3473f26592
The Sourcery CodeBench Lite 2014.05 toolchain (gcc 4.8.3, binutils
2.24.51) has a GCC which implements -fuse-ld, and it doesn't include
the gold linker, but it lacks an ld.bfd executable in its
installation. This means that passing -fuse-ld=bfd fails with:
VDSO arch/arm/vdso/vdso.so.raw
collect2: fatal error: cannot find 'ld'
Arguably this is a deficiency in the toolchain, but I suspect it's
commonly used enough that it's worth accommodating: just use
cc-ldoption (to cause a link attempt) instead of cc-option to test
whether we can use -fuse-ld. So -fuse-ld=bfd won't be used with this
toolchain, but the build will rightly succeed, just as it does for
toolchains which don't implement -fuse-ld (and don't use gold as the
default linker).
Note: this will change the failure mode for a corner case I was trying
to handle in d2b30cd4b7, where the toolchain defaults to the gold
linker and the BFD linker is not found in PATH, from:
VDSO arch/arm/vdso/vdso.so.raw
collect2: fatal error: cannot find 'ld'
i.e. the BFD linker is not found, to:
OBJCOPY arch/arm/vdso/vdso.so
BFD: arch/arm/vdso/vdso.so: Not enough room for program headers, try
linking with -N
that is, we fail to prevent gold from being used as the linker, and it
produces an object that objcopy can't digest.
Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Raphaël Poggi <poggi.raph@gmail.com>
Fixes: d2b30cd4b7 ("ARM: 8384/1: VDSO: force use of BFD linker")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
79 lines
2.3 KiB
Makefile
79 lines
2.3 KiB
Makefile
hostprogs-y := vdsomunge
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obj-vdso := vgettimeofday.o datapage.o
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# Build rules
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targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
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obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
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ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector
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ccflags-y += -DDISABLE_BRANCH_PROFILING
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VDSO_LDFLAGS := -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1
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VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
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VDSO_LDFLAGS += -nostdlib -shared
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VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
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VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--build-id)
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VDSO_LDFLAGS += $(call cc-ldoption, -fuse-ld=bfd)
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obj-$(CONFIG_VDSO) += vdso.o
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extra-$(CONFIG_VDSO) += vdso.lds
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CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
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CFLAGS_REMOVE_vdso.o = -pg
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# Force -O2 to avoid libgcc dependencies
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CFLAGS_REMOVE_vgettimeofday.o = -pg -Os
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CFLAGS_vgettimeofday.o = -O2
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# Disable gcov profiling for VDSO code
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GCOV_PROFILE := n
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# Force dependency
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$(obj)/vdso.o : $(obj)/vdso.so
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# Link rule for the .so file
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$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
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$(call if_changed,vdsold)
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$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
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$(call if_changed,vdsomunge)
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# Strip rule for the .so file
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$(obj)/%.so: OBJCOPYFLAGS := -S
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$(obj)/%.so: $(obj)/%.so.dbg FORCE
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$(call if_changed,objcopy)
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# Actual build commands
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quiet_cmd_vdsold = VDSO $@
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cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
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-Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
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quiet_cmd_vdsomunge = MUNGE $@
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cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
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#
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# Install the unstripped copy of vdso.so.dbg. If our toolchain
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# supports build-id, install .build-id links as well.
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#
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# Cribbed from arch/x86/vdso/Makefile.
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#
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quiet_cmd_vdso_install = INSTALL $<
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define cmd_vdso_install
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cp $< "$(MODLIB)/vdso/vdso.so"; \
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if readelf -n $< | grep -q 'Build ID'; then \
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buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
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first=`echo $$buildid | cut -b-2`; \
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last=`echo $$buildid | cut -b3-`; \
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mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
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ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
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fi
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endef
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$(MODLIB)/vdso: FORCE
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@mkdir -p $(MODLIB)/vdso
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PHONY += vdso_install
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vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso FORCE
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$(call cmd,vdso_install)
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