# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1719316586 -7200
# Node ID 17fdaa8a8117ae1e6c1d36acd889c3e7e73f7a3e
# Parent  7201710c78748d92ae2dd130861f5d36e85313ad
Fixed memory deallocation to properly discard dataspaces, extending the
signature of ipc_detach_dataspace to expose the capability involved. This
prevents the accumulation of redundant dataspace capabilities, such as in
filesystem server tasks.

diff -r 7201710c7874 -r 17fdaa8a8117 libexec/lib/src/external_pager.cc
--- a/libexec/lib/src/external_pager.cc	Tue Jun 25 13:53:18 2024 +0200
+++ b/libexec/lib/src/external_pager.cc	Tue Jun 25 13:56:26 2024 +0200
@@ -90,7 +90,7 @@
     MemoryArea *r = *it;
 
     if (r->is_mapped())
-      ipc_detach_dataspace((void *) r->dataspace_start());
+      ipc_detach_dataspace((void *) r->dataspace_start(), NULL);
   }
 
   /* Free all capabilities. */
diff -r 7201710c7874 -r 17fdaa8a8117 libexec/lib/src/segment.cc
--- a/libexec/lib/src/segment.cc	Tue Jun 25 13:53:18 2024 +0200
+++ b/libexec/lib/src/segment.cc	Tue Jun 25 13:56:26 2024 +0200
@@ -39,7 +39,7 @@
   if (_allocated)
   {
     if (_attached)
-      ipc_detach_dataspace(_buf);
+      ipc_detach_dataspace(_buf, NULL);
 
     /* Also unmap the dataspace, not apparently done by the underlying
        functions. */
diff -r 7201710c7874 -r 17fdaa8a8117 libfsclient/lib/src/file.cc
--- a/libfsclient/lib/src/file.cc	Tue Jun 25 13:53:18 2024 +0200
+++ b/libfsclient/lib/src/file.cc	Tue Jun 25 13:56:26 2024 +0200
@@ -120,7 +120,7 @@
   }
 
   if (file->memory != NULL)
-    ipc_detach_dataspace(file->memory);
+    ipc_detach_dataspace(file->memory, NULL);
 
   file_init(file);
 }
@@ -380,7 +380,7 @@
 
   if (file->memory != NULL)
   {
-    err = ipc_detach_dataspace(file->memory);
+    err = ipc_detach_dataspace(file->memory, NULL);
     if (err)
       return err;
 
@@ -419,7 +419,7 @@
 
   if (file->memory != NULL)
   {
-    err = ipc_detach_dataspace(file->memory);
+    err = ipc_detach_dataspace(file->memory, NULL);
     if (err)
       return err;
 
@@ -766,7 +766,7 @@
   _update_extent(pipe);
 
   if (pipe->memory != NULL)
-    err = ipc_detach_dataspace(pipe->memory);
+    err = ipc_detach_dataspace(pipe->memory, NULL);
 
   if (err)
     return err;
diff -r 7201710c7874 -r 17fdaa8a8117 libipc/include/ipc/mem_ipc.h
--- a/libipc/include/ipc/mem_ipc.h	Tue Jun 25 13:53:18 2024 +0200
+++ b/libipc/include/ipc/mem_ipc.h	Tue Jun 25 13:56:26 2024 +0200
@@ -40,7 +40,7 @@
                                 rm_flags_t flags, unsigned char align,
                                 void **addr);
 
-long ipc_detach_dataspace(void *addr);
+long ipc_detach_dataspace(void *addr, l4_cap_idx_t *cap);
 
 long ipc_dataspace_size(l4_cap_idx_t cap, offset_t *size);
 
diff -r 7201710c7874 -r 17fdaa8a8117 libipc/lib/src/mem_ipc.c
--- a/libipc/lib/src/mem_ipc.c	Tue Jun 25 13:53:18 2024 +0200
+++ b/libipc/lib/src/mem_ipc.c	Tue Jun 25 13:56:26 2024 +0200
@@ -107,9 +107,9 @@
   return err;
 }
 
-/* Detach a dataspace region. Equivalent to l4re_rm_detach_unmap. */
+/* Detach a dataspace region. Equivalent to l4re_rm_detach_ds_unmap. */
 
-long ipc_detach_dataspace(void *addr)
+long ipc_detach_dataspace(void *addr, l4_cap_idx_t *cap)
 {
   long err;
 
@@ -117,7 +117,10 @@
   if (err)
     return err;
 
-  err = l4re_rm_detach_unmap((l4_addr_t) addr, L4RE_THIS_TASK_CAP);
+  if (cap != NULL)
+    err = l4re_rm_detach_ds_unmap((l4_addr_t) addr, cap, L4RE_THIS_TASK_CAP);
+  else
+    err = l4re_rm_detach_unmap((l4_addr_t) addr, L4RE_THIS_TASK_CAP);
 
   ipc_semaphore_up(ipc_mem_semaphore);
 
diff -r 7201710c7874 -r 17fdaa8a8117 libipc/lib/src/message.c
--- a/libipc/lib/src/message.c	Tue Jun 25 13:53:18 2024 +0200
+++ b/libipc/lib/src/message.c	Tue Jun 25 13:56:26 2024 +0200
@@ -436,7 +436,7 @@
 void ipc_message_discard_dataspace(ipc_message_t *msg, l4_cap_idx_t mem, l4_addr_t addr)
 {
   ipc_message_discard_capability(msg, mem);
-  ipc_detach_dataspace((void *) addr);
+  ipc_detach_dataspace((void *) addr, NULL);
 }
 
 /* Reserve the given number slots from zero for incoming capabilities. */
diff -r 7201710c7874 -r 17fdaa8a8117 libmem/lib/src/memory_incremental.cc
--- a/libmem/lib/src/memory_incremental.cc	Tue Jun 25 13:53:18 2024 +0200
+++ b/libmem/lib/src/memory_incremental.cc	Tue Jun 25 13:56:26 2024 +0200
@@ -24,6 +24,7 @@
 
 #include "memory_incremental.h"
 
+#include <ipc/cap_alloc.h>
 #include <ipc/mem_ipc.h>
 
 #include <stdlib.h>
@@ -101,7 +102,13 @@
 
 void MemoryIncremental::deallocate(Region *region)
 {
-    ipc_detach_dataspace((void *) region->start);
+    l4_cap_idx_t cap;
+
+    ipc_detach_dataspace((void *) region->start, &cap);
+
+    if (l4_is_valid_cap(cap))
+        ipc_cap_free_um(cap);
+
     delete region;
 }