There is a bunch of places in the kernel entry points where we don't

hold the kernel lock, but still need call one function that needs it.

Instead of grabbing the lock all over the place, move the locks into
the affected functions: trapsignal, scdebug*, ktrsyscall, ktrsysret,
systrace_redirect and ADDUPROF. In the cases we already hold the biglock
we'll just recurse.

kettenis@, beck@ ok

3 files changed, 3 insertions, 35 deletions

diff --git a/sys/arch/amd64/amd64/fpu.c b/sys/arch/amd64/amd64/fpu.c
index 1c36e6e7443..ae53cbf65fb 100644
--- a/sys/arch/amd64/amd64/fpu.c
+++ b/sys/arch/amd64/amd64/fpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fpu.c,v 1.23 2011/07/06 21:41:37 art Exp $	*/
+/*	$OpenBSD: fpu.c,v 1.24 2011/07/07 18:11:23 art Exp $	*/
 /*	$NetBSD: fpu.c,v 1.1 2003/04/26 18:39:28 fvdl Exp $	*/
 
 /*-
@@ -166,9 +166,7 @@ fputrap(struct trapframe *frame)
 	sfp->fp_ex_sw = sfp->fp_fxsave.fx_fsw;
 	code = x86fpflags_to_siginfo (statbits);
 	sv.sival_ptr = (void *)frame->tf_rip;	/* XXX - ? */
-	KERNEL_LOCK();
 	trapsignal(p, SIGFPE, frame->tf_err, code, sv);
-	KERNEL_UNLOCK();
 }
 
 static int
diff --git a/sys/arch/amd64/amd64/syscall.c b/sys/arch/amd64/amd64/syscall.c
index e43c2f61227..e8fa341ef92 100644
--- a/sys/arch/amd64/amd64/syscall.c
+++ b/sys/arch/amd64/amd64/syscall.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: syscall.c,v 1.17 2011/07/06 21:41:37 art Exp $	*/
+/*	$OpenBSD: syscall.c,v 1.18 2011/07/07 18:11:23 art Exp $	*/
 /*	$NetBSD: syscall.c,v 1.1 2003/04/26 18:39:32 fvdl Exp $	*/
 
 /*-
@@ -127,24 +127,18 @@ syscall(struct trapframe *frame)
 	lock = !(callp->sy_flags & SY_NOLOCK);
 
 #ifdef SYSCALL_DEBUG
-	KERNEL_LOCK();
 	scdebug_call(p, code, argp);
-	KERNEL_UNLOCK();
 #endif
 #ifdef KTRACE
 	if (KTRPOINT(p, KTR_SYSCALL)) {
-		KERNEL_LOCK();
 		ktrsyscall(p, code, callp->sy_argsize, argp);
-		KERNEL_UNLOCK();
 	}
 #endif
 	rval[0] = 0;
 	rval[1] = frame->tf_rdx;
 #if NSYSTRACE > 0
 	if (ISSET(p->p_flag, P_SYSTRACE)) {
-		KERNEL_LOCK();
 		error = systrace_redirect(code, p, argp, rval);
-		KERNEL_UNLOCK();
 	} else
 #endif
 	{
@@ -179,16 +173,12 @@ syscall(struct trapframe *frame)
 	}
 
 #ifdef SYSCALL_DEBUG
-	KERNEL_LOCK();
 	scdebug_ret(p, code, error, rval);
-	KERNEL_UNLOCK();
 #endif
 	userret(p);
 #ifdef KTRACE
 	if (KTRPOINT(p, KTR_SYSRET)) {
-		KERNEL_LOCK();
 		ktrsysret(p, code, error, rval[0]);
-		KERNEL_UNLOCK();
 	}
 #endif
 }
@@ -208,12 +198,10 @@ child_return(void *arg)
 	userret(p);
 #ifdef KTRACE
 	if (KTRPOINT(p, KTR_SYSRET)) {
-		KERNEL_LOCK();
 		ktrsysret(p,
 		    (p->p_flag & P_THREAD) ? SYS_rfork :
 		    (p->p_p->ps_flags & PS_PPWAIT) ? SYS_vfork : SYS_fork,
 		    0, 0);
-		KERNEL_UNLOCK();
 	}
 #endif
 }
diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 10d1cc5ce2b..ff2c2330724 100644
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.23 2011/07/06 21:41:37 art Exp $	*/
+/*	$OpenBSD: trap.c,v 1.24 2011/07/07 18:11:23 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $	*/
 
 /*-
@@ -250,22 +250,16 @@ copyfault:
 		frame_dump(frame);
 #endif
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGBUS, type & ~T_USER, BUS_OBJERR, sv);
-		KERNEL_UNLOCK();
 		goto out;
 	case T_ALIGNFLT|T_USER:
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGBUS, type & ~T_USER, BUS_ADRALN, sv);
-		KERNEL_UNLOCK();
 		goto out;
 
 	case T_PRIVINFLT|T_USER:	/* privileged instruction fault */
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGILL, type & ~T_USER, ILL_PRVOPC, sv);
-		KERNEL_UNLOCK();
 		goto out;
 	case T_FPOPFLT|T_USER:		/* coprocessor operand fault */
 #ifdef TRAP_SIGDEBUG
@@ -274,17 +268,13 @@ copyfault:
 		frame_dump(frame);
 #endif
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGILL, type & ~T_USER, ILL_COPROC, sv);
-		KERNEL_UNLOCK();
 		goto out;
 
 	case T_ASTFLT|T_USER:		/* Allow process switch */
 		uvmexp.softs++;
 		if (p->p_flag & P_OWEUPC) {
-			KERNEL_LOCK();
 			ADDUPROF(p);
-			KERNEL_UNLOCK();
 		}
 		/* Allow a forced task switch. */
 		if (curcpu()->ci_want_resched)
@@ -293,21 +283,15 @@ copyfault:
 
 	case T_BOUND|T_USER:
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGFPE, type &~ T_USER, FPE_FLTSUB, sv);
-		KERNEL_UNLOCK();
 		goto out;
 	case T_OFLOW|T_USER:
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTOVF, sv);
-		KERNEL_UNLOCK();
 		goto out;
 	case T_DIVIDE|T_USER:
 		sv.sival_ptr = (void *)frame->tf_rip;
-		KERNEL_LOCK();
 		trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTDIV, sv);
-		KERNEL_UNLOCK();
 		goto out;
 
 	case T_ARITHTRAP|T_USER:
@@ -421,9 +405,7 @@ faultcommon:
 #ifdef MATH_EMULATE
 	trace:
 #endif
-		KERNEL_LOCK();
 		trapsignal(p, SIGTRAP, type &~ T_USER, TRAP_BRKPT, sv);
-		KERNEL_UNLOCK();
 		break;
 
 #if	NISA > 0