[hurd,commited] hurd: Add execveat

[Samuel Thibault]

---
 include/unistd.h             |  2 +
 sysdeps/mach/hurd/execve.c   | 44 +----------------
 sysdeps/mach/hurd/execveat.c | 92 ++++++++++++++++++++++++++++++++++++
 sysdeps/mach/hurd/getcwd.h   | 28 +++++++++++
 4 files changed, 123 insertions(+), 43 deletions(-)
 create mode 100644 sysdeps/mach/hurd/execveat.c
 create mode 100644 sysdeps/mach/hurd/getcwd.h

diff --git a/include/unistd.h b/include/unistd.h
index 96c066c0d9..8ed8b1ea4b 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -103,6 +103,8 @@ extern int __dup3 (int __fd, int __fd2, int flags);
 libc_hidden_proto (__dup3)
 extern int __execve (const char *__path, char *const __argv[],
                     char *const __envp[]) attribute_hidden;
+extern int __execveat (int dirfd, const char *__path, char *const __argv[],
+                      char *const __envp[], int flags) attribute_hidden;
 extern long int __pathconf (const char *__path, int __name);
 extern long int __fpathconf (int __fd, int __name);
 extern long int __sysconf (int __name);
diff --git a/sysdeps/mach/hurd/execve.c b/sysdeps/mach/hurd/execve.c
index 3e49fa570b..071f879fad 100644
--- a/sysdeps/mach/hurd/execve.c
+++ b/sysdeps/mach/hurd/execve.c
@@ -26,49 +26,7 @@
 int
 __execve (const char *file_name, char *const argv[], char *const envp[])
 {
-  error_t err;
-  char *concat_name = NULL;
-  const char *abs_path;
-
-  file_t file = __file_name_lookup (file_name, O_EXEC, 0);
-  if (file == MACH_PORT_NULL)
-    return -1;
-
-  if (file_name[0] == '/')
-    {
-      /* Already an absolute path */
-      abs_path = file_name;
-    }
-  else
-    {
-      /* Relative path */
-      char *cwd = __getcwd (NULL, 0);
-      if (cwd == NULL)
-       {
-         __mach_port_deallocate (__mach_task_self (), file);
-         return -1;
-       }
-
-      int res = __asprintf (&concat_name, "%s/%s", cwd, file_name);
-      free (cwd);
-      if (res == -1)
-       {
-         __mach_port_deallocate (__mach_task_self (), file);
-         return -1;
-       }
-
-      abs_path = concat_name;
-    }
-
-  /* Hopefully this will not return.  */
-  err = _hurd_exec_paths (__mach_task_self (), file,
-                         file_name, abs_path, argv, envp);
-
-  /* Oh well.  Might as well be tidy.  */
-  __mach_port_deallocate (__mach_task_self (), file);
-  free (concat_name);
-
-  return __hurd_fail (err);
+  return __execveat (AT_FDCWD, file_name, argv, envp, 0);
 }
 
 weak_alias (__execve, execve)
diff --git a/sysdeps/mach/hurd/execveat.c b/sysdeps/mach/hurd/execveat.c
new file mode 100644
index 0000000000..f8be069a86
--- /dev/null
+++ b/sysdeps/mach/hurd/execveat.c
@@ -0,0 +1,92 @@
+/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <getcwd.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+/* Replace the current process, executing FILE_NAME with arguments ARGV and
+   environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
+int
+__execveat (int dirfd, const char *file_name, char *const argv[],
+            char *const envp[], int flags)
+{
+  error_t err;
+  char *concat_name = NULL;
+  const char *abs_path;
+
+  file_t file = __file_name_lookup_at (dirfd, flags, file_name, O_EXEC, 0);
+  if (file == MACH_PORT_NULL)
+    return -1;
+
+  if (file_name[0] == '/')
+    {
+      /* Already an absolute path */
+      abs_path = file_name;
+    }
+  else
+    {
+      /* Relative path */
+      char *cwd;
+      if (dirfd == AT_FDCWD)
+       {
+         cwd = __getcwd (NULL, 0);
+         if (cwd == NULL)
+           {
+             __mach_port_deallocate (__mach_task_self (), file);
+             return -1;
+           }
+       }
+      else
+       {
+         err = HURD_DPORT_USE (dirfd,
+           (cwd = __hurd_canonicalize_directory_name_internal (port, NULL, 0),
+            cwd == NULL ? errno : 0));
+         if (err)
+           {
+             __mach_port_deallocate (__mach_task_self (), file);
+             return __hurd_fail (err);
+           }
+       }
+
+      int res = __asprintf (&concat_name, "%s/%s", cwd, file_name);
+      free (cwd);
+      if (res == -1)
+       {
+         __mach_port_deallocate (__mach_task_self (), file);
+         return -1;
+       }
+
+      abs_path = concat_name;
+    }
+
+  /* Hopefully this will not return.  */
+  err = _hurd_exec_paths (__mach_task_self (), file,
+                         file_name, abs_path, argv, envp);
+
+  /* Oh well.  Might as well be tidy.  */
+  __mach_port_deallocate (__mach_task_self (), file);
+  free (concat_name);
+
+  return __hurd_fail (err);
+}
+
+weak_alias (__execveat, execveat)
diff --git a/sysdeps/mach/hurd/getcwd.h b/sysdeps/mach/hurd/getcwd.h
new file mode 100644
index 0000000000..29ae9f8b40
--- /dev/null
+++ b/sysdeps/mach/hurd/getcwd.h
@@ -0,0 +1,28 @@
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef        _GETCWD_H
+#define        _GETCWD_H       1
+
+#include <hurd.h>
+
+char *
+__hurd_canonicalize_directory_name_internal (file_t thisdir,
+                                            char *buf,
+                                            size_t size);
+
+#endif /* getcwd.h */
-- 
2.30.2