Detect asprintf's ENOMEM in procfs.c rather than everywhere

* procfs.h: Make CONTENTS_LEN an ssize_t rather than a size_t,
  and document the change.
* procfs.c (procfs_get_contents): Initialize CONTENTS_LEN to a
  negative value, and fail with ENOMEM if it's still negative after the
  callback returns.  (everywhere): Update to ssize_t.
* dircat.c, netfs.c, process.c,
  procfs_dir.c, proclist.c, rootdir.c: Update to
  ssize_t and the new GET_CONTENTS semantics.

1 files changed, 8 insertions, 6 deletions

diff --git a/procfs.h b/procfs.h
index 8336ee85..e8ef18b3 100644
--- a/procfs.h
+++ b/procfs.h
@@ -16,9 +16,11 @@ struct procfs_node_ops
      symlink or directory, as determined by the file mode in
      netnode->nn_stat.  For regular files and symlinks, they are what
      you would expect; for directories, they are an argz vector of the
-     names of the entries.  */
-  error_t (*get_contents) (void *hook, char **contents, size_t *contents_len);
-  void (*cleanup_contents) (void *hook, char *contents, size_t contents_len);
+     names of the entries.  If upon return, *CONTENTS_LEN is negative or
+     unchanged, the call is considered to have failed because of a memory
+     allocation error.  */
+  error_t (*get_contents) (void *hook, char **contents, ssize_t *contents_len);
+  void (*cleanup_contents) (void *hook, char *contents, ssize_t contents_len);
 
   /* Lookup NAME in this directory, and store the result in *np.  The
      returned node should be created by lookup() using procfs_make_node() 
@@ -41,8 +43,8 @@ struct procfs_node_ops
 };
 
 /* These helper functions can be used as procfs_node_ops.cleanup_contents. */
-void procfs_cleanup_contents_with_free (void *, char *, size_t);
-void procfs_cleanup_contents_with_vm_deallocate (void *, char *, size_t);
+void procfs_cleanup_contents_with_free (void *, char *, ssize_t);
+void procfs_cleanup_contents_with_vm_deallocate (void *, char *, ssize_t);
 
 /* Create a new node and return it.  Returns NULL if it fails to allocate
    enough memory.  In this case, ops->cleanup will be invoked.  */
@@ -69,7 +71,7 @@ void procfs_node_chtype (struct node *np, mode_t type);
    corresponding child nodes.  */
 ino64_t procfs_make_ino (struct node *np, const char *filename);
 
-error_t procfs_get_contents (struct node *np, char **data, size_t *data_len);
+error_t procfs_get_contents (struct node *np, char **data, ssize_t *data_len);
 error_t procfs_lookup (struct node *np, const char *name, struct node **npp);
 void procfs_cleanup (struct node *np);