Pre-quote macros passed to .incbin to avoid unwanted substitution

Currently for the MFS, firmware and VDSO template assembly files we pass
the path to include with .incbin unquoted and use __XSTRING within the
assembly file to stringify it. However, __XSTRING doesn't just perform a
single level of expansion, it performs the normal full expansion of the
macro, and so if the path itself happens to tokenise to something that
includes a defined macro in it that will itself be substituted. For
example, with #define MACRO 1, a path like /path/containing/MACRO/in/it
will expand to /path/containing/1/in/it and then, when stringified, end
up as "/path/containing/1/in/it", not the intended string. Normally,
macros have names that start or end witih underscores and are unlikely
to appear in a tokenised path (even if technically they could), but now
that we've switched to GNU C as of commit ec41a96daa ("sys: Switch the
kernel's C standard from C99 to GNU99.") there are a few new macros
defined which don't start or end with underscores: unix, which is always
defined to 1, and i386, which is defined to 1 on i386. The former
probably doesn't appear in user paths in practice, but the latter has
been seen to and is likely quite common in the wild.

Fix this by defining the macro pre-quoted instead of using __XSTRING.
Note that technically we don't need to do this for vdso_wrap.S today as
all the paths passed to it are safe file names with no user-controlled
prefix but we should do it anyway for consistency and robustness against
future changes.

This allows make tinderbox to pass when built with source and object
directories inside ~/path-with-unix, which would otherwise expand to
~/path-with-1 and break.

PR:	272744
Fixes:	ec41a96daa ("sys: Switch the kernel's C standard from C99 to GNU99.")

sys/conf/kern.post.mk

@@ -466,7 +466,7 @@ vnode_if_typedef.h:
 .if ${MFS_IMAGE:Uno} != "no"
 .if empty(MD_ROOT_SIZE_CONFIGURED)
 embedfs_${MFS_IMAGE:T:R}.o: ${MFS_IMAGE} $S/dev/md/embedfs.S
-	${CC} ${CFLAGS} ${ACFLAGS} -DMFS_IMAGE="${MFS_IMAGE}" -c \
+	${CC} ${CFLAGS} ${ACFLAGS} -DMFS_IMAGE=\""${MFS_IMAGE}"\" -c \
 	    $S/dev/md/embedfs.S -o ${.TARGET}
 .endif
 .endif

sys/conf/kern.pre.mk

@@ -200,7 +200,7 @@ NORMAL_M= ${AWK} -f $S/tools/makeobjops.awk ${.IMPSRC} -c ; \
 
 NORMAL_FW= uudecode -o ${.TARGET} ${.ALLSRC}
 NORMAL_FWO= ${CC:N${CCACHE_BIN}} -c ${ASM_CFLAGS} ${WERROR} -o ${.TARGET} \
-	$S/kern/firmw.S -DFIRMW_FILE="${.ALLSRC:M*.fw}" \
+	$S/kern/firmw.S -DFIRMW_FILE=\""${.ALLSRC:M*.fw}"\" \
 	-DFIRMW_SYMBOL="${.ALLSRC:M*.fw:C/[-.\/]/_/g}"
 
 # for ZSTD in the kernel (include zstd/lib/freebsd before other CFLAGS)

sys/conf/kmod.mk

@@ -210,7 +210,7 @@ ${_firmw:C/\:.*$/.fwo/:T}:	${_firmw:C/\:.*$//} ${SYSDIR}/kern/firmw.S
 	@${ECHO} ${_firmw:C/\:.*$//} ${.ALLSRC:M*${_firmw:C/\:.*$//}}
 	${CC:N${CCACHE_BIN}} -c -x assembler-with-cpp -DLOCORE 	\
 	    ${CFLAGS} ${WERROR} 				\
-	    -DFIRMW_FILE="${.ALLSRC:M*${_firmw:C/\:.*$//}}" 	\
+	    -DFIRMW_FILE=\""${.ALLSRC:M*${_firmw:C/\:.*$//}}"\"	\
 	    -DFIRMW_SYMBOL="${_firmw:C/\:.*$//:C/[-.\/@]/_/g}"	\
 	    ${SYSDIR}/kern/firmw.S -o ${.TARGET}
 

sys/dev/md/embedfs.S

@@ -38,7 +38,7 @@
 	.globl	mfs_root
 	.type	mfs_root, %object
 mfs_root:
-	.incbin	__XSTRING(MFS_IMAGE)
+	.incbin	MFS_IMAGE
 	.size	mfs_root, . - mfs_root
 	.globl	mfs_root_end
 	.type	mfs_root_end, %object

sys/kern/firmw.S

@@ -41,7 +41,7 @@
 	.globl	FIRMW_START(FIRMW_SYMBOL)
 	.type	FIRMW_START(FIRMW_SYMBOL), %object
 FIRMW_START(FIRMW_SYMBOL):
-	.incbin	__XSTRING(FIRMW_FILE)
+	.incbin	FIRMW_FILE
 	.size	FIRMW_START(FIRMW_SYMBOL), . - FIRMW_START(FIRMW_SYMBOL)
 	.globl	FIRMW_END(FIRMW_SYMBOL)
 	.type	FIRMW_END(FIRMW_SYMBOL), %object

sys/tools/amd64_ia32_vdso.sh

@@ -55,7 +55,7 @@ fi
 
 ${CC} ${DEBUG} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
    -o elf-vdso32.so.o -I. -I"${S}" -include opt_global.h \
-   -DVDSO_NAME=elf_vdso32_so_1 -DVDSO_FILE=elf-vdso32.so.1 \
+   -DVDSO_NAME=elf_vdso32_so_1 -DVDSO_FILE=\"elf-vdso32.so.1\" \
    "${S}"/tools/vdso_wrap.S
 
 ${NM} -D elf-vdso32.so.1 | ${AWK} \

sys/tools/amd64_vdso.sh

@@ -64,7 +64,7 @@ fi
 
 ${CC} ${DEBUG} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
    -o elf-vdso.so.o -I. -I"${S}" -include opt_global.h \
-   -DVDSO_NAME=elf_vdso_so_1 -DVDSO_FILE=elf-vdso.so.1 \
+   -DVDSO_NAME=elf_vdso_so_1 -DVDSO_FILE=\"elf-vdso.so.1\" \
    "${S}"/tools/vdso_wrap.S
 
 ${NM} -D elf-vdso.so.1 | \

sys/tools/vdso_wrap.S

@@ -39,7 +39,7 @@
 	.type	VDSO_BLOB_START(VDSO_NAME), %object
 	.size	VDSO_BLOB_START(VDSO_NAME), 0
 VDSO_BLOB_START(VDSO_NAME):
-	.incbin	__XSTRING(VDSO_FILE)
+	.incbin	VDSO_FILE
 	.globl	VDSO_BLOB_END(VDSO_NAME)
 	.type	VDSO_BLOB_END(VDSO_NAME), %object
 	.size	VDSO_BLOB_END(VDSO_NAME), 0