From 65b4b95259c5be80f21ebbfbf258aa91c6ee12c5 Mon Sep 17 00:00:00 2001
From: Cristiano Giuffrida <giuffrida@cs.vu.nl>
Date: Wed, 12 Mar 2014 00:23:01 +0100
Subject: [PATCH] vm: Allow VM to make self calls when needed.

Change-Id: I7aada24adad3dc6bfe5b0bd4a50b5005c79ff887
---
 minix/servers/vm/acl.c     |  5 +++++
 minix/servers/vm/mmap.c    | 43 +++++++++++++++++++++++++++++++++++++-
 minix/servers/vm/utility.c |  3 +++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/minix/servers/vm/acl.c b/minix/servers/vm/acl.c
index a31b22cf9..d7e11bde0 100644
--- a/minix/servers/vm/acl.c
+++ b/minix/servers/vm/acl.c
@@ -36,6 +36,11 @@ acl_init(void)
 int
 acl_check(struct vmproc *vmp, int call)
 {
+
+	/* VM makes asynchronous calls to itself.  Always allow those. */
+	if (vmp->vm_endpoint == VM_PROC_NR)
+		return OK;
+
 	/* If the process has no ACL, all calls are allowed.. for now. */
 	if (vmp->vm_acl == NO_ACL) {
 		printf("VM: calling process %u has no ACL!\n",
diff --git a/minix/servers/vm/mmap.c b/minix/servers/vm/mmap.c
index 727914482..8c472a141 100644
--- a/minix/servers/vm/mmap.c
+++ b/minix/servers/vm/mmap.c
@@ -483,6 +483,30 @@ int do_get_refcount(message *m)
 	return r;
 }
 
+/*===========================================================================*
+ *                             munmap_vm_lin                                 *
+ *===========================================================================*/
+int munmap_vm_lin(vir_bytes addr, size_t len)
+{
+	if(addr % VM_PAGE_SIZE) {
+		printf("munmap_vm_lin: offset not page aligned\n");
+		return EFAULT;
+	}
+
+	if(len % VM_PAGE_SIZE) {
+		printf("munmap_vm_lin: len not page aligned\n");
+		return EFAULT;
+	}
+
+	if(pt_writemap(NULL, &vmproc[VM_PROC_NR].vm_pt, addr, MAP_NONE, len, 0,
+		WMF_OVERWRITE | WMF_FREE) != OK) {
+		printf("munmap_vm_lin: pt_writemap failed\n");
+		return EFAULT;
+	}
+
+	return OK;
+}
+
 /*===========================================================================*
  *                              do_munmap                                    *
  *===========================================================================*/
@@ -490,6 +514,7 @@ int do_munmap(message *m)
 {
         int r, n;
         struct vmproc *vmp;
+	struct vir_region *vr;
         vir_bytes addr, len;
 	endpoint_t target = SELF;
 
@@ -505,9 +530,25 @@ int do_munmap(message *m)
         if((r=vm_isokendpt(target, &n)) != OK) {
                 panic("do_mmap: message from strange source: %d", m->m_source);
         }
- 
+
         vmp = &vmproc[n];
 
+	if(m->m_source == VM_PROC_NR) {
+		/* VM munmap is a special case, the region we want to
+		 * munmap may or may not be there in our data structures,
+		 * depending on whether this is an updated VM instance or not.
+		 */
+		if(!region_search_root(&vmp->vm_regions_avl)) {
+			munmap_vm_lin(addr, m->VMUM_LEN);
+		}
+		else if((vr = map_lookup(vmp, addr, NULL))) {
+			if(map_unmap_region(vmp, vr, 0, m->VMUM_LEN) != OK) {
+				printf("VM: self map_unmap_region failed\n");
+			}
+		}
+		return SUSPEND;
+	}
+
 	if(m->m_type == VM_UNMAP_PHYS) {
 		addr = (vir_bytes) m->m_lsys_vm_unmap_phys.vaddr;
 	} else if(m->m_type == VM_SHM_UNMAP) {
diff --git a/minix/servers/vm/utility.c b/minix/servers/vm/utility.c
index 63a6217ec..81417870c 100644
--- a/minix/servers/vm/utility.c
+++ b/minix/servers/vm/utility.c
@@ -142,6 +142,9 @@ int do_info(message *m)
 		break;
 
 	case VMIW_REGION:
+		if(m->m_lsys_vm_info.ep == SELF) {
+			m->m_lsys_vm_info.ep = m->m_source;
+		}
 		if (vm_isokendpt(m->m_lsys_vm_info.ep, &pr) != OK)
 			return EINVAL;