udaddr, size_t len));
 void	i686_pagezero __P((void *addr));
 int	is_physical_memory __P((vm_offset_t addr));
 u_long	kvtop __P((void *addr));
-int	load_gs_param __P((u_int sel));
 void	setidt __P((int idx, alias_for_inthand_t *func, int typ, int dpl,
 		    int selec));
 void	swi_vm __P((void));
diff --git a/sys/i386/include/ucontext.h b/sys/i386/include/ucontext.h
index 6397a31..c0a3aa8 100644
--- a/sys/i386/include/ucontext.h
+++ b/sys/i386/include/ucontext.h
@@ -31,8 +31,6 @@
 #ifndef _MACHINE_UCONTEXT_H_
 #define	_MACHINE_UCONTEXT_H_
 
-#include <machine/frame.h>
-
 typedef struct __mcontext {
 	/*
 	 * The first 20 fields must match the definition of
diff --git a/sys/i386/linux/linux_locore.s b/sys/i386/linux/linux_locore.s
index dbe2126..0cbf12e 100644
--- a/sys/i386/linux/linux_locore.s
+++ b/sys/i386/linux/linux_locore.s
@@ -1,3 +1,5 @@
+/* $FreeBSD$ */
+
 #include "linux_assym.h"			/* system definitions */
 #include <machine/asmacros.h>		/* miscellaneous asm macros */
 
@@ -6,12 +8,11 @@
 NON_GPROF_ENTRY(linux_sigcode)
 	call	LINUX_SIGF_HANDLER(%esp)
 	leal	LINUX_SIGF_SC(%esp),%ebx	/* linux scp */
-	movl	LINUX_SC_GS(%ebx),%edx
-	movl	%dx,%gs
+	movl	LINUX_SC_GS(%ebx),%gs
 	push	%eax				/* fake ret addr */
 	movl	$LINUX_SYS_linux_sigreturn,%eax	/* linux_sigreturn() */
-	int	$0x80				/* enter kernel with args on stack */
-	hlt					/* never gets here */
+	int	$0x80				/* enter kernel with args */
+0:	jmp	0b
 	ALIGN_TEXT
 _linux_esigcode:
 
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index ecaa359..d282439 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -198,7 +198,7 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
+	oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 
 #ifdef DEBUG
 	printf("Linux-emul(%ld): linux_sendsig(%p, %d, %p, %lu)\n",
@@ -207,11 +207,11 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/*
 	 * Allocate space for the signal handler context.
 	 */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, 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;
+		fp = (struct linux_sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct linux_sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else {
 		fp = (struct linux_sigframe *)regs->tf_esp - 1;
 	}
@@ -287,6 +287,7 @@ linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
 	regs->tf_fs = _udatasel;
+	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
 
@@ -354,12 +355,9 @@ linux_sigreturn(p, args)
 		return(EINVAL);
 	}
 
-	p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
-	SIGEMPTYSET(p->p_sigmask);
-	p->p_sigmask.__bits[0] = context.sc_mask;
-	SIGDELSET(p->p_sigmask, SIGKILL);
-	SIGDELSET(p->p_sigmask, SIGCONT);
-	SIGDELSET(p->p_sigmask, SIGSTOP);
+	p->p_sigstk.ss_flags &= ~SS_ONSTACK;
+	SIGSETOLD(p->p_sigmask, context.sc_mask);
+	SIG_CANTMASK(p->p_sigmask);
 
 	/*
 	 * Restore signal context.
diff --git a/sys/i386/svr4/svr4_locore.s b/sys/i386/svr4/svr4_locore.s
index 6c3b0ae..f6fb4ee 100644
--- a/sys/i386/svr4/svr4_locore.s
+++ b/sys/i386/svr4/svr4_locore.s
@@ -9,20 +9,16 @@ NON_GPROF_ENTRY(svr4_sigcode)
 	call	SVR4_SIGF_HANDLER(%esp)
 	leal	SVR4_SIGF_UC(%esp),%eax	# ucp (the call may have clobbered the
 					# copy at SIGF_UCP(%esp))
-#if defined(NOTYET)
 #ifdef VM86
 	testl	$PSL_VM,SVR4_UC_EFLAGS(%eax)
 	jnz	1f
 #endif
-#endif
-	movl	SVR4_UC_GS(%eax),%edx
-	movl	%dx,%gs
-1:	pushl	%eax			# fake return address
-	pushl	$1			# pointer to ucontext
+	movl	SVR4_UC_GS(%eax),%gs
+1:	pushl	%eax			# pointer to ucontext
+	pushl	$1			# set context
 	movl	$_svr4_sys_context,%eax
 	int	$0x80	 		# enter kernel with args on stack
-	movl	$exit,%eax
-	int	$0x80			# exit if sigreturn fails
+0:	jmp	0b
 
 	ALIGN_TEXT
 svr4_esigcode:
diff --git a/sys/i386/svr4/svr4_machdep.c b/sys/i386/svr4/svr4_machdep.c
index bc2e469..dc8e681 100644
--- a/sys/i386/svr4/svr4_machdep.c
+++ b/sys/i386/svr4/svr4_machdep.c
@@ -112,7 +112,7 @@ svr4_getcontext(p, uc, mask, oonstack)
 	struct svr4_sigaltstack *s = &uc->uc_stack;
 #ifdef DONE_MORE_SIGALTSTACK_WORK
 	struct sigacts *psp = p->p_sigacts;
-	struct sigaltstack *sf = &psp->ps_sigstk;
+	struct sigaltstack *sf = &p->p_sigstk;
 #endif
 
 	memset(uc, 0, sizeof(struct svr4_ucontext));
@@ -199,7 +199,7 @@ svr4_setcontext(p, uc)
 	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;
+	struct sigaltstack *sf = &p->p_sigstk;
 	sigset_t mask;
 
 	/*
@@ -276,8 +276,8 @@ svr4_setcontext(p, uc)
 	 */
 	if (uc->uc_flags & SVR4_UC_SIGMASK) {
 		svr4_to_bsd_sigset(&uc->uc_sigmask, &mask);
+		SIG_CANTMASK(mask);
 		p->p_sigmask = mask;
-		SIG_CANTMASK(p->p_sigmask);
 	}
 
 	return 0; /*EJUSTRETURN;*/
@@ -401,16 +401,16 @@ svr4_sendsig(catcher, sig, mask, code)
 	int oonstack;
 
 	tf = p->p_md.md_regs;
-	oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
+	oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 
 	/*
 	 * Allocate space for the signal handler context.
 	 */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, 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;
+		fp = (struct svr4_sigframe *)((caddr_t)p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct svr4_sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else {
 		fp = (struct svr4_sigframe *)tf->tf_esp - 1;
 	}
@@ -466,6 +466,7 @@ svr4_sendsig(catcher, sig, mask, code)
 	tf->tf_ds = _udatasel;
 	tf->tf_es = _udatasel;
 	tf->tf_fs = _udatasel;
+	load_gs(_udatasel);
 	tf->tf_ss = _udatasel;
 #endif
 }
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index ccb6a02..c82eca2 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -307,11 +307,11 @@ exit1(p, rv)
 	switchticks = ticks;
 
 	/*
-	 * Notify parent that we're gone.  If parent has the P_NOCLDWAIT
+	 * Notify parent that we're gone.  If parent has the PS_NOCLDWAIT
 	 * flag set, notify process 1 instead (and hope it will handle
 	 * this situation).
 	 */
-	if (p->p_pptr->p_procsig->ps_flag & P_NOCLDWAIT) {
+	if (p->p_pptr->p_procsig->ps_flag & PS_NOCLDWAIT) {
 		struct proc *pp = p->p_pptr;
 		proc_reparent(p, initproc);
 		/*
diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
index f5b0c1d..b375fbb 100644
--- a/sys/kern/kern_kthread.c
+++ b/sys/kern/kern_kthread.c
@@ -76,7 +76,8 @@ kthread_create(void (*func)(void *), void *arg,
 		*newpp = p2;
 
 	/* this is a non-swapped system process */
-	p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT;
+	p2->p_flag |= P_INMEM | P_SYSTEM;
+	p2->p_procsig->ps_flag |= PS_NOCLDWAIT;
 	PHOLD(p2);
 
 	/* set up arg0 for 'ps', et al */
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 3d3aaba..61cf219 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -71,9 +71,9 @@ static int sigprop	__P((int sig));
 static int sig_ffs	__P((sigset_t *set));
 static int killpg1	__P((struct proc *cp, int sig, int pgid, int all));
 static int do_sigaction	__P((struct proc *p, int sig, struct sigaction *act,
-			     struct sigaction *oact));
+			     struct sigaction *oact, int old));
 static int do_sigprocmask	__P((struct proc *p, int how, sigset_t *set,
-				     sigset_t *oset));
+				     sigset_t *oset, int old));
 static void stop	__P((struct proc *));
 static char *expand_name	__P((const char *, uid_t, pid_t));
 static int coredump	__P((struct proc *));
@@ -180,10 +180,11 @@ extern __inline int sig_ffs(sigset_t *set)
  * osigaction
  */
 static int
-do_sigaction(p, sig, act, oact)
+do_sigaction(p, sig, act, oact, old)
 	struct proc *p;
 	register int sig;
 	struct sigaction *act, *oact;
+	int old;
 {
 	register struct sigacts *ps = p->p_sigacts;
 
@@ -204,9 +205,9 @@ do_sigaction(p, sig, act, oact)
 			oact->sa_flags |= SA_NODEFER;
 		if (SIGISMEMBER(ps->ps_siginfo, sig))
 			oact->sa_flags |= SA_SIGINFO;
-		if (sig == SIGCHLD && p->p_procsig->ps_flag & P_NOCLDSTOP)
+		if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
 			oact->sa_flags |= SA_NOCLDSTOP;
-		if (sig == SIGCHLD && p->p_procsig->ps_flag & P_NOCLDWAIT)
+		if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
 			oact->sa_flags |= SA_NOCLDWAIT;
 	}
 	if (act) {
@@ -254,9 +255,9 @@ do_sigaction(p, sig, act, oact)
 #endif
 		if (sig == SIGCHLD) {
 			if (act->sa_flags & SA_NOCLDSTOP)
-				p->p_procsig->ps_flag |= P_NOCLDSTOP;
+				p->p_procsig->ps_flag |= PS_NOCLDSTOP;
 			else
-				p->p_procsig->ps_flag &= ~P_NOCLDSTOP;
+				p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
 			if (act->sa_flags & SA_NOCLDWAIT) {
 				/*
 				 * Paranoia: since SA_NOCLDWAIT is implemented
@@ -265,11 +266,11 @@ do_sigaction(p, sig, act, oact)
 				 * is forbidden to set SA_NOCLDWAIT.
 				 */
 				if (p->p_pid == 1)
-					p->p_procsig->ps_flag &= ~P_NOCLDWAIT;
+					p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
 				else
-					p->p_procsig->ps_flag |= P_NOCLDWAIT;
+					p->p_procsig->ps_flag |= PS_NOCLDWAIT;
 			} else
-				p->p_procsig->ps_flag &= ~P_NOCLDWAIT;
+				p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
 		}
 		/*
 		 * Set bit in p_sigignore for signals that are set to SIG_IGN,
@@ -286,14 +287,18 @@ do_sigaction(p, sig, act, oact)
 				/* easier in psignal */
 				SIGADDSET(p->p_sigignore, sig);
 			SIGDELSET(p->p_sigcatch, sig);
-		}
-		else {
+		} else {
 			SIGDELSET(p->p_sigignore, sig);
 			if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
 				SIGDELSET(p->p_sigcatch, sig);
 			else
 				SIGADDSET(p->p_sigcatch, sig);
 		}
+		if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
+		    ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old)
+			SIGDELSET(ps->ps_osigset, sig);
+		else
+			SIGADDSET(ps->ps_osigset, sig);
 
 		(void) spl0();
 	}
@@ -317,8 +322,6 @@ sigaction(p, uap)
 	register struct sigaction *actp, *oactp;
 	int error;
 
-	p->p_flag |= P_NEWSIGSET;
-
 	actp = (uap->act) ? &act : NULL;
 	oactp = (uap->oact) ? &oact : NULL;
 	if (actp) {
@@ -327,7 +330,7 @@ sigaction(p, uap)
 		if (error)
 			return (error);
 	}
-	error = do_sigaction(p, uap->sig, actp, oactp);
+	error = do_sigaction(p, uap->sig, actp, oactp, 0);
 	if (oactp && !error) {
 		error = copyout((caddr_t)oactp, (caddr_t)uap->oact,
 				sizeof(oact));
@@ -363,7 +366,7 @@ osigaction(p, uap)
 		nsap->sa_flags = sa.sa_flags;
 		OSIG2SIG(sa.sa_mask, nsap->sa_mask);
 	}
-	error = do_sigaction(p, uap->signum, nsap, osap);
+	error = do_sigaction(p, uap->signum, nsap, osap, 1);
 	if (osap && !error) {
 		sa.sa_handler = osap->sa_handler;
 		sa.sa_flags = osap->sa_flags;
@@ -417,14 +420,13 @@ execsigs(p)
 	 * Reset stack state to the user stack.
 	 * Clear set of signals caught on the signal stack.
 	 */
-	ps->ps_sigstk.ss_flags = SS_DISABLE;
-	ps->ps_sigstk.ss_size = 0;
-	ps->ps_sigstk.ss_sp = 0;
-	ps->ps_flags = 0;
+	p->p_sigstk.ss_flags = SS_DISABLE;
+	p->p_sigstk.ss_size = 0;
+	p->p_sigstk.ss_sp = 0;
 	/*
 	 * Reset no zombies if child dies flag as Solaris does.
 	 */
-	p->p_procsig->ps_flag &= ~P_NOCLDWAIT;
+	p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
 }
 
 /*
@@ -434,10 +436,11 @@ execsigs(p)
  * the library stub does the rest.
  */
 static int
-do_sigprocmask(p, how, set, oset)
+do_sigprocmask(p, how, set, oset, old)
 	struct proc *p;
 	int how;
 	sigset_t *set, *oset;
+	int old;
 {
 	int error;
 
@@ -449,15 +452,18 @@ do_sigprocmask(p, how, set, oset)
 		(void) splhigh();
 		switch (how) {
 		case SIG_BLOCK:
+			SIG_CANTMASK(*set);
 			SIGSETOR(p->p_sigmask, *set);
-			SIG_CANTMASK(p->p_sigmask);
 			break;
 		case SIG_UNBLOCK:
 			SIGSETNAND(p->p_sigmask, *set);
 			break;
 		case SIG_SETMASK:
-			p->p_sigmask = *set;
-			SIG_CANTMASK(p->p_sigmask);
+			SIG_CANTMASK(*set);
+			if (old)
+				SIGSETLO(p->p_sigmask, *set);
+			else
+				p->p_sigmask = *set;
 			break;
 		default:
 			error = EINVAL;
@@ -492,7 +498,7 @@ sigprocmask(p, uap)
 		if (error)
 			return (error);
 	}
-	error = do_sigprocmask(p, uap->how, setp, osetp);
+	error = do_sigprocmask(p, uap->how, setp, osetp, 0);
 	if (osetp && !error) {
 		error = copyout((caddr_t)osetp, (caddr_t)uap->oset,
 				sizeof(oset));
@@ -515,7 +521,7 @@ osigprocmask(p, uap)
 	int error;
 
 	OSIG2SIG(uap->mask, set);
-	error = do_sigprocmask(p, uap->how, &set, &oset);
+	error = do_sigprocmask(p, uap->how, &set, &oset, 1);
 	SIG2OSIG(oset, p->p_retval[0]);
 	return (error);
 }
@@ -588,7 +594,7 @@ osigvec(p, uap)
 		nsap->sa_flags |= SA_USERTRAMP;
 #endif
 	}
-	error = do_sigaction(p, uap->signum, nsap, osap);
+	error = do_sigaction(p, uap->signum, nsap, osap, 1);
 	if (osap && !error) {
 		vec.sv_handler = osap->sa_handler;
 		SIG2OSIG(osap->sa_mask, vec.sv_mask);
@@ -640,7 +646,7 @@ osigsetmask(p, uap)
 	SIG_CANTMASK(set);
 	(void) splhigh();
 	SIG2OSIG(p->p_sigmask, p->p_retval[0]);
-	p->p_sigmask = set;
+	SIGSETLO(p->p_sigmask, set);
 	(void) spl0();
 	return (0);
 }
@@ -671,15 +677,17 @@ sigsuspend(p, uap)
 		return (error);
 
 	/*
-	 * When returning from sigpause, we want
+	 * When returning from sigsuspend, we want
 	 * the old mask to be restored after the
 	 * signal handler has finished.  Thus, we
 	 * save it here and mark the sigacts structure
 	 * to indicate this.
 	 */
 	p->p_oldsigmask = p->p_sigmask;
+	p->p_flag |= P_OLDMASK;
+
+	SIG_CANTMASK(mask);
 	p->p_sigmask = mask;
-	SIG_CANTMASK(p->p_sigmask);
 	while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0)
 		/* void */;
 	/* always return EINTR rather than ERESTART... */
@@ -697,14 +705,15 @@ osigsuspend(p, uap)
 	register struct proc *p;
 	struct osigsuspend_args *uap;
 {
-	sigset_t set;
+	sigset_t mask;
 	register struct sigacts *ps = p->p_sigacts;
 
-	OSIG2SIG(uap->mask, set);
-	SIG_CANTMASK(set);
 	p->p_oldsigmask = p->p_sigmask;
-	p->p_sigmask = set;
-	while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0)
+	p->p_flag |= P_OLDMASK;
+	OSIG2SIG(uap->mask, mask);
+	SIG_CANTMASK(mask);
+	SIGSETLO(p->p_sigmask, mask);
+	while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "opause", 0) == 0)
 		/* void */;
 	/* always return EINTR rather than ERESTART... */
 	return (EINTR);
@@ -724,21 +733,19 @@ osigstack(p, uap)
 	register struct osigstack_args *uap;
 {
 	struct sigstack ss;
-	struct sigacts *psp;
 	int error = 0;
 
-	psp = p->p_sigacts;
-	ss.ss_sp = psp->ps_sigstk.ss_sp;
-	ss.ss_onstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
+	ss.ss_sp = p->p_sigstk.ss_sp;
+	ss.ss_onstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 	if (uap->oss && (error = copyout((caddr_t)&ss, (caddr_t)uap->oss,
 	    sizeof (struct sigstack))))
 		return (error);
 	if (uap->nss && (error = copyin((caddr_t)uap->nss, (caddr_t)&ss,
 	    sizeof (ss))) == 0) {
-		psp->ps_sigstk.ss_sp = ss.ss_sp;
-		psp->ps_sigstk.ss_size = 0;
-		psp->ps_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK;
-		psp->ps_flags |= SAS_ALTSTACK;
+		p->p_sigstk.ss_sp = ss.ss_sp;
+		p->p_sigstk.ss_size = 0;
+		p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK;
+		p->p_flag |= P_ALTSTACK;
 	}
 	return (error);
 }
@@ -756,14 +763,12 @@ sigaltstack(p, uap)
 	struct proc *p;
 	register struct sigaltstack_args *uap;
 {
-	struct sigacts *psp;
 	stack_t ss;
 	int error;
 
-	psp = p->p_sigacts;
-	if ((psp->ps_flags & SAS_ALTSTACK) == 0)
-		psp->ps_sigstk.ss_flags |= SS_DISABLE;
-	if (uap->oss && (error = copyout((caddr_t)&psp->ps_sigstk,
+	if ((p->p_flag & P_ALTSTACK) == 0)
+		p->p_sigstk.ss_flags |= SS_DISABLE;
+	if (uap->oss && (error = copyout((caddr_t)&p->p_sigstk,
 	    (caddr_t)uap->oss, sizeof (stack_t))))
 		return (error);
 	if (uap->ss == 0)
@@ -771,16 +776,16 @@ sigaltstack(p, uap)
 	if ((error = copyin((caddr_t)uap->ss, (caddr_t)&ss, sizeof (ss))))
 		return (error);
 	if (ss.ss_flags & SS_DISABLE) {
-		if (psp->ps_sigstk.ss_flags & SS_ONSTACK)
+		if (p->p_sigstk.ss_flags & SS_ONSTACK)
 			return (EINVAL);
-		psp->ps_flags &= ~SAS_ALTSTACK;
-		psp->ps_sigstk.ss_flags = ss.ss_flags;
+		p->p_flag &= ~P_ALTSTACK;
+		p->p_sigstk.ss_flags = ss.ss_flags;
 		return (0);
 	}
 	if (ss.ss_size < MINSIGSTKSZ)
 		return (ENOMEM);
-	psp->ps_flags |= SAS_ALTSTACK;
-	psp->ps_sigstk = ss;
+	p->p_flag |= P_ALTSTACK;
+	p->p_sigstk = ss;
 	return (0);
 }
 
@@ -1093,7 +1098,7 @@ psignal(p, sig)
 				goto out;
 			SIGDELSET(p->p_siglist, sig);
 			p->p_xstat = sig;
-			if ((p->p_pptr->p_procsig->ps_flag & P_NOCLDSTOP) == 0)
+			if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
 				psignal(p->p_pptr, SIGCHLD);
 			stop(p);
 			goto out;
@@ -1300,7 +1305,7 @@ issignal(p)
 					break;	/* == ignore */
 				p->p_xstat = sig;
 				stop(p);
-				if ((p->p_pptr->p_procsig->ps_flag & P_NOCLDSTOP) == 0)
+				if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
 					psignal(p->p_pptr, SIGCHLD);
 				mi_switch();
 				break;
@@ -1372,8 +1377,7 @@ postsig(sig)
 	action = ps->ps_sigact[_SIG_IDX(sig)];
 #ifdef KTRACE
 	if (KTRPOINT(p, KTR_PSIG))
-		ktrpsig(p->p_tracep,
-		    sig, action, SIGNOTEMPTY(p->p_oldsigmask) ?
+		ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ?
 		    &p->p_oldsigmask : &p->p_sigmask, 0);
 #endif
 	STOPEVENT(p, S_SIG, sig);
@@ -1393,17 +1397,17 @@ postsig(sig)
 		    ("postsig action"));
 		/*
 		 * Set the new mask value and also defer further
-		 * occurences of this signal.
+		 * occurrences of this signal.
 		 *
-		 * Special case: user has done a sigpause.  Here the
+		 * Special case: user has done a sigsuspend.  Here the
 		 * current mask is not of interest, but rather the
-		 * mask from before the sigpause is what we want
+		 * mask from before the sigsuspend is what we want
 		 * restored after the signal processing is completed.
 		 */
 		(void) splhigh();
-		if (SIGNOTEMPTY(p->p_oldsigmask)) {
+		if (p->p_flag & P_OLDMASK) {
 			returnmask = p->p_oldsigmask;
-			SIGEMPTYSET(p->p_oldsigmask);
+			p->p_flag &= ~P_OLDMASK;
 		} else
 			returnmask = p->p_sigmask;
 
diff --git a/sys/pc98/i386/machdep.c b/sys/pc98/i386/machdep.c
index 08430ca..c69e339 100644
--- a/sys/pc98/i386/machdep.c
+++ b/sys/pc98/i386/machdep.c
@@ -496,14 +496,14 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* Allocate and validate space for the signal handler context. */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct osigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct osigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		fp = (struct osigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct osigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		fp = (struct osigframe *)regs->tf_esp - 1;
@@ -546,11 +546,10 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	else {
 		/* Old FreeBSD-style arguments. */
 		sf.sf_arg2 = code;
+		sf.sf_addr = (char *)regs->tf_err;
 		sf.sf_ahu.sf_handler = catcher;
 	}
 
-	sf.sf_addr = (char *) regs->tf_err;
-
 	/* save scratch registers */
 	sf.sf_siginfo.si_sc.sc_eax = regs->tf_eax;
 	sf.sf_siginfo.si_sc.sc_ebx = regs->tf_ebx;
@@ -608,7 +607,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	}
 
 	regs->tf_esp = (int)fp;
-	regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	regs->tf_eip = PS_STRINGS - oszsigcode;
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
@@ -624,37 +623,34 @@ sendsig(catcher, sig, mask, code)
 	sigset_t *mask;
 	u_long code;
 {
-	struct proc *p;
+	struct proc *p = curproc;
 	struct trapframe *regs;
-	struct sigacts *psp;
+	struct sigacts *psp = p->p_sigacts;
 	struct sigframe sf, *sfp;
-	int onstack;
-
-	p = curproc;
+	int oonstack;
 
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
+	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
 
 	regs = p->p_md.md_regs;
-	psp = p->p_sigacts;
-	onstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* save user context */
 	bzero(&sf, sizeof(struct sigframe));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = psp->ps_sigstk;
-	sf.sf_uc.uc_mcontext.mc_onstack = onstack;
+	sf.sf_uc.uc_stack = p->p_sigstk;
+	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(struct trapframe));
 
 	/* Allocate and validate space for the signal handler context. */
-        if ((psp->ps_flags & SAS_ALTSTACK) != 0 && !onstack &&
+        if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct sigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sfp = (struct sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		sfp = (struct sigframe *)regs->tf_esp - 1;
@@ -703,6 +699,7 @@ sendsig(catcher, sig, mask, code)
 	else {
 		/* Old FreeBSD-style arguments. */
 		sf.sf_siginfo = code;
+		sf.sf_addr = (char *)regs->tf_err;
 		sf.sf_ahu.sf_handler = catcher;
 	}
 
@@ -783,9 +780,6 @@ osigreturn(p, uap)
 	register struct trapframe *regs = p->p_md.md_regs;
 	int eflags;
 
-	if ((p->p_flag & P_NEWSIGSET) != 0)
-		return sigreturn(p, (struct sigreturn_args *)uap);
-
 	scp = uap->sigcntxp;
 
 	if (useracc((caddr_t)scp, sizeof (struct osigcontext), B_WRITE) == 0)
@@ -854,10 +848,6 @@ osigreturn(p, uap)
 		regs->tf_ds = scp->sc_ds;
 		regs->tf_es = scp->sc_es;
 		regs->tf_fs = scp->sc_fs;
-		if (load_gs_param(scp->sc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	/* restore scratch registers */
@@ -872,11 +862,11 @@ osigreturn(p, uap)
 	regs->tf_isp = scp->sc_isp;
 
 	if (scp->sc_onstack & 01)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
-	OSIG2SIG(scp->sc_mask, p->p_sigmask);
+	SIGSETOLD(p->p_sigmask, scp->sc_mask);
 	SIG_CANTMASK(p->p_sigmask);
 	regs->tf_ebp = scp->sc_fp;
 	regs->tf_esp = scp->sc_sp;
@@ -896,7 +886,8 @@ sigreturn(p, uap)
 	ucontext_t *ucp;
 	int cs, eflags;
 
-	p->p_flag |= P_NEWSIGSET;
+	if (((struct osigcontext *)uap->sigcntxp)->sc_trapno == 0x01d516)
+		return osigreturn(p, (struct osigreturn_args *)uap);
 
 	regs = p->p_md.md_regs;
 	ucp = uap->sigcntxp;
@@ -969,16 +960,12 @@ sigreturn(p, uap)
 			return(EINVAL);
 		}
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(struct trapframe));
-		if (load_gs_param(ucp->uc_mcontext.mc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	p->p_sigmask = ucp->uc_sigmask;
 	SIG_CANTMASK(p->p_sigmask);
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index 08430ca..c69e339 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -496,14 +496,14 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	int oonstack;
 
 	regs = p->p_md.md_regs;
-	oonstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* Allocate and validate space for the signal handler context. */
-	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
+	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct osigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct osigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		fp = (struct osigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct osigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		fp = (struct osigframe *)regs->tf_esp - 1;
@@ -546,11 +546,10 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	else {
 		/* Old FreeBSD-style arguments. */
 		sf.sf_arg2 = code;
+		sf.sf_addr = (char *)regs->tf_err;
 		sf.sf_ahu.sf_handler = catcher;
 	}
 
-	sf.sf_addr = (char *) regs->tf_err;
-
 	/* save scratch registers */
 	sf.sf_siginfo.si_sc.sc_eax = regs->tf_eax;
 	sf.sf_siginfo.si_sc.sc_ebx = regs->tf_ebx;
@@ -608,7 +607,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	}
 
 	regs->tf_esp = (int)fp;
-	regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	regs->tf_eip = PS_STRINGS - oszsigcode;
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
@@ -624,37 +623,34 @@ sendsig(catcher, sig, mask, code)
 	sigset_t *mask;
 	u_long code;
 {
-	struct proc *p;
+	struct proc *p = curproc;
 	struct trapframe *regs;
-	struct sigacts *psp;
+	struct sigacts *psp = p->p_sigacts;
 	struct sigframe sf, *sfp;
-	int onstack;
-
-	p = curproc;
+	int oonstack;
 
-	if ((p->p_flag & P_NEWSIGSET) == 0) {
+	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
 
 	regs = p->p_md.md_regs;
-	psp = p->p_sigacts;
-	onstack = (psp->ps_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
+	oonstack = (p->p_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
 
 	/* save user context */
 	bzero(&sf, sizeof(struct sigframe));
 	sf.sf_uc.uc_sigmask = *mask;
-	sf.sf_uc.uc_stack = psp->ps_sigstk;
-	sf.sf_uc.uc_mcontext.mc_onstack = onstack;
+	sf.sf_uc.uc_stack = p->p_sigstk;
+	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
 	sf.sf_uc.uc_mcontext.mc_gs = rgs();
 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(struct trapframe));
 
 	/* Allocate and validate space for the signal handler context. */
-        if ((psp->ps_flags & SAS_ALTSTACK) != 0 && !onstack &&
+        if ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		sfp = (struct sigframe *)(psp->ps_sigstk.ss_sp +
-		    psp->ps_sigstk.ss_size - sizeof(struct sigframe));
-		psp->ps_sigstk.ss_flags |= SS_ONSTACK;
+		sfp = (struct sigframe *)(p->p_sigstk.ss_sp +
+		    p->p_sigstk.ss_size - sizeof(struct sigframe));
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	}
 	else
 		sfp = (struct sigframe *)regs->tf_esp - 1;
@@ -703,6 +699,7 @@ sendsig(catcher, sig, mask, code)
 	else {
 		/* Old FreeBSD-style arguments. */
 		sf.sf_siginfo = code;
+		sf.sf_addr = (char *)regs->tf_err;
 		sf.sf_ahu.sf_handler = catcher;
 	}
 
@@ -783,9 +780,6 @@ osigreturn(p, uap)
 	register struct trapframe *regs = p->p_md.md_regs;
 	int eflags;
 
-	if ((p->p_flag & P_NEWSIGSET) != 0)
-		return sigreturn(p, (struct sigreturn_args *)uap);
-
 	scp = uap->sigcntxp;
 
 	if (useracc((caddr_t)scp, sizeof (struct osigcontext), B_WRITE) == 0)
@@ -854,10 +848,6 @@ osigreturn(p, uap)
 		regs->tf_ds = scp->sc_ds;
 		regs->tf_es = scp->sc_es;
 		regs->tf_fs = scp->sc_fs;
-		if (load_gs_param(scp->sc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	/* restore scratch registers */
@@ -872,11 +862,11 @@ osigreturn(p, uap)
 	regs->tf_isp = scp->sc_isp;
 
 	if (scp->sc_onstack & 01)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
-	OSIG2SIG(scp->sc_mask, p->p_sigmask);
+	SIGSETOLD(p->p_sigmask, scp->sc_mask);
 	SIG_CANTMASK(p->p_sigmask);
 	regs->tf_ebp = scp->sc_fp;
 	regs->tf_esp = scp->sc_sp;
@@ -896,7 +886,8 @@ sigreturn(p, uap)
 	ucontext_t *ucp;
 	int cs, eflags;
 
-	p->p_flag |= P_NEWSIGSET;
+	if (((struct osigcontext *)uap->sigcntxp)->sc_trapno == 0x01d516)
+		return osigreturn(p, (struct osigreturn_args *)uap);
 
 	regs = p->p_md.md_regs;
 	ucp = uap->sigcntxp;
@@ -969,16 +960,12 @@ sigreturn(p, uap)
 			return(EINVAL);
 		}
 		bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(struct trapframe));
-		if (load_gs_param(ucp->uc_mcontext.mc_gs)) {
-			trapsignal(p, SIGBUS, T_SEGNPFLT);
-			return (EFAULT);
-		}
 	}
 
 	if (ucp->uc_mcontext.mc_onstack & 1)
-		p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK;
+		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	else
-		p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
+		p->p_sigstk.ss_flags &= ~SS_ONSTACK;
 
 	p->p_sigmask = ucp->uc_sigmask;
 	SIG_CANTMASK(p->p_sigmask);
diff --git a/sys/svr4/svr4_signal.c b/sys/svr4/svr4_signal.c
index 5b8838c..791e9f2 100644
--- a/sys/svr4/svr4_signal.c
+++ b/sys/svr4/svr4_signal.c
@@ -602,7 +602,7 @@ svr4_sys_context(p, uap)
 	case 0:
 		DPRINTF(("getcontext(%p)\n", uap->uc));
 		svr4_getcontext(p, &uc, &p->p_sigmask,
-		    p->p_sigacts->ps_sigstk.ss_flags & SS_ONSTACK);
+		    p->p_sigstk.ss_flags & SS_ONSTACK);
 		return copyout(&uc, uap->uc, sizeof(uc));
 
 	case 1: 
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index f3cee66..8144a46 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -85,6 +85,9 @@ struct	procsig {
 	int	 ps_refcnt;
 };
 
+#define	PS_NOCLDWAIT	0x0001	/* No zombies if child dies */
+#define	PS_NOCLDSTOP	0x0002	/* No SIGCHLD when children stop. */
+
 /*
  * pasleep structure, used by asleep() syscall to hold requested priority
  * and timeout values for await().
@@ -197,6 +200,7 @@ struct	proc {
 #define	p_startcopy	p_sigmask
 
 	sigset_t p_sigmask;	/* Current signal mask. */
+	stack_t	p_sigstk;	/* sp & on stack state variable */
 	u_char	p_priority;	/* Process priority. */
 	u_char	p_usrpri;	/* User-priority based on p_cpu and p_nice. */
 	char	p_nice;		/* Process "nice" value. */
@@ -240,7 +244,6 @@ struct	proc {
 #define	P_ADVLOCK	0x00001	/* Process may hold a POSIX advisory lock. */
 #define	P_CONTROLT	0x00002	/* Has a controlling terminal. */
 #define	P_INMEM		0x00004	/* Loaded into memory. */
-#define	P_NOCLDSTOP	0x00008	/* No SIGCHLD when children stop. */
 #define	P_PPWAIT	0x00010	/* Parent is waiting for child to exec/exit. */
 #define	P_PROFIL	0x00020	/* Has started profiling. */
 #define	P_SELECT	0x00040	/* Selecting; wakeup/waiting danger. */
@@ -264,14 +267,14 @@ struct	proc {
 #define	P_SWAPINREQ	0x80000	/* Swapin request due to wakeup */
 
 /* Marked a kernel thread */
-#define P_BUFEXHAUST	0x100000 /* dirty buffers flush is in progress */
-#define P_KTHREADP	0x200000 /* Process is really a kernel thread */
+#define	P_BUFEXHAUST	0x100000 /* dirty buffers flush is in progress */
+#define	P_KTHREADP	0x200000 /* Process is really a kernel thread */
 
-#define	P_NOCLDWAIT	0x400000 /* No zombies if child dies */
-#define P_DEADLKTREAT   0x800000 /* lock aquisition - deadlock treatment */
+#define	P_DEADLKTREAT   0x800000 /* lock aquisition - deadlock treatment */
 
-#define P_JAILED	0x1000000 /* Process is in jail */
-#define P_NEWSIGSET	0x2000000 /* Process uses new sigset_t */
+#define	P_JAILED	0x1000000 /* Process is in jail */
+#define	P_OLDMASK	0x2000000 /* need to restore mask before pause */
+#define	P_ALTSTACK	0x4000000 /* have alternate signal stack */
 
 /*
  * MOVE TO ucred.h?
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index 99b26bd..554d649 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -59,15 +59,9 @@ struct	sigacts {
 	sigset_t ps_sigreset;		/* signals that reset when caught */
 	sigset_t ps_signodefer;		/* signals not masked while handled */
 	sigset_t ps_siginfo;		/* signals that want SA_SIGINFO args */
-	int	ps_flags;		/* signal flags, below */
-	stack_t	ps_sigstk;		/* sp & on stack state variable */
-	sigset_t ps_usertramp;		/* SunOS compat; libc sigtramp XXX */
+	sigset_t ps_osigset;		/* signals that use osigset_t */
 };
 
-/* signal flags */
-#define	SAS_OLDMASK	0x01		/* need to restore mask before pause */
-#define	SAS_ALTSTACK	0x02		/* have alternate signal stack */
-
 /*
  * Compatibility
  */
@@ -154,6 +148,9 @@ typedef void __osiginfohandler_t __P((int, osiginfo_t *, void *));
 			(set1).__bits[__i] &= ~(set2).__bits[__i];	\
 	} while (0)
 
+#define SIGSETLO(set1, set2)	((set1).__bits[0] = (set2).__bits[0])
+#define SIGSETOLD(set, oset)	((set).__bits[0] = (oset))
+
 #define SIG_CANTMASK(set)						\
 	SIGDELSET(set, SIGKILL), SIGDELSET(set, SIGSTOP)
 
diff --git a/sys/sys/ucontext.h b/sys/sys/ucontext.h
index 8f554e0..7f10da5 100644
--- a/sys/sys/ucontext.h
+++ b/sys/sys/ucontext.h
@@ -45,7 +45,7 @@ typedef struct __ucontext {
 	sigset_t	uc_sigmask;
 	mcontext_t	uc_mcontext;
 
-	struct __ucontext_t *uc_link;
+	struct __ucontext *uc_link;
 	stack_t		uc_stack;
 	int		__spare__[8];
 } ucontext_t;