Modify acpi translator to allow write to existing tables

4 files changed, 68 insertions, 31 deletions

diff --git a/acpi/acpifs.c b/acpi/acpifs.c
index e779e0f9..d572c5ac 100644
--- a/acpi/acpifs.c
+++ b/acpi/acpifs.c
@@ -166,9 +166,9 @@ create_fs_tree (struct acpifs *fs)
   /* Remove all permissions to others */
   e_stat.st_mode &= ~(S_IROTH | S_IWOTH | S_IXOTH);
 
-  /* Change mode to a regular read-only file */
-  e_stat.st_mode &= ~(S_IFDIR | S_IXUSR | S_IXGRP | S_IWUSR | S_IWGRP);
-  e_stat.st_mode |= S_IFREG;
+  /* Change mode to a regular file */
+  e_stat.st_mode &= ~(S_IFDIR | S_IXUSR | S_IXGRP);
+  e_stat.st_mode |= S_IFREG | S_IWUSR | S_IWGRP;
 
   /* Get all ACPI tables */
   err = acpi_get_tables(&iter);
diff --git a/acpi/func_files.c b/acpi/func_files.c
index 371f989a..99f18036 100644
--- a/acpi/func_files.c
+++ b/acpi/func_files.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 2017 Free Software Foundation, Inc.
+   Copyright (C) 2018 Free Software Foundation, Inc.
 
    This file is part of the GNU Hurd.
 
@@ -17,18 +17,12 @@
    along with the GNU Hurd.  If not, see <<a rel="nofollow" href="http://www.gnu.org/licenses/">http://www.gnu.org/licenses/</a>>.
 */
 
-/*
- * Per-function files implementation.
- *
- * Implementation of all files repeated for each function.
- */
-
 #include <func_files.h>
 #include <assert.h>
 
 /* Read an acpi table */
 error_t
-io_acpi_table (struct acpi_table *t, off_t offset, size_t *len, void *data)
+io_read_table (struct acpi_table *t, off_t offset, size_t *len, void *data)
 {
   error_t err;
   size_t datalen;
@@ -49,28 +43,63 @@ io_acpi_table (struct acpi_table *t, off_t offset, size_t *len, void *data)
   return err;
 }
 
-/* Read from an acpi table file */
+/* Write values to an existing acpi table
+ * (dangerous, mainly for implementing power off)
+ */
 error_t
-io_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len,
-              void *data)
+io_write_table (struct acpi_table *t, off_t offset, size_t *len, void *data)
 {
+  error_t err;
   size_t datalen;
-  struct acpi_table *table;
 
   /* This should never happen */
-  assert_backtrace (e->acpitable != 0);
+  assert_backtrace (t != 0);
 
-  /* Get the table */
-  table = e->acpitable;
+  datalen = t->datalen;
 
-  datalen = table->datalen;
-  /* Don't exceed the region size */
+  /* Don't exceed the size of the acpi table */
   if (offset > datalen)
     return EINVAL;
   if ((offset + *len) > datalen)
     *len = datalen - offset;
 
-  memcpy (data, table->data + offset, *len);
+  memcpy (t->data + offset, data, *len);
+
+  return err;
+}
+
+/* Read from an acpi table file */
+error_t
+io_read_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len,
+                   void *data)
+{
+  struct acpi_table *table;
+
+  /* This should never happen */
+  assert_backtrace (e->acpitable != 0);
+
+  /* Get the table */
+  table = e->acpitable;
+
+  io_read_table (table, offset, len, data);
+
+  return 0;
+}
+
+/* Write to an acpi table file */
+error_t
+io_write_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len,
+                    void *data)
+{
+  struct acpi_table *table;
+
+  /* This should never happen */
+  assert_backtrace (e->acpitable != 0);
+
+  /* Get the table */
+  table = e->acpitable;
+
+  io_write_table (table, offset, len, data);
 
   return 0;
 }
diff --git a/acpi/func_files.h b/acpi/func_files.h
index 90d92cc3..c8e4bbdf 100644
--- a/acpi/func_files.h
+++ b/acpi/func_files.h
@@ -25,15 +25,12 @@
 #include <acpifs.h>
 #include <acpi.h>
 
-typedef int (*acpi_read_op_t) (struct acpi_table *t, void *data,
-                               off_t offset, size_t *len);
-
 /* Tables */
-#define DIR_TABLES_NAME	"tables"
+#define DIR_TABLES_NAME	"acpi"
 
-error_t io_read_table (struct acpi_table *t, struct acpifs_dirent *e,
-                       off_t offset, size_t *len, void *data);
-error_t io_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len,
-                      void *data);
+error_t io_read_table (struct acpi_table *t, off_t offset, size_t *len, void *data);
+error_t io_write_table (struct acpi_table *t, off_t offset, size_t *len, void *data);
+error_t io_read_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len, void *data);
+error_t io_write_acpi_file (struct acpifs_dirent *e, off_t offset, size_t *len, void *data);
 
 #endif /* FUNC_FILES_H */
diff --git a/acpi/netfs_impl.c b/acpi/netfs_impl.c
index 84f52c89..f9f8df9c 100644
--- a/acpi/netfs_impl.c
+++ b/acpi/netfs_impl.c
@@ -499,7 +499,7 @@ netfs_attempt_read (struct iouser * cred, struct node * node,
       return EOPNOTSUPP;
   else
     {
-      err = io_acpi_file (node->nn->ln, offset, len, data);
+      err = io_read_acpi_file (node->nn->ln, offset, len, data);
       if (!err)
         /* Update atime */
         UPDATE_TIMES (node->nn->ln, TOUCH_ATIME);
@@ -514,7 +514,18 @@ error_t
 netfs_attempt_write (struct iouser * cred, struct node * node,
                     off_t offset, size_t * len, void *data)
 {
-  return EOPNOTSUPP;
+  error_t err;
+
+  if (!strncmp (node->nn->ln->name, DIR_TABLES_NAME, NAME_SIZE))
+      return EOPNOTSUPP;
+  else
+    {
+      err = io_write_acpi_file (node->nn->ln, offset, len, data);
+      if (!err)
+        /* Update mtime */
+        UPDATE_TIMES (node->nn->ln, TOUCH_MTIME);
+    }
+  return err;
 }
 
 /* Node NP is all done; free all its associated storage. */