locks: allow lockd to process blocked locks during grace period

[safe/jmp/linux-2.6] / include / linux / securebits.h

diff --git a/include/linux/securebits.h b/include/linux/securebits.h
index 5b06178..92f09bd 100644 (file)
--- a/include/linux/securebits.h
+++ b/include/linux/securebits.h
@@ -3,28 +3,40 @@
 
 #define SECUREBITS_DEFAULT 0x00000000
 
-extern unsigned securebits;
-
 /* 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 inheritable bitmask of the
+   0. If the real uid is 0, we raise the effective (legacy) bit of the
    executable file. */
-#define SECURE_NOROOT            0
+#define SECURE_NOROOT                  0
+#define SECURE_NOROOT_LOCKED           1  /* make bit-0 immutable */
+
+/* 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 */
 
-/* When set, setuid to/from uid 0 does not trigger capability-"fixes"
-   to be compatible with old programs relying on set*uid to loose
-   privileges. When unset, setuid doesn't change privileges. */
-#define SECURE_NO_SETUID_FIXUP   2
+/* 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 */
 
-/* Each securesetting is implemented using two bits. One bit specify
+/* 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 fixed or not. A setting which is fixed cannot be changed
-   from user-level. */
+   setting is locked or not. A setting which is locked cannot be
+   changed from user-level. */
+#define issecure_mask(X)       (1 << (X))
+#define issecure(X)            (issecure_mask(X) & current->securebits)
 
-#define issecure(X) ( (1 << (X+1)) & SECUREBITS_DEFAULT ?      \
-                     (1 << (X)) & SECUREBITS_DEFAULT :         \
-                     (1 << (X)) & securebits )
+#define SECURE_ALL_BITS                (issecure_mask(SECURE_NOROOT) | \
+                                issecure_mask(SECURE_NO_SETUID_FIXUP) | \
+                                issecure_mask(SECURE_KEEP_CAPS))
+#define SECURE_ALL_LOCKS       (SECURE_ALL_BITS << 1)
 
 #endif /* !_LINUX_SECUREBITS_H */