csu: Define a "csu" compartment policy

This policy file is installed to /usr/lib alongside the relevant crt*
object files.  bsd.(lib|prog).mk add this policy to LDFLAGS when
linking an output that already has at least one other policy file.

Author: bsdjhb

lib/csu/Makefile.inc

@@ -36,7 +36,7 @@ CFLAGS+=	-I${.CURDIR:H}/common-cheri
 
 CFLAGS_CRTS+=	-DSHARED ${PICFLAG}
 
-FILES=		${OBJS}
+FILES=		${OBJS} crt.json
 FILESMODE=	${LIBMODE}
 FILESOWN=	${LIBOWN}
 FILESGRP=	${LIBGRP}

lib/csu/common/crt.json

@@ -0,0 +1,16 @@
+{
+    "compartments": {
+	"csu": {
+	    "files": [
+		"crt1.o",
+		"crtbegin.o",
+		"crtbeginS.o",
+		"crtbeginT.o",
+		"crtend.o",
+		"crtendS.o",
+		"crti.o",
+		"crtn.o"
+	    ]
+	}
+    }
+}

share/mk/bsd.lib.mk

@@ -299,6 +299,7 @@ LDFLAGS+=	-Wl,--undefined-version
 
 .if ${MK_COMPARTMENT_POLICY} != "no" && ${MACHINE_ABI:Mpurecap}
 .if !empty(COMPARTMENT_POLICY)
+COMPARTMENT_POLICY+=	${SYSROOT}/usr/lib/crt.json
 ${SHLIB_NAME_FULL}:	${COMPARTMENT_POLICY}
 LDFLAGS+=	${COMPARTMENT_POLICY:S/^/-Wl,--compartment-policy=/}
 .endif

share/mk/bsd.prog.mk

@@ -177,6 +177,7 @@ PROG_FULL=	${PROG}
 
 .if ${MK_COMPARTMENT_POLICY} != "no" && ${MACHINE_ABI:Mpurecap}
 .if !empty(COMPARTMENT_POLICY)
+COMPARTMENT_POLICY+=	${SYSROOT}/usr/lib/crt.json
 ${PROG_FULL}:	${COMPARTMENT_POLICY}
 LDFLAGS+=	${COMPARTMENT_POLICY:S/^/-Wl,--compartment-policy=/}
 .endif