linux/Documentation/lguest/Makefile
Ronald G. Minnich e3bcf5e278 lguest: avoid shared libraries mapped over guest memory
Some versions of ld.so mmap the shared libraries right in over guest
memory, so compile lguest statically by default.

[ FC7 maps shared libraries very low, where the launcher maps guest's
  physical memory.  Quick fix is to link Launcher static, real fix is
  for 2.6.24. ]

-static is a simple fix. I expect this problem will be more common than we
like, as different distro's make different "improvements" to ld.so

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-09 08:14:56 -07:00

29 lines
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Makefile

# This creates the demonstration utility "lguest" which runs a Linux guest.
# For those people that have a separate object dir, look there for .config
KBUILD_OUTPUT := ../..
ifdef O
ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
endif
# We rely on CONFIG_PAGE_OFFSET to know where to put lguest binary.
include $(KBUILD_OUTPUT)/.config
LGUEST_GUEST_TOP := ($(CONFIG_PAGE_OFFSET) - 0x08000000)
CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -Wl,-T,lguest.lds
LDLIBS:=-lz
# Removing this works for some versions of ld.so (eg. Ubuntu Feisty) and
# not others (eg. FC7).
LDFLAGS+=-static
all: lguest.lds lguest
# The linker script on x86 is so complex the only way of creating one
# which will link our binary in the right place is to mangle the
# default one.
lguest.lds:
$(LD) --verbose | awk '/^==========/ { PRINT=1; next; } /SIZEOF_HEADERS/ { gsub(/0x[0-9A-F]*/, "$(LGUEST_GUEST_TOP)") } { if (PRINT) print $$0; }' > $@
clean:
rm -f lguest.lds lguest