From: Joan Lledó <jlle...@member.fsf.org>
To get a proxy to the region a given address belongs to,
with protection and range limited to the region ones.
* include/mach/mach4.defs: memory_object_get_proxy RPC declaration
* vm/memory_object_proxy.c: memory_object_get_proxy implementation
---
include/mach/mach4.defs | 10 ++++++++
vm/memory_object_proxy.c | 50 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/include/mach/mach4.defs b/include/mach/mach4.defs
index 98af5905..e1641146 100644
--- a/include/mach/mach4.defs
+++ b/include/mach/mach4.defs
@@ -110,3 +110,13 @@ routine memory_object_create_proxy(
start : vm_offset_array_t;
len : vm_offset_array_t;
out proxy : mach_port_t);
+
+/* Gets a proxy to the region that ADDRESS belongs to, starting at the region
+ start, with MAX_PROTECTION and LEN limited by the region ones, and returns
+ it in *PORT. */
+routine memory_object_get_proxy(
+ task : task_t;
+ address : vm_address_t;
+ max_protection : vm_prot_t;
+ len : vm_offset_t;
+ out proxy : mach_port_t);
diff --git a/vm/memory_object_proxy.c b/vm/memory_object_proxy.c
index b55a17f1..b6c73576 100644
--- a/vm/memory_object_proxy.c
+++ b/vm/memory_object_proxy.c
@@ -191,6 +191,56 @@ memory_object_create_proxy (const ipc_space_t space,
vm_prot_t max_protection,
return KERN_SUCCESS;
}
+/* Gets a proxy to the region that ADDRESS belongs to, starting at the region
+ start, with MAX_PROTECTION and LEN limited by the region ones, and returns
+ it in *PORT. */
+kern_return_t
+memory_object_get_proxy (task_t task, const vm_offset_t address,
+ vm_prot_t max_protection, vm_offset_t len,
+ ipc_port_t *port)
+{
+ kern_return_t ret;
+ vm_map_entry_t entry, tmp_entry;
+ vm_offset_t offset, start;
+ ipc_port_t pager;
+
+ if (task == TASK_NULL)
+ return(KERN_INVALID_ARGUMENT);
+
+ vm_map_lock_read(task->map);
+ if (!vm_map_lookup_entry(task->map, address, &tmp_entry)) {
+ if ((entry = tmp_entry->vme_next) == vm_map_to_entry(task->map)) {
+ vm_map_unlock_read(task->map);
+ return(KERN_NO_SPACE);
+ }
+ } else {
+ entry = tmp_entry;
+ }
+
+ /* Limit the allowed protection and range to the entry ones */
+ if (len > entry->vme_end - entry->vme_start) {
+ vm_map_unlock_read(task->map);
+ return(KERN_INVALID_ARGUMENT);
+ }
+
+ max_protection &= entry->max_protection;
+ pager = ipc_port_copy_send(entry->object.vm_object->pager);
+ offset = entry->offset;
+ start = 0;
+
+ vm_map_unlock_read(task->map);
+
+ ret = memory_object_create_proxy(task->itk_space, max_protection,
+ &pager, 1,
+ &offset, 1,
+ &start, 1,
+ &len, 1, port);
+ if (ret)
+ ipc_port_release_send(pager);
+
+ return ret;
+}
+
/* Lookup the real memory object and maximum protection for the proxy
memory object port PORT, for which the caller holds a reference.
*OBJECT is only guaranteed to be valid as long as the caller holds
--
2.31.1
