[tip:x86/build] x86, vdso: Error out if the vdso contains external references
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From: tip-bot for H. Peter Anvin on 18 Jun 2010 18:20 Commit-ID: 05d0b0889ca9d033a960542af7f8a13b3ad4f630 Gitweb: http://git.kernel.org/tip/05d0b0889ca9d033a960542af7f8a13b3ad4f630 Author: H. Peter Anvin <hpa(a)linux.intel.com> AuthorDate: Fri, 18 Jun 2010 14:36:26 -0700 Committer: H. Peter Anvin <hpa(a)linux.intel.com> CommitDate: Fri, 18 Jun 2010 14:46:21 -0700 x86, vdso: Error out if the vdso contains external references The vdso is a piece of userspace code which is supposed to be fully self-contained. Any external (undefined) reference is an error, and should be caught at compile time. This was giving us trouble when compiling with -Os on gcc 4.5.0, for example (failed inline). The need to do a buildtime check was pointed out by Andi Kleen. Reported-by: Andi Kleen <andi(a)firstfloor.org> LKML-Reference: <tip-*@vger.kernel.org> Signed-off-by: H. Peter Anvin <hpa(a)linux.intel.com> --- arch/x86/vdso/Makefile | 3 ++- arch/x86/vdso/checkundef.sh | 10 ++++++++++ 2 files changed, 12 insertions(+), 1 deletions(-) diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index 6b4ffed..4a2afa1 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -120,7 +120,8 @@ $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE quiet_cmd_vdso = VDSO $@ cmd_vdso = $(CC) -nostdlib -o $@ \ $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ - -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) + -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ + sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) GCOV_PROFILE := n diff --git a/arch/x86/vdso/checkundef.sh b/arch/x86/vdso/checkundef.sh new file mode 100755 index 0000000..490be1c --- /dev/null +++ b/arch/x86/vdso/checkundef.sh @@ -0,0 +1,10 @@ +#!/bin/sh +nm="$1" +file="$2" +"$nm" "$file" | grep '^ *U' > /dev/null 2>&1 +if [ $? -eq 1 ]; then + exit 0 +else + echo "$file: undefined symbols found" >&2 + exit 1 +fi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |