Files
xen/Config.mk
T
Konrad Rzeszutek Wilk a353cab905 build_id: Provide ld-embedded build-ids
This patch enables the Elf to be built with the build-id
and provide in the Xen hypervisor the code to extract it.

The man-page for ld --build-id says it is:

"Request the creation of a ".note.gnu.build-id" ELF note
section or a ".build-id" COFF section.  The contents of the
note are unique bits identifying this linked file. style can be
"uuid" to use 128 random bits, "sha1" to use a 160-bit SHA1 hash
on the normative parts of the output contents, ..."

One can also retrieve the value of the build-id by doing
'readelf -n xen-syms'.

For EFI builds we re-use the same build-id that the xen-syms
was built with.

The version of ld that first implemented --build-id is v2.18.
We check for to see if the linker supports the --build-id
parameter and if so use it.

For x86 we have two binaries - the xen-syms and the xen - an
smaller version with lots of sections removed. To make it possible
for readelf -n xen we also modify mkelf32 and xen.lds.S to include
the PT_NOTE ELF section.

The EFI binary is more complicated. We only build one type of
binary and expanding the amount of sections the EFI binary has to
include an .note one is pointless - as there is no concept of
PT_NOTE. The best we can do is move this .note in the .rodata section.

Further development wise should move it to .buildid section
so that DataDirectory debug data nor CodeView can view it.
(The author has no clue what those are).

Note that in earlier patches the linker script had:

 __note_gnu_build_id_start = .;
 *(.rodata.note.gnu.build-id)
 __note_gnu_build_id_end = .;
 *(.note)
 *(.note.*)

Which meant you could have different ELF notes _outside_ the
__note_gnu_build_id_end. However for EFI builds we take the whole
.note* section and jam it in the EFI to be between
__note_gnu_build_id_start and __note_gnu_build_id_end.
To not make this happend we make on the ELF build the section
be called .note.gnu.build-id  (instead of just .note).
If there is a need for a different type of note other folks
can add it as a different section name.

Note that we do call --binary-id=sha1 on all linker invocations.
We have to do to enforce that the symbol offsets don't changes
(the side effect is that we we would have multiple binary ids -
except that the last one is the final one).

Without this working the symbol table embedded in Xen ends
up incorrect - some of the values it contains would be offset by the
size of the included build id.

This obviously causes problems when resolving symbols.

We also define the NT_GNU_BUILD_ID in the elfstructs.h as we
need to use it in various places.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Martin Pohlack <mpohlack@amazon.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-04-29 03:59:03 -04:00

304 lines
10 KiB
Makefile

# -*- mode: Makefile; -*-
ifeq ($(filter /%,$(XEN_ROOT)),)
$(error XEN_ROOT must be absolute)
endif
# Convenient variables
comma := ,
squote := '
empty :=
space := $(empty) $(empty)
# fallback for older make
realpath = $(wildcard $(foreach file,$(1),$(shell cd -P $(dir $(file)) && echo "$$PWD/$(notdir $(file))")))
or = $(if $(strip $(1)),$(1),$(if $(strip $(2)),$(2),$(if $(strip $(3)),$(3),$(if $(strip $(4)),$(4)))))
-include $(XEN_ROOT)/.config
# A debug build of Xen and tools?
debug ?= y
debug_symbols ?= $(debug)
# Test coverage support
coverage ?= n
XEN_COMPILE_ARCH ?= $(shell uname -m | sed -e s/i.86/x86_32/ \
-e s/i86pc/x86_32/ -e s/amd64/x86_64/ \
-e s/armv7.*/arm32/ -e s/armv8.*/arm64/ \
-e s/aarch64/arm64/)
XEN_TARGET_ARCH ?= $(XEN_COMPILE_ARCH)
XEN_OS ?= $(shell uname -s)
CONFIG_$(XEN_OS) := y
SHELL ?= /bin/sh
# Tools to run on system hosting the build
HOSTCFLAGS = -Wall -Werror -Wstrict-prototypes -O2 -fomit-frame-pointer
HOSTCFLAGS += -fno-strict-aliasing
DISTDIR ?= $(XEN_ROOT)/dist
DESTDIR ?= /
# Allow phony attribute to be listed as dependency rather than fake target
.PHONY: .phony
# If we are not cross-compiling, default HOSTC{C/XX} to C{C/XX}
ifeq ($(XEN_TARGET_ARCH), $(XEN_COMPILE_ARCH))
HOSTCC ?= $(CC)
HOSTCXX ?= $(CXX)
endif
# Use Clang/LLVM instead of GCC?
clang ?= n
ifeq ($(clang),n)
gcc := y
HOSTCC ?= gcc
HOSTCXX ?= g++
else
gcc := n
HOSTCC ?= clang
HOSTCXX ?= clang++
endif
include $(XEN_ROOT)/config/$(XEN_OS).mk
include $(XEN_ROOT)/config/$(XEN_TARGET_ARCH).mk
# arguments: variable, common path part, path to test, if yes, if no
define setvar_dir
ifndef $(1)
ifneq (,$(wildcard $(2)$(3)))
$(1) ?= $(2)$(4)
else
$(1) ?= $(2)$(5)
endif
endif
endef
ifneq ($(EXTRA_PREFIX),)
EXTRA_INCLUDES += $(EXTRA_PREFIX)/include
EXTRA_LIB += $(EXTRA_PREFIX)/lib
endif
PYTHON ?= python
PYTHON_PREFIX_ARG ?= --prefix="$(prefix)"
# The above requires that prefix contains *no spaces*. This variable is here
# to permit the user to set PYTHON_PREFIX_ARG to '' to workaround this bug:
# https://bugs.launchpad.net/ubuntu/+bug/362570
# cc-option: Check if compiler supports first option, else fall back to second.
#
# This is complicated by the fact that unrecognised -Wno-* options:
# (a) are ignored unless the compilation emits a warning; and
# (b) even then produce a warning rather than an error
# To handle this we do a test compile, passing the option-under-test, on a code
# fragment that will always produce a warning (integer assigned to pointer).
# We then grep for the option-under-test in the compiler's output, the presence
# of which would indicate an "unrecognized command-line option" warning/error.
#
# Usage: cflags-y += $(call cc-option,$(CC),-march=winchip-c6,-march=i586)
cc-option = $(shell if test -z "`echo 'void*p=1;' | \
$(1) $(2) -S -o /dev/null -x c - 2>&1 | grep -- $(2) -`"; \
then echo "$(2)"; else echo "$(3)"; fi ;)
# cc-option-add: Add an option to compilation flags, but only if supported.
# Usage: $(call cc-option-add CFLAGS,CC,-march=winchip-c6)
cc-option-add = $(eval $(call cc-option-add-closure,$(1),$(2),$(3)))
define cc-option-add-closure
ifneq ($$(call cc-option,$$($(2)),$(3),n),n)
$(1) += $(3)
endif
endef
cc-options-add = $(foreach o,$(3),$(call cc-option-add,$(1),$(2),$(o)))
# cc-ver: Check compiler is at least specified version. Return boolean 'y'/'n'.
# Usage: ifeq ($(call cc-ver,$(CC),0x030400),y)
cc-ver = $(shell if [ $$((`$(1) -dumpversion | awk -F. \
'{ printf "0x%02x%02x%02x", $$1, $$2, $$3}'`)) -ge $$(($(2))) ]; \
then echo y; else echo n; fi ;)
# cc-ver-check: Check compiler is at least specified version, else fail.
# Usage: $(call cc-ver-check,CC,0x030400,"Require at least gcc-3.4")
cc-ver-check = $(eval $(call cc-ver-check-closure,$(1),$(2),$(3)))
define cc-ver-check-closure
ifeq ($$(call cc-ver,$$($(1)),$(2)),n)
override $(1) = echo "*** FATAL BUILD ERROR: "$(3) >&2; exit 1;
cc-option := n
endif
endef
# Require GCC v4.1+
check-$(gcc) = $(call cc-ver-check,CC,0x040100,"Xen requires at least gcc-4.1")
$(eval $(check-y))
ld-ver-build-id = $(shell $(1) --build-id 2>&1 | \
grep -q build-id && echo n || echo y)
export XEN_HAS_BUILD_ID ?= n
ifeq ($(call ld-ver-build-id,$(LD)),n)
build_id_linker :=
else
CFLAGS += -DBUILD_ID
build_id_linker := --build-id=sha1
endif
# as-insn: Check whether assembler supports an instruction.
# Usage: cflags-y += $(call as-insn "insn",option-yes,option-no)
as-insn = $(if $(shell echo 'void _(void) { asm volatile ( $(2) ); }' \
| $(1) $(AFLAGS) -c -x c -o /dev/null - 2>&1),$(4),$(3))
# as-insn-check: Add an option to compilation flags, but only if insn is
# supported by assembler.
# Usage: $(call as-insn-check CFLAGS,CC,"nop",-DHAVE_GAS_NOP)
as-insn-check = $(eval $(call as-insn-check-closure,$(1),$(2),$(3),$(4)))
define as-insn-check-closure
ifeq ($$(call as-insn,$$($(2)),$(3),y,n),y)
$(1) += $(4)
endif
endef
define buildmakevars2shellvars
export PREFIX="$(prefix)"; \
export XEN_SCRIPT_DIR="$(XEN_SCRIPT_DIR)"; \
export XEN_ROOT="$(XEN_ROOT)"
endef
#
# Compare $(1) and $(2) and replace $(2) with $(1) if they differ
#
# Typically $(1) is a newly generated file and $(2) is the target file
# being regenerated. This prevents changing the timestamp of $(2) only
# due to being auto regenereated with the same contents.
define move-if-changed
if ! cmp -s $(1) $(2); then mv -f $(1) $(2); else rm -f $(1); fi
endef
BUILD_MAKE_VARS := sbindir bindir LIBEXEC LIBEXEC_BIN libdir SHAREDIR \
XENFIRMWAREDIR XEN_CONFIG_DIR XEN_SCRIPT_DIR XEN_LOCK_DIR \
XEN_RUN_DIR XEN_PAGING_DIR XEN_DUMP_DIR
buildmakevars2file = $(eval $(call buildmakevars2file-closure,$(1)))
define buildmakevars2file-closure
$(1): .phony
rm -f $(1).tmp; \
$(foreach var, $(BUILD_MAKE_VARS), \
echo "$(var)=\"$($(var))\"" >>$(1).tmp;) \
$(call move-if-changed,$(1).tmp,$(1))
endef
buildmakevars2header = $(eval $(call buildmakevars2header-closure,$(1)))
define buildmakevars2header-closure
$(1): .phony
rm -f $(1).tmp; \
$(foreach var, $(BUILD_MAKE_VARS), \
echo "#define $(var) \"$($(var))\"" >>$(1).tmp;) \
$(call move-if-changed,$(1).tmp,$(1))
endef
ifeq ($(debug_symbols),y)
CFLAGS += -g
endif
CFLAGS += -fno-strict-aliasing
CFLAGS += -std=gnu99
CFLAGS += -Wall -Wstrict-prototypes
# Clang complains about macros that expand to 'if ( ( foo == bar ) ) ...'
# and is over-zealous with the printf format lint
# and is a bit too fierce about unused return values
CFLAGS-$(clang) += -Wno-parentheses -Wno-format -Wno-unused-value
$(call cc-option-add,HOSTCFLAGS,HOSTCC,-Wdeclaration-after-statement)
$(call cc-option-add,CFLAGS,CC,-Wdeclaration-after-statement)
$(call cc-option-add,CFLAGS,CC,-Wno-unused-but-set-variable)
$(call cc-option-add,CFLAGS,CC,-Wno-unused-local-typedefs)
LDFLAGS += $(foreach i, $(EXTRA_LIB), -L$(i))
CFLAGS += $(foreach i, $(EXTRA_INCLUDES), -I$(i))
LDFLAGS += $(foreach i, $(PREPEND_LIB), -L$(i))
CFLAGS += $(foreach i, $(PREPEND_INCLUDES), -I$(i))
ifeq ($(XEN_TOOLS_RPATH),y)
LDFLAGS += -Wl,-rpath,$(libdir)
endif
APPEND_LDFLAGS += $(foreach i, $(APPEND_LIB), -L$(i))
APPEND_CFLAGS += $(foreach i, $(APPEND_INCLUDES), -I$(i))
EMBEDDED_EXTRA_CFLAGS := -nopie -fno-stack-protector -fno-stack-protector-all
EMBEDDED_EXTRA_CFLAGS += -fno-exceptions
XEN_EXTFILES_URL ?= http://xenbits.xen.org/xen-extfiles
# All the files at that location were downloaded from elsewhere on
# the internet. The original download URL is preserved as a comment
# near the place in the Xen Makefiles where the file is used.
# Where to look for inlined subtrees (for example, from a tarball)
QEMU_UPSTREAM_INTREE ?= $(XEN_ROOT)/tools/qemu-xen
QEMU_TRADITIONAL_INTREE ?= $(XEN_ROOT)/tools/qemu-xen-traditional
# Handle legacy options
ifneq (,$(SEABIOS_UPSTREAM_TAG))
SEABIOS_UPSTREAM_REVISION ?= $(SEABIOS_UPSTREAM_TAG)
endif
ifneq (,$(QEMU_REMOTE))
QEMU_TRADITIONAL_URL ?= $(QEMU_REMOTE)
endif
ifneq (,$(CONFIG_QEMU))
QEMU_TRADITIONAL_LOC ?= $(CONFIG_QEMU)
endif
ifneq (,$(QEMU_TAG))
QEMU_TRADITIONAL_REVISION ?= $(QEMU_TAG)
endif
ifeq ($(GIT_HTTP),y)
OVMF_UPSTREAM_URL ?= http://xenbits.xen.org/git-http/ovmf.git
QEMU_UPSTREAM_URL ?= http://xenbits.xen.org/git-http/qemu-xen.git
QEMU_TRADITIONAL_URL ?= http://xenbits.xen.org/git-http/qemu-xen-traditional.git
SEABIOS_UPSTREAM_URL ?= http://xenbits.xen.org/git-http/seabios.git
MINIOS_UPSTREAM_URL ?= http://xenbits.xen.org/git-http/mini-os.git
else
OVMF_UPSTREAM_URL ?= git://xenbits.xen.org/ovmf.git
QEMU_UPSTREAM_URL ?= git://xenbits.xen.org/qemu-xen.git
QEMU_TRADITIONAL_URL ?= git://xenbits.xen.org/qemu-xen-traditional.git
SEABIOS_UPSTREAM_URL ?= git://xenbits.xen.org/seabios.git
MINIOS_UPSTREAM_URL ?= git://xenbits.xen.org/mini-os.git
endif
OVMF_UPSTREAM_REVISION ?= 52a99493cce88a9d4ec8a02d7f1bd1a1001ce60d
QEMU_UPSTREAM_REVISION ?= master
MINIOS_UPSTREAM_REVISION ?= e085b7e5613576601e2f100e6f1ee9e0778c3eb9
# Sun Apr 10 00:46:32 2016 +0200
# Fix time update
SEABIOS_UPSTREAM_REVISION ?= rel-1.9.2
# Tue, 1 Mar 2016 15:06:45 +0100 (16:06 +0200)
# fw/pci: add Q35 S3 support
ETHERBOOT_NICS ?= rtl8139 8086100e
QEMU_TRADITIONAL_REVISION ?= 21f6526d1da331611ac5fe12967549d1a04e149b
# Fri Jan 15 13:23:56 2016 +0000
# qemu-xen-traditional: Add libxenforeignmemory to rpath-link
# Specify which qemu-dm to use. This may be `ioemu' to use the old
# Mercurial in-tree version, or a local directory, or a git URL.
# QEMU_UPSTREAM_LOC ?= `pwd`/$(XEN_ROOT)/../qemu-xen.git
# Defaults for subtree locations
QEMU_TRADITIONAL_LOC ?= $(call or,$(wildcard $(QEMU_TRADITIONAL_INTREE)),\
$(QEMU_TRADITIONAL_URL))
QEMU_UPSTREAM_LOC ?= $(call or,$(wildcard $(QEMU_UPSTREAM_INTREE)),\
$(QEMU_UPSTREAM_URL))
# Short answer -- do not enable this unless you know what you are
# doing and are prepared for some pain.
CONFIG_TESTS ?= y