[Letux-kernel] [PATCH 1/2] x86/tools/relocs: Fix non-POSIX regexp

H. Nikolaus Schaller hns at goldelico.com
Sat Jul 3 15:48:37 CEST 2021

Trying to run the x86 relocs tool on a BSD based HOSTCC leads
to errors like

  VOFFSET arch/x86/boot/compressed/../voffset.h - due to: vmlinux
  CC      arch/x86/boot/compressed/misc.o - due to: arch/x86/boot/compressed/../voffset.h
  OBJCOPY arch/x86/boot/compressed/vmlinux.bin - due to: vmlinux
  RELOCS  arch/x86/boot/compressed/vmlinux.relocs - due to: vmlinux
empty (sub)expressionarch/x86/boot/compressed/Makefile:118: recipe for target 'arch/x86/boot/compressed/vmlinux.relocs' failed
make[3]: *** [arch/x86/boot/compressed/vmlinux.relocs] Error 1

and when cross-cpmpiling for MIPS

  SYNC    include/config/auto.conf.cmd - due to: .config
egrep: empty (sub)expression
  UPD     include/config/kernel.release
  HOSTCC  scripts/dtc/dtc.o - due to target missing

It turns out that relocs.c and egrep use patterns like


This is not valid syntax according to POSIX 9.5.3 ERE Grammar


but seems to be silently accepted by the Linux regcmp() implementation
while a BSD host complains.

They can be replaced by a transformation like

	"(|p1|p2)" -> "(p1|p2)?"

Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
 arch/x86/tools/relocs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 04c5a44b96827..9ba700dc47de4 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -57,12 +57,12 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
 	[S_REL] =
-	"(__parainstructions|__alt_instructions)(|_end)|"
-	"(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
+	"(__parainstructions|__alt_instructions)(_end)?|"
+	"(__iommu_table|__apicdrivers|__smp_locks)(_end)?|"
-	"__(start|stop)___ksymtab(|_gpl)|"
-	"__(start|stop)___kcrctab(|_gpl)|"
+	"__(start|stop)___ksymtab(_gpl)?|"
+	"__(start|stop)___kcrctab(_gpl)?|"

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