Add build system scaffolding and libc headers

1 files changed, 85 insertions, 0 deletions

diff --git a/include/arch/x86_64/linux/securebits.h b/include/arch/x86_64/linux/securebits.h
new file mode 100644
index 00000000..6606366a
--- /dev/null
+++ b/include/arch/x86_64/linux/securebits.h
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _LINUX_SECUREBITS_H
+#define _LINUX_SECUREBITS_H
+
+/* Each securesetting is implemented using two bits. One bit specifies
+   whether the setting is on or off. The other bit specify whether the
+   setting is locked or not. A setting which is locked cannot be
+   changed from user-level. */
+#define issecure_mask(X) (1 << (X))
+
+#define SECUREBITS_DEFAULT 0x00000000
+
+/* When set UID 0 has no special privileges. When unset, we support
+   inheritance of root-permissions and suid-root executable under
+   compatibility mode. We raise the effective and inheritable bitmasks
+   *of the executable file* if the effective uid of the new process is
+   0. If the real uid is 0, we raise the effective (legacy) bit of the
+   executable file. */
+#define SECURE_NOROOT	     0
+#define SECURE_NOROOT_LOCKED 1 /* make bit-0 immutable */
+
+#define SECBIT_NOROOT	     (issecure_mask(SECURE_NOROOT))
+#define SECBIT_NOROOT_LOCKED (issecure_mask(SECURE_NOROOT_LOCKED))
+
+/* When set, setuid to/from uid 0 does not trigger capability-"fixup".
+   When unset, to provide compatiblility with old programs relying on
+   set*uid to gain/lose privilege, transitions to/from uid 0 cause
+   capabilities to be gained/lost. */
+#define SECURE_NO_SETUID_FIXUP	      2
+#define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */
+
+#define SECBIT_NO_SETUID_FIXUP (issecure_mask(SECURE_NO_SETUID_FIXUP))
+#define SECBIT_NO_SETUID_FIXUP_LOCKED \
+	(issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED))
+
+/* When set, a process can retain its capabilities even after
+   transitioning to a non-root user (the set-uid fixup suppressed by
+   bit 2). Bit-4 is cleared when a process calls exec(); setting both
+   bit 4 and 5 will create a barrier through exec that no exec()'d
+   child can use this feature again. */
+#define SECURE_KEEP_CAPS	4
+#define SECURE_KEEP_CAPS_LOCKED 5 /* make bit-4 immutable */
+
+#define SECBIT_KEEP_CAPS	(issecure_mask(SECURE_KEEP_CAPS))
+#define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED))
+
+/* When set, a process cannot add new capabilities to its ambient set. */
+#define SECURE_NO_CAP_AMBIENT_RAISE	   6
+#define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED 7 /* make bit-6 immutable */
+
+#define SECBIT_NO_CAP_AMBIENT_RAISE (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
+#define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED \
+	(issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED))
+
+/* See Documentation/userspace-api/check_exec.rst */
+#define SECURE_EXEC_RESTRICT_FILE	 8
+#define SECURE_EXEC_RESTRICT_FILE_LOCKED 9 /* make bit-8 immutable */
+
+#define SECBIT_EXEC_RESTRICT_FILE (issecure_mask(SECURE_EXEC_RESTRICT_FILE))
+#define SECBIT_EXEC_RESTRICT_FILE_LOCKED \
+	(issecure_mask(SECURE_EXEC_RESTRICT_FILE_LOCKED))
+
+/* See Documentation/userspace-api/check_exec.rst */
+#define SECURE_EXEC_DENY_INTERACTIVE	    10
+#define SECURE_EXEC_DENY_INTERACTIVE_LOCKED 11 /* make bit-10 immutable */
+
+#define SECBIT_EXEC_DENY_INTERACTIVE \
+	(issecure_mask(SECURE_EXEC_DENY_INTERACTIVE))
+#define SECBIT_EXEC_DENY_INTERACTIVE_LOCKED \
+	(issecure_mask(SECURE_EXEC_DENY_INTERACTIVE_LOCKED))
+
+#define SECURE_ALL_BITS                               \
+	(issecure_mask(SECURE_NOROOT) |               \
+	 issecure_mask(SECURE_NO_SETUID_FIXUP) |      \
+	 issecure_mask(SECURE_KEEP_CAPS) |            \
+	 issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE) | \
+	 issecure_mask(SECURE_EXEC_RESTRICT_FILE) |   \
+	 issecure_mask(SECURE_EXEC_DENY_INTERACTIVE))
+#define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1)
+
+#define SECURE_ALL_UNPRIVILEGED                     \
+	(issecure_mask(SECURE_EXEC_RESTRICT_FILE) | \
+	 issecure_mask(SECURE_EXEC_DENY_INTERACTIVE))
+
+#endif /* _LINUX_SECUREBITS_H */