- Fixup / remove obsolete comments.

- ktrace no longer requires Giant so do ktrace syscall events before and
  after acquiring and releasing Giant, respectively.
- For i386, ia32 syscalls on ia64, powerpc, and sparc64, get rid of the
  goto bad hack and instead use the model on ia64 and alpha were we
  skip the actual syscall invocation if error != 0.  This fixes a bug
  where if we the copyin() of the arguments failed for a syscall that
  was not marked MP safe, we would try to release Giant when we had
  not acquired it.

1 files changed, 31 insertions, 41 deletions

diff --git a/sys/ia64/ia64/trap.c b/sys/ia64/ia64/trap.c
index 3745ad8..0ae02d7 100644
--- a/sys/ia64/ia64/trap.c
+++ b/sys/ia64/ia64/trap.c
@@ -837,8 +837,8 @@ syscall(int code, u_int64_t *args, struct trapframe *framep)
 	if ((callp->sy_narg & SYF_MPSAFE) == 0)
 		mtx_lock(&Giant);
 #ifdef KTRACE
-	if (KTRPOINT(p, KTR_SYSCALL))
-		ktrsyscall(p->p_tracep, code, (callp->sy_narg & SYF_ARGMASK), args);
+	if (KTRPOINT(td, KTR_SYSCALL))
+		ktrsyscall(code, (callp->sy_narg & SYF_ARGMASK), args);
 #endif
 	if (error == 0) {
 		td->td_retval[0] = 0;
@@ -876,16 +876,17 @@ syscall(int code, u_int64_t *args, struct trapframe *framep)
 	}
 
 	userret(td, framep, sticks);
-#ifdef KTRACE
-	if (KTRPOINT(p, KTR_SYSRET))
-		ktrsysret(p->p_tracep, code, error, td->td_retval[0]);
-#endif
+
 	/*
 	 * Release Giant if we had to get it.
 	 */
 	if ((callp->sy_narg & SYF_MPSAFE) == 0)
 		mtx_unlock(&Giant);
 
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_SYSRET))
+		ktrsysret(code, error, td->td_retval[0]);
+#endif
 	/*
 	 * This works because errno is findable through the
 	 * register set.  If we ever support an emulation where this
@@ -980,40 +981,34 @@ ia32_syscall(struct trapframe *framep)
 	/*
 	 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware
 	 */
-	if (params && (i = narg * sizeof(u_int32_t)) &&
-	    (error = copyin(params, (caddr_t)args, i))) {
-#ifdef KTRACE
-		if (KTRPOINT(p, KTR_SYSCALL))
-			ktrsyscall(p->p_tracep, code, narg, args64);
-#endif
-		goto bad;
-	}
+	if (params != NULL && narg != 0)
+		error = copyin(params, (caddr_t)args,
+		    (u_int)(narg * sizeof(int)));
+	else
+		error = 0;
+
 	for (i = 0; i < narg; i++)
 		args64[i] = args[i];
 
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_SYSCALL))
+		ktrsyscall(code, narg, args64);
+#endif
 	/*
 	 * Try to run the syscall without Giant if the syscall
 	 * is MP safe.
 	 */
-	if ((callp->sy_narg & SYF_MPSAFE) == 0) {
+	if ((callp->sy_narg & SYF_MPSAFE) == 0)
 		mtx_lock(&Giant);
-	}
 
-#ifdef KTRACE
-	/*
-	 * We have to obtain Giant no matter what if 
-	 * we are ktracing
-	 */
-	if (KTRPOINT(p, KTR_SYSCALL)) {
-		ktrsyscall(p->p_tracep, code, narg, args64);
-	}
-#endif
-	td->td_retval[0] = 0;
-	td->td_retval[1] = framep->tf_r[FRAME_R10]; /* edx */
+	if (error == 0) {
+		td->td_retval[0] = 0;
+		td->td_retval[1] = framep->tf_r[FRAME_R10]; /* edx */
 
-	STOPEVENT(p, S_SCE, narg);
+		STOPEVENT(p, S_SCE, narg);
 
-	error = (*callp->sy_call)(td, args64);
+		error = (*callp->sy_call)(td, args64);
+	}
 
 	switch (error) {
 	case 0:
@@ -1034,7 +1029,6 @@ ia32_syscall(struct trapframe *framep)
 		break;
 
 	default:
-bad:
  		if (p->p_sysent->sv_errsize) {
  			if (error >= p->p_sysent->sv_errsize)
   				error = -1;	/* XXX */
@@ -1059,20 +1053,16 @@ bad:
 	 */
 	userret(td, framep, sticks);
 
-#ifdef KTRACE
-	if (KTRPOINT(p, KTR_SYSRET)) {
-		ktrsysret(p->p_tracep, code, error, td->td_retval[0]);
-	}
-#endif
-
 	/*
-	 * Release Giant if we previously set it.  Do not
-	 * release based on mtx_owned() - we want to catch
-	 * broken syscalls.
+	 * Release Giant if we previously set it.
 	 */
-	if ((callp->sy_narg & SYF_MPSAFE) == 0) {
+	if ((callp->sy_narg & SYF_MPSAFE) == 0)
 		mtx_unlock(&Giant);
-	}
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_SYSRET))
+		ktrsysret(code, error, td->td_retval[0]);
+#endif
 
 	/*
 	 * This works because errno is findable through the