From 73e2418107dd10274464a3938a87997e827fe29d Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Tue, 23 Mar 2010 15:27:40 -0700
Subject: [PATCH] vkernel64 - Add missing bits from later kernel work in the
 main tree

* Add missing virtual kernel intercept in 64-bit real kernel trap.c code.

* Add td_ucred caching to userenter() in vkernel64 trap.c code.

* Set PG_RW, PG_U, PG_V in pcb_cr3.  It is unclear whether these
  are necessary.

* Remove debugging.
---
 sys/platform/pc64/x86_64/pmap.c           |  1 +
 sys/platform/pc64/x86_64/trap.c           | 10 ++++++++
 sys/platform/vkernel64/x86_64/exception.c |  2 +-
 sys/platform/vkernel64/x86_64/trap.c      | 29 +++++++++++++++++------
 4 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/sys/platform/pc64/x86_64/pmap.c b/sys/platform/pc64/x86_64/pmap.c
index cd343dbfb7..7c45c0d6ce 100644
--- a/sys/platform/pc64/x86_64/pmap.c
+++ b/sys/platform/pc64/x86_64/pmap.c
@@ -3764,6 +3764,7 @@ pmap_setlwpvm(struct lwp *lp, struct vmspace *newvm)
 			tlb_flush_count++;
 #endif
 			curthread->td_pcb->pcb_cr3 = vtophys(pmap->pm_pml4);
+			curthread->td_pcb->pcb_cr3 |= PG_RW | PG_U | PG_V;
 			load_cr3(curthread->td_pcb->pcb_cr3);
 			pmap = vmspace_pmap(oldvm);
 #if defined(SMP)
diff --git a/sys/platform/pc64/x86_64/trap.c b/sys/platform/pc64/x86_64/trap.c
index ecdcdd9582..b394da5852 100644
--- a/sys/platform/pc64/x86_64/trap.c
+++ b/sys/platform/pc64/x86_64/trap.c
@@ -747,6 +747,16 @@ trap(struct trapframe *frame)
 		}
 		MAKEMPSAFE(have_mplock);
 		trap_fatal(frame, 0);
+		goto out2;
+	}
+
+	/*
+	 * Virtual kernel intercept - if the fault is directly related to a
+	 * VM context managed by a virtual kernel then let the virtual kernel
+	 * handle it.
+	 */
+	if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
+		vkernel_trap(lp, frame);
 		goto out;
 	}
 
diff --git a/sys/platform/vkernel64/x86_64/exception.c b/sys/platform/vkernel64/x86_64/exception.c
index 28afac21c6..6236a2effa 100644
--- a/sys/platform/vkernel64/x86_64/exception.c
+++ b/sys/platform/vkernel64/x86_64/exception.c
@@ -181,7 +181,7 @@ exc_segfault(int signo, siginfo_t *info, void *ctxp)
 {
 	ucontext_t *ctx = ctxp;
 
-#if 1
+#if 0
 	kprintf("CAUGHT SIG %d RIP %08lx ERR %08lx TRAPNO %ld "
 		"err %ld addr %08lx\n",
 		signo,
diff --git a/sys/platform/vkernel64/x86_64/trap.c b/sys/platform/vkernel64/x86_64/trap.c
index 431daa54d7..ff8ae75f91 100644
--- a/sys/platform/vkernel64/x86_64/trap.c
+++ b/sys/platform/vkernel64/x86_64/trap.c
@@ -184,15 +184,30 @@ MALLOC_DEFINE(M_SYSMSG, "sysmsg", "sysmsg structure");
 extern int max_sysmsg;
 
 /*
- * userenter() passively intercepts the thread switch function to increase
- * the thread priority from a user priority to a kernel priority, reducing
+ * Passively intercepts the thread switch function to increase the thread
+ * priority from a user priority to a kernel priority, reducing
  * syscall and trap overhead for the case where no switch occurs.
+ *
+ * Synchronizes td_ucred with p_ucred.  This is used by system calls,
+ * signal handling, faults, AST traps, and anything else that enters the
+ * kernel from userland and provides the kernel with a stable read-only
+ * copy of the process ucred.
  */
-
 static __inline void
-userenter(struct thread *curtd)
+userenter(struct thread *curtd, struct proc *curp)
 {
+	struct ucred *ocred;
+	struct ucred *ncred;
+
 	curtd->td_release = lwkt_passive_release;
+
+	if (curtd->td_ucred != curp->p_ucred) {
+		ncred = crhold(curp->p_ucred);
+		ocred = curtd->td_ucred;
+		curtd->td_ucred = ncred;
+		if (ocred)
+			crfree(ocred);
+	}
 }
 
 /*
@@ -419,7 +434,7 @@ restart:
 	type = frame->tf_trapno;
 	code = frame->tf_err;
 
-	userenter(td);
+	userenter(td, p);
 
 	sticks = (int)td->td_sticks;
 	lp->lwp_md.md_regs = frame;
@@ -1148,7 +1163,7 @@ syscall2(struct trapframe *frame)
 	if (syscall_mpsafe == 0)
 		MAKEMPSAFE(have_mplock);
 #endif
-	userenter(td);		/* lazy raise our priority */
+	userenter(td, p);	/* lazy raise our priority */
 
 	reg = 0;
 	regcnt = 6;
@@ -1387,7 +1402,7 @@ generic_lwp_return(struct lwp *lp, struct trapframe *frame)
 	 * released when the thread goes to sleep.
 	 */
 	lwkt_setpri_self(TDPRI_USER_NORM);
-	userenter(lp->lwp_thread);
+	userenter(lp->lwp_thread, p);
 	userret(lp, frame, 0);
 #ifdef KTRACE
 	if (KTRPOINT(lp->lwp_thread, KTR_SYSRET))
-- 
2.41.0