system/VmaName: new library

src/system/VmaName.hxx

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2022 CM4all GmbH
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#ifdef __linux__
+# include <sys/prctl.h>
+
+/* fallback definitions if our libc is older than the kernel */
+# ifndef PR_SET_VMA
+#  define PR_SET_VMA 0x53564d41
+# endif
+# ifndef PR_SET_VMA_ANON_NAME
+#  define PR_SET_VMA_ANON_NAME 0
+# endif
+#endif // __linux__
+
+/**
+ * Set a name for the specified virtual memory area.
+ *
+ * This feature requires Linux 5.17.
+ */
+inline void
+SetVmaName(const void *start, size_t len, const char *name)
+{
+#ifdef __linux__
+	prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, (unsigned long)start, len,
+	      (unsigned long)name);
+#endif
+}