Pre-freeze cleanups: Conditionalize debugging writes on DEBUG_SVR4,

eliminate warnings, etc.

Note that svr4_setcontext() and svr4_getcontext() currently don't work
correctly, which makes returning from signal handlers somewhat problematic
(for reference:  the SysVR4 setcontext() and getcontext() syscalls behave
like a low-level version of setjmp() and longjmp(), in that they save and
restore process context.  SysVR4 uses this to implement its signal handler
trampoline:  The context which is saved before a signal handler is called
is restored by an implicit call to the setcontext() syscall when the signal
handler returns.  That currently doesn't work right in this emulator,
although it used to).

I'm committing this anyway, with a caveat that it's buggy, so that I can
(a) note the bug for anyone who is wondering about it, and (b) get the
stuff I've done to improve (but not fix) the situation in the tree before
4.0 is released.  If I have time to fix it totally RSN I'll talk to Jordan
to see if I can bend him into letting me commit a bugfix :-)

Note that the situation now is somewhat better than it was yesterday
anyway, because I've fixed the handling of svr4_sigsets which previously
was causing signal handlers to not get called at all.  Stay tuned for
an upcoming commit to svr4_signal.c...

1 files changed, 32 insertions, 11 deletions

diff --git a/sys/i386/svr4/svr4_machdep.c b/sys/i386/svr4/svr4_machdep.c
index bd44470..d6fa3b9 100644
--- a/sys/i386/svr4/svr4_machdep.c
+++ b/sys/i386/svr4/svr4_machdep.c
@@ -97,7 +97,7 @@ svr4_getcontext(p, uc, mask, oonstack)
 	struct trapframe *tf = p->p_md.md_regs;
 	svr4_greg_t *r = uc->uc_mcontext.greg;
 	struct svr4_sigaltstack *s = &uc->uc_stack;
-#ifdef DONE_MORE_SIGALTSTACK_WORK
+#if defined(DONE_MORE_SIGALTSTACK_WORK)
 	struct sigacts *psp = p->p_sigacts;
 	struct sigaltstack *sf = &p->p_sigstk;
 #endif
@@ -147,7 +147,7 @@ svr4_getcontext(p, uc, mask, oonstack)
 	/*
 	 * Set the signal stack
 	 */
-#if DONE_MORE_SIGALTSTACK_WORK
+#if defined(DONE_MORE_SIGALTSTACK_WORK)
 	bsd_to_svr4_sigaltstack(sf, s);
 #else
 	s->ss_sp = (void *)(((u_long) tf->tf_esp) & ~(16384 - 1));
@@ -163,13 +163,12 @@ svr4_getcontext(p, uc, mask, oonstack)
 	/*
 	 * Set the flags
 	 */
-	uc->uc_flags = SVR4_UC_STACK|SVR4_UC_SIGMASK|SVR4_UC_CPU;
+	uc->uc_flags = SVR4_UC_SIGMASK|SVR4_UC_CPU|SVR4_UC_STACK;
 }
 
 
 /*
- * Set to ucontext specified.
- * has been taken.  Reset signal mask and
+ * 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
@@ -182,7 +181,9 @@ svr4_setcontext(p, uc)
 	struct proc *p;
 	struct svr4_ucontext *uc;
 {
+#if defined(DONE_MORE_SIGALTSTACK_WORK)
 	struct sigacts *psp = p->p_sigacts;
+#endif
 	register struct trapframe *tf;
 	svr4_greg_t *r = uc->uc_mcontext.greg;
 	struct svr4_sigaltstack *s = &uc->uc_stack;
@@ -201,12 +202,15 @@ svr4_setcontext(p, uc)
 	if ((uc->uc_flags & SVR4_UC_CPU) == 0)
 		return 0;
 
+	DPRINTF(("svr4_setcontext(%d)\n", p->p_pid));
+
 	tf = p->p_md.md_regs;
 
 	/*
 	 * 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];
@@ -262,6 +266,14 @@ svr4_setcontext(p, uc)
 	 * 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);
 		p->p_sigmask = mask;
@@ -356,9 +368,9 @@ svr4_getsiginfo(si, sig, code, addr)
 	default:
 		si->si_code = 0;
 		si->si_trap = 0;
-#ifdef DIAGNOSTIC
+#if defined(DEBUG_SVR4)
 		printf("sig %d code %ld\n", sig, code);
-		panic("svr4_getsiginfo");
+/*		panic("svr4_getsiginfo");*/
 #endif
 		break;
 	}
@@ -387,6 +399,10 @@ svr4_sendsig(catcher, sig, mask, code)
 	struct sigacts *psp = p->p_sigacts;
 	int oonstack;
 
+#if defined(DEBUG_SVR4)
+	printf("svr4_sendsig(%d)\n", sig);
+#endif
+
 	tf = p->p_md.md_regs;
 	oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
 
@@ -395,7 +411,7 @@ svr4_sendsig(catcher, sig, mask, code)
 	 */
 	if ((p->p_flag & P_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
-		fp = (struct svr4_sigframe *)((caddr_t)p->p_sigstk.ss_sp +
+		fp = (struct svr4_sigframe *)(p->p_sigstk.ss_sp +
 		    p->p_sigstk.ss_size - sizeof(struct svr4_sigframe));
 		p->p_sigstk.ss_flags |= SS_ONSTACK;
 	} else {
@@ -413,14 +429,18 @@ svr4_sendsig(catcher, sig, mask, code)
 	 */
 
 	svr4_getcontext(p, &frame.sf_uc, mask, oonstack);
-	DPRINTF(("obtained ucontext\n"));
+#if defined(DEBUG_SVR4)
+	printf("obtained ucontext\n");
+#endif
 	svr4_getsiginfo(&frame.sf_si, sig, code, (caddr_t) tf->tf_eip);
-	DPRINTF(("obtained siginfo\n"));
+#if defined(DEBUG_SVR4)
+	printf("obtained siginfo\n");
+#endif
 	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
+#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
@@ -476,6 +496,7 @@ svr4_sys_sysarch(p, v)
 
 	case SVR4_SYSARCH_DSCR:
 #ifdef 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;