# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1653255977 -7200
# Node ID 8349c51951e2cec851670601227a62042ff30db0
# Parent  a3c858aa56bbf63a18c5ff69928885bf3de8f573
Changed the mmap interface to employ explicit visible region limits.

diff -r a3c858aa56bb -r 8349c51951e2 libexec/lib/src/segment.cc
--- a/libexec/lib/src/segment.cc	Sun May 22 22:55:53 2022 +0200
+++ b/libexec/lib/src/segment.cc	Sun May 22 23:46:17 2022 +0200
@@ -96,7 +96,7 @@
 
   /* Provide the exposed file contents in a masked memory mapped region. */
 
-  _buf = (char *) client_mmap(file, _file_offset - _region_offset, _region_size, 0, _flags);
+  _buf = (char *) client_mmap(file, _file_offset - _region_offset, _region_size, 0, 0, _flags);
 
   if (_buf == NULL)
     return -L4_EIO;
diff -r a3c858aa56bb -r 8349c51951e2 libfsclient/include/fsclient/client.h
--- a/libfsclient/include/fsclient/client.h	Sun May 22 22:55:53 2022 +0200
+++ b/libfsclient/include/fsclient/client.h	Sun May 22 23:46:17 2022 +0200
@@ -64,7 +64,8 @@
 /* File and region operations. */
 
 long client_flush(file_t *file);
-void *client_mmap(file_t *file, offset_t position, offset_t length, int masked,
+void *client_mmap(file_t *file, offset_t position, offset_t length,
+                  offset_t start_visible, offset_t end_visible,
                   l4re_rm_flags_t region_flags);
 l4re_rm_flags_t client_region_flags(prot_t prot, flags_t flags);
 
diff -r a3c858aa56bb -r 8349c51951e2 libfsclient/include/fsclient/file.h
--- a/libfsclient/include/fsclient/file.h	Sun May 22 22:55:53 2022 +0200
+++ b/libfsclient/include/fsclient/file.h	Sun May 22 23:46:17 2022 +0200
@@ -109,7 +109,8 @@
 /* File and region operations. */
 
 long file_flush(file_t *file);
-long file_mmap(file_t *file, offset_t position, offset_t length, int masked,
+long file_mmap(file_t *file, offset_t position, offset_t length,
+               offset_t start_visible, offset_t end_visible,
                l4re_rm_flags_t region_flags);
 l4re_rm_flags_t file_region_flags(flags_t flags);
 long file_resize(file_t *file, offset_t size);
diff -r a3c858aa56bb -r 8349c51951e2 libfsclient/lib/src/client.cc
--- a/libfsclient/lib/src/client.cc	Sun May 22 22:55:53 2022 +0200
+++ b/libfsclient/lib/src/client.cc	Sun May 22 23:46:17 2022 +0200
@@ -81,7 +81,7 @@
 
     if ((position < file->start_pos) || (position >= file->end_pos))
     {
-      if (file_mmap(file, position, file_span(file), 0,
+      if (file_mmap(file, position, file_span(file), 0, 0,
                     file_region_flags(file->flags)))
         return -L4_EIO;
     }
@@ -191,7 +191,7 @@
   if (file->memory == NULL)
   {
     if (file->object_flags & OBJECT_SUPPORTS_MMAP)
-      return client_mmap(file, client_tell(file), count, 0,
+      return client_mmap(file, client_tell(file), count, 0, 0,
                          file_region_flags(file->flags));
     else if (pipe_current(file))
       return NULL;
@@ -487,10 +487,12 @@
 
 /* Map a memory region to a file. */
 
-void *client_mmap(file_t *file, offset_t position, offset_t length, int masked,
+void *client_mmap(file_t *file, offset_t position, offset_t length,
+                  offset_t start_visible, offset_t end_visible,
                   l4re_rm_flags_t region_flags)
 {
-  if ((file == NULL) || file_mmap(file, position, length, masked, region_flags))
+  if ((file == NULL) || file_mmap(file, position, length, start_visible,
+                                  end_visible, region_flags))
     return NULL;
 
   return file->memory;
diff -r a3c858aa56bb -r 8349c51951e2 libfsclient/lib/src/file.cc
--- a/libfsclient/lib/src/file.cc	Sun May 22 22:55:53 2022 +0200
+++ b/libfsclient/lib/src/file.cc	Sun May 22 23:46:17 2022 +0200
@@ -351,13 +351,14 @@
 /* Map a region of the given file to a memory region, obtaining an updated file
    size and populated data details. Unmap any previously mapped region. */
 
-long file_mmap(file_t *file, offset_t position, offset_t length, int masked,
+long file_mmap(file_t *file, offset_t position, offset_t length,
+               offset_t start_visible, offset_t end_visible,
                l4re_rm_flags_t region_flags)
 {
   char *memory = file->memory;
   client_MappedFile mapped_file(file->ref);
-  long err = mapped_file.mmap(position, length, masked, &file->start_pos,
-                              &file->end_pos, &file->size);
+  long err = mapped_file.mmap(position, length, start_visible, end_visible,
+                              &file->start_pos, &file->end_pos, &file->size);
 
   if (err)
     return err;
diff -r a3c858aa56bb -r 8349c51951e2 libfsserver/include/fsserver/file_pager.h
--- a/libfsserver/include/fsserver/file_pager.h	Sun May 22 22:55:53 2022 +0200
+++ b/libfsserver/include/fsserver/file_pager.h	Sun May 22 23:46:17 2022 +0200
@@ -69,7 +69,8 @@
     virtual long map(offset_t offset, address_t hot_spot, map_flags_t flags,
                      l4_snd_fpage_t *region);
 
-    virtual long mmap(offset_t position, offset_t length, int masked,
+    virtual long mmap(offset_t position, offset_t length,
+                      offset_t start_visible, offset_t end_visible,
                       offset_t *start_pos, offset_t *end_pos, offset_t *size);
 
     /* Notification methods. */
diff -r a3c858aa56bb -r 8349c51951e2 libfsserver/include/fsserver/pager.h
--- a/libfsserver/include/fsserver/pager.h	Sun May 22 22:55:53 2022 +0200
+++ b/libfsserver/include/fsserver/pager.h	Sun May 22 23:46:17 2022 +0200
@@ -74,7 +74,8 @@
 
     /* Mapped file methods. */
 
-    virtual long mmap(offset_t position, offset_t length, int masked,
+    virtual long mmap(offset_t position, offset_t length,
+                      offset_t start_visible, offset_t end_visible,
                       offset_t *start_pos, offset_t *end_pos, offset_t *size);
 };
 
diff -r a3c858aa56bb -r 8349c51951e2 libfsserver/lib/files/file_pager.cc
--- a/libfsserver/lib/files/file_pager.cc	Sun May 22 22:55:53 2022 +0200
+++ b/libfsserver/lib/files/file_pager.cc	Sun May 22 23:46:17 2022 +0200
@@ -1,7 +1,7 @@
 /*
  * File-specific pager functionality.
  *
- * Copyright (C) 2021 Paul Boddie <paul@boddie.org.uk>
+ * Copyright (C) 2021, 2022 Paul Boddie <paul@boddie.org.uk>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -90,12 +90,14 @@
     return err;
 }
 
-long FilePager::mmap(offset_t position, offset_t length, int masked,
+long FilePager::mmap(offset_t position, offset_t length,
+                     offset_t start_visible, offset_t end_visible,
                      offset_t *start_pos, offset_t *end_pos, offset_t *size)
 {
     /* Set the limits of the paged region. */
 
-    return Pager::mmap(position, length, masked, start_pos, end_pos, size);
+    return Pager::mmap(position, length, start_visible, end_visible, start_pos,
+                       end_pos, size);
 }
 
 
diff -r a3c858aa56bb -r 8349c51951e2 libfsserver/lib/generic/pager.cc
--- a/libfsserver/lib/generic/pager.cc	Sun May 22 22:55:53 2022 +0200
+++ b/libfsserver/lib/generic/pager.cc	Sun May 22 23:46:17 2022 +0200
@@ -64,7 +64,8 @@
 
 /* Expose a region of the file. */
 
-long Pager::mmap(offset_t position, offset_t length, int masked,
+long Pager::mmap(offset_t position, offset_t length,
+                 offset_t start_visible, offset_t end_visible,
                  offset_t *start_pos, offset_t *end_pos, offset_t *size)
 {
     /* Define region characteristics. */
@@ -80,10 +81,10 @@
 
     /* Permit masking of mapped regions. */
 
-    if (masked)
+    if (start_visible || end_visible)
     {
-        _start_visible = position;
-        _end_visible = position + length;
+        _start_visible = start_visible;
+        _end_visible = end_visible;
         _is_masked = (*start_pos != _start_visible) || (*end_pos != _end_visible);
     }
     else
diff -r a3c858aa56bb -r 8349c51951e2 libsystypes/idl/mapped_file.idl
--- a/libsystypes/idl/mapped_file.idl	Sun May 22 22:55:53 2022 +0200
+++ b/libsystypes/idl/mapped_file.idl	Sun May 22 23:46:17 2022 +0200
@@ -4,12 +4,12 @@
 
 interface MappedFile
 {
-  /* Memory-map a file for the given file position and length, masking out of
-     range regions if indicated, obtaining the limits of the mapped region and
-     the size of the file. */
+  /* Memory-map a file for the given file position and length, masking regions
+     beyond any visible range if indicated, obtaining the limits of the mapped
+     region and the size of the file. */
 
   [opcode(7)] void mmap(in offset_t position, in offset_t length,
-                        in int masked,
+                        in offset_t start_visible, in offset_t end_visible,
                         out offset_t start_pos, out offset_t end_pos,
                         out offset_t size);
 };
diff -r a3c858aa56bb -r 8349c51951e2 tests/dstest_block_client.cc
--- a/tests/dstest_block_client.cc	Sun May 22 22:55:53 2022 +0200
+++ b/tests/dstest_block_client.cc	Sun May 22 23:46:17 2022 +0200
@@ -98,7 +98,7 @@
   /* A region of the file is mapped. Here, the start and length will not provide
      page-aligned offsets, but the region is nevertheless not masked. */
 
-  err = file_mmap(&file, 10, 290, 0, file_region_flags(file.flags));
+  err = file_mmap(&file, 10, 290, 0, 0, file_region_flags(file.flags));
 
   if (err)
   {
@@ -115,7 +115,7 @@
   /* A region of the file is mapped. Here, the resulting offsets will be used to
      define a masked region. */
 
-  err = file_mmap(&file, 10, 290, 1, file_region_flags(file.flags));
+  err = file_mmap(&file, 10, 290, 10, 290, file_region_flags(file.flags));
 
   if (err)
   {
@@ -150,7 +150,7 @@
 
   /* Re-map to avoid masking the region. */
 
-  err = file_mmap(&file, 10, new_size - 20, 0, file_region_flags(file.flags));
+  err = file_mmap(&file, 10, new_size - 20, 0, 0, file_region_flags(file.flags));
 
   if (err)
   {
@@ -178,7 +178,7 @@
 
   /* Re-map to mask the region again. */
 
-  err = file_mmap(&file, 10, new_size - 20, 1, file_region_flags(file.flags));
+  err = file_mmap(&file, 0, new_size, 10, new_size - 20, file_region_flags(file.flags));
 
   if (err)
   {
diff -r a3c858aa56bb -r 8349c51951e2 tests/dstest_host_client.cc
--- a/tests/dstest_host_client.cc	Sun May 22 22:55:53 2022 +0200
+++ b/tests/dstest_host_client.cc	Sun May 22 23:46:17 2022 +0200
@@ -68,7 +68,7 @@
 
   /* A region of the file is mapped. */
 
-  err = file_mmap(&file, 0, page(10), 0, file_region_flags(file.flags));
+  err = file_mmap(&file, 0, page(10), 0, 0, file_region_flags(file.flags));
 
   if (err)
   {
diff -r a3c858aa56bb -r 8349c51951e2 tests/dstest_test_client.cc
--- a/tests/dstest_test_client.cc	Sun May 22 22:55:53 2022 +0200
+++ b/tests/dstest_test_client.cc	Sun May 22 23:46:17 2022 +0200
@@ -77,7 +77,7 @@
 
   /* A region of the file is mapped. */
 
-  err = file_mmap(&file, page(start_page), page(MAP_PAGES), 0, file_region_flags(file.flags));
+  err = file_mmap(&file, page(start_page), page(MAP_PAGES), 0, 0, file_region_flags(file.flags));
 
   if (err)
   {