support: Add support_set_vma_name

Check if kernel supports prctl (PR_SET_VMA, PR_SET_VMA_ANON_NAME, ...).
Reviewed-by: DJ Delorie <dj@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/support/support_set_vma_name_supported.c b/support/support_set_vma_name_supported.c
new file mode 100644
index 0000000000..712caa9b9b
--- /dev/null
+++ b/support/support_set_vma_name_supported.c
@@ -0,0 +1,49 @@
+/* Check if kernel supports set VMA range name.
+   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/>.  */
+
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+#include <sys/mman.h>
+#ifdef __linux__
+# include <sys/prctl.h>
+#endif
+
+bool
+support_set_vma_name_supported (void)
+{
+#ifdef __linux__
+  size_t size = sysconf (_SC_PAGESIZE);
+  if (size == -1)
+    FAIL_EXIT1 ("sysconf (_SC_PAGESIZE): %m\n");
+
+  void *vma = xmmap (0,
+		     size,
+		     PROT_NONE,
+		     MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
+		     -1);
+
+  int r = prctl (PR_SET_VMA, PR_SET_VMA_ANON_NAME, vma, size, "vmaname");
+
+  xmunmap (vma, size);
+
+  return r == 0;
+#else
+  return false;
+#endif
+}