linux: Add PR_SET_VMA_ANON_NAME support

Linux 5.17 added support to naming anonymous virtual memory areas
through the prctl syscall.  The __set_vma_name is a wrapper to avoid
optimizing the prctl call if the kernel does not support it.

If the kernel does not support PR_SET_VMA_ANON_NAME, prctl returns
EINVAL. And it also returns the same error for an invalid argument.
Since it is an internal-only API, it assumes well-formatted input:
aligned START, with (START, START+LEN) being a valid memory range,
and NAME with a limit of 80 characters without an invalid one
("\\`$[]").
Reviewed-by: DJ Delorie <dj@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/sysdeps/generic/setvmaname.h b/sysdeps/generic/setvmaname.h
new file mode 100644
index 0000000000..2824587e9f
--- /dev/null
+++ b/sysdeps/generic/setvmaname.h
@@ -0,0 +1,27 @@
+/* Utilities functions to name memory mappings.
+   Copyright (C) 2023 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 __SETVMANAME_H
+#define __SETVMANAME_H
+
+static inline
+void __set_vma_name (void *start, size_t len, const char *name)
+{
+}
+
+#endif