[OE-core] [PATCH V2] busybox: Use CC instead of bare LD to be the Linker
Khem Raj
raj.khem at gmail.com
Fri Sep 25 05:06:02 UTC 2015
this is a resend of the very same patch which was send 2-3 weeks ago
> On Sep 24, 2015, at 9:59 PM, Khem Raj <raj.khem at gmail.com> wrote:
>
> This patch was on mailing list, another patch to make sure -r is not
> passed directly but via -Wl switch is added.
>
> This was exposed when using clang and gold linker, clang does not have
> -r switch to do relocatable objects and problem happens specific to OE
> becuase we use LD = CC
>
> now what happens is that busybox assumes that linker will be called
> directly, and hence sprinkles linkers options in its kbuild system which
> aggregate into LDFLAGS, some of these options are happily ignored by gcc
> as well but it passes -r options rightly to linker so it all works,
> however when using clang, this falls apart since -r is not known option
> for clang so it drops this option and all obects which should be
> partially linked becomes ET_EXEC and when they are added to final link
> then gold starts to get confused
>
> /mnt/home/kraj/work/angstrom/build/tmp-angstrom-glibc/sysroots/x86_64-linux/usr/bin/arm-angstrom-linux-gnueabi/arm-angstrom-linux-gnueabi-ld:
> error: applets/built-in.o: unsupported ELF file type 2
> clang-3.7: error: linker command failed with exit code 1 (use -v to see invocation)
>
> Signed-off-by: Khem Raj <raj.khem at gmail.com>
> ---
> ...-linking-instead-of-LD-and-use-CFLAGS-and.patch | 114 +++++++++++++++++++++
> .../busybox/0002-Passthrough-r-to-linker.patch | 32 ++++++
> meta/recipes-core/busybox/busybox_1.23.2.bb | 2 +
> 3 files changed, 148 insertions(+)
> create mode 100644 meta/recipes-core/busybox/busybox/0001-Use-CC-when-linking-instead-of-LD-and-use-CFLAGS-and.patch
> create mode 100644 meta/recipes-core/busybox/busybox/0002-Passthrough-r-to-linker.patch
>
> diff --git a/meta/recipes-core/busybox/busybox/0001-Use-CC-when-linking-instead-of-LD-and-use-CFLAGS-and.patch b/meta/recipes-core/busybox/busybox/0001-Use-CC-when-linking-instead-of-LD-and-use-CFLAGS-and.patch
> new file mode 100644
> index 0000000..2bf2b91
> --- /dev/null
> +++ b/meta/recipes-core/busybox/busybox/0001-Use-CC-when-linking-instead-of-LD-and-use-CFLAGS-and.patch
> @@ -0,0 +1,114 @@
> +From a9333eb6a7b8dbda735947cd5bc981ff9352a2c9 Mon Sep 17 00:00:00 2001
> +From: Nathan Phillip Brink <ohnobinki at ohnopublishing.net>
> +Date: Thu, 10 Mar 2011 00:27:08 -0500
> +Subject: [PATCH 1/2] Use $(CC) when linking instead of $(LD) and use $(CFLAGS)
> + and $(EXTRA_CFLAGS) when linking.
> +
> +This fixes the issue where LDFLAGS escaped with -Wl are ignored during
> +compilation. It also simplifies using CFLAGS or EXTRA_CFLAGS (such as
> +-m32 on x86_64 or -flto) which apply to both compilation and linking
> +situations.
> +
> +Signed-off-by: Nathan Phillip Brink <ohnobinki at ohnopublishing.net>
> +---
> +Upstream-Status: Pending
> +
> + Makefile | 7 ++++---
> + scripts/Makefile.build | 8 ++++----
> + scripts/Makefile.lib | 13 +++----------
> + 3 files changed, 11 insertions(+), 17 deletions(-)
> +
> +Index: busybox-1.23.2/Makefile
> +===================================================================
> +--- busybox-1.23.2.orig/Makefile
> ++++ busybox-1.23.2/Makefile
> +@@ -309,7 +309,8 @@ CHECKFLAGS := -D__linux__ -Dlinux -D
> + MODFLAGS = -DMODULE
> + CFLAGS_MODULE = $(MODFLAGS)
> + AFLAGS_MODULE = $(MODFLAGS)
> +-LDFLAGS_MODULE = -r
> ++LDFLAGS_RELOCATABLE = -r -nostdlib
> ++LDFLAGS_MODULE = $(LDFLAGS_RELOCATABLE)
> + CFLAGS_KERNEL =
> + AFLAGS_KERNEL =
> +
> +@@ -331,7 +332,7 @@ KERNELVERSION = $(VERSION).$(PATCHLEVEL)
> + export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION \
> + ARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC \
> + CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE \
> +- HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
> ++ HOSTCXX HOSTCXXFLAGS LDFLAGS_RELOCATABLE LDFLAGS_MODULE CHECK CHECKFLAGS
> +
> + export CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
> + export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
> +@@ -610,7 +611,7 @@ quiet_cmd_busybox__ ?= LINK $@
> + cmd_busybox__ ?= $(srctree)/scripts/trylink \
> + "$@" \
> + "$(CC)" \
> +- "$(CFLAGS) $(CFLAGS_busybox)" \
> ++ "$(CFLAGS) $(CFLAGS_busybox) $(EXTRA_CFLAGS)" \
> + "$(LDFLAGS) $(EXTRA_LDFLAGS)" \
> + "$(core-y)" \
> + "$(libs-y)" \
> +Index: busybox-1.23.2/scripts/Makefile.build
> +===================================================================
> +--- busybox-1.23.2.orig/scripts/Makefile.build
> ++++ busybox-1.23.2/scripts/Makefile.build
> +@@ -174,7 +174,7 @@ cmd_modversions = \
> + | $(GENKSYMS) -a $(ARCH) \
> + > $(@D)/.tmp_$(@F:.o=.ver); \
> + \
> +- $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
> ++ $(CC) $(ld_flags_partial) $(LDFLAGS_RELOCATABLE) -o $@ $(@D)/.tmp_$(@F) \
> + -T $(@D)/.tmp_$(@F:.o=.ver); \
> + rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
> + else \
> +@@ -257,7 +257,7 @@ quiet_cmd_link_o_target = LD $@
> + # If the list of objects to link is empty, just create an empty built-in.o
> + # -nostdlib is added to make "make LD=gcc ..." work (some people use that)
> + cmd_link_o_target = $(if $(strip $(obj-y)),\
> +- $(LD) -nostdlib $(ld_flags) -r -o $@ $(filter $(obj-y), $^),\
> ++ $(CC) $(ld_flags_partial) $(LDFLAGS_RELOCATABLE) -o $@ $(filter $(obj-y), $^),\
> + rm -f $@; $(AR) rcs $@)
> +
> + $(builtin-target): $(obj-y) FORCE
> +@@ -292,10 +292,10 @@ $($(subst $(obj)/,,$(@:.o=-objs))) \
> + $($(subst $(obj)/,,$(@:.o=-y)))), $^)
> +
> + quiet_cmd_link_multi-y = LD $@
> +-cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps)
> ++cmd_link_multi-y = $(CC) $(ld_flags_partial) $(LDFLAGS_RELOCATABLE) -o $@ $(link_multi_deps)
> +
> + quiet_cmd_link_multi-m = LD [M] $@
> +-cmd_link_multi-m = $(LD) $(ld_flags) $(LDFLAGS_MODULE) -o $@ $(link_multi_deps)
> ++cmd_link_multi-m = $(CC) $(ld_flags) $(LDFLAGS_MODULE) -o $@ $(link_multi_deps)
> +
> + # We would rather have a list of rules like
> + # foo.o: $(foo-objs)
> +Index: busybox-1.23.2/scripts/Makefile.lib
> +===================================================================
> +--- busybox-1.23.2.orig/scripts/Makefile.lib
> ++++ busybox-1.23.2/scripts/Makefile.lib
> +@@ -121,7 +121,8 @@ cpp_flags = -Wp,-MD,$(depfile) $(NO
> + # yet ld_flags is fed to ld.
> + #ld_flags = $(LDFLAGS) $(EXTRA_LDFLAGS)
> + # Remove the -Wl, prefix from linker options normally passed through gcc
> +-ld_flags = $(filter-out -Wl$(comma)%,$(LDFLAGS) $(EXTRA_LDFLAGS))
> ++ld_flags = $(filter-out -Wl$(comma)%,$(LDFLAGS) $(EXTRA_LDFLAGS) $(CFLAGS) $(EXTRA_CFLAGS))
> ++ld_flags_partial = $($(filter-out -shared%, $(filter-out -pie%,$(ld_flags))))
> +
> +
> + # Finds the multi-part object the current object will be linked into
> +@@ -151,10 +152,8 @@ $(obj)/%:: $(src)/%_shipped
> + # Linking
> + # ---------------------------------------------------------------------------
> +
> +-# TODO: LDFLAGS usually is supposed to contain gcc's flags, not ld's.
> +-# but here we feed them to ld!
> +-quiet_cmd_ld = LD $@
> +-cmd_ld = $(LD) $(LDFLAGS) $(EXTRA_LDFLAGS) $(LDFLAGS_$(@F)) \
> ++quiet_cmd_ld = CC $@
> ++cmd_ld = $(CC) $(ld_flags) $(LDFLAGS_$(@F)) \
> + $(filter-out FORCE,$^) -o $@
> +
> + # Objcopy
> diff --git a/meta/recipes-core/busybox/busybox/0002-Passthrough-r-to-linker.patch b/meta/recipes-core/busybox/busybox/0002-Passthrough-r-to-linker.patch
> new file mode 100644
> index 0000000..de286fb
> --- /dev/null
> +++ b/meta/recipes-core/busybox/busybox/0002-Passthrough-r-to-linker.patch
> @@ -0,0 +1,32 @@
> +From df2cc76cdebc4773361477f3db203790f6986e3b Mon Sep 17 00:00:00 2001
> +From: Khem Raj <raj.khem at gmail.com>
> +Date: Sat, 22 Aug 2015 23:42:40 -0700
> +Subject: [PATCH 2/2] Passthrough -r to linker
> +
> +clang does not have -r switch and it does not pass it down to linker
> +either, LDFLAGS_RELOCATABLE is used when CC is used for LD, so this
> +should not cause side effects
> +
> +Signed-off-by: Khem Raj <raj.khem at gmail.com>
> +---
> +Upstream-Status: Pending
> +
> + Makefile | 2 +-
> + 1 file changed, 1 insertion(+), 1 deletion(-)
> +
> +diff --git a/Makefile b/Makefile
> +index 9da02cb..10dd4a9 100644
> +--- a/Makefile
> ++++ b/Makefile
> +@@ -309,7 +309,7 @@ CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise $(C
> + MODFLAGS = -DMODULE
> + CFLAGS_MODULE = $(MODFLAGS)
> + AFLAGS_MODULE = $(MODFLAGS)
> +-LDFLAGS_RELOCATABLE = -r -nostdlib
> ++LDFLAGS_RELOCATABLE = -Xlinker -r -nostdlib
> + LDFLAGS_MODULE = $(LDFLAGS_RELOCATABLE)
> + CFLAGS_KERNEL =
> + AFLAGS_KERNEL =
> +--
> +2.1.4
> +
> diff --git a/meta/recipes-core/busybox/busybox_1.23.2.bb b/meta/recipes-core/busybox/busybox_1.23.2.bb
> index 5e02732..2559823 100644
> --- a/meta/recipes-core/busybox/busybox_1.23.2.bb
> +++ b/meta/recipes-core/busybox/busybox_1.23.2.bb
> @@ -33,6 +33,8 @@ SRC_URI = "http://www.busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
> file://0001-Switch-to-POSIX-utmpx-API.patch \
> file://0001-ifconfig-fix-double-free-fatal-error-in-INET_sprint.patch \
> file://0001-chown-fix-help-text.patch \
> + file://0001-Use-CC-when-linking-instead-of-LD-and-use-CFLAGS-and.patch \
> + file://0002-Passthrough-r-to-linker.patch \
> file://mount-via-label.cfg \
> file://sha1sum.cfg \
> file://sha256sum.cfg \
> --
> 2.5.1
>
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